| Author | Message | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 1 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
What would cause the starter to engage but only give a clunk when it does? I think it's out of gear as I can move the levers at the transmission but I am not entirely sure if it is in neutral. How can I determine if it is in neutral by the levers? If it does turn out to be in neutral but the transmission is binding for some reason, can I give the bus a tug and see if that will release it? What other problems can cause the engine not to spin over? Thanks Bill | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 68 Registered: 5-2007 Posted From: 76.68.229.149  Rating: N/A |
Not fully charged batteries? If you have a good charge and connections (+ and -) is the solenoide not engaging all the way? If not can you safely help it engage? Neutral is not too much of an issue if you have the clutch depressed. I have trouble "feeling" neutral with the stick on my bus (worn linkages) so I really need the engine running so I can hear/feel neutral, as a result if I shut down in gear I need to start in gear with clutch depressed and then find neutral with a little coaching from the clutch | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 71 Registered: 1-2006 Posted From: 66.218.33.156 Rating: N/A |
Low batteries, starter solenoid that needs replacing. Push in the clutch and try starting it that way. Good Luck, TomC | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 2 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
I tried to start it from the rear and the fan moves about an inch and then the loud clunk. I talked to my mechanic and he suggested trying to turn the motor counter-clockwise with a 1 1/2 socket on the cam nut at the front of the engine to see if it was the starter and it won't budge (actually popped a rib out of joint trying to do this). He is coming over this afternoon but I wanted to try to save him the trip and figure this out with the help of this board and another I frequent. The bus ran great from his shop yesterday (45 minute drive) and after sitting for 2 hrs I went to start it and move it. It started fine and while I was waiting for the pressure to build it just shut-off. It didn't shudder or anything it just turned off. Then when I tried to start it (clutch in or out) it just makes the clunk sound and I can see the fan try to move but that is all it will do. Bill | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 69 Registered: 5-2007 Posted From: 76.68.229.149 Rating: N/A |
2 things can be going on at the same time. 1. an emergency shut down system(no oil pressure or whatever) shut down the motor 2.a) drained batteries can't restart.b)starter motor solenoide malfuntion etc... | ||
| john daniels (Big_john)
Registered Member Username: Big_john Post Number: 16 Registered: 3-2007 Posted From: 75.109.199.111 Rating: N/A |
My pd4903 has a start overide button on dash. Try that. | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 70 Registered: 5-2007 Posted From: 76.68.229.149 Rating: N/A |
oh yeah..or something really bad happened....but keep it simple for now. Also the more info the better re bus engine management systems still in place etc... | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 3 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
I'm hoping it's something simple. I know that when the bus was running it had 40lbs of oil pressure and that temp never got above 180 degrees on the ride home. Everything seemed normal until it shut down and I don't remember if it was as I let the clutch out or if it was already out. As far as I know, all management systems are in place and are intact. | ||
| Greg Roberts (Eagle 20) (Gregeagle20)
Registered Member Username: Gregeagle20 Post Number: 252 Registered: 4-2002 Posted From: 66.18.167.76 Rating: N/A |
The problem could well be internal to the starter and, more specifically, the contact is likely not engaging properly when the solenoid extends. Of course all grounds and cable connections should be checked to make sure there is not excess resistance across a bad connection. My advice would be to remove the starter and pin it to the ground and hit the button and see if it will first extend and then spin as it is designed. If not, disassemble the solenoid from the starter and check for contact wear or displacement. Also, make certain that the solenoid is able to press the gear fully to the extent of the bushing. If the gear is not able to reach the bushing then the rotation contacts are likely not being contacted as designed. Good luck! | ||
| Len Silva (Lsilva)
Registered Member Username: Lsilva Post Number: 208 Registered: 12-2000 Posted From: 68.200.10.81  Rating: N/A |
