Hi all,

This is an issue from the previous owner of the car and I don't know the exact history.

Car is an Evo4/5/6 (frankenstein).

When turning left or right at any speed, I can feel through the car and steering wheel, a similar feeling as a locked rear diff on a RWD car. Almost like the wheels are trying to turn at the same speed, and one side is scrubbing.

The car has had its wheel bearings checked, suspension doesn't show any damage. So am thinking it is drivetrain internal related.

Nothing else unusual about the handling of the car, under braking it is fine, under forward acceleration etc, all fine.

Is this a symptom of the 'diff bolt' problem I have read about on here? Or a welded centre diff? Welded front diff?

The whole car noticeably shudders when turning (even a wider sweeping corner) which is very unsettling. I call it shuddering because it is not at a frequency where you would call it a vibration. Maybe a frequency closer to axle tramp on a RWD car? Maybe even slightly slower?


Any help is much appreciated.

FYI the drivetrain is supposed to be Evo5 gear (gearbox etc). Hubs are either Evo5 or6 as they are the brembos. Engine is definitely a 5+ as it has the 560cc injectors, and the larger 10.5T turbo and the tuneable ecu.

 

What style of front differential? The plated ones required friction modifier.

Also have a look at Losedogs rebuilding a plated front LSD. It looks like a project.

 

Thanks for the response - not sure what sort of front differential it is - is there any way to tell from the exterior or a test?

If it is a plated LSD and has the wrong fluid in it, would that explain the shuddering??

Thanks!

 

There's been people driving the USDM Evo with the disabled plated rear differential that went with the wrong gear oil and encountered your problem.

How grabby you want the differential to be depends on the cars use. An owner of a competition vehicle might think your differential is working fine.

 

Thanks again for your response - is there any way to tell it is a plate LSD and that changing the oil will reduce the binding?

(the car was put together by an ex Group N WRC competitor so it is possible the diffs have been set to competition grade)

 

You could pull it apart and look, its not too hard. With the car's history, that might be the only way. What I think I would try first is the Mitsu gear lube made for the transfer case.

 

Thanks - will try get hold of some OEM diff oil for the front and get that replaced to see if it helps.

So there is no other way to tell (having the car up on a hoist and turning wheels to see which goes which way etc?)

 

Someone with experience with all the various differentials that have been used in Evos needs to chime in. Sorry, but that is not me.

 

I've flushed out the transfercase and front diff oil .. it was pretty horrible when it came out .. very metallic. I ran one change through it, ran the car on the hoist in gear for a couple of minutes, then flushed it again and now driving it on the road for a while before I flush it again. It definitely binds up less than before, but it is still there. Hopefully as I can keep running clean oil through it, it will continue to get better.

There were no big chunks of metal coming out so thats a ... good sign.

In the meantime - I have picked up a evo6.5 centre diff, just incase that is the problem - the centre diff might not be the problem but for $38, i figured that it would be a handy spare to have in the event of the current front diff spitting the dummy.

I could not find any standard mitsi diff oil, so have been running 85w140 lsd oil fully synthetic. I see a lot of debate on what to use .. the car being built from ex rally car items, i suspect there might be some sort of lsd in there, perhaps a plate lsd, but I won't be able to know until I pull it all apart (which I will only do if it really grenades itself, or if I finally get really sick of this binding and the oil changes dont help anymore).

thanks for all your input.