4WS with 4 Bolt diff

[89Patches]

Ok so no I am not asking if this is possible. Well sorta

I recently bought a JDM parts car and it has a 4WS/4 bolt non lsd. Is it possible to swap the Viscous carrier in the NON LSD housing while retaining the gear on the carrier that drives the 4WS pump that's mounted on top of the diff? I hope that made sense.


This is the first 4WS system I have ever seen for our cars so I don't really know what I am up against.

 

[prove_it]

No the diff carrier is different. You will need to swap in a whole 4 bolt diff carrier. You can still keep the 4ws when doing this though.

 

[mitsuturbo]

I just outlined this in another thread. I believe it was this morning, or last night. Not sure. Busy at work and trolling FB DSM groups.

 

[mitsuturbo]

Yup. It was just this morning. The thread is right under this one in the Tech section, and actually a discussion with the other member commenting here.

Pinion stays put. Differential comes out. Ring gear comes off. Bearing comes off on 4ws gear side. 4ws gear comes off. Bearing comes off (very carefully unless you have a new one) 4ws side of new differential. Ring gear and 4ws drive gear goes on new 4 bolt differential. Bearing goes back on. Clean everything, mark it, put it in, check teeth engagement... the few times i've done this both with a new bearing and reusing the one side, it's been within spec and good for many many miles of happy driving/racing/backofaflatbedtrucking.

 

[prove_it]

Yep, my thread. /ubbthreads/images/graemlins/rofl.gif Saw the post and said, huh when it rains it pours.

 

[89Patches]

So the 4WS gear (that drives the pump) from a 4 bolt Non LSD carrier will fit a 4 bolt LSD carrier? I was always under the impression they were different and that's why they was never a 4 bolt/4WS diff that was LSD in the JDM cars all were non LSD.

And sorry I made this thread I guess? I didn't some how see the other one...

 

[prove_it]

It was a different topic. It's a hybrid build. You need to swap the drive gear over. Mitsu probably never used lsd with 4ws due to either cost to purchase car or cause they thought the 4ws wouldn't need a lsd.

 

[BENE38A]

The jdm e39a evolution has 4ws and LSD and 4 bolt rear.

 

[89Patches]

Sweet that's what I like to hear!! All the 4 bolt/4WS diff's I have ever seen have been Non LSD.

And the diff I have is from a E39a Evolution as well.

 

[fuel]

Quoting 89Patches:
So the 4WS gear (that drives the pump) from a 4 bolt Non LSD carrier will fit a 4 bolt LSD carrier? I was always under the impression they were different and that's why they was never a 4 bolt/4WS diff that was LSD in the JDM cars all were non LSD.



Not quite correct. My JDM '91 Evolution has the four bolt with viscous LSD and 4WS (3.909 ratio) from factory. It's the plate type LSD you can't fit the 4WS drive gear to, but viscous LSD is fine.

 

[dandanger]

Quoting BENE38A:
The jdm e39a evolution has 4ws and LSD and 4 bolt rear.



It's a factory option. I have 91 jdm evolution without lsd, 3 bolt/4ws, two friends have 3 bolt lsd/4ws(90), other one is a Monte Carlo. So there's also 3 bolt lsd's.

 

[fuel]

If your Evolution has a 3 bolt rear diff then it's not factory fitted. All Evolutions had the four bolt rear diffs, as did the non-Evolution RS from October 89 onwards.

dandanger can you PM me your chassis number? I'll look it up in ASA to confirm what model it really is. 1991 should be Evolution if it is a JDM, but if it was originally automatic then it wont be, and therefore will indeed have a three bolt rear.

 

[dandanger]

Pm'ed. Haven't really looked into this earlier, but my researches tell me that my car has 3 bolt diff, and with 4ws there's very hard to get lsd's.

 

[89Patches]

Quoting fuel:
Quoting 89Patches:
So the 4WS gear (that drives the pump) from a 4 bolt Non LSD carrier will fit a 4 bolt LSD carrier? I was always under the impression they were different and that's why they was never a 4 bolt/4WS diff that was LSD in the JDM cars all were non LSD.



Not quite correct. My JDM '91 Evolution has the four bolt with viscous LSD and 4WS (3.909 ratio) from factory. It's the plate type LSD you can't fit the 4WS drive gear to, but viscous LSD is fine.



Sweet that you!! That's all I needed!!

 

[ade]

although i deleted 4ws, i installed the 4ws ring gear onto my 3 bolt viscous lsd just in case i found a clean 4ws system
open diff above lsd

 

[dandanger]

Reviving old topic..

So, as mentioned above, I stand corrected about the rear in my car, it's a 4-bolt with 4ws(got under my car cause it's under work now).

Question is, what are my options for rear lsd if I want to retain 4ws? Since every aftermarket manufacturer catalog i've searched gives absolutely nothing for my car I got to take it from somewhere else, or maybe someone could point to a different models lsd which would 100% sure fit.

 

[GSTwithPSI]

Quoting ade:
although i deleted 4ws, i installed the 4ws ring gear onto my 3 bolt viscous lsd just in case i found a clean 4ws system
open diff above lsd



I have a functioning and fairly clean 4WS system in my car. I'm planning to drop the entire rear subframe and replace it with a 4 bolt LSD and DSM subframe. I just need to find a DSM subframe before I can ditch mine...

 

[prove_it]

Why? Are you that worried about two little holes?

 

[prove_it]

Quoting dandanger:
Reviving old topic..

So, as mentioned above, I stand corrected about the rear in my car, it's a 4-bolt with 4ws(got under my car cause it's under work now).

Question is, what are my options for rear lsd if I want to retain 4ws? Since every aftermarket manufacturer catalog i've searched gives absolutely nothing for my car I got to take it from somewhere else, or maybe someone could point to a different models lsd which would 100% sure fit.




4 Bolt axles in the states indicate a rear lsd is installed. Not 100% positive, but you might already have LSD. Check the rear diff cover for the service sticker. That will indicate.

As for LSD options, being that your in Europe, you can swap any year EVO rear diff carrier into the pumpkin. There are a few write-ups on how to do this. Internally the dimensions are the same. In the states we can use the Eclipse/Talon rear Viscous carrier with 4ws drive gear installed. Also I know several that have used the Evo 8 rear mechanical rear diff carrier, but not sure if the 4WS drive gear fits with that set-up.

 

[GSTwithPSI]

Quoting prove_it:
Why? Are you that worried about two little holes?



No, I want to get rid of all the unnecessary garbage associated with the 4WS. That will probably include a DSM front steering rack as well.