Hey everyone,

I'm utterly confused with this one and don't know much of the history with the car so wondering if someone here may be able to shed some light on what's gong on.

I have ~3000km on the car since buying it last year and the previous owner said there were 5000km on the clutch when he bought the car. Last summer the car went from driving smoothly to undriveable in a matter of minutes. The shop has the transmission out of the car right now, machine the flywheel (to my knowledge this one is the 3.4 flywheel, not one from an 88 for the swap) and there were some 'hot marks' on the flywheel and clutch disc with the material getting worn fairly close to the rivets. Much more wear than there should be on an 8000km clutch (assuming the previous owner was correct with the age of the clutch).

The part I find really confusing is that the shop is telling me the throw out bearing that came with the V6 Luk clutch kit isn't fitting on to the transmission, and doesn't match the throw out bearing that was previously on the car. They got a throw out bearing for a four cylinder and it's a perfect match to what was on the car prior to the clutch failure. From what I can tell the casting numbers on the transmission are 14073796 and GM-CFM-3 if that helps at all.

Anyone have any idea what might be going on here that there is a 4 cylinder throw out bearing on a 4 speed transmission with a 3.4 PR conversion? I'm no pro but this seems quite strange... Could something like this lead to a clutch wearing out prematurely?

Thanks for any help you can give.

The TO bearing is matched to the transmission. It does not care what engine you have. The 4 speed 'Muncie' was behind the 4 cylinder engine in 1984, so the same TO bearing is very likely correct for that transmission in 1986.

[This message has been edited by Gall757 (edited 03-04-2015).]

When you say, not fitting, is it due to the ID of the T/O bearing or some other dimension?

Pretty sure I figured out the problem. Apparently parts suppliers in Alberta only have one listing for V6 clutch kits and that's the 5 speed which is what the shop ended up with. Got them to reorder one for an 85GT so hopefully that solves the problems. I totally didn't realize that the 84's used the same 4 speed as early GT's that makes a lot more sense now though. Would the Isuzu 5 speeds use the same bearing too? The shop said they ordered a bearing listed for an 86 4 cylinder and it matched up no problem.

Yes...the 86 has that problem with the parts books....everywhere. They list the 5 speed and ignore the 4 speed. The 85 listing will be correct for your car.

Ok, thanks! Glad to hear a little bit of closure on knowing the right parts are going in.

Here's another question maybe you guys can answer. The car has a leaky rear main seal and oil pan after a rebuild 3000km ago by the previous owner. 93-95 camaro 3.4 block and it's using a 2.8 oil pan. Will there be any issues using a rear main seal for an 86 2.8l? I'm pretty sure that's what the mechanic put in today to fix the leak and I'm wondering if it needs to be something else.

You can go to the RockAuto website and check the crankshaft seal numbers for both engines. I think they will be the same.