1) Can I take the LSD parts from a 3.7 and put them into a 3.9, or vice versa for future reference??

 

2) Please correct me if I am wrong, but I beleive the non-aspirated 5spd dual range differentials were 3.9, and the aspirated 5spd single range differentials were 3.7??

1) Can I take the LSD parts from a 3.7 and put them into a 3.9, or vice versa for future reference??

 

2) Please correct me if I am wrong, but I beleive the non-aspirated 5spd dual range differentials were 3.9, and the aspirated 5spd single range differentials were 3.7??

Yes, I do it all the time, infact I have two of them to do for someone right now. You need to take the LSD diff from 3.7 ring gear and bolt it to the 3.9 ring gear, you just need to grind a few spots on the 3.9 case, those spots will be obvious.

Hey RX (or do I have to call you Dr.?:-\), if you do this all of the time does that mean you have a complete non-LSD 3.7 (or two) kicking around and under