I agree with Greg, check the starter first. Pay particular attention to where he said "pin it to the ground". If it's not firmly tied down when you spin it, it might end up across the shop. Check the starter mounting bolts first. A loose starter will have those symptoms. (Message edited by lsilva on March 10, 2009) | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 115 Registered: 7-2006 Posted From: 64.180.196.209 Rating: N/A |
get another source of battery like a pickup truck that you can jumper from the truck to the starter hot side and then see what happens then. the battery of a pickup truck should turn the motor over even if it is slow. if it does then you know that you have either a dead battery OR poor ground return. this is more than likely on the back bulkhead that needs to be cleaned up. you can also take a big screw driver and short accoss the 2 big posts of the starter and that will tell you if the starter will turn without be ingaged.be sure when useing the screw drive to only contact the nuts on the selinoid as the ark will ruin the threads if contacted. be sure to put the jumper cable to the hot wire coming from the battery so that you came use the start switch to start it. | ||
| Wayne Ellenburg (Wlnburg)
Registered Member Username: Wlnburg Post Number: 46 Registered: 6-2008 Posted From: 128.158.1.163  Rating: N/A |
I had a similiar problem and the guy I got my bus from had put steel washers between the battery stud and the battery terminal and they finally rusted enough to prevent starting. Could not see them until I was about to take the batteries out to test them individually. Just a thought. | ||
| John Lacey (Junkman42)
Registered Member Username: Junkman42 Post Number: 74 Registered: 3-2007 Posted From: 69.19.14.26  Rating: N/A |
Bill, if You cannot turn the engine with a wrench then try that with the clutch disengaged. If You can not turn it, then remove the starter and see if you can then turn it with the wrench. Good luck with Your engine. John | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 4 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
My mechanic came over and he is almost certain that the problem is in the fan assembly. He tried turning the fan using one of the bolts on the assembly with a 9/16 wrench and it wouldn't budge. He believes that the bearings locked up and that is what is keeping the motor from turning. That's why it stopped the motor at idle, he said that if I was going down the highway the motor would have kept it going regardless. I trust his judgment so I have a wrecker coming to move it from the side of the road and to put it in my driveway (200ft). I will keep everybody up to date on it and if it's not that then I will keep you posted on the progress. Thanks again for the replies Bill | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1358 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
"The bus ran great from his shop" What was done while it was there? Fan bearings? I doubt it, the fan runs directly off the crankshaft. Does that coach have an accessory shaft coming off the fan drive? The play in the fan / accessory drive bevel gears could give you that little bit of play. Be better to see if you can move the flywheel with a pry bar. Full of antifreeze? Full of oil? | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 361 Registered: 2-2001 Posted From: 69.77.144.28 Rating: N/A |
Doesn't a 4903 have the same hydraulicly driven fan that a 4905 has? If so, it wouldn't matter if the fan locked up(when cold)except it would overheat after a while. If it is gear driven, I don't think you'll be able to turn the engine via the fan assembly. That ain't no smallblock Chevy! As has been suggested, turn the crankshaft either way from the flywheel teeth if you can. You might have to pull the starter to do this if there is not a little inspection cover to look at the flywheel teeth. Check to be sure the radiator is still full and check that the oil is at the correct level, not higher than it should be. (If engine will not turn 1 complete revolution by wrench or big screwdriver on teeth, don't try with the starter any more until you find what is holding it, like coolant in a cylinder. (water does not compress) | ||
| Leslie Robinson (Lesrmc9)
Registered Member Username: Lesrmc9 Post Number: 68 Registered: 10-2004 Posted From: 205.250.196.67 Rating: N/A |
This sounds similar to my big truck problem, sometimes it would turn over a little bit then go clunk,I found a loose ground strap the first time, second time the solenoid just clicked, the same ground strap had arched enough to eat the metal away. checking the starter is a good place to start [pun which ever way] but it's the ground. Check all grounds with a wrench not just wiggle them. DON'T LET THE MECHANIC DO ANYTHING UNTIL THE GROUNDS ARE CONFIRMED TO BE SOLID AND CLEAN | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 237 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Bill The simplest way to check the engine is the 1 1/2" socket on the cam. Just watch your ribs. Try it clockwise and anticlockwise a little to see if the engine is free. If it moves then you know the engine is okay. Next thing is to look at the battery conections. Try to start it and right away feel each post to see if one is hot. Try the other connections as well. If they are hot then you have a bad connection were the heat is. If all okay there then it has to be the starter with a bad section in the armature or burned brushes. Good luck. Bill | ||
