driveshaft play

[hungryjoseph]

I have about 1 to 2 mm of up and down, left to right play where the driveshaft inserts into the gearbox. what is the cause of this?

[Dream240]

Worn teeth on either end? Maybe? 1-2mm is not a whole lot. As long as the teeth are grabbing inside the driveshaft you should be okay. If they're not you'll know it right away. Do they looked damaged at all?

The tranny output shaft will have a little movement in it due to being old and used. The only problem with the lateral movement that I can think of, is you might leak out a little oil from time to time from the rear seal.

The driveshaft has the center support bearing to help absorb the movement. So expect to notice a vibration increase if you go to a 1-piece. Not alot but noticeable.

[g6civcx]

Go to a 1 piece shaft, solid gearbox and engine mounts, and that will help out a lot with the play.

[Dream240]

Go to a 1 piece shaft, solid gearbox and engine mounts, and that will help out a lot with the play.

I think he's talking about having actual tranny output shaft lateral freeplay. Or maybe he's talking about have space between the output shaft teeth and the driveshaft teeth?

I'm confused already..... :( More elaboration?

[let5l1de]

seems to me that he is talking about the play at the output shaft. I fully support Dream240s' theory of the transmission having movement in it (output shaft bearings/seals) due to being old and used. It just happens to all mechanical parts over time... Just swap the trans with a good used unit. rebuilding is an option however a bit more expensive.

[hungryjoseph]

I have a 1 piece, and what's been happening is that the transmission has been making grinding noises on deceleration between 2200 and 3200 rpms, very faint at other rpms, above 3200 the exhaust drowns it out. not as noticeable on 5th gear but still there. it's actualy a loud grinding noise when i try to accelerate in 5th gear below 2200rpms.

I've been through 5 transmissions and they all did the same thing. This leads me to conclude that it's something on the car and not the transmission because I highly doubt i'd have 5 bad output shafts. The teeth do grab because the car does drive. I even went to a drift event like this and it was fine.

I don't know whether theres space between the teeth or not though, all i know is that if i push the dirveshaft up or to the side, it will move a little bit be a millimeter or two. It's very faint but still noticeable

[Dream240]

ah....now I get it.

You've got driveline balance issues.

I would venture to say you have an aftermarket clutch and flywheel correct?
Also you have a short throw shifter right?

If you do then you've most likely got an out of balance flyhweel/clutch plate combo. Not that they're out of balance individually, but out of balance when put together and then on the car.

Also you would definitely have this problem even with 5 different trannys, cause the clutch/flywheel remain the same.

EDIT:

These vibration problems become amplified when you start swapping in aftermarket aluminum/steel parts that remove OEM dampner components, like the OEM cltuch PP, two-piece driveshaft, underdrive pulley, OEM shifter with rubber guts, etc.

Sometimes this new vibration isn't really new at all. It's just that you've uncovered the vibration by removing it's masks. If it's becomes absolutely unbearable, you can try switching back to a OEM shifter with a new boot. This alleviates some of the noise and vibration without sacrificing too much performance.

I had your exact problem with an aluminum driveshaft, flywheel, crank pulley, B&M shifter, Nismo mounts, SPEC stage II clutch. I just dealt with it and kept from engine braking unless absolutely necessary.

[hungryjoseph]

i don't have a short shifter but i DID have an exedy stage 2 clutch + 11lb flywheel, did the same thing, then on my 5th trans i swapped the clutch to a competition stage 4 and new 11lb flywheel, and it did the same thing. i guess i'll have to deal with it too, maybe i'll swap over an oem driveshaft and see what happens. But the play with the driveshaft kind of seem slike the culprit. from what you guys are telling me, i'm guessing it's not supposed to be there. should i go ahead and try another driveshaft? i can hear a little bit of virbation from the gearbox at idle when the engine is revved it

[Dream240]

The driveshaft movement coming from where you described IS normal to a degree. Remember you talking about a used transmission with wear-and-tear. There's going to be some worn down metal components to your trannys just from that everyday use. So a little driveshaft movement is normal.

Now if you've got enough movement that you can actually rattle the driveshaft while it's on the car, the rattle coming from the area where the splines mate up, then it's sounds like you might have a driveshaft problem. Since you said it's a 1-piece aftermarket DS, was the rattle the same BEFORE you put the DS on?

[g6civcx]

joe, I feel so bad for you. If it's not one thing it's another.

Do you have any money to actually get a shop to look at it? If so it may be worth it to pull the transmission and driveshaft and get it checked out since you've gone through so many.

[devonkyle77]

i have a 1 pc driveshaft and am close if you want to try it to see if it helps.
its for a non abs s14

[hungryjoseph]

thanks devon, but i have an s13...

yeah if it's not one thing it's another... couple of the trannies had bad gears, bearings, this ones the only good one. i'm debating on taking my car to jeimport. the rattling was never there when the motorset and driveshaft were in my other car, it happened when i swapped it over to my new chassis. maybe i chipped a spline or something on the driveshaft...