| Author | Message | ||
| Robert A. Symonds (Bob_symonds)
Rating: N/A |
I have a new to me 4104 with a 671... how difficult is it to setup the rack and governor. What tools will I need? I have years of automotive experience and assume it should not be that difficult. | ||
| Geoff (Geoff)
Rating: N/A |
Most diesel mechanics (guys that do this for a living) won't touch a Detroit 2-stroke rack-- it takes a lot of practice to adjust the rack and governor properly and if you do something wrong you could have a runaway engine. Adjusting the valves is a little easier. My advice is to find someone who knows what they are doing and have them show you how it is done, but once the controls are set you shouldn't have to touch them for 100,000 miles unless something breaks, so you are not going to get much practice! --Geoff '82 RTS AZ | ||
| Tim Hoskinson (Tdh37514151)
Rating: N/A |
Get a book for the 671 and read the procedure its really not that difficult. | ||
| Dallas Farnworth (Dal300)
Rating: N/A |
I go along with both Geoff and Tim, but for different reasons. What Geoff says is correct, most modern diesel mechanics won't touch a DD 2stroke, mainly because they don't have the proper tools to do a tune up with any more. The tools are available from MAC or Snap-on or even DD, but usually are not used enough to justify the cost of purchase. I bought my tune up tool kit off eBay , mostly one piece at a time. Some pieces were cheap, some were way over priced. Geoff is also correct about having a runaway.... if you adjust the rack too tight it can stick in the full fuel position and blow parts everywhere. Tim is also correct in advising you to get the book, "Detroit Diesel Inline Series 71 Service Manual" available on eBay all the time for about $20. Buy the newest one you can, because of updated proceedures. The tune up proceedure is easy enough,IF YOU CAN FOLLOW DIRECTIONS TO THE LETTER! There are no short cuts. Do it right or don't do it at all. That's my 2¢ worth, Dallas PD4103-1085 http://www.busconversionstuff.com/eventpage.htm | ||
| mel 4104 Rating: N/A |
i think that one of the reasons that Canada changed the gun laws wastoo many people told mechanics that if you fouch my dd i will shot you.as we do not put hte miles on our buses and run them steady all day long we get away with some things. it is not as simple as buying the book and some tools, you have to have an ear that likes the sound of a DD and can tell different sounds that it makes also a good sense of touch is required so that when you are doing the work you can tell when it is not right. the real good shops guys will all tell you real good DD guys are out there you just have to find one. to put a DD together and do a tune up on it and put 5,000 miles on it and then start having trouble is not the work of a good DD guy. try and put a DD together and put the engine in a boom boat that screams at 2,400 rpm all day long and after 2 years and you have not had to work on it then you know that you did it right. when there were a lot of logging and freight trucks around with jakes in them the the people that had them would tell you that there was only a very few that could do it right. and would raise hell if the shop let some one else work on it except the fellow that they saked for. i have seen truckers refuse to leave the shop until the right guy worked on it and said ok, take it. a fellow that i know is a cat engine lover and he put a DD together as a rebuild and he can read however it was back after 15,000 miles with a big hole in the side of the block, so we asked him if that is how they mount a turbo on a Cat, even to this day whena sked he does not smile. but them again it is your engine so do it your way. | ||
| Geoff (Geoff)
Rating: N/A |
I think Mel is making a good point-- you can get the book and get the tools and try to work on your own Detroit, but if you don't have anyone checking your work how do you know it's right? I been working on Detroits for 30 years and was a factory trained and certified 2-stroke mechanic. When I quit Detroit I went into business for myself and used to go all over Northern California doing specialized Detroit work. I often had to clean up other people's work and straighten out tune-ups to get their engines purring. Experience is everything with these engines, if you can do it with the book and get it right you are gifted! --Geoff '82 RTS AZ | ||
| Dallas Farnworth (Dal300)
Rating: N/A |
Geoff, I think you are exactly right. You not only have to have the tools, you have to have the 'touch'. I've worked on DD's for about as long as you have and have had to clean up other peoples messes. But if a person can follow directions EXACTLY there shouldn't be too much of a problem. The DD manuals spell it out so that a 5 year old can do it... IF they follow directions. If theres any doubt about the ability to do it right, DON'T DO IT! Dallas | ||
| Joe Cochran Rating: N/A |
I need a lot of help, i bought a pd 4104 71 model oh here it goes...it has no batteries if i get new D8 to replace how can i tell if its negative or positive ground does it take one or two?? also noted that there is a new rebuilt 6v71 dd in it but it sure hasnt any power who has the wiring harness that i might get to replace the frazzeled ones in it or a good parts bin where i can get what i need really neeeds power steering lol | ||
| Jim-Bob Rating: |
