Gearbox problem

The Monty · 05-02-2010, 03:52 PM

The last few mornings when I take off and do a quick u-turn, the gearbox has slipped and/or held gear to long, then slammed into gear.

Gearbox was full, and hasnt leaked at all.

Coming home today, the car was vibrating more than usual, with lots of harmonic sounds at certain RPM, accelerating, then decelrating. After 15km of this at 100km/h, the car went dead silent, and drove smoother than Ive ever felt it, gears shifting good and solid, and everything normal.

5km from home, gave the car a little stab, kicked back into third, and the vibrating returned worse than ever to the point where I have had to slow down to about 60km/h.

All of a sudden, everything back to smooth, turned a left handcorner, and it came back again.

So I got home, stopped, and put it straight on ramps. In this time (5 minutes) its left a pool of fluid all over the ground. Its tranny fluid (obviously) and its coming from the output shaft seal again, I only replaced it 10000km ago, and havent been to the drags, but had that world record attempt day.

There is also a peice of circular (perfect circle) that looks like wire/shorn off something metallic/metal o-ring hanging from the out put shaft, about the diameter of the tailshaft.

The vibrations and slipping lately, and the amount of fluid it lost so quickly has me thinking that its something more than just the output shaft seal.

Anyone have any ideas?

auxr · 05-02-2010, 04:07 PM

Auto tranny specialist would be the only option that I can think of - seems to be a need for a specialist to have a look at the problem.

Good luck though, hopefully not too much of a fix.

The Monty · 05-02-2010, 04:40 PM

The metal thing that was hanging around the output shaft is a spring.
It looks to be the spring on the output shaft seal , and now its stetched a hell of a lot.
I was thinking it could be just the seal again, but if so, why all the massive vibrations etc?
And why would the seal just go again with no warning at all?

auxr · 05-02-2010, 05:03 PM

Vibration - thought just came to mind - tailshaft out of balance by any chance ?

FPV+fteT3 · 05-02-2010, 05:54 PM

output shaft bearing in the box could be worn causing premature wear to seal and vibration or as stated maybe the shaft has dropped a weight cause and effect syndrome. Good luck with it.

The Monty · 05-02-2010, 06:44 PM

The tailshaft does get into a decent vibration when it is at 200-220 indicated (160-170 real life) on the track.
I wouldnt suggest that the vibration I felt this time was the same vibration, as it would be very violent, then very smooth at the same RPM.
It goes in Monday morning to my local guru, so until then I guess its all a guessing game. If anyone wants to throw any more suggestions around, please do.

mik · 05-02-2010, 11:25 PM

universal joints ok?, a tailshaft with some movement could explain the vibration and the destruction of the rear seal.

The Monty · 06-02-2010, 04:35 AM

We checked the uni's and they were fine, there was about .5mm of lash in the diff.

The Monty · 06-02-2010, 08:25 AM

Cheked the tailshaft this morning before work, and there is absolutely no movement at all in the uni's.

Sox · 06-02-2010, 06:46 PM

Quote:

Originally Posted by The Monty

It goes in Monday morning to my local guru, so until then I guess its all a guessing game. If anyone wants to throw any more suggestions around, please do.

Tell him to fit a manual box.

The Monty · 06-02-2010, 08:24 PM

Ahaha, I wish, but no. If the gearbox needs doing, Ill be buying blackers auto, built like a mofo, and a red diamond 2800 stall which should actually stall to 2800 in my car, along with some freaky hard shifting.
If I can, I will also be fitting either a LOKKA or a spool (yes I know the legalities etc etc) new unis, and getting the tailshaft balanced.

08XR8 · 06-02-2010, 08:38 PM

The metal spring is from the seal, you may have damaged the bush in the extension housing with the metal spring.

The Monty · 08-02-2010, 07:29 AM

Back under the car this morning, the whole seal is out of place, and just sliding up and down the out put shaft. I pressed it back in (I know it wont stay there) and took the car off ramps and parked, it, still shifting fine like I said it was, although it will be low on oil. Ill just baby it to the trans shop (3.5Km away) and see what he says.

Also, after the day doing donuts when the car overheated and cracked the radiator, is there a chance the the trans fluid has been overheated as well, causing some damage inside the box?

The Monty · 08-02-2010, 10:50 AM

Car drove to the shop fine, looks to just be extension housing, and output shaft bearing and seal. Including full flush and service, and up the S5 solenoid another half turn (cant resist), Im looking around the $5-600 mark. Crap happens sometimes.

The Monty · 08-02-2010, 11:32 AM

Just got a phone call back, the yoke is bent, tailshaft is bent. Yay for team deep pockets.

Stattic · 08-02-2010, 01:06 PM

Ouch... Sorry to hear the news, is it time to now get a 2 piece tailshaft you can't afford right now?

The Monty · 08-02-2010, 01:33 PM

nah, second hand one will do. The complete bill came back at $600.

Some suggestions he made were to put another trans cooler on ( so Ill have two plus the stock one) and change my service intervale back to 10-15k's as I do such heavy driving, and he can jump on top of things before the let go so badly.

Stattic · 08-02-2010, 05:10 PM

That's alright what did the 2nd hand one cost?

The Monty · 08-02-2010, 05:22 PM

$150 :( Good thing is this should get rid of my vibration at 160km/h plus.

I have some interesting photos uploading now.

The Monty · 08-02-2010, 05:27 PM

What he done was: New extension housing, extension housing seal, bush and output shaft bearing, tail shaft including uni and output shaft, flush and service. $600.

Sooo, this is how to kill the rear end of your gearbox: Add liberal power to slicks, do a few hard launches, and some donuts. Make sure you have damaged tailshaft.
Repeat until it dies.

Extension housing:

Output shaft:

Stattic · 08-02-2010, 05:57 PM

I'll be joining the club in a few months for sure

The Monty · 09-02-2010, 06:20 PM

Youd want to hope you dont, lol.

White_sr_taxi · 09-02-2010, 08:22 PM

wow looks like i have the same issue, excessive heat to the box cause the same problem? i don't have a tranny cooler so maybe yes? is a good 2nd hand extension housing just as good as a new one?

The Monty · 09-02-2010, 08:58 PM

Well, I did overheat only a couple of weeks ago, enough for the radiator to spilt, so I assume so. I dont see why a second hand job wouldnt work for a temporary fix.

grandpa_spec_F6 · 09-02-2010, 09:32 PM

Well at least you killed it thoroughly Monty

The Monty · 10-02-2010, 05:26 AM

I sure did

I wont do anything silly till at least winter now, except skidpan day at Easter, and then I might be able to retire this one to the race track/burnout pad/etc.