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So tonight on a standard drive, I was shifting into 5th at 70mph and it kicked it back out of gear...tried again, and it popped out. I don’t know if I mis-shifted or what the hell happened.
I got home just fine in 4th, but noticed a loud rattle when in neutral.
It sounds like a spray paint can at idle. The clutch doesn’t seem to have as much pressure now, but I could be imagining.
First thing: check gearbox level. IIRC you pull the upper (filler) plug, stick a tooth-pick or similar "down" 1/2" into the hole, you should have oil on the stick.
2: Drain the oil, see if there is metal bits.
Rebuilds can be bought for about $650. I have seen a Co. that adverts on ebay occasionally, if it comes to that. And no, I do not recall the name, apologies...
You might want to describe how the 'box shifts in the other gears, etc. to give our tech-gurus here an idea of how it is performing thru the range of gears...
Maybe pilot bearing but you won't know till you pull the tranny. Do what 7aull suggested firs to see if the oil level is at the fill hole and then drain the oil and check it for metal. If it all seems good get ready to pull it out and see whats up. Has the clutch ever been replaced to your knowledge?
So it sounds like it ONLY shifts cleanly into 1st four gears.
With 5th being uncooperative, it sounds more like an internal gearbox prob.
Since the T/O bearing is only really engaged when depressed, not sure it would make a racket just 'idling' on the drive shaft?
If/when, you will want to change the T/O bearing too. you can use the 2nd Gen TURBO's T/O bearing. Heavier-duty component fits all 7's to '92.
Recommended by Guru Rob Gold at Pineappleracing.com. Link: Heavy Duty Throwout Bearing (turbo and non-turbo)
Please keep us posted as you work thru this. We will all learn something! Best of luck-
Yep - if it is the part I think (not a mechanic, if you couldn't tell...) it is, it is a 'plate' that bolts to the front of the actual gearbox, inside the bell housing. The Good New is that it only requires dropping the tranny and swapping on a replacement 'plate' (thru which the drive shaft runs to the motor). Pretty easy fix. The Bad: SA RX7s Input Bearing Assy is unique (as is the whole tranny) and the part is NLA unless you can stumble on some old dealer stock. Good luck with that.
I 'heard' (via mazdatrix?) that there was a way to mod the FB part to fit/work on SA tranny. But that might be a fairytale...
Might try folks like Atkins Rotary. Or my guru Rob at Pineappleracing. They like to keep useable old parts around.
And: if you haven't yet started to run Synth oil in the 'box, now is as good a time as any! Redline or Amsoil are popular...
If you end up finding a FB trans I'd go for it; unless perhaps you're running a fully stock Cali-spec SA. They have an extra sensor on the transmision, although that might not be Cali-specific, not certain. If I recall correctly it's called the 'top-switch'.
Conveniently the FB trans will fit so long as you swap over the tail housing and 'shift fingers' (I still don't know the proper term for them). I know this is true of the smooth case tranny's, and it's probably true for the rib case's as well but I'm not positive. Perhaps this will allow you to widen your search a bit more. The only thing I'd try and sort out is that sensor and whether or not it's needed or even present.
The SA transmissions are pretty tough; my 80LS went 212k miles and I didn't baby that thing at all. Several seasons of parking lot racing took it's toll on the engine, but the transmission was still fine on it. The input shaft bearing may be a lot easier to replace than you think. On the FB, it's just under the trans input shaft front cover and nose where the Throwout Bearing slides, and is just a big bearing with a groove around the edge that seats a big C-clip for depth and can be swapped from inside the bell housing of the trans. Usually when doing this, you just replace the gasket and input shaft cover, since it's all off anyway.
This sounds to me like it could also be a noisy Throwout Bearing, so you may get off cheap once it's out and you can get to it. Pilot Bearings fail in different ways, usually exhibiting conditions where you can't get the trans into gear with the clutch in, or the car shifts poorly because the engine is spinning the trans ALL the time due to a binding Pilot Bearing.
If you end up finding a FB trans I'd go for it; unless perhaps you're running a fully stock Cali-spec SA. They have an extra sensor on the transmision, although that might not be Cali-specific, not certain. If I recall correctly it's called the 'top-switch'.
Conveniently the FB trans will fit so long as you swap over the tail housing and 'shift fingers' (I still don't know the proper term for them). I know this is true of the smooth case tranny's, and it's probably true for the rib case's as well but I'm not positive. Perhaps this will allow you to widen your search a bit more. The only thing I'd try and sort out is that sensor and whether or not it's needed or even present.
That only works with certain SA and FB transmissions. Early SAs I think can't be swapped and the correct FB transmission for a swap is like 81-82 1/2 or so. If you go to do this, so some research, its possible but you need to know the right details to make it happen.
That only works with certain SA and FB transmissions. Early SAs I think can't be swapped and the correct FB transmission for a swap is like 81-82 1/2 or so. If you go to do this, so some research, its possible but you need to know the right details to make it happen.
