uggghhhhh, transmission woes.....

[SlowS13Silvia]

I hate the sr transmission, first off it is too weak for even my minimal power output and it is the biggest pain to drop.

Ok now that i got that off my chest. There seems to be this problem with my input shaft carrier bearing snapping off under load. Has anyone ever heard of this problem before? God I hope so because this is the third time ive replaced it on my car in 2.5 years and the sixth I've helped to replace it.

-----piktchas!!-----

this thing \/

did this \/

under here is the new one.

ugh.....

any ideas why this happens????

[codyace]

What are you doing when it breaks?

[SlowS13Silvia]

Driving normally or harsh cant remember. but it still drives semi fine with it broken it'll just grind when going into gears due to the t/o bearing not compressing the preasure plate completly, and also it will squeak with the clutch not pressd in. and i hate squeakys!! !!!

[homeslicej2]

We were just talking about this squeaky noise in this thread too

zerothread?id=316824

I hope this isn't the freaking problem If it is, I'll just put up with the noise. Mine has a high pitched squeal until you apply light pressure to the clutch pedal or you can actually put light pressure on fork and it stops as well. My transmission also grinds a bit, esp. going into 2nd, but I assume that it's just the synchros (sp?). I have a new clutch as well TOB and all. I guess I'll just have to drop the transmission and see.

[Clawhammer]

****! I grind going into 1st, 2nd, 3rd randomly...not all the time but yea...and I squeak when idling unless I put pressure on the clutch. And when driving in like second....through a neighborhood...as soon as I stop accelerating (so holding a constant speed) or I coast in 2nd gear from like 3K rpm I get this horrible rattling like a chunk of metal bouncing around in a metal can...slightest bit of gas and it goes away...

[Hijacker]

That piece should only be breaking if you're doing something very wrong. I have worked on a ton of SR transmissions and I have yet to see anyone thoroughly trash a trans unless they just plain don't take care of them and abuse the f*** out of them.

On a side note, the SR trans is not weak. It's easily capable of holding 400 HP, but like any transmission, if you're doing 6k RPM clutch dumps, something is bound to take a sh1t on you. Just be glad it's that thing, and not the shaft bearing.

Inspect the clutch fork to make sure it's not putting undue stress on the cover neck. To break that many tells me something is going wrong with the way the forks are being installed, or perhaps the type of T.O. bearing being used.

Another, less likely cuplrit could be the shaft bearing. If its getting old and wobbly (read over-abused), I could possible see it making contact with the cover neck and snapping it off under load. However, I have never seen something like that happen. When the shaft bearings start to go, they tend to make gears not want to mesh correctly instead. However, you would be doing yourself a favor to inspect the input shaft to make sure it's not making contact with the neck.

[rustest86]

sounds like you keep getting transmissions with a wornout imput shaft bearing. if you have any amount of play in it, it puts extra load on that front cover assembly which already has very little clearance for the shaft to move around to begin with.

[homeslicej2]

I'm going to have to upload that video (if I still have it) of me pressing the fork by the slave cylinder and squeaky going away.

[natguerrero]

yeah i just had mine replaced at a trans shop it cost me $ 450 !!!

my driving conditions are not bad , i think when they did the clutch and flywheel some thing was not placed right so thats what caused it to break ! ??

[SlowS13Silvia]

Clawhammer it sounds like you have the same problem that I had.. looks like you may need to drop it bud...

Also to anyone else, I abuse my car heavily and dont care, but I do keep up on basic matinence and I pay attention to things that need help. It just seems like this problem shouldn't happen like this so offten.

I also just noticed my engine mount gave out this week, which is after the transmission problem... so maybe I have something bigger to deal with...

[SlowS13Silvia]

Ok Hijacker, the input shaft bearing doesnt have any play in it as in ZERO (it feels perfect.) and everything is being installed to factory specs, so that is not the problem. It doesnt seem like the fork is putting too much pressure on the t/o bearing but it would be hard to tell with the transmission out or in the car... soooooooooooooooooooo i dunno what the deal is... all i know after replacing it it feels awesome again.... any more input??

[Clawhammer]

How much does that part cost by the way and where do you get it?

[SlowS13Silvia]

like 40 bucks from nissan off of a ka transmission, i used the one frmo the pick up.

[rustest86]

if you use the front cover from the pickup transmission you will have a problem. the trucks use the same clutch as the old school 300zx therefore a different throwout bearing, that might have a slightly bigger/smaller hole and put too much pressure on the plate's snout and break it again.also busted motor mounts wont do that the trans is mounted solid to the motor, theres no movement because of that. the amount of bearing play that im talking about is in the thousanth's your not gonna be able to "feel" by moving it. you also have the counter shaft and all gears supporting the main shaft so it dosent move as much to the "touch". its one of those things that you have to check unless its really noticeable.

and i just thought of this..... when was the last time you changed your imput shaft bushing? if its worn too much it allows the shaft to move to much.

Modified by rustest86 at 9:57 PM 3/5/2008
Modified by rustest86 at 10:02 PM 3/5/2008

[Clawhammer]

Yeap...mine's broken.

[homeslicej2]

Suck! i hope that's not what's wrong with mine. If it is, it'll have to wait to be rebuilt. i don't drive it that much anyway.

[Clawhammer]

Pilot busing is MIA, probably why it broke?

[rustest86]

thats exactly why it broke. its a $2 part from anywhere. that front cover is dealer item or find an old transmission. i just had my transmission out yesterday to swap the guts out and changed the pilot bushing just for good measure.