Is some play at the Transfer case normal 917/Mog drivetrain?

[Joe917]

Truck is a 1993 MB-917AF (same drive train as a Mog minus the portal axels)
My mechanic and I have been going over the vehicle with a fine tooth comb. All mechanical issues have been addressed except for the fact that we have found a small amount (maybe 5 thou) of play where the rear drive shaft yoke meets the transfer case. We split the yoke to drop the drive shaft and tighten the center bolt but there was nothing to gain. Bearings spin perfectly and are quiet. Is this small amount anything to be concerned over? I am in Ottawa Canada and these vehicles are a complete unknown to truck shops.
One other thing, the tach quit today, offhand does anyone know where it outputs from (alternator,transmission etc) before I go lie on the ground.
Thanks, Joe.

 

[CragMog]

Hi Joe - I have the same problem on my U1300L which Atkinson Vos diagnosed as output gear shimming. The shims sit behind the front output shaft. Result is I get a metallic "clack" pulling away or changing gears. Parts were not expensive. Hopefully I'll have the work done next week and will post more after that - regards Craig

 

[Joe917]

Thanks for the response Craig. I'm not sure this is the same issue (I don't hear the "clack"). The play is not rotational. you can flex the joint slightly by pushing on it laterally. Flex is the same up and down, side to side. If you could ask your mechanic his opinion it would be much appreciated, regards Joe.

 

[Tennmogger]

I know nothing about the 917, but, it does not have torque tubes, does it? I'm thinking the 917 has exposed drive shafts, quite a difference from a Unimog, especially with regard to your question. Does it have front wheel drive too? (Mogs don't have transfer cases, does your 917?)

If the transmission IS the same as a Unimog (and there's a huge variation between models), typically tightening the nut in the yoke would not adjust output bearing pre-loading. That is done by a faced-nut that's on the output flange, the flange to which the yoke would bolt, probably. Again, I'm just guessing but think you will have to disassemble deeper into the rear of the tranny to pre-load it properly (uses a crush washer)....and that's assuming you do have a Unimog transmission.

Is that '5 thou' end play? If it were mine, and if it were not leaking trans fluid, then the side play can't be bad enough to damage the seal. I'd drive it.


Bob

 

[mogwildRW1]

Bob's right. The 917AF transmission is nothing like the Unimogs. There are a few different options for transmission, I'd need your VIN number to be sure which one you have. Regardless, it doesn't look anything like a Unimog transmission in any variation. (two of 5 variations of transmission for the 917AF attached for reference)

 

[mogwildRW1]

Joe sent me his VIN and I was able to determine his transmission type in the EPC.

Someone smarter than me will have to comment what parts if any are responsible for the end play, and what can be done about it (if it's of any concern).

Here's the exploded diagrams of the transmission:

 

[Joe917]

Thanks Trev,
Just to clarify the play is at the output of the TRANSFER case to the rear diff
Joe.

 

[mogwildRW1]

Right. Sorry. Used to Unimogs which don't have a Tcase

And now, exploded diagram of the transfer case

:ylsmoke: