Yellow Streak

After two track events with my car, the rearend started making noise at balanced throttle at slow speeds. We decided to swap out the diff fluid (which was new at the first track event). When we dropped the drain plug, we found a chunk of the ring gear on the drain plug. I can speculate on what caused the failure, but the prime candidates are:

1. 303 RWHP
2. Driving on the track (tight turns, sticky tires and lots power)
3. The Exedy clutch not slipping at all (6 puck/2200 pound of clamping force)

The car had never been launched hard and I don't powershift or bang gears - so I don't think it is direct-abuse induced.

After taking the diff apart, my tech checked it out and said the wear patterns looked good, the specs for backlash, etc. were all right on (according to the Helm manual). He didn't see any signs that something was wrong with the unit apart from the chipped tooth on the ring gear.

Because I don't know if either a) the stock LSD is messed up or b) it caused the ring/pinion failure, I am going to replace it.

My plan at this point is:

1. Kaaz diff
2. J's racing gears
3. Comptech bearing caps
4. All new OEM bearings, seals, other parts (thanks Hardtopguy)

My only complication now is that I am under a time constraint for upcoming track events. I have found a set of J's 4.77s in stock, but I fear that is too much gear. I don't want to run out of gear on the straights and with the power I am making, that is a very real possibility (especially considering the Kumhos I run on the rear are only 24.3" in diameter). I can likely get a set of 4.30s or 4.44s air freighted, but that impacts the schedule somewhat.

Also, I was told that the J's gears are heat treated and that cryo treating them wasn't necessary - what is the concensus?

Is there anything else I am missing?

When offering advice, please keep in mind that I primarily track the car and drive it on the street very little.

Thanks in advance for opinions and advice.

-YS

Yellow Streak

Since the carrier bearings seem to be back-ordered until almost the end of April, I am looking for an alternative. Anybody have any ideas?

-YS

Hobbyholic

I heard something about Kaaz rear ends they are suposed to be beefed up. By the way u guys habe the cen28s in stock now, And I can get cheaper then price quoted..E-mail me..

Squeezer

the kaaz diff uses clutches. don't they wear out over time?

RT

over time the Kaaz seems to develop backlash within itself, don't know if it's a problem or not ..... mines been loose 10k miles or so ..... good luck Pete

Yellow Streak

Thanks Ray. Just a minor setback. Comptech housing is on the way to be cryo'd. Gears are inbound then to the cryo treatment. Kaaz diff is on the way as are all of the OEM parts.

I wasn't planning to do this upgrade right now, but I am sorta stoked to see how the car pulls with 4.44s and 300whp Also, my gearing will be a little different since the Kumhos are actually 24.3" in diameter.

-Pete

S2000RAT

Been there done that. Now that you will have the Comptech housing, Say bye, bye to your tranny.

Yellow Streak

What makes you say that?

S2000RAT

What makes me say that. Well all was well and good until I got the Comptech case and ring caps. (I also have a SC and a ton of other stuff). Then about two weeks later bang! crunch there go's the tranny. Then it took 5 months to get my Spoon tranny. Well I would of rather herd the rear end some times than have my car down for so long. Just this is how it went with me. U may have better luck. I hope.

Yellow Streak

[QUOTE]Originally posted by S2000RAT
[B]What makes me say that. Well all was well and good until I got the Comptech case and ring caps. (I also have a SC and a ton of other stuff). Then about two weeks later bang! crunch there go's the tranny.