You may remember a few weeks a ago I posed a question about what would cause my basically brand new TOB to go bad.
Car is a 88 bmw 325i but with a 97 328i motor and transmission.
well, in addition to that the input shaft seal also failed soon after. so, I had to pull the tranny for that, I might as well replace the TOB too.
fast forward to today. after 7 hours we got the transmission out and got to inspect the throw out bearing. it is grittier than Clint Eastwood's acting. so definitely bad. another thing that I noticed is that the pilot bearing came out of the crankshaft and was still on the input shaft. not seized on. it slid right off without any problem but it does the same thing to the crankshaft, slides right in and out. as does my brand new pilot bearing. is that a problem??
Bonus points: My father insists that the reason that the throwout bearing failed is because the bearing was spinning on the pressure plate all the time. which it is. But as far as I can see it BMW designed the system that way. the slave cylinder has a "spring" that forces the slave rod out all the way at low pressure. any BMW guys out there that have run into this? do you know if that is how the system is designed? am I missing something?
Are you missing a dowel pin anywhere on the bellhousing? The three failures you mention all point towards a mis-aligned transmission.
Tell dad that he used to be right, but many cars run with the release bearing touching the pressure plate these days.
Crap parts from O'vancezone?
ChasH
New Reader
3/12/18 4:29 p.m.
The bore for pilot bearing is worn too big, likely due to a failed pilot bearing spinning around. Use some locking compound made for loose fit bearings to hold the bearing in place.
ToBs have been running in constant contact with the PP for decades-it's part of the self adjusting feature. As posted already there seems to be a mis alignment of the trans to engine.
ChasH said:
The bore for pilot bearing is worn too big, likely due to a failed pilot bearing spinning around. Use some locking compound made for loose fit bearings to hold the bearing in place.
ToBs have been running in constant contact with the PP for decades-it's part of the self adjusting feature. As posted already there seems to be a mis alignment of the trans to engine.
I would argue that this would kill the pilot bearing, not tob
Sounds like bad grease, too high of temp, or bad spacing. If there is not enough space for the tob, it can ruin the input shaft seal and the tob.
I had that happen on our gbody swap. I had to space the trans a bit.
ChasH
New Reader
3/12/18 5:56 p.m.
wvumtnbkr said:
ChasH said:
The bore for pilot bearing is worn too big, likely due to a failed pilot bearing spinning around. Use some locking compound made for loose fit bearings to hold the bearing in place.
ToBs have been running in constant contact with the PP for decades-it's part of the self adjusting feature. As posted already there seems to be a mis alignment of the trans to engine.
I would argue that this would kill the pilot bearing, not tob
Sounds like bad grease, too high of temp, or bad spacing. If there is not enough space for the tob, it can ruin the input shaft seal and the tob.
I had that happen on our gbody swap. I had to space the trans a bit.
I think a misalignment could affect both. Pressure from misalignment on one side of a ToB could lead to early failure.
No missing dowel pins. All bolts were threaded in correctly and the bellhousing fit flush to the engine all the way around. I don't see how it could get misaligned with all that.
Any tips to make sure that it is aligned correctly?
