I haven't had a chance to rip into it yet. I need to buy some bits and pieces to drop the engine so stockpiling up stuff + oils + AOS + ims.

Might aswell do it whilst its out.

Please update this thread if you run into anything. Have you seen pumptechs stuff above? It's pretty darn useful stuff there

 

Also, would appreciate it greatly if anyone has part numbers and suppliers for the various bearings within the transfer case. Thx

 

Nearly ALL of the seals, gaskets, bearings, sprags, updated parts, snap rings, etc are Mercedes Benz and described in the ATSG 722.6 repair manual listed below. The only bearings I found that were difficult to find are detailed about 6-10 post previous to this. They are not a requirement to replace and a PITA to get.

I pieced together an entire rebuild kit that has about twice what IPT's kit has for about $700. This includes aftermarket clutches and steels, but does not include valve body rebuild. iPT's kit is not a rebuild kit but an upgrade kit. Between wittrans and Mercedes everything that needs replacing and more can be found.

http://www.amazon.com/gp/aw/d/B005QBO9MS

 

Thanks for the info.

Having the same clanking issues described by maor in the posted video. Opened up the transfer case cover and all gears and bearings appear to be in good shape - might have been a slight issue with the preload on the center gear between the output shaft and the gear that goes to the rear wheels. Will replace the tapered roller bearings (TIMKEN HM88649) while I'm there anyways. With the transfer case gears disconnected I was able to still get the clacking noise by rotating the shaft that leads to the rear diff. back and forth. Opened up the rear diff and it seems the noise is due to some lash between the gear on the differential lock and the pinion head of the output shaft (black shaft from transfer case to rear diff). The gears themselves appear to be in good condition and I couldn't detect any axial movement. A quick look through the shop manual suggests that there is a procedure to adjust backlash using adjusting shims. Anyone have any suggestions?
Cheers,
Jay

 

I can't really help but I just wana say thanks for actually taking the time to update your findings and let us know whats going on.

People rarely bother coming back to the thread to update so it's a great help

Best of luck as I have the same issue and I still haven't got time to get my hands dirty

 

Well after a bit of effort I have hopefully solved the differential problem I was having. Just to recap, my diff was making a progressively louder clacking noise when accelerating or decelerating. After checking for loose trans/engine mounts and other suspension parts I finally narrowed it down to the differential. Similar to Moar I could reproduce the symptoms by turning the pinion shaft by hand. Pulling apart the diff and removing the carrier bearings I noticed that the outer one had quite a bit of galling on the race but didn't notice anything else. For reference both bearings and cups are from Timken (outer bearing LM806649, cup LM806610 and inner bearing and cup 32010X). Replaced with new bearings and cups and added back the original shims but still had quite a bit of backlash.

At this point decided to readjust the shims beneath the cups. The procedure I used was similar to that described for the GT2 (couldn't find any info for the 996tt tip). The first step was to determine the total width of S1 + S2. To do this I added 1mm to both and measured the remaining play to be 0.5mm. To this I added 0.35mm preload for a S1+S2 total of 2mm +0.5mm +0.4mm. In the end the optimal backlash was found by using a 1mm stack height for S1 and 1.85mm for S2 (as close as I could get to 1.9mm using the shims on hand). As soon as I am able to get a replacement seal I will bolt everything up and test it out on the road. Hope that this might be of some help to others in the future.

 

Again look at previous body styles porsche manuals for a lot of turbo tippy and differential parts.

 

I now feel sufficiently dumb. Nice work.

 

Good info.

 

Thats quite interesting actually. Do you have a copy of the GT2 guidelines

How diyable is this fix if it works? I am at a diy level of removing the engine, never worked on a diff or transmission before, not a clue what to do?

 

Spoke with a specialist today who had the same car in with a similar issue.

He said he added a chim and it cured it but he doesn't know exactly why it was cured as everything looked in spec anyway..

 

Did you flush your tip after T. Eckart Method?

http://www.fzth.de/en/products/trans...-flushing.html