Viscous cv cups in mechanical

Hi,

my ZR4 has 4 bolt rear axles with a locked viscous LSD and is running RWD. I am wanting to fit a mechanical LSD from a Evo 2/3 and need to know if the inner cv cups for a viscous diff with the 1 side longer than the other will fit in a mechanical diff? If not is it possible to cut the viscous 1 down to fit and machine a groove in it for the C clip to slot into?

Thanks in advance.

 

[SouthCaliVR4]

I recall cheekychimp (paul) ran into this very situation, perhaps he or curtis will jump in & remind us how they dealt with it.

 

Fingers crossed they do since I have found a Evo 3 one that has just been rebuilt with Ralliart bits for a good price.

 

[H05TYL]

No they don't. Even 3-bolt mech lsd ones won't work, Evo diff's have bigger splines the same as 4-bolt diffs (it's this that makes them stronger).

You'll need a pair of 4-bolt axles (from either open diff or super rare mech lsd ones - or you'll have to swap the inner cups for Evo ones).

I'm in the same position, have a rebuilt+shimmed Evo2 mech lsd waiting to go into my spare RS housing but need to sort out some axles.

 

[RedTwo]

There's a 'washer' in the exact center of the mechanical LSD that makes it impossible to fit the longer viscous LSD axle spline.



You said in another post that you already had 4 bolt axles? If so you all you need is the axle cup - the green metal housing with the spline that fits into the diff.
What you are after is either the short spline from a viscous LSD or the equal length spline from an open diff or mechanical LSD, luckily you can get these from heaps of cars (Evo 1, 2, 3, GTO and 4WD Diamantes). Just cut the CV boot clamp and remove the axle cup from your donor axle and fit it in place of your long viscous spline.


From left: Open, Long Viscous, Open, Short Viscous.

H0STYL, If you can stomach the shipping, there's a stack of 4 bolt axles in the USA /ubbthreads/images/graemlins/rofl.gif

 

[curtis]

Quoting SouthCaliVR4:
I recall cheekychimp (paul) ran into this very situation, perhaps he or curtis will jump in & remind us how they dealt with it.




That ordeal Alex and the guys at dentsport helped him with. I know I sold and shipped a lsd diff to a guy this past spring in Australia and he wanted me to take it apart and fit the diff and the axle ends in the flat rate box first and if anything else fit drop it in as well. It didn't but the two ends and the diff went in but the diff had to be unbolted and placed inside in 2 pieces. I think it was a 3 bolt lsd but not sure. How ever he said in an email he's been down this road before and said the inside spines are the same on the axle ends. But don't quote me all 3rd hand info.. Maybe someone with a broken or screwed up 4 bolt axle and tear the shaft out of the joint and measure for you guys.. if so the 4 bolt axles and diff will fit in a flat rate box which is like $54 to you.

 

[curtis]

Info might be in here, to tired right now and time for the couch and the tv

click me

 

Yes It already has the 4 bolt axles in the rear and I was told it had a EVO 0 VR4 diff which was locked but now im not to sure. I have measured the diameter of the inner cv cup spline going into the diff and it is 26mm, is this the diameter of a standard VR4 diff cup spline axle whatever you want to call it /ubbthreads/images/graemlins/laugh.gif ? Or is it a EVO 1 2 3 size diameter spline?

 

[RedTwo]

Yeah about 26mm with a tape measure. The 4 bolt VR4 splines are the same as the Evo/GTO ones (I forgot to specify N/A GTO only! Turbo GTO's have monster axles).

 

Ok cool so the 26mm inner cv cup splines I have will fit in a Evo 3 mechanical? I have found lying around the garage another pair of viscous 26mm spline diameter cv cups so I will take the short spline cup from that one and use the short spline one from my viscous and hey presto /ubbthreads/images/graemlins/laugh.gif .

 

[H05TYL]

The viscous short spline axles are shorter than the open/mech spline ones, so it won't work (the circlip won't lock it in place).

 

[RedTwo]

Really? That's pretty rank then. I could have sworn it worked :/

 

Oh that sucks!! Mitsi's are to confusing /ubbthreads/images/graemlins/frown.gif