Evo 1 LSD into VR4 pumpkin???

Ok guys, I've got the opportunity to pick up an Evo 1 rear diff (which includes a viscous LSD) pumpkin for real cheap. As I'm not too familiar with diffs, my question is can I just remove the LSD cartridge and insert it into my VR4 pumpkin? Is there anything else involved e.g. can I still use my 3-bolt axles?

I'm guessing I can't swap out the entire internals as the ratio is 3.909, but any pointers on this would be great.

 

[turboflanagan]

I think that the only difference in how the axles are connected is the outside portion that has either three or four bolts. The splines should be the same, and therefore the carrier should swap over just fine. Unbolt the ring gear from the carrier, swap the one from your car on the LSD carrier and plop it back in. You will want to measure your clearances of course, but the carriers should interchange.

And you may hold on to the ring and pinion because from time to time we get people who put a JDM(yo) tranny in their car and end up needing the 3.9 diff gears to compliment $$ the tranny.

 

[supervr4]

I'm running one on my car you have to have 4 bolt axles as the splines are a different size that goes into the pumpkin.

 

[V8EATER]

I would say that you need to check the ratios to make sure they are the same. I'm not too sure if the ratios on EUDM and JDM are different from each other, but you wouldn't want to burn up a tranny or transfer case finding out.

 

[supervr4]

Sorry ment to say you also need to change the crown wheel over to the vr4 one

 

Sorry guys, I should have been more clear. My ratio is 3.545, not the 3,909 of the Evo/VR4 RS. Believe me, it would make life a lot easier if I had the 3.909 drivetrain.

It's looking like it's going to be no-go unless I change over essentially the entire drivetrain /ubbthreads/images/graemlins/uhh.gif. I just wish someone knew for sure if the 4-bolt rear axles on an Evo are the same as the 4-bolt axles on the VR4 RS (or 4-bolt DSM). If they were, I reckon it could be done. I'm gussing not though as the Evo is '2g', but you never know with Mitsubishi.

Looks like I'll just have to keep my eyes peeled for a DSM/ZR4 LSD and axles (gold-dust in the UK).

 

[misterfixit]

Early evo's do not have the same halfshafts, the end of the shaft has a CV joint with no flange. The inner joints will be the same though.
Owen,

If you get the diff cartrige you'll have to just swap it in by swapping your crownwheel onto it, then shim it and for the gear mesh. You shouldn't need to touch the pinion as the pinion to crown direction will still be ok. Might be worth reading the runout on the crown wheel of your pumpkin before you pill it apart, then compare it to the runout when you have reassembled the lsd. If these are the same you'll only need to shim the side clearance to get the pitch point mate correct.

For axles any 1g 4bolts will do, if you want cheap shipping from the us then just ship the axles and use the outer CV joint and the Flange from a 3000gt, I Understand these are the same. You may even find that the evo shafts will work with 3000gt outerjoints.

Rich

 

Rich, you're an absolute mine of information /ubbthreads/images/graemlins/grin.gif. One last question; using the method you describe, will it matter if the cartridge is a viscous unit (Evo1 GSR/Evo2 GSR/VR4 Evo) or a clutch type LSD (RS all models)?

If you don't mind, if and when I get hold of of this diff, I may PM about some of the details. I'm on unfamiliar ground here /ubbthreads/images/graemlins/wink.gif.

 

[OldHairyBastard]

I have a front Diff and drive gear out of an RS if it is the same ratio and you need it. What you need to know is that the front diff is so big that the standard GVR4 transmission housing is too small in diameter to hold the front diff gear. You'll need a case that has a bigger diff housing like the RS just to house it unless there are others out there that can that I don't know about.

Doug

 

[misterfixit]

thats one to ask super vr4... i know the pumpkin itself is diffrent, you could just see if the 3000gt route is cheaper. I remember mromik saying alot of the rear is compatible if slightly bigger to make up for the in crease in track, i'll look on caps as both vr4 and3kgt were engineered ata similar time. the evo came after the 3kgt.

Rich

 

[misterfixit]

Update:

Here are some numbers from caps, all jdm cars. all diffs.

vr4 8802.1-8909.3 diff mb393069
9080.1-9203.3 diff mb664374

Evo 1 9210.1-9311.3 diff mb664734
9210.1-9311.3 diff mb837570/1

3kgt non turbo mb837571 (mpnm/mrpm)
turbo mb837462

Where is the diff located? Could you aquire 2?

I posted the 3kgt jdm numbers s I know there are shedloads here in the uk and the gertrag box is crap so there are loads being broken because of terminal expense problems.

Rich

 

[misterfixit]

Another nugget...

the crown wheel and pinion wheel are the same for evo and rs!

Evo 1 rear end crown and pinion
MB860149 3.909.1

VR-4 RS Rear end
MB860149 3.909.1

But then its a full rebuild and reshim on both pinion a diff shims. but worth knowing for the time you drop on an evo box as well!

Rich