GTR Front Diffs

[Piggaz]

A topic that isnt talked about very much on here... Front Diff's. After going through Toby's (kismetcapitan's) rebuild thread it has given me an idea for a thread regarding this topic.

This is one part of my car that im a little worried about smashing to bits. So tell me, what is the best upgrade for a street driven (athough angry) GTR?

What have you got? Any complaints?

[EvolutionVI]

cant speak over the GTR´s,but on my Evo wagon im running a ATS Carbonetic LSD.really awesome,transforms the handling of the car without beeing noisy as most "metal" LSD´s

[mifn21]

A one-way lsd on the front would be ideal for getting rid of any understeer

[GT-R Glenn]

How angry is it ?
Ive seen over 700hp all day through the factory front with no issues, mind you same car runs a standard R33 box and lots of opinions say it cant be done.

[Piggaz]

400 KW at the treads give or take a little. Brief spec is a 2.8 litre with twin RS's

[Tommyk]

AND Paul just broke his 11,000km old gearbox ...
Thing makes a bucketload of torque and it comes on way too hard
The previous owner broke the front diff before rebuilding it with a stock? unit....

How hard is it to install a new front diff? Does the motor need to come out?

[kismetcapitan]

you have to remove the oilpan - and the easiest way to do that is to remove the engine. Fortunately, pulling the RB26 is pretty easy.

[max1]

CAN BE DONE IN THE CAR NO NEED TO REMOVE OIL PAN
some aftermarket diffs require machining of casing and pinion
like the os ones not easy but can be done

[GT-R Glenn]

You can definately change the front diff without removing the engine.
Another option is to put more oil in it, you can buy aftermarket covers that give more capacity as well.
I just made mine.
I very much doubt 400wkws will worry the front diff, remember the most you can ever put through it is 50% and thats usually not for very long.

[beaumackenzie]

you dont have to worry too much about blowing your front diff to pieces , the gtr's 4wd system is a gradual incrimentation which means it will never feel the full effect of a "jolt" for example like the rear diff will receive when you dump the clutch,

[kismetcapitan]

I didn't know that - so the front diff case is detachable from the oil pan? I assume this also means that the differential is completely sealed off from the oil pan (and that only the driveshaft goes through it)?

This would be important to know - if you blow up your front diff, if it's sealed off, then there's no worry of getting front diff shrapnel into your oil pan. But I think someone had once said that was a possibility.

[kismetcapitan]

to further limit torque, a mechanical solution is to remove some of the clutch discs in the transfer case. I've seen pictures of this done, but not in person.

[kismetcapitan]

and lastly, wouldn't the front subframe need to be dropped? or can the front diff bolts be reached with the subframe in place? easy job? just remove propshaft and right driveshaft and then unbolt the diff case? or a cursing, sweating nightmare?

[beaumackenzie]

download the pdf file for mechanical servicing for gtr

[GT-R Glenn]

Kis

Nah its not too bad, on a hoist.
Pretty easy to get off but the crownwheel only comes out in "exactly the right position" so sometimes first go and sometimes it gets stuck and you push it back in and rotate a few degrees then it pops out etc:

so the front diff case is detachable from the oil pan?

No, its part of the sump casting / the cover is removable.
The engine oil is separate to the diff oil.
I suppose if you did a really reaaly good job of blowing the front diff parts could break through the casting into the engine oil but it would be 1 in a million ....

Ive posted my sump mods before, but heres the start of it which clearly shows the casting for front diff etc:
Lol see the date....