A/T LSD Rear Diff on M/T

[Moonlight GSX]

I saw a thread that mentioned that the A/T and M/T rear differentials shouldn't be crossed between each other... after reading up more in the thread I came across the 3 letter names for each and now have cause for concern.

My car makes a "locking" sound on the rear axle anytime I go into reverse or initially take off in 1st and occasionally feel that same "locking" when engaging in 2nd-5th. I know that viscous LSD heats up and then locks but my question isn't that but merely what happens if you cross the A/T rear differential with the M/T? I currently have a LSD A/T (JFH 3.307) on a M/T would this be the cause of the "locking?" And would I run the chance of damaging my transmission?

 

[Bud92gsx]

The autos will not work in the 5 speeds..The gear ratios are waaay different and you will blow the auto stuff right up..

When people swap form auto to manual, or manual to auto, you have to swap the whole shabang.

 

[danl]

Your viscous coupler is dead.

 

[Moonlight GSX]

So what you're saying is when the person swapped over the diff they didn't do the research before it was done. Would this affect the transmission at all or just the rear differential?

 

[GRNDSM]

Your viscous coupler is dead.

To clarify: his center diff viscous coupler is probably bad . Otherwise it can be confused with a rear end VC on LSD rear ends. And in all likelihood he also worn out his center diff as well...

You need to start by swapping in a 5sp rear diff (I actually have a non-LSD one for sale). Then, follow up by inspecting/replacing your transmission center diff and VC.

 

[Moonlight GSX]

To clarify: his center diff viscous coupler is probably bad . Otherwise it can be confused with a rear end VC on LSD rear ends. And in all likelihood he also worn out his center diff as well...

You need to start by swapping in a 5sp rear diff (I actually have a non-LSD one for sale). Then, follow up by inspecting/replacing your transmission center diff and VC.

I actually just bought a LSD Rear Diff (BFH), so I should have that installed prior to installing the new transmission (TRE Stage 3)? That's not good as I have the diff with me but the transmission is with the car (I'm in the UK at the moment, car is in Missouri).