Imasin999

Good afternoon, all. I've searched everywhere- here, lancer register, and went down a rabbit hole of research to find a solution/upgrade to my problem. Long story short, I believe I have a problem with my Evo 6 Viscous Coupling Unit (the circular disc that is coupled with the front differential in the transfer case) and am looking for a new unit or an upgrade to it. It seems like a used unit is the only solution and a refurbished/upgraded unit is not available anywhere (Cusco and GSC made a product years ago but has been discontinued for some time). I thought about getting an upgraded LSD center diff (the one that is housed in the transmission like Quaife's QDH11B, or Kaaz's DBM2070) and remove the VCU, but it appears like these were meant to be used with the VCU installed. I'm at a lost and can't be the only person with a failed VCU. Again, I've looked everywhere in historical forums with no luck. I'm looking for some direction and guidance on how I can solve this issue.


For reference, my 1999 Evo sounds exactly like this, except it stops when the clutch is pressed (no power going through the drivetrain) (

You Tube

) It's not my CV joints as I've replaced all of them. It could be my driveshaft Lobro joints (there's two) which I'm waiting for to arrive. I'm just planning for the worst and preparing to replace the VCU. Please point in the right direction.

RSMike

iTrader: (1)

If you have a torsen front LSD, it might be that too. They are prone to breaking the bolts that hold the housing together.
Best to pull the transfer case off (very easy to do) and check it and go from there

Imasin999

I've heard of this too, due to the short, counter sunk bolts being snapped in the planetary gears. I will be removing my transfer case sometime in the next month to inspect them. Do you have personal experience with this issue? If so, did it sound like the above?'

Note: The noise goes away when coasting

RSMike

iTrader: (1)

Yeah sounded similar.

Go to a parking lot or similar with decent space.
With my issue it was clicking more turning one way then the other. Give that a go and see what you find.

Imasin999

When you had this problem, did the noise go away when coasting or was it still present? Also, where did you hear the noise?

Imasin999

***It was my rear diff fluid. I added half a bottle of redline LSD fluid and it went away instantly***