diffferential output flange preload?

[Rabbit 16v]

So, the repair manual once again failed. I searched here and didnt find a whole lot. still trying to sort this haffie out. I replaced all the bearings and seals from the output of the backbone forward relating to the front drivetrain. Previous symptoms were broken 4wd engagement lever, really loud bearings, and leaks. Got it all back together and the good news is there are no more bad noises and the leaks are gone (yes, there is fluid in there too!). Bad news is it felt like the front locker was on all the time. Pulled it all apart and it seems the front diff now has too much preload on the planetary set? In the parts catalog and from what I can see, it appears that if I take the circlip out, then the thrust sleeve between the diff housing and the output flange should just slide out. It does not. How does one disassemble the assembly? Im not sure what changed here as it did not present these symptoms (pulls really hard to the right too) prior to me working on it. It should be noted there is a lot of rust that was in there.

any help is appreciated as always!

[heinkeljb]

I think I had the same thing on the rear diff in one of my rear diff / gear box units. That was down to an OVAL diff lock sleeve. I didn't cure that issue, because I just used another diff internals set.
Have you tried putting the diff unit into a bucket of vinagar or Coke a Cola to remove the rust?

John

[Rabbit 16v]

I have not tried that. I did put it in an industrial part washer to help clean it, but of course thats not great for rust removal. Diff lock sleeve moves freely without issue. But when I put that shim in along with the clip, it will bind. I did cheat a little and machine the shim down to be a little thinner, but I didnt want to get too greedy. Not like I had an array of shims for these lying around...

I suspect this may be related to some beating I did to seat the carrier bearings when installing the side covers. But, I have no idea how to get inside the differential in order to inspect things. I did remove the bolts holding the ring gear on thinking there might be something sandwiched in there, but no luck.

Thanks John!

[AustHaflinger]

I am afraid I cannot help much but I did pull my front diff off the tube about 9 years ago to replace some noisy bearings. I cannot remember much except it was easy to do and everything seemed quite logical - i had it completely apart - so I suspect you have some issues there.

Some pics.

[heinkeljb]

According to the parts book, the shim starts at 1mm and goes up in 0.05 steps all the way to 2mm. The sliding sleve should come out and allow you to remove ALL the internals right down to two little cog which are at 90 degrees to the bigger cogs on the end of the sleeves. (the sleeves come into the housing from both sides, but you know that already).
As you say there does not appear to be any description with numbers for setting the correct thickness / tension of the sliding sleeve tubes.
Maybe reach out to Jim who goes by the name of goatwerks on here and on http://real4x4forums.com/ - He has the knowlledge you seek - I am not sure he visits this forum very often so probably better to try a PM on real4x4fourms.


John

[Rabbit 16v]

I am afraid I cannot help much but I did pull my front diff off the tube about 9 years ago to replace some noisy bearings. I cannot remember much except it was easy to do and everything seemed quite logical - i had it completely apart - so I suspect you have some issues there.

Some pics.

2014-10-26_14-44-50_792_zps2943cae8.jpg2014-10-26_14-44-36_413.jpg2014-10-31_14-30-36_851.jpg2014-10-31_19-15-44_984.jpg2014-10-31_17-09-30_843.jpg2014-10-31_19-20-26_129.jpg

yeah, I did all the same stuff there too. I must have screwed something up!

[Rabbit 16v]

According to the parts book, the shim starts at 1mm and goes up in 0.05 steps all the way to 2mm. The sliding sleve should come out and allow you to remove ALL the internals right down to two little cog which are at 90 degrees to the bigger cogs on the end of the sleeves. (the sleeves come into the housing from both sides, but you know that already).
As you say there does not appear to be any description with numbers for setting the correct thickness / tension of the sliding sleeve tubes.
Maybe reach out to Jim who goes by the name of goatwerks on here and on http://real4x4forums.com/ - He has the knowlledge you seek - I am not sure he visits this forum very often so probably better to try a PM on real4x4fourms.


John

yeah, I saw all the shims in the catalog. im guessing there is rust on the sleeve or the flange with the gear on the end. it has to be something I did during all this work. Ill go back at it more this week and see. I just cant imagine what I could have done to cause this issue, but since I cant get it apart, I cant inspect it. I really dont like the idea of machining the shim thinner, but there is pitting on the planetary gears, so its kind of screwed up anyway. I doubt this thing will see more than a couple thousand miles ever in its future anyway. So, I may just do that and if something happens, I will put a new diff in there. I just need to get it back on the road, ha

[Rabbit 16v]

Ok, I know what happened now. Apparently during assembly, my tapping must have had one of the square drive block misaligned. This in turn squished the channel that the circlip goes into. If you have ever looked at these shims, they are not just flat. They have a chamfer in the corner to help secure the snap ring in its groove. well, since the groove got squished, this pushed the circlip toward the centre of the diff thereby increasing pressure on the circlip where its tapered. so, thats the issue. Im going to see if I can fix it before having to buy a whole new diff. Argh!!

[heinkeljb]

Well done on finding the issue!

Maybe take it to a machine shop and get them to put it in a big lathe and use that to re-make the groove. Unless of course you happen to have a lathe big enough to fit the diff sleeve in!

John

[Rabbit 16v]

Thanks. I was able to get it all sorted. Took a few hours of machining and such and the result is nothing I would offer a customer, but its done. Its not all back together yet, but it spins freely and im confident thermal expansion isnt going to be an issue. Ugh, what a shitty lesson. If anyone ever buys this from me, note, this may be an issue in the future. It wont be in my future though!

hope to have it all finally dont next week. weather is picking up here and looking forward to driving it around.