I just pulled out my transmission to get at an ailing clutch, which I believe was slipping due to a mainseal leak on the crankshaft. The drivetrain is a 2.8 with an Isuzu 5 speed. As I live in Mexico, I anticipated a parts availability issue in Mazatlan, and purchased a clutch set from Autozone in Tucson a year ago. Only one clutch set option was available ( and still is on their website) Pressure plate, disc, release bearing, and allignment tool. Upon comparing the unit I pulled off the car ( it is an 86 Ferrari F40 body conversion) I noticed some differences: First, the new release bearing is different, and wont slide onto the input shaft on my transmission. Second, Although the discs appear to be real close, the spline collar on the replacement is 22 mm outside to outside, as compared to 28 mm on my Isuzu unit. Lastly, the pressure plate fingers on the replacement stick up 2 to 3 mm less, than the Isuzu unit, when measured from flywheel contact surfaces. So the questions: I am assuming the Getrag 4 and 5 speed clutches are different than for the Isuzu 5 speed? Is the 5 to 6 mm difference on the spline collars on the discs going to make a difference, if I use the new replacement disc with my old pressure plate and release bearing? ( the old disc was worn and oil soaked) I am sceptical I can get my Isuzu clutch pack replaced here, so it would be either try to resurface the old disc, or put in the replacement disc and use the rest of my old parts. Any knowledge shared on this would be really appreciated; I don't want to put it all back together to find I made a mistake!! thanks in advance.
First, V6 engines used larger diameter clutch disks.
The Isuzu transmission uses a different throwout bearing than the V6 Muncie or Getrag trasmissions.
For these reasons you're seeing that the throwout bearing won't mount to the transmission forks.
In order to get the right combination, you must order the disk and pressure plate separate from the throwout bearing. If you have a friend in the US, have them order a clutch and pressure plate for an 87 V6 and a throwout bearing for an 85 or 88 4-cylinder. Due to the crossover year of 86, you're safer ordering the parts for the years I listed. Or you can order the disk, pressure plate and throwout bearing as individual pieces from The Fiero Store. I would suggest just replacing everything while you're in there and not take a chance on putting back part of your old stuff.
Check the cam cover plate while you have the flywheel removed. That's a common place for an oil leak. It may not be your rear main seal.
Thankyou for the info! Mexico charges 100% duty at the border for car parts brought from the US. I always try to have a wish list in place when we go annually to Tucson, and then try to hide them when coming back. Unfortunately, that trip is not until Easter. I found a business here who will rebuild my clutch disc, and resurface both the flywheel and oressure plate for $75 . The clutch only had about 7000 miles on it since it was installed new, so I may take a chance on the throwout bearing. From what i can see, there is no fsult with the main seal, or cam cover; The oil leak appears to have come from somewhere on the transmission, as it had syncromesh oil all over it and the sealing plate. As I recall, there is one bolt somewhere on reinstall, that requires sealant?
There are no bolts inside the bellhousing that need to be loosened when replacing the clutch, so there should be none that needs to have sealer put on them and tightened. But if you're sure it's synchromesh oil, then I'd do a careful inspection, especially of the input shaft seal area.
