Hi,
We lost our drive shaft due to the propeller shaft flange nut coming off. This differential was set-up and installed last Oct. and has about 1500 mi. since. The guy who did the set-up claims this happened because the drive shaft was installed backwards. Which way should the drive shaft be installed?
By the way this failure caused major damage to our toad, including; bumper cover damage, undercarriage replacement, control arm replacement, steering gear replacement, exhaust system replacement, floor pan replacement due to 6" hole... I do feel the car prevented serious problems for the heavy traffic around us. We were traveling at 60mph when the shaft exited.
Thanks,
Bob
That nut torques to 6 hundred foot pounds and is safetied with a cotter key,,,somebody screwed up,, they don't just fall off .>>>Dan
Dan,
Agreed they don't just fall off. The manual says 800 to 1100 foot pounds and this one was a locking nut, no cotter pin. The guy I bought this differential from "set it up" and replaced the pinion seal. I feel the nut was never tightened correctly.
Even if it had been a paltry 200 pounds with a lock nut it would not have loosened. It smacks of a "home garage" job >>>Dan
The guy who did this work is well known and has a good reputation.
Anybody have an opinion on the orientation of the drive shaft? 8V71 with V730.
Typically the spline side of the drive shaft is on the transmission side. And to make sure the splines are lined up correctly, the U-joints should be positioned the same on either end. Good Luck, TomC
Thank you Tom,
All the GM buses I have been around have arrows to align the shaft on a original drive shaft,the slip joint is always on the transmission end
Another question,
The threads on the pinion shaft are stripped, we are considering two options to fix this. One is to machine new threads a size smaller and the other is to build up missing metal by welding and machine new threads to the original size. My concern with the second option is, will the heat produced by welding effect the pinion shaft in a negative way.
Thoughts appreciated,
They spray the metal on to stay away from the heat I wouldn't weld on the pinion shaft myself
Quote from: Bob & Tracey on May 08, 2016, 10:52:11 AM
Another question,
The threads on the pinion shaft are stripped, we are considering two options to fix this. One is to machine new threads a size smaller and the other is to build up missing metal by welding and machine new threads to the original size. My concern with the second option is, will the heat produced by welding effect the pinion shaft in a negative way.
Thoughts appreciated,
i would source a new one... are you disassembling this differential ?
Eagle,
No, we do not plan to remove the differential, the pinion cage has been removed and the shaft/gear removed from the cage. We feel it would be a mistake to replace the pinion shaft/gear without changing the ring gear.
Quote from: Bob & Tracey on May 08, 2016, 11:20:36 AM
Eagle,
No, we do not plan to remove the differential, the pinion cage has been removed and the shaft/gear removed from the cage. We feel it would be a mistake to replace the pinion shaft/gear without changing the ring gear.
Agreed a big mistake take it to automotive machine shop most can spray the metal.I would pull the differential,how is he going to set the back lash without pulling the complete assembly
The backlash is set by shims between the differential housing and the pinion cage? If we reassemble everything the way it was it should be ok? We are at Eagle Nest in Nashville.
Quote from: Bob & Tracey on May 08, 2016, 11:33:20 AM
The backlash is set by shims between the differential housing and the pinion cage? If we reassemble everything the way it was it should be ok? We are at Eagle Nest in Nashville.
That's your call
luvrbus,
I thought we had a good plan, please share your concerns.
They never go back to the same lash for me, your luck maybe better though but all the vibration I bet the contact between the ring gear and pinion has changed
Thanks, I guess we need to rethink this...
The backlash is set by shims between the differential housing and the pinion cage? If we reassemble everything the way it was it should be ok? We are at Eagle Nest in Nashville.
Those shims are for setting pinion depth. They will affect backlash, But that is set by moving the ring gear toward or away from the pinion.
There may be some numbers etched into the end of the pinion, That is the deviation from "standard". They assist with the depth set shim selection. Just reuse yours or replace them with the same thickness.
Backlash is set with the pinion held firm and the ring gear "rocked" to find the lash/freeplay.
It may be OK still, But if it clunks or whines, You're going back in again.
Verify that the splines are not worn, A loose yoke can tear them up.
You can replace the yoke if the fit is a little loose.
Thank you azdieselman, luvrbus, Tom and eagle
I am going to share what we have discussed here with the guys in the shop and hopefully we get it right.
Bob
I agree with Cliff. I would not feel comfortable unless I pulled the pumpkin.
A lot of damage could have happened when pinion bearings lost their preload.
Sounds like the "mechanic" dropped the ball big time. I rebuilt mine about 8
years ago myself. It is not a small time job.
Dave Rasor
4104-2375
I saw your question about a driveshaft on 4104 - I assume that this has been a conversion to a V8 and a 730 tranny. In order for this to work in a 4104 the housing has to be out of a 4106 or 4905, anything that had a 730 in it. If you don't change the rear end you will have some really hideous driveshaft angles. In other words, the 730 transmission has a completely different angle from a 4104 transmission. In order to do it correctly you have to change the housing which moves the center section to the left of the bus and allows the driveshaft to have minimal angles. If this hasn't been done you are running really bad angles and you will never keep a driveshaft in it. I have not looked up the exact changes that will correct his and there is probably a better source than me. My 04 has been around too long and I've forgotten most of what I ever knew about it. Hope this helps you get going in the right direction. Thank you.
Since my 4905 sits over my pit, I went out and measured. First a 4106, 07, 08, and 4903,05, have their differential mounted to the right of the rear axle housing,(looking from rear of coach) about as far right as it will go without hitting suspension beam. The distance from the right side of the differential mounting flange to the back side of the brake drum is about 9 1/2 inches with its 10 inch brakes. Probably would be 11 1/2 with 8 inch brakes on a 4106,07, and 08, and if it still had 4104- 7 inch brakes, it would be 12 1/2. Btw, what is the ol of your driveshaft? Mine is 22 1/2 flange to flange. (V730) I think that the differential on the 4104 is mounted to the left of center of housing. The drive shaft on our 4104 was about 4 feet long, from memory.
Thanks for the help,
The housing is 4104 but the differential is out of a 4106. This conversion was done in the 80's and has not had driveshaft problems. This repair is a result of the propeller shaft/pinion nut backing off and allowing the shaft to exit.
Quote from: Bob & Tracey on May 17, 2016, 05:04:29 PM
The housing is 4104 but the differential is out of a 4106.
Bob -Which side of the coach centerline does the differential housing/pumpkin sit, when viewing from the rear of the coach? Street or curb?
FWIW & HTH. . .
;)
RJ,
Without measuring it looks like it is on the street side.
RJ in all my doing around 04's it have came to the belief that the only difference in the 04 and the 06 is the pumpkin.
I helped Jara Smith put 2 6v92'S and 730's IN 04'S and all he changed was the pumpkin.
he had to do some cutting in side of the axle so the pumpkin would fit.
I would bet that my 04 which he installed the 6v92 in about 12 years or more ago.
Had engine problems but never a drive shaft or axle problem.
Hard Headed Ken can give more info than any one than I know.
uncle ned