Hi Chaps,

A friend of mine owns the above car with a Hayabusa engine in. It has a 3.14 7" diff fitted but it keeps breaking the diff where the bolts go through the frame into the four mounting holes (on the diff). This is the second time this has happened and it breaks the mounting lugs off on the diff from the top and bottom N/S and the bottom O/S.

The last time this happened the car was in second gear slowing down to about 4k rpm, the power was brought back in and the diff exploded and the three mounts broke!!!

Any ideas as to why this is happening?

There is obviously a serious problem somewhere.

was the diff mounted in securely? if not it could cause a slight twist in diff when under load,causing mounts to crack.these bolts can work loose if no locktite is used

Yes I think so, the bolts were still tight into the 3 pieces of diff that broke off.

saw the car at mnr last night suspect wrong drive shafts have been fitted.

regards

Agriv8

with regards to what dimension?

what bolts is he using ? (size, length, grade....)

got any pics ?

The car is currently at MNR so I can't see the grade or length of bolts.

I think that because the bolts were still in the lugs that broke off then perhaps that may not be the problem.

I will try to get a pic

I've heard of some people having a similar/ the same problem on really high powered dax's

so some of us got some long M12 Gr 12.9 bolts to mount it more like it is in the sierra (the needed to be 300mm long for the dax chassis)

the thinking being that the lugs may have snapped of as the diff was able to twist a little, so one long bolt right through should helg with that

Yes I agree, that is the same setup I had on my Mk Indy.

Ok quick update, got the car back from MNR with a new diff fitted. After only 30 miles of driving home again the diff bolts have come loose??? Mainly top N/S was 10mm out and bottom N/S was 1mm out. Chris has replaced the bolts with 12.9 Cap Screws. Why does this keep happening when the car moves? I understand these car need checking all the time, but surely not after 30 miles!

have they fitted steel washers between the alloy casing and whatever its bolted up against ?