| Cullen Newsom (Cullennewsom)
Registered Member Username: Cullennewsom Post Number: 22 Registered: 2-2009 Posted From: 98.201.161.214 Rating: N/A |
Corroded or loose terminals, cable lugs, could be at either end. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 835 Registered: 11-2005 Posted From: 208.54.200.1 Rating: N/A |
Bill, I assume you have a manual transmission? If so it is locked in gear. One of the shift levers on the trans did not return to the neutral position even with the other. Check for this by seeing if they are both in the same position when the front lever is in the neutral position. This is not unusual. Get someone to hold in the clutch while you pull the off-center lever at the trans even with the other one. My 4104 does this sometimes when I get sloppy and don't push the clutch in enough when down shifting or try to shift, engine off, when parked without using the clutch. A DD will absolutely not turn over in gear. | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 72 Registered: 1-2009 Posted From: 24.129.235.190  Rating: N/A |
I would start right at the starter electric supply, doing a voltage drop and current draw. Several types of starter faults could cause this symptom, anything from windings burnt, commuter bars burnt, drive pinon binding or broken in half and jamming the flywheel against the housing. Just ( not to make a starter ectomy sound simple) taking out the starter for inspection and finding you can now bar over the engine will narrow things down or send you in a different direction. | ||
| Mel La Plante (Mel_4104)
Registered Member Username: Mel_4104 Post Number: 116 Registered: 7-2006 Posted From: 64.180.205.111 Rating: N/A |
right on Leslie, never let some guy with a hand full of tools touch your engine until you have checked you battries for full charge, ALL cable connections both +&- to be sure of the connections, neg. are the worst for this problem as they corrode very bad and they get checked the least as they are not in very easy places to get at and they get negelected. and as stated meter for power and voltage drop at the starter. whill you are doing this be sure that the guy with the hand full of tools has a beer in the other hand that will keep him busy while you do first things first. and a lot cheaper too.... | ||
| Patrick levenson (Zubzub)
Registered Member Username: Zubzub Post Number: 71 Registered: 5-2007 Posted From: 76.66.201.3 Rating: N/A |
Pretty sure that if your mechanic thinks the fan hub can lock the engine he doesn not know what he's talking about. Buses are different than trucks in the way the DD fan works (sometimes). OTOH I seem to remeber that the drive shaft for the compressor can shatter causing the engine to feel locked. Anyhoo lots of basic trouble shooting before you start tearing everything apart. | ||
| Mark Renner (Boomer)
Registered Member Username: Boomer Post Number: 147 Registered: 11-2006 Posted From: 75.208.221.204  Rating: N/A |
My money is with Gus. Caught between two gears. Bring the shift levers back into alignment (neutral) and she will probably turn over. Do check for hydrostatic lock though. If a cylinder is full of coolant and you turn it over you can suffer bent/broken rods or worse. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 754 Registered: 8-2006 Posted From: 64.55.111.6 Rating: N/A |
We do need to look at Bill's post of 3/10, 1140am. In it he says "...while running to build up pressure, it just stopped." That takes out the stuck in gear theory, not to mention depressing the clutch. Low oil pressure emergency shutdowns are all overridden by the start circuit, otherwise an engine would never start, because it has no oil pressure sitting still... So, it stopped and won't restart because of a thrown rod, and the starter is OK, or an elctrical failure which opened the Skinner valve circuit, and the start cable. The solenoid is energized thru the start switch, and probably a relay from the front, and it energizes the starter motor. So, it will still clunk if the battery cable isn't connected to it... Real quick diagnosis? Just like a car, turn on the headlights and hit the start switch. If the lights dim, the engine is stuck. If they stay on bright, open circuit. Lights go out=bad battery, but a bad batt wouldn't make the engine stop. Happy hunting, George | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1360 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
