As many of you know...

Our company produces our own 4.44s and ect...
Because of above issue, we test rear diff on various power levels.


Recently, I have found another weak link on stock S2k.
(It happened on my car... )



With well over 400rwhp+, Part #15(bolts that holds ring gear + LSD) were strecthed badly.
ALL 10 bolts were stretched same.
I could easily loosen those bolts with my hand.


My diff is totally stock(even gears)
I open my diff every 5000miles to check the backlash, and condition of diff.
After I installed turbo, I found this issue.


Diff caps and bearings are fine, since I try not to give any shock to my diff.
I was VERY LUCKY to find out this before whole diff blew...
Our observations are it was caused by high engine torque produced by turbo set-up.


For those who run high torque level, please check these bolts too when you open up your diff.


I will post up the detail pix of the bolts later.
Time for R200 conversion.

 

 

gonna save up for that conversion, someone make a cheaper conversion lol

 

This is a first for me to here of. The bolts are a flange head grade 12 they are not very long, maybe 20 mm to twist a set of 10 would take a force greater than 100,000 PSI X 10.
I am not sure how you were able to twist these bolts without blowing the entire rear

There is a remote chance they were not all tight or a freak thing of bad steel, not sure how it happened.

I hope this thread dose not start a panic, I have been working on the S2000 rear diff for 2 + years now and have never seen a bad, twisted, or stretched LSD bolt.

This was a stock rear that came out of a car with a 2JZ conversion. This rear was so badly damaged that nothing was salvageable. The pinion teeth broke off, got lodged, then locked up the rear. The driver was still applying power to rear and caused catastrophic damage to the differential. The LSD bolts were fine, the heads of the bolts showed scaring but, the integrity of the bolt was still intact. Even there torque setting of 55 foot pounds was still right on.

 

[QUOTE=S2KPUDDYDAD,Mar 30 2008, 05:12 AM] This is a first for me to here of.

 

What do you set the back lash at? and in 5k miles what does it end up at?

As for pinion movement, I make a solid steel sleeve and custom fit it (no shims) in the rear not a crush sleeve like the factory.
I find in many rears I have worked on that the preload is almost no existent on the two pinion bearings. I also cryogenically treat every metal part of the differential.






My philosophy on my builds are, to keep things in place and keep them tight. If it cant move, it is less likely to brake.
My other philosophy is, NOTHING, AND I MEAN NOTHING IS BULLETPROOF
You can only make it stronger than the next week link.

 

I have no experience with the S2000 but I have seen the ring gear bolts shear in a Trans Am wearing 315's and making 650hp. This car had aftermarket gears and I would be that the bolts were tightened with an impact.

 

In yesterdays NASCAR race 3 cars blew there rears. They were racing at the Martinsville track. Martinsville is a short track and the cars don

 

informative.

 

your missing the point, this is a pretty rare case, you will DIY on these bolts that dont even need to be replaced and the next day another part can fail.