hey guys this is a picture from my 96 version 3 sti! My rear diff has a crack down it, does anyone know how this could have got there??? is it serious and has anyone on here ever had this on their scooby???

 

It normally denotes that you hit something, you can get diff guards for the rear diff, not too expensive either

Tony

 

Strange that no oil is seeping out either its been like that for a long time or its not cracked all the way through. Also could be that the plugs have been over tightened because they are taper threads.

 

I'd say its likely to be something to do with the plugs.

The way they seize in the threads wouldn't supise me that it could damage the diff cover. In the past I've swung off a 3ft lever arm to get them to budge. Which makes me think that maybe somebody could have used an impact wrench on it .....

 

The crack is exactly on both the threads , id put money on that being done by whoever did the diff oil.

Id get it changed before it gets worse and starts leaking. Looks like just the front cover part is needed.

 

Well you'd think a bump would cause it but it amazes me that the exhaust is lower than the differential

 

I agree but it maynot be leaking because theres very little oil in it> just best change the cover and top with oil

 

Hey guys you prob right about it being overtightened! Will a new outer cover cost alot?? And is it a hard job to put on??

Oh thanks for the replies guys

 

I think I have an old diff at work somewhere that is no good if you want the cover off it, just pay the postage which shouldnt be much.
I wont be able to find out till Monday though

 

I had something similar on my diff, thought it was cracked, gave it a good clean and it was just oil sticking to the plate in a fine line like yours because its so thick. I would try giving it a good clean. Maybe just the same. Try it nothing to lose.

 

^^^^ as above ^^^^

I had exactly the same looking thing - I thought it was a crack too!!

Got underneath and rubbed it off ... was some kind of resin - could these diffs be coated when they come out the factory and sometimes a string is left?

 

Hey Marx your a star if you personal message me your address if you do have that plate I'll send you the price of postage, that would be amazing! It's been really worrying me, just want it sorted!

 

Cracked rear diff covers is quite common and caused by numpties over tightening the hex bungs in the alloy cover plate.
A replacement cover plate is easy to pick up. Just drain the oil if there is any in there, replace the cover and torque it up evenly and then refill with oil to the level of the oil fill bung. Job done. Obviously don't over tighten the filling or level bungs in the aluminium casing.
For your infromation there are only two sizes of cover plate. The common one is for the AR160 diff and the rarer one is for the bigger AR180. From what I can see you have the AR160 and you can tell by measuring the distance between the mounting pins which should be 160mm.

 

harvey thats very helpful thanks do you know how much torque the bolts have to be tightened to?

 

Cover bolts 29±5 N·m (3.0±0.5 kg-m, 21.7±3.6 ft-lb)

Level Plugs 44±4 N·m (4.5±0.4 kg-m, 32.5±2.9 ft-lb)

Like Harvey, assuming it is the common cover, which it looks like.

Good luck

 

You have PM mate

 

such helpful peeps on here, its awesome thanks everyone for your help! Sent ya a PM marx, ta!