What was done at the shop? How long have you been owning/ using the coach/ newbie? Trying to get some ideas as to what the problem most likely is without a lot of unnecessary diagnosis. A couple of points: 4903's had manual transmissions; anything else would have been added later. 4903's had engine driven fans, not hydraulic unless it was added later. Open the transmission access door on right rear. With a flashlight, look at the top of the transmission where the shift linkage attaches. The shift rods come over from the shift tower at back center of engine bulkhead. There are three rods. One is clutch and other two are the shift rods. These two rods connect to bell cranks on top of transmission cover. When either shift rod is moved, these bell cranks rotate to change gears. At the other end of these two shift bell cranks is a forked end that rides on a ball shaped end of the shift levers that connect to the internal transmission shafts. Look at these short shift levers with the ball shaped end. Both of these levers should be straight up in neutral. | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 5 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
I am definitely new to the bus scene. The bus was not stuck in gear as I mentioned/thought. If it were than I think it would have been a real chore for the tow truck driver to move it forward and then back it up into my driveway. If it were still stuck in gear then I would have thought that the wheels would have been real hesitant to go either forward or reverse without either causing him to really pull it or the grass under it would have had chunks pulled up if the wheels didn't want to turn. I read have all that is posted and right for now the bus is sitting next to my house and when I get a chance to look more at it I will. My mechanic is supposed to come back in about 3 weeks and take a look at it again for me (he is really busy and I am 45 minutes from the shop). But I am going to help him when he returns so I can learn more about my bus. I trust my mechanic as he is from a reputable shop and has been servicing buses (especially DD for a long time and comes highly recommended). So for now I will wait for him to come back, I need the time as well since whatever popped in my side causes discomfort if I twist too far or pick up anything moderately heavy so I can't even turn a wrench or lift. I really appreciate the help so far and I will update the thread when I get more information. Thanks again. Bill | ||
| Keith Wood (Ft6)
Registered Member Username: Ft6 Post Number: 95 Registered: 8-2008 Posted From: 75.209.119.223 Rating: N/A |
" I have a wrecker coming to move it from the side of the road and to put it in my driveway (200ft). " That's the problem with this modern age. It's just not that easy to get 100 peasants with ropes to pull stuff any more. | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 6 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
I don't think I even know 100 people.  | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 415 Registered: 3-2007 Posted From: 71.55.228.218  Rating: N/A |
Bill you think you don't know 100 people? Boy are you in for a surprise on the greatest Bus Nut site In the world. Also welcome from Gomer, I believe you have a starter problem,but why did it shut down? Hummm I am still thinking about that. I had an 4106 with 4-speed and the bell housing loosened up and tranny went,clutch,pressure plate,flywheel and the list goes on. However mine did not shut down. Still thinking??? gomer | ||
| Glenn Williams (Glenn)
Registered Member Username: Glenn Post Number: 189 Registered: 6-2006 Posted From: 216.163.56.194 Rating: N/A |
Bill, When the engine shut down, did it go from idle to stop immediatley, or did the rpm's slow down until it stopped? Did it make a "Bang" or other noise when it stopped? Now to anyone who has had hydro lock- does this sound like what happend to you? Glenn | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 7 Registered: 4-2008 Posted From: 198.152.13.67 Rating: N/A |
It went from idling and building air pressure to a shutdown, it didn't shake or act erradically. No noises like metal on metal or clanking, it just shutdown like I threw the run switch to off. It is very weird in how it shutdown. But at no time did the temperature of the bus run hot or the oil pressure bottom out. Bill | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 8 Registered: 4-2008 Posted From: 198.152.13.67 Rating: N/A |
If it did hydrolock, wouldn't it have thrown antifreeze out of the exhaust as it was filling up a cylinder? I mean, not to contradict anybody who suggested it, wouldn't the headgasket have been leaking some into the cylinder for me to see white smoke or have it run out of the exhaust pipe when the bus was lifted into the air and towed? I may not have a lot of experience with the DD engines but I have worked around cars and jetskis where hydrolocking has happened but this was definitely different in the way it felt when it shutdown. Bill | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 188 Registered: 1-2007 Posted From: 208.81.157.90  Rating: N/A |
