1G Finally took transmission apart, advice needed on which parts need replacement. (More photos!)

[Mello]

I have a 2G but it has this same shield piece. Your FSM image shown orientation is confusing to me but I believe it's to protect the rubber hanger from the heat radiating off the CAT.

 

[XC92]

Ah, that would make sense. Thanks. I was just curious. Literally every part on the car serves some purpose, or is at least meant to or should.

Btw, finally got everything back together today, filled the trans & t-case with oil, put the wheels back on, lowered the car, reinstalled the battery, everything but the center console which still has to go back on, got inside, turned on the ignition, engine started, released the clutch pedal, and...nothing happened, as should have been the case (I had this paranoid fear of the trans blowing up).

Then the real test. Put it in 1st, didn't pop out (the main reason for the rebuild), car moved forward a few feet. Put it in rev, car moved back a few feet. Tried both a few more times, everything checked out. So, initial tests are that the rebuild took and I didn't break or otherwise damage anything. But the real test is when I actually drive it around the block a few times and then further. But it works!

 

[XC92]

Ok, first test ride, just once around the block. The trans shifted fine, no blocking, no grinding, no popping out, easy in easy out. But there was this weird sound coming from the trans area, that goes away whenever I disengaged the clutch (i.e. pedal all the way down). It sounds like a pneumatic sound, like air rushing through an opening, sort of a whooshing sound, and is present whether in gear or neutral. Only disengaging the clutch makes it go away.

I don't remember this sound from back years ago before the car sat for 5-6 years. After I swapped the clutch last year but before I fixed the trans, this sound was also present, but less pronounced. Now it's quite pronounced and I'm concerned that something's not right and damage could ensue if I drive it much.

Could this simply be due to new bearings and slightly thicker shims, so everything's tighter than it once was, and I need to drive it for a while and let it break in? Or is this a bad sound and I need to find out what it is and fix it? Could it be a prop shaft that needs new grease or cleaning? Could it be a hole in the exhaust that I maybe created when I dropped it to fix the trans? Something else?

I'll try to record it and post it here later.

 

[92AWDHX40]

Could be a number of things hard to say gonna have to get it on the road for a minute

 

[XC92]

I thought a bit more about it and since I hear it in neutral but not when the clutch is disengaged then it's likely coming from somewhere between the clutch disc and intermediate shaft. It's not likely beyond there, e.g. center or front diff, output shaft, t-case, prop shaft, etc., because it happens when there's no output.

I wonder if this sound is the clutch disc slipping, if the clutch isn't fully engaging? I do have to take the pedal assembly out because disengagement is way too close to the floor and the shaft probably needs to be welded, so maybe that's it.

Perhaps before I take the assembly out I can test this theory out by turning the MC rod in a bit. This might cause disengagement issues but so long as the trans stays in neutral this shouldn't be an issue. I'm hoping it's this because I really don't want to have to pull the trans again.

 

[Mello]

My thoughts, it could be the TOB. My TOB(s) has a very faint whine when not engaged (pedal up) that quiets when pushed to the floor. This is on both my FWD & AWD with OEM TOB.

 

[XC92]

I thought it might be that too but it's OEM & only has a few hundred miles on it, same as the SBC DD S2 clutch & PP. New CC fork & fulcrum (shimmed with a 1mm washer, more to spread the load than to move the fork towards the PP).

I greased every surface I was supposed to grease but not excessively so it didn't get on the friction surfaces by accident, e.g. input & clutch splines, TOB & trans sleeve, TOB PP surface, fork, fulcrum, etc.

Only thing I forgot to grease was the flywheel inner bore where the tip of the input shaft goes. But I don't think that matters as they spin in sync and there's probably a tiny air gap anyway.

Also, I let the car sit for a while then started it up again, to record this sound, and while it was still there, it was a lot less loud, almost imperceptible unless you knew to listen for it. I don't think my phone would pick it up. Maybe it was just a break-in thing?

In any case I need to remove and fix the pedal assembly and hopefully that will take care of it if the clutch is slipping slightly as I suspect.

Oh, and I just read on a BMW forum that apparently the speedometer mechanism can cause this sound too, and goes away after everything warms up.