Hi Joe, Your 4104 can not be newer than 1960 but folks sometimes refer to the date it was converted as the "model year". If you provide the serial number, several guys on here can tell you what year it is & who it was originally sold to. It was originally positive ground but many/most have been converted to negative ground. A good clue to polarity might be the existing battery cables. Since the positive terminal on the battery is larger than the negative, the cables should fit fhe replacement battery nicely one way but not the other. A 4104 IN GOOD RUNNING CONDITION will start on a pickup truck battery. In summer a good 4104 will start very well on one 8-D. In cold weather you will need 2 batteries. You might decide to buy 3 size 27 batteries. That is what starts the 8V-92TA in my my Eagle. More amps & MUCH easier to carry! Three case 27 batts fit in the same area as one 8-D. You will have to have some new cables made (usually at a starter shop) with multiple terminals to connect all three into one bank. (Using 3 patts will free up the other battery shelf for house batts or???) The original engine in your bus is a two valve inline 6-71 (not a 6v-71). The original had 170HP and the more modern model would be a max of 240 HP. Not a lot of power for a 12 ton bus. But mostly, you are comparing your bus with modern vehicles like cars & trucks. You should not do that. For one thing, the governor on the 4104 engine fights your foot so that acceleration is gentle & gradual. This is because it was designed to carry passengers & to keep you from breaking drivetrain components. Though it is made from big truck parts, it is not geared or set up like a big truck. When you learn how to drive this bus, (and it definitely takes a learning period) you will appreciate it's durability, fuel efficiency & simplicity. There are NO new wiring harnesses for a 4104! I can't see what your wiring looks like from here, but you should know that when they built the 4104, they used aircraft grade wiring. It has a fabric cover over the actual WWII type insulation. After a half century, the outer cover can look really frazzled, especially at the ends by the connection strips. But look carefully, it's very rare that you will have an electrical fire because all of the original circuits & wiring were well protected by self resetting breakers. Sometimes you might have to repair a couple of ends. Power steering is nice, but you should consider that your bus has likely gone 2-3 million miles already without power steering. You won't need it on the open road. If your tires are correctly inflated & you move the bus a little as you turn the wheel, the steering (if in proper repair) should not be that bad. We are all used to cranking the wheels around on cars while standing still & that will be tough when the bus is stopped. If you really want power steering, the easiest way is to swap in the steering box (on the axle) and the right angle box (under driver's feet) from a later GM like a 4106 or 4905. You will need the pump, adaptor, filter & reservoir from the engine compartment as well as run piping (better than hose) from back to front. Use short hoses at each end to allow movement. | ||
| FAST FRED Rating: N/A |
If you really want power steering, for the ease of getting into a campsite (only use) be sure to get the steering columm from the donor too. The non power GM have a geared steering columm and with PS you wont need the extra gearing. Drive the bus a few thousand miles AS IS and enjoy the finger tip road steering , with out massive PS play. Use the info on shifting in the archives of this board. To get into a tight PP simply rock the bus with the clutch (DTS), as you turn the wheel. Its best to turn the wheel Almost stopped , as the many turns, lock to lock take a while to wind in. With technique you will have a really Handy coach, and be ably to get places the 40 ft big boxes can't even dream of! FAST FRED | ||
| Joe Cochran Rating: N/A |
Thanks for the reply ok the serial number is 4V1WDBJF4LN626883 now on these batteries do i run all together such as 2-8 D or one i know if you connect two the amperage doubles.. I do have the orignal wiring diagram but it would take a genius to figure out..There is a kill switch in the batt compartment for voltage and i thought if i shut the bus down to turn that off to save the drainage just cant figure out whats draining the battery | ||
| Richard Bowyer (Drivingmisslazy)
Rating: N/A |
Joe, are you really sure you have a 4104? First, they were not manufactured in 1971, second, they did not come with a 6V72, third, the serial number will be 4104-XXXX. The 4104 is a 12 volt system, so if you install 8D batteries, they should be in parallel. And you really do not need two batteries during warm weather. The switch may only kill the starter circuit. It may not kill the complete 12 volt system. There are lots of things that can drain the battery, but maybe it is just bad batteries and nothing is wrong with the wiring. If you connect the batteries up wrong, that could drain the batteries. Where are you located? Sounds like you need to find an old timer familiar with 4104's, or whatever you have, to give you a hand in figuring things out. Richard | ||
| Tom Caffrey (Pvcces)
Rating: N/A |
Joe, it would help some of us old timers a lot if you could separate the ideas you are trying to get across into separate sentences or paragraphs. It's very hard to understand what you want when you run all your ideas together. Tom Caffrey PD4106-2576 Suncatcher Ketchikan, Alaska | ||
| Joe Cochran Rating: N/A |
ok the bus is a PD4104-3621 something is draining the battery with everything shut off. Should it have two 8D batteries in parallel or just use one. I also noticed there is a master kill switch in the battery compartment that shuts all power off in the the system if thats left on will it drain the battery. cant tell if its a 12 or 24 volt system postive or negative ground | ||
| Richard Bowyer (Drivingmisslazy)
Rating: N/A |
Now we are getting somewhere. We know you have a 4104. We therefore know it is a 12 volt system. We also know that one 8D battery is sufficient to start the bus in warm weather, so lets just install one battery for now. Positive or negative ground is difficult to diagnose from afar. Hopefully you can look at the battery connection leads and determine that the hole in one of the connectors is larger than the other. The one with the larger hole goes to the positive terminal of the battery. If this cable is hooked to the frame of the bus, then it is positive ground, otherwise it is negative ground. The easiest way to find what is draining the battery is to remove one of the battery cables and connect a 12 volt test light in series between the battery cable and the battery post. If the light glows, there is something turned on in the bus that is drawing current. The brighter the light, the larger the load. Start disconnecting/turning switches until the light goes out. Let us know what you find. Richard | ||
| joecochran Rating: N/A |
ha thanks anyone want to buy it |