I don't think I would worry about why it shut down. That could be as simple as a stuck skinner valve that let the shut down cylinder activate when the air pressure built up. When you find out why it will not crank you may solve the shut down mystery. You need to find out if the engine is locked up or the starter is not working. As others have said, turn the engine by hand to see if it is locked up and/or check out the starter to see if it is the starter itself or a wiring problem. A heavy duty set of jumper cables hooked directly to the starter from a vehicle with a good battery will help determine whether the problem is the starter or connections. I would make sure the engine is not locked up first. Good luck Don 4107 | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 9 Registered: 4-2008 Posted From: 198.152.13.67 Rating: N/A |
I can't turn the motor by hand, I tried and that's what caused the problem with my ribs/side right now. I guess I'll just wait to heal and then tackle it when the mechanic comes back in a few weeks. Thanks again Bill | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 194 Registered: 3-2006 Posted From: 75.88.252.75 Rating: N/A |
I hope it isn't.....  | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 10 Registered: 4-2008 Posted From: 198.152.13.67 Rating: N/A |
Help me out....What is that ^^^^ I think it might be a piston but not sure. Bill | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1363 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Dallas; a little compound and that will buff out like new. Bill, when you tried to turn the engine over by hand, how long of a breaker bar or piece of pipe helper did you try to use? 1/2 inch drive or 3/4 inch drive? | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 11 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
I have a 1" drive ratchet and socket set. I didn't use anything other than the ratchet, 1 1/2" socket and an 6" extension to try to turn it. In hindsight I probably should have used a long pipe and slipped it over the ratchet handle and tried to turn it counter-clockwise that way. Bill | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 189 Registered: 1-2007 Posted From: 208.81.157.90 Rating: N/A |
Bill, I have a idea what that rib feels like. I had one pop over the next trying to lift something stupid. Takes forever for it to give up hurting.  My solution these days is to find someone younger and more resilient than me to do the heavy stuff. Maybe you have someone that can help out? Don 4107 | ||
| Dallas (Dal300)
Registered Member Username: Dal300 Post Number: 195 Registered: 3-2006 Posted From: 75.88.252.75 Rating: N/A |
Bill, That picture is a piston skirt and half a piston liner. I rebuilt an engine for a fella last fall and it ran great, for about 247 miles. He got to the show he was going to and had no problems getting parked. engine was running fine. Came out the next day to go home and the engine turned half a turn and stopped..... The liner had broken, wedged itself against the airbox and caught the piston. The rod ripped out of the wrist pin and when the rad went down and came back up the rod caught on the liner jamming it and the piston and the other half of the liner all together. PC Industries wouldn't stand behind their parts and left me with an extra $4K labor bill and the owner with another $450 in parts. Good luck. By the way.. the parts were from Federal Mogul. Dallas | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 73 Registered: 1-2009 Posted From: 24.129.235.190 Rating: N/A |
BigD enough with the scary pictures, your going to inhibit the poor guys ability to sit in the bus sipping tea while dreaming the conversion plans during his rib cage recuperation period. One thing to consider while using those "snips" for leverage, you don't want to loose focus on the size & snapping torque of the fastener (and all parts connected) that your trying to get clever with. ;;; "and now for something completely different", at least you have the coach in the driveway, even if it did take the effort of a hundred men. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1364 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Did you have any engine work/ service done at the garage? I went out in the shop to check the rotating torque on mine; the muffler is too close to even get a wrench on it, but I can see the nut on the pulley. sigh... Maybe someone on here with a 4106,07,08,4903,4905,H8H649 with the out of sight muffler could check theirs. | ||
| Larry D Baker (Lbaker4106)
Registered Member Username: Lbaker4106 Post Number: 87 Registered: 5-2005 Posted From: 174.42.226.175 Rating: N/A |
You guys scare me. If I rolled my 8v71 on my 4106 it would start immediately unless I wired the shutoff closed. Don't try to roll the engine without air pressure or the shutoff wire closed. | ||