True, I had forgotten about the early 4-speeds for which I do not believe it works. And yeah, if you decide to check into that route some further investigation would definitely be called for. So far I've done it with both an 82 and an 83 transmission. The ribbed-case transmissions (84 - ?) is where it starts getting fuzzy for me.
Recently I found out that a certain gen Miata (not sure which off the top of my head, but I've got it recorded somewhere) has a trans where the center case will bolt up to the FB/SA tail housing and bell housing perfectly. The only change is of course the ratios and also that the input shaft is slightly longer. Apparently cutting down the input spline just a hair is all that is needed to make it fit, but that's a whole 'nother rabbit hole for neither here or now.
In regards to the current issue, I'd second the idea that it could be the input shaft bearing, although the 5th gear bit seems odd. Really you're going to need to drop the trans to get much further here. Pilot bearings can/do fail in weird ways but usually it ends up with the input shaft staying engaged regardless of the clutch (so that when the engine is on it's difficult or impossible to get into gear), or that there is a grinding noise when the clutch is put in due to the bearing having grenaded and acting like a rock tumbler.
Quick question guys...if just the the main input bearing is bad, do you have to rebuild the whole tranny or can you just replace that single bearing?
I won’t be able to drop the transmission, I don’t have the skills, tools, or time.
I’ll have to take to a local place, and right now I am trying to find out about rebuilt transmissions and how long it will take, as I don’t want to leave my car at the transmission shops for a long time.
Its gets into gear no problem and shifts fine 1st through 4th.
Last edited by watchknut; Apr 26, 2020 at 07:18 AM.
Pretty sure you can replace just the front bearing.
It would be worth a shot to take the shift lever out from the top, easy to do from in the car and just see if you see a loose part causing a jam up or other issue. Sometimes its the simple things that fail.
Quick question guys...if just the the main input bearing is bad, do you have to rebuild the whole tranny or can you just replace that single bearing?
I won’t be able to drop the transmission, I don’t have the skills, tools, or time.
I’ll have to take to a local place, and right now I am trying to find out about rebuilt transmissions and how long it will take, as I don’t want to leave my car at the transmission shops for a long time.
Its gets into gear no problem and shifts fine 1st through 4th.
car is near 40 years old,don’t count on a single part needing replacement,all the parts are in same wear condition. Script never plays out that way.
I’m certain there is more needing to be replaced than one bearing.
FYI,damaged main input bearing not solely responsible for sudden loss of 5th gear...
car is near 40 years old,don’t count on a single part needing replacement,all the parts are in same wear condition. Script never plays out that way.
I’m certain there is more needing to be replaced than one bearing.
FYI,damaged main input bearing not solely responsible for sudden loss of 5th gear...
Has to be 79-80 transmission only. a later FB one will either require mods or mod the car to allow it to fit. 81-85 TX is longer...
There IS a PN, but useless for this.
Rob is great. I would work with him with confidence.
I hear you. My sympathies. Been There! Had a horrid non-start prob one spring, while pulling the RX out of winter storage. I was swapping in all sorts of electrical/ignition bits. Nothing. Wits end. Finally: dropped in a new set of (-Duh!-) plugs. Boom: ran like new. Ugh.
So, yeah: I try to check the Obvious first. Now.
Sorry about your tranny taking the Fifth!
I developed shifting problems on my SA22C on the way to the track last year. I lost 5th gear about a couple of miles outward bound and then I quickly lost 4th and 3rd gear (could not shift into gear) and I ended up limping the car home (about 10 miles) in 2nd gear. Bought a used FB gearbox that I was going to swap in. But I decided to drop and open the broken SA gearbox so that I can get experience in servicing gearboxes. After I cracked the gearbox open, I found that one of the bolts that secured the 3/4 gear shifter finger had backed out and and fallen off. The bolt had fallen to the bottom of the gearbox and was preventing the 5th and reverse gear from being selected. Bought a new bolt, used red loctite and bolted everything back up. Installed fresh throwout bearings and used fresh racing gearbox oil. Fixed the problem. Suggest you drop the gearbox and open it up first before deciding the next step.
Rob at Pineapple Racing rebuilt a transmission with all OEM bearings, synchros and seals, upgraded Turbo II throw out bearing, and shift bushing. It arrived last week as well as an Exedy clutch rebuild kit, master and slave cylinders.
I am going to most likely install it later this Summer or when my father in law has room in his shop.
The transmission has been fine for the past 3 weeks since I added some gear oil.
Tonight I drained the trans and filled with Royal Purple since I don’t mind driving without 5th.
The drain plug didn’t have too much metal shavings which is good, but when I cleaned up and looked into the catch basin, I found half of a metal ring that is a little larger in diameter than a quarter.
What is that?!? Definitely what was rattling around in there.
She shifts smooth as butter with the new oil in there.
