Hey dudes,

So i took my 88' GTU to the mechanic to replace the goddamn leaking radiator, and i figured while i was there i would ask him about the noisy transmission (a rattling sound when accelerating). He said the problem is common in Rx7 trannies and that it was because of deteriorating front transmission bearings. He also said that my car would soon stop shifting and that it would have to RIP if i didn't replace the bearings ... which he said would cost me $800 parts and labor.

Don't get me wrong, i want to believe him.. but i need a second opinion. Do you guys have any advice? Should i look for a new tranny in jimmy t's boneyard or should i just ignore it?

Thanks for your time,
C

 

boink.

You sure this isn't just a worn shift lever bushing causing your shift ****/lever to vibrate against metal?

The manual tranmissions rarely go bad, it's usually worn out syncros or broken shifter fork.

 

i replaced the shifter bushings last summer

 

even if you needed a new tranny I believe spd has em for 200 used.

 

the mech told me 1300 for a tranny change.. and 800 for the bearing change

 

Replacing the tranny:

You can do it yourself, its not that hard.

That is a LOT to ask for that job, IMO. Sure it is tedious, but its not THAT many hours to do.

 

So basically, i should just wait till i start losin gears and then make it a project to replace my transmission... sounds like fun (im being serious).

-c

 

Pretty much. Just remember to drain the transmission before you drop it!

Also you might want new exhaust gaskets and bolts, as those things tend to go on our old systems. When you do the tranny, do any exhaust work you were planning at the same time (especially if you're getting headers/new cat/new catback) since you'll have it out and apart anyway.

If you buy a used transmission, Replace the front and rear seals, and the throwout bearing. Replace the gland-nut (pinion) bearing as well. Now is the time to get a lightweight flywheel/sprot clutch kit if you were planning on it

 

im more than happy to do it myself... the mechanic also claims that i need "special tools" to change it... that's what turned me off to the idea. do you think i could get by with haines and a brain?

 

No way man, a ratchet with a 14mm socket is *totally* a special tool. There's no way you have one of those. You also need a 14mm wrench. Those are high dollar items, which won't come from just anywhere. Find a new mechanic.

 

I'm gonna go throw a goddamn 14mm wrench through his shop window.

 

Rx-7 transmissions are know to have bearing noises. Something about their long shaft in the transmission. If its slight, i would leave it and try some syn gear oil.

 

synthetic huh? this guy was tellin me it was no good for my tranny problem

 

OK so i looked up the manual transmission disassembly and supposedly i need a "puller." Is that an expensive tool?

 

Thats the only problem I personally ran into. Its to get the needle bearing out of the gland nut.

I rented this tool for $10 from a local tool rental place. However, you can probably buy a decent one for like, $50.

You will aslo need the seal that covers that needle bearing. (Doesnt come with most clutch kits. you ARE changing the clutch/pressure plate/throwout bearing/front seal/rear seal/gland nut bearing while you've got it out, right?)

I seriously would not worry about this problem untill you notice a real problem other then a slight rattling noise that you dont even know if it is the tranny for sure. Most RX-7 transmissions that I have encountered did not 'rattle' though they made a host of other noises. I say dont worry about it unless it starts getting worse.

 

Tofuball, i get the impression that you think it could just be the pilot or throwout bearings .. meaning i could just replace the clutch instead of the whole transmission.

 

Correct, I think it is the throwout bearing.

 

is there any possible way to tell if it's the throwout vs. countershaft or pilot etc

 

Hey, you gotta replace all that when you're in there anyway

 

I've replaced my tranny twice now. In terms of dificulty, if you have tools, a jack and 4 jackstands, and about a week (couple days if you're in a hurry), (5 hours if you've done it before)

6 months if ou try and do a auto-5spd swap w/o having the tranny with you at the time

 

Yeah dropping a tranny and popping it back in are no big deals if you've got the jackstands, jack, and the tools. And I agree with the others its quite possibly one of the typically replaced bearings anyway (throwout, pilot, etc...). Also, while you are working on it, get Red Line MTL tranny fluid... I thought I had tranny problems... I put that fluid in, zero problems since then. That stuff also theoretically prolongs your synchro life due to not containing the sulphur elements that differentials require which are typically in most tranny fluids according to their marketing stuff.

Regardless, once you've done it, its a relative breeze after that. And as it seems you have an FSM, go ahead and read the troubleshooting methodology for your problem. Might be a nice prioritized list which most likely will match what most people said here.

That mechanic is apparently talking crap since, like most people said, you can get a good used tranny for around $200 (I'm selling one, in fact) should yours break, plus the way RX-7 trannies are designed they don't seem to be completely un-rebuildable even if the worst were to happen. And a full rebuild is usually about $250-300 plus parts, which is a lot less (usually) than the $800 he was talking about, since most used trannys only need synchros and bearings, which are usually included in the rebuild price anyway, if you find a good shop.

 

The mechanic may be calculating the price for removal of the transmission and rebiulding it, plus a clutch kit, and all the labor involved. That might be where the $800 is coming from.

However, $1.3K for a tranny change? He either has bad transmission rebiuld suppliers, or is just seriously into ripping you off.

However, based on his comment about needing a special tool to change out the tranny, I'm going to have to assume he's not talking about doing all the work implied for the $800 charge.

As previously stated, find a new mechanic

 

First thing - change to synthetic gear oil.

That stuff is almost magic in our trannys.

Sound troubleshooting:
Idling - In gear - only the tranny input & countershaft are spinning - the pilot bearing is static & the T/O bearing is clear.

Just start to push the clutch pedal – the T/O bearing starts to spin also.

Push the clutch on down – the tranny input & countershaft spin down - the pilot bearing starts to spin up - & the T/O continues to spin with load.

 

most NA trannies in the FC make some noise at idle...you'll know when something is going really wrong if you hear clanking/banging or if it's very hard to get into and out of gear.

 

The tranny is VERY easy to change, first time took me a day just cus it was the first major mechanical thing ive done. successive times have been very quick. probably less then 3 hours, all you gotta do it take off part of the exhaust/shields, drain it, unbolt the drive shaft/pull it out, take the shifter off, lossen all the bell housing bolts and drop it out. Also the NA FC transsmission is very light, most ppl can just pull it onto there chest. Ive done it bymyself this way, same for putting it back, just press it up and slide it into place, somtimes you may need to jack up the front of the engine to tilt it down a little , but no special tools are required, not even a tranny jack.