| Clint Hunter (Truthhunter)
Registered Member Username: Truthhunter Post Number: 78 Registered: 1-2009 Posted From: 24.129.235.190 Rating: N/A |
yes you do raise a point of possibility if there is fuel and enough heat produced in the compression your making , so you'll want to make sure your ratchet can free wheel in the direction your engine rotates in (oh oh , they can be stared backwards) or play it safe and get your oversized "know it all neighbor" to roll it over for you (just kidding on the neighbor bit hope we didn't make you laugh , laughing always made my sore ribs hurt) | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 362 Registered: 2-2001 Posted From: 69.77.144.28 Rating: N/A |
I doubt you will turn the engine fast enough with a ratchet to start it. Normally, when I turn mine, I can't turn it hard enough to overcome the compression but must turn it slowly while the compression leaks down & I can turn it a little farther. When you "bump" it over with the starter, and it starts in 1/2 turn ot so, you are turning it hard & fast enough to compress the air in the cylinders. No squezee, no start. If you bar it slowly, you are just making sure there is no mechanical resistance to rotating that might cause real mayhem if you hit the starter. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1365 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
Turning with a ratchet or bar can't build enough heat on that engine since it is cold. I wouldn't try it on a hot engine though, even though it would be hardly turned. We want enough to see if it will freely move a few degrees. Apparently no one can check theirs. | ||
| MacGyver (91flyer)
Registered Member Username: 91flyer Post Number: 296 Registered: 11-2004 Posted From: 74.193.225.134 Rating: N/A |
Eh, it might not be relevant, but... A bus I recently sold had a 6v92 in it.. Using a 3/4" drive bar of 24" length and the appropriate socket, I *WAS* able to move the crank... Just barely. I stood on it. I weigh 250lbs. I broke out my 8ft cheater bar and still had to practically HANG off it to get the engine to budge... Yes, all safeties were on. No power to the electrical system (DDEC-II) and shutoff was in place... Point is... It took a LOT of torque to move the 6v92 even a few degrees... My "new" 4905 (which I still have to go get) has an 8v71.. If the 6v92 was that hard to turn, I can only imagine it's that much more difficult. And I was working with an 8 foot cheater... So the fact you didn't budge yours with what you were using doesn't surprise me in the least... I had the same problem as you on my old bus... (the 6v92)... I'd hit the start button, I'd hear the selenoid fire off and I'd just hear a *THUNK*. No movement on the engine whatsoever... I'd read that in certain cases, the engine and starter could possibly get into an alignment that would simply prevent the starter from engaging altogether, and cause this problem... I was told to rotate the engine by hand 45 to 90 degrees and try again... I did. It fired right up. Get a cheater, work slowly... See if the engine will turn a few degrees... Or, just wait for your mechanic. ;) -Mac (Message edited by 91flyer on March 20, 2009) | ||
| Bill Laird (Billaird99)
Registered Member Username: Billaird99 Post Number: 13 Registered: 4-2008 Posted From: 24.163.34.244 Rating: N/A |
Well, today was the day for my mechanic to come back and find out what happened to my bus. He was still convinced that the fan hub locked up so we started taking the radiator out. When I had the tow truck driver tow the bus next to the house, it was found to be too close to my deck to be able to get the side cover open enough to swing out the radiator. Once out, he proceeded to take the fan off and then the actual hub drive off. As soon as he removed it, he tried to rotate it and it was locked solid. We then put the 1 1/2 socket and ratchet on the cam nut and then could rotate over the engine rather easy. So off he went to take it back to his shop and he'll return in a few weeks after he gets it rebuilt for me. I'm really excited that it appears to have been the problem but why it locked up I'm not sure. He showed me where the oil hole is to lubricate the bearings and that he did have the gasket lined up and not covering the oil passage on either the hub or the mounting. I did not notice a lot of oil come out of the hub when he did get it separated from the engine. I worked the rest of the day to get the gasket material off and have a clean surface for him when he gets back to put on the gasket and then the repaired hub. I then got out the grinder and took off the rivets holding the radiator side cover to the hinge because all of the screw holding the hinge to the body are rusted solid. Hopefully I can remount the radiator next weekend but for now I am more relieved than anything. Bill |