| Author |
Message |
Dan Murray (Rdmtsk)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 1:30 pm: | |
I have a 1954 GMC 4104 I was given by my father. It is in excellent condition but recently when I was parking it next to my garage I lost 1st and 2nd gear. I believe it to be a linkage problem as I can still "Manually" shift the trans into 1st or 2nd at the transmission. I have pulled the access panel on the floor around the shift tree and can see that both shift sliders move when I manipulate the shifter. The difference is when I am in the 1st and 2nd side of the shift tree the stick moves and the shift slider moves but there is no resistance like there is on the 3rd and 4th gear side of the shift tree. In 3rd and 4th I can feel the transmission shift from 3rd to nuetral to 4th. I gave checked everything that I know how to check ( which isn't much ) and was just wondering if someone could point me in the right direction. I have the service manual but it is very vague and the diagrams aren't very good. I can't find the first place the linkage connects after going throug the bulkhead just behiund the drivers seat. Help ! |
j l vickers
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 1:36 pm: | |
Check the shifting rod over the drive axle it's out in the open over the differental the old 4104 have a habit of those shifting rod'a rusting through.
Also check the clevis pin at the bell crank on the engine bulk head some times the bell crank lever will wear through at that point.
J.L.Vickers |
Cliff (Floridacracker)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 1:37 pm: | |
Dan,
On my 4905 there is more linkage under the steps in the isle. I am not familiar with your 4104, but this may give you a place to look until you get some real help from the 4104 Guru's.
Cliff
1975 4905-1160 |
Jim Bob
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 04, 2005 - 1:51 pm: | |
Dan the linkage is two loooong rods that go all the way to the bulkhead in front of the engine. At that point, there is a belcrank assembly that changes the forward & rear motion to side to side. If you get someone to shift the lever, and you don't see the 1-2 rod moving at the back, most likely the rod has rusted away in the section over the rear axle where there would be salt & moisture. There could also be a failed clevis but that's less likely.
The body is unit body and is designed to be blocked or lifted under the bulkheads. If you jack the bus up or run it up on blocks to get underneath, BE CERTAIN TO BLOCK THE BODY UP at the front corners of the rear wheelwells. This is an air suspension vehicle. If a component should fail, the bus can come down in seconds, way faster than you can get out. There probably will not be room to survive! People are injured & killed every year this way. |
mel 4104
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 05, 2005 - 11:09 am: | |
Dan asstated the shift rod where it goes over the rear axel is where i would look,as Jim said block it proper then crawl under and have someone move the gear shift lever from the 1st to 2nd positions back and foreth, just hang on to the rod and you can feel vigrations in the proper rod. some of the still have the original covering and when you find where the brake is you can do a quick fiz and get the bus going again by goin to the local auto parts store and get a piece of heavy duty rad hose that has a inside diameter than the rod and 6 hose clamps.to put it on go back under the bus with the hose ,and some dish washer liquid soap,and the clamps. pull the rod back together so that it looks like it would if not brokenthe place your hose up by the rod and wrap some tape around the bod at each end of the hose this is to be able to locate the proper length once the hose is back onas you will want the tape to show out of the hoseto be sure it is right. put 3 hose clamps on each end of the rod , the pour some liquid soap into the hose and on the rod this will make it easy to slip the hose over the rodand when in place put the clamps on the hosespacing them apart for better grip. now try your shifteras see how it works. this fix will get you a long way if needed, but this fix is only good if it is the rod that has ruster through.. mel 4104 |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 05, 2005 - 9:46 pm: | |
Mel, at least some dishwasher soap is dangerous on wet skin. It can cause severe burns. If you meant the kind that is usually called "dish soap", that's no big deal.
If it was me, I think I would try a piece of wire-bound hydraulic hose for more strength.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska |
mel 4104
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 05, 2005 - 11:59 pm: | |
Tom that is a good idea of the hose but the auto parts shop we went to did not have hyd. hose and we got the heavest rad hose they had and then used wire from the hase clamps then put a little duct tape over it to hold the wire in place. it happened just as you make that 90*right hand turn as you are headed south from Wells Nev. and it is still on the fellows bus 10,000miles later and the driver likes it as he says that it gives a softer feel to the shifting of those 2 low gears. mel 4104 |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 06, 2005 - 12:33 am: | |
Hello.
I don't know anything about this, and I encourage someone to knock me down, but...
I'd be afraid the wire bound hose would be a bear to get to slide over the rods, and if it was easy to slide on, then the hose clamps would have a devil of a time squeezing it hard enough to clamp on the rod.
There isn't much force involved in the movement of the rods, and the rot will have only allowed it to break at a point, so regular heater/rad hose should do the trick to keep the solid bits in line and in relation to one another.
Mel, you are one smart cookie!
this is opposite to an airline fix, where you put the copper pipe into the broken air hose and clamp it on to regain air integrity.
happy coaching!
buswarrior |
bobm
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, October 06, 2005 - 9:33 pm: | |
I had one of the shifting rods (tube) snap above the differential. It originally had a fabric protective cover but over the years road debris damages the covering allowing corrosion. I cut the corroded area out found a rod that was a tight fit into the shifting tube and found some compression fittings that fit the tube (3/8th I think) I put the insde rod in place with plenty of JB weld and put length of brass pipe over the outside with compression fittings.. A little overkill but probably stronger than new. Just be careful not to pull the shifting rod very far from the front bulkhead towards the rear as you will pull the shifting levers out from under the shift, pain to put back. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 07, 2005 - 12:32 am: | |
Buswarrior, you may well be right about the hose. Perhaps I was sort of allowing for the force I put on our shift lever now and then.
I believe there must be something like a 5 to 1 mechanical advantage in the lever.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher
Ketchikan, Alaska |