 

[We're on Boost]

If your clutch was slightly slipping when there is basically no load on it (like when you are in neutral) then just think how bad it would slip when there is load on it. You would not even be able to drive around the block. So I doubt that is the noise.

But maybe it could be the TOB since it does still have a small amount of force pushing it into the clutch fingers with the pedal up - the force of the little spring in the slave. Then when you step into the pedal a bit, there is more force on the TOB and it sort of cleans up that situation.

 

[XC92]

The sound is basically there or not, and doesn't really go away until the clutch is fully disengaged. Until then it's the same sound and level. So it's not the slave spring. Could it be the TOB sleeve slipping against the input shaft sleeve?

Any chance that my putting a 1mm washer under the fulcrum is causing this, since the fork, fulcrum, PP & clutch are all new? In any case the sound appears to be going away, so I'll just monitor it and see if it returns.

 

[We're on Boost]

Any chance that my putting a 1mm washer under the fulcrum is causing this, since the fork, fulcrum, PP & clutch are all new? In any case the sound appears to be going away, so I'll just monitor it and see if it returns.

I suppose what you are referring to is that with some PP - fork combinations the fork needs to be "clearanced" to clear the PP. Anyway I don't know about this combination but if your washer is only 0.040" thick, I wouldn't think that would be it. Gee, is your washer really only 0.040" ? My 10mm flat washers are all about 0.077" thick.

 

[XC92]

Like I wrote above it was as much to spread the load of the fulcrum as it was to compensate for the several resurfacings the flywheel's gone through. I think that around 0.03" is taken off each time.

 

[dwb]

Sorry if this was mentioned already but you *can* pull all the bearings from the stacks with a bearing separator, a large gear puller and a series of large sockets/pipe. You will most likely trash a few bearings in the process so don't plan on reinstalling them. A hammer and the same sockets/pipe along with the old bearing inner races (to seat perfectly against the new inner race) will allow you to press (hammer) them back on. You have to get creative sometimes to get a grip on the bearings.

I rebuilt my 1g this way. And just did it again after my 2nd gear synchro split.

 

[XC92]

Thanks. As I wrote above I've already put the stacks and trans back together and back on the car and it's running again w/o apparent issue save the one I noted above that's probably not anything serious.

But that's what I did, pulled the stacks apart with a bearing splitter, 10 ton push-puller and sockets, since I didn't have, couldn't source and was not interested in buying a full size press. I was also able to use these to put the intermediate stack back together since it was short enough to fit into the push-puller I used.

But the input stack was too long and I ended up using a hammer to slowly tap everything back using sockets and an old inner race as drifts.

I was a little worried about damaging things but I was slow and careful and made sure to only hit on the inner race of the outer bearing (I didn't replace the inner bearing since it was in good shape), and so far there's no indication that it damaged anything. Of course only time and miles will tell.

I could have put the stacks in the freezer and heated up the parts to go back on it but ended up not using this method and it wasn't really necessary in the end. I even thought of building a DIY press using a 6 ton bottle jack I had but couldn't figure out how to build one that would be safe and effective to use. I'll probably take that on at some point as having a small mini press would be useful.

Ok, this will probably be my last post in this thread. It's way past time to start a new one regarding the second half of my trans rebuild and related tasks.

But, before I start that, I just wanted to say that after completing the last few remaining tasks earlier today, I finally took it for a real test ride. Previously I'd just moved it back and forth a few times then around the block once.

And, it drives great. The trans is super-fine, no problems whatsoever, shifts into every gear w/o a problem (well, to the extent that a 1G AWD manual trans does), no noise, no blocking, no grinding, and most importantly of all, it no longer pops out of 1st gear, which was the primary reason for all this.

Only ran through 1st-3rd gears and reverse as I didn't want to chance it on roads and highways yet. I'll try that in the next few days.

So, original problem solved and no new ones created (it would appear). I did a good job, if I say so myself. Of course, it would not have been possible without the amazing and patient help of so many here, and you know who you are. Thanks a million all. Hopefully I can pass off some of this advice to others someday.