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I just rejoined the site today after a long hiatus. I'm going to post a quick summary of an issue I have with the car and I'm hoping for some possible input on causes, etc. I have been searching tirelessly for similar transmission issues online as well as on here and haven't seen anything similar so here goes...
First off, this is a 90 RX-7 convertible with about 149k miles in very good condition. Original motor but I've had two transmission swaps in the last ten years. Both with used units. (yes, first potential red flag !) Anyway, the car was last driven about 3 yrs ago. It was running fine. I pulled out into traffic and realizing it was moving rather quickly, I accelerated quickly and shifted hard into 2nd gear. It was at that point I heard a clunk or some sort of loud noise...Granted, it's been about 3 yrs, so my story telling may not be the best. The car seemed to quickly loose power and as I recall , I wasn't able at that point to change gears. I turned around and nursed my car back home which was thankfully very close. On the way home I noticed some vibrations that seemed to either come from the motor or the transmission. Again, hard to remember. I pulled into my driveway and was able to get the car into reverse and back into the garage. It was running rough at this point and when I went to try putting the car back into 1st, it went into gear but with no forward movement. The car still was running rough.
Fast forward a bit after having a baby and life taking precedence, I am trying to get her back on the road. I've kept it running by starting it 1-2 times a month. I should mention that the "roughness" of the motor is completely gone. There seems to be power and good compression again. Only thing I've done is reset the ECU. Perhaps that reset the computer and everything there is kosher, but the transmission issue remains. I can shift into any gear , but there is no movement. There is no grinding going into any gears. As mentioned, the motor sounds great... I did notice that the clutch feels a bit spongier than before. Oh, and I should add that in the last few years when doing the transmission swaps , I DID do a clutch replacement.
I'm hoping this may spark some useful suggestions. I'm fairly competent mechanically but by no means am I an expert. My dad (who is 75!) is coming up to help me take a look at it next week . I think this may be a great way to get some ideas on possible issues. But most importantly, I really just needed a 2nd set of eyes and someone familiar with transmissions to help me. He's pretty good with this stuff so we shall see. Oh, and here is a pic of the RX collecting dust.
Thanks in advance for any advice/suggestions,etc !
pull out the starter and see if you see chunks of clutch material lying about inside the bellhousing.
I can shift into any gear without grinding or any sort of issue. The car just won't move when I disengage the clutch with it in gear. It's a fairly new clutch... I could be wrong, but my logic tells me it wouldn't be the clutch considering the symptoms. Again, I could be wrong , I'm just not seeing how it could be the clutch.
You said that you heard a loud clunk. Have you checked the driveshaft? It might have broke at the front yoke.
I haven't. That seems to be a logical issue. Once I have my dad here with me next week and we can get under the car, I think looking at the final drive is where we were thinking of starting. I understand the transmission on these is a weak points. At least that is what I've read . And after already replacing it twice, I tend to agree... Thanks !
Hot Dog, that also could explain how I was able to make it home but eventually had no power to the rear. Perhaps it didn't give way completely and therefore the motor was able to still turn the driveshaft for less than a mile back to the house. Got it into reverse and then it was done.. Also could explain why the vibration disappeared once it stopped turning the driveshaft.
Hmm. Jack it up, put on the parking brake, let it idle in gear with the cluch pedal up. Does the driveshaft turn? If yes, but the wheels are not turning, and the inner part of the CV axles are not spinning, you done shelled the rear end. Does the driveshaft not turn? Check the clutch out.
If the driveshaft failed to the point of it not moving at all, it would be either missing or hanging. An internal failure in the transmission is unlikely if you can easily select all gears yet none do anything.
Based off your description, if the clutch pedal feels ok and clearly releases in the pedal movement, if it can shift smoothly into every gear with the engine running, but doesn't move, the probable issue is the rear end or a failed CV axle. I don't think CV shaft failure is common on a stock NA car.
If the clutch pedal doesn't clearly release in the pedal movement, its guaranteed to be clutch failure. If the clutch has completely failed, you would be able to easily select gears, because nothing in the transmission is spinning.
To sum it up. If the driveshaft isn't turning, clutch. If it is turning, rear end or failed cv axle.
Hmm. Jack it up, put on the parking brake, let it idle in gear with the cluch pedal up. Does the driveshaft turn? If yes, but the wheels are not turning, and the inner part of the CV axles are not spinning, you done shelled the rear end. Does the driveshaft not turn? Check the clutch out.
