Driveline Refresh
 

Hey guys,

Hoping you can assist with my driveline refresh project.

My symptoms: noticeable slack in the driveline when going on/off throttle. "clink" sound when shifting into D or R at a stop. When you get under the truck and shift into D or R, you can see the driveshafts twisting.

At this point I am unsure if I have stripping "splines" as many do. I know it will likely make sense to rebuild the front driveshaft with the longer splines, my concern is installing it... what's the final word on installing the extended driveshaft? PITA?

Do you guys recommend rebuilding/replacing the rear driveshaft "while I'm in there"? It seems like most of the sudden failures come from the front driveshaft (splines stripping). If the rear is likely OK, do I just replace the guibo and be done?

Parts I want to order:
front guibo 26117503159 77.39
nuts for front 07129904473 .98
rear guibo 26117511454 50.90
nuts for rear 26127536563 1.66
center mount 26121229726 71.70
rear driveshaft cv seal 26111229078 8.51
rear driveshaft grease 07551225051 this isnt avail

http://www.realoem.com/bmw/diagrams/o/w/97.png

Do I need any more parts?
ie:
centering flange 26117507533
protection cap 26207503105

Anyone done this job recently? Please advise. Thank you!

How about transfer case chain slack? I would look there first. Search for this. I think there were members that were able to check the slack with the transfer case still on the car.

Yes, I will check for slack in the chain. I hope that is not the case but I might as well be prepared for it. There is a method to check with a screwdriver.

Yea thats it. Don't stress it, not that hard to do. Seen some DIYs.

Thanks Slick.

I have a source on a re-man TC for $1500. Totally gone through and good as new. I might go that route if I have the chain stretch, just to be sure.

Truck goes in the air this weekend/early next week!

Although for most of the people here the problem was caused by the front driveshaft in my case it was the rear. I think that's just $150 or so for that piece.
I had the same problem and I replaced the front first with long splines shaft (no luck), then the chain in TC (no difference again) and then the rear driveshaft joint. I think it's called constant velocity joint - 26117526822. I replaced the rubber donut joints as well but the old ones were as good.
So, just to get rid of the noise from D to R I would do the 26117526822 first. It's the cheapest, then the front drive shaft splines if the noise doesn't go away and then the chain in the TC... but that's based on my experience.

darks, while you're in there, i'd consider doing motor and or tranny mounts. they can allow a lot of flex in the driveline when worn out.

Thanks for your input. It's really not the noise that's bothering me, it's the slack. If I drive it, it's no issue, as I am more careful on and off the throttle. But if I mash the gas from a stop I will get a nice "clunk" which makes be believe my splines are stripping?

@dinane39

Trans mounts were done about 30k miles ago with the new transmission. Engine mounts may be original though, I didn't suspect the mounts to be bad, so I will look closer now, thanks.

I have rebuilt transfer cases before, but never on one of these. In general, it's VERY simple compared to a tranny or even a differential. First question...are the parts readily available for one of these cases? Seals, chain, ouput flanges, etc. (if that front flange gets damaged by the too short driveshaft)???

But I'd be 100% sure of the diagnosis before tearing into it. Or spending $1,500 for a rebuilt case. I'd also bet that anything other than the bearings is pretty costly if you're going to tear it down yourself, but still a good choice to DIY.

If the motor mounts were bad, you'd probably be feeling a constant vibration. Mine were totally shot, and I did not get any clunk. Also, on mine, the engine was sitting noticably low.