westcoastRX

Hi all,

After going down a rabbit hole of forums, I believe I've diagnosed the transmission whine in my 88 N/A vert (which has been there since purchase). The transmission whine that occurs when the clutch is not depressed and while in gear looks to be the input shaft bearing. I'm looking to hear opinions on what else might be a smart while your in there replacement which would be easy with the transmission is out. I've never dealt with transmission repairs specifically but I'm fairly mechanically inclined so I figure it's still something I can figure out.

Thanks!

DR_Knight

iTrader: (23)

New throw out bearing for sure.


new clutch, pressure plate depending on how yours is. If so, then have to replace/resurface flywheel and change the rear main seal.

mazdaverx713b

iTrader: (91)

If you've got the trans apart, I would replace all of the bearings, synchronizers and cones, and inspect the gear faces and input and output shafts for any wear.

It may however, be cheaper and faster to install a known good transmission. I understand that the parts inside will not be new but sourcing parts to rebuild the transmission may be difficult and could take some time to get. Not to mention the cost involved.

DR_Knight

iTrader: (23)

I’ve torn a manual transmission down and rebuilt it and it was not fun. The most attention to detail I’ve given anything, and that’s along with getting a mechanical engineering degree.

I’d advise on either just using your trans or another one if it’s still good, or paying someone for the labor of fully rebuilding it.


long story short, it took about 4 tables, removing every single component one at a time and placing them in the same orientation of how they were removed, and aligning each matching part from different shafts. Totally doable, but just don’t mess up… at all. Not a 6 pack in one night activity.

Banzai

iTrader: (13)

Seals, bearings and synchro's are normal wear items. You will also encounter some lock nuts that are generally single use items but could be hard to find or NLA. Generally, engineers will design using standard bearings and seals, so even if the factory item may be NLA, you can still find appropriate replacements using the original brand and P/N's to cross reference. Other than that, as Dave says, inspect other parts for wear or damage and replace accordingly. Take your time, keep things organized as you disassemble and you'll be fine. Take some pics as you go, to later reference if needed.

westcoastRX

Appreciate the insight, I'll keep that in mind before diving into any sort of transmission work. I have been keeping an eye out for replacement whole transmissions as that would be the easiest option if need be. Mine is still in full working order aside from the input shaft whine. If i were to forgo a full rebuild and just replace the input shaft bearing, I imagine this would be a much less overwhelming/complicated process?

DR_Knight

iTrader: (23)

I think there is a misunderstanding of component terms. From your initial post, I’m reading your symptoms and dialog as being the pilot bearing which sits in the crankshaft. Repair would consist of removing the transmission, removing the pilot bearing, flywheel, clutch, throw out bearing. Flywheel either gets resurfaced or replaced, clutch gets inspected and replaced if necessary, new throw out bearing installed, new pilot bearing installed, reinstall transmission. That’s it.


if your transmission has other issues such as grinds or pops out of gear, then you open the transmission case.

westcoastRX

Fantastic, exactly the info I'm looking for, thank you for clarifying! I guess I had my terminology wrong, shows how much I know. I'll look into replacing the pilot bearing and throw out bearings. From what I was told, the vehicle had a new Exedy clutch put in. Ill inspect to confirm this and the flywheel at the same time.