If the driveshaft failed to the point of it not moving at all, it would be either missing or hanging. An internal failure in the transmission is unlikely if you can easily select all gears yet none do anything.
Based off your description, if the clutch pedal feels ok and clearly releases in the pedal movement, if it can shift smoothly into every gear with the engine running, but doesn't move, the probable issue is the rear end or a failed CV axle. I don't think CV shaft failure is common on a stock NA car.
If the clutch pedal doesn't clearly release in the pedal movement, its guaranteed to be clutch failure. If the clutch has completely failed, you would be able to easily select gears, because nothing in the transmission is spinning.
To sum it up. If the driveshaft isn't turning, clutch. If it is turning, rear end or failed cv axle.
Good luck
Thanks ! Yea, I've never been able to easily work on it by myself so having a second set of eyes will help once we get it up on jack stands. I can then see if the driveshaft is turning. There's nothing dragging the ground so best I can tell the driveshaft is attached. That was the first thing I checked (from the ground) when it happened. I'll post an update next week to what we find. I am praying it's something with the drivetrain past the transmission since like I said, it's been replaced twice already ! I'm hoping it's something we can figure out and get her back on the road soon.
considering you said it kept losing power, i still bet your clutch failed.
were your RPMs dropping as you lost power or were the RPMs going up but you kept decelerating?
clutches can disintegrate at or near redline due to the centrifugal force applied on them at such high RPMs, it was rather common for the RX8s to blow a clutch at redline and the S5 n/a is more than capable of the same RPMs.
considering you said it kept losing power, i still bet your clutch failed.
were your RPMs dropping as you lost power or were the RPMs going up but you kept decelerating?
clutches can disintegrate at or near redline due to the centrifugal force applied on them at such high RPMs, it was rather common for the RX8s to blow a clutch at redline and the S5 n/a is more than capable of the same RPMs.
It happened roughly 3 yrs ago. So details about the lose of power could be a bit sketchy. When I start it now, the motor runs, revs and idles good as ever. As if nothing ever happened. Once I have it up on jacks and can see if the driveshaft is turning, that should help a lot. I should know in a week.
Really great insight from everyone. Truly appreciated... I'll take some pics as well once things are underway. I had a kid in the last 2 1/2 yrs so the car has just sat, which is sad. It's in very good condition and I'm looking forward to hopefully getting it back on the road soon.
UPDATE: I haven't been on here in quite some time. I realized that I had not gotten back on here to update the status of my convertible. She's back on the road. Turns out I had broken the driveshaft at the u joint on the output shaft. As you may know, you have to replace the entire driveshaft as the u-joint is not replaceable. At least that's the information I have..Anyway, it was a wonderful feeling to get the RX-7 back on the road .Here's where things get ironic...
So after several great trips in the car ,I walked out into the garage and my damn driver's side window was shattered. Garage door was down. No signs of foul play, etc. I've since sourced another driver side window from Ebay. Unfortunately it seems like it doesn't fit. I may have to try and reach out to some local folks in Raleigh to see if anyone has experience with these or not but it should be pretty straight forward. I've replaced the power motor for the window previously but damn this replacement does not seem to fit. I may start a separate thread. See if there is anyone locally with experience with these windows. Also would be nice to connect with some local owners. Anyway, hopefully the convertible will be back on the road yet again. Guess I can drive it for now with the broken window.
>>> First off, this is a 90 RX-7 convertible with about 149k miles in very good condition.
From my experience, 100k-150k miles seems to be the average lifetime of a driveshaft on these cars. Haven't heard many instances of a yoke breaking, but it certainly does happen on occasion.
I have 149k miles on my car so I suppose that's right on par with your experience. I remember pulling out into traffic and have to accelerate hard when it happened. When I threw it into 2nd it snapped. Now if I can just get the dang window replaced.
On that same topic, is the coupe window on a 2nd gen similar but perhaps slightly bigger than the one on the convertible ? I'm thinking the one I got of Ebay may actually be one from a coupe, despite the description that stated otherwise... Seems like it's a good bit bigger on the bottom than it should be but is close in shape.
Have you tried a replacement glass company yet? You might be surprised. You can always post a "Want to buy" ad in the 2nd gen for sale section here on the forum.
12-13-17, 11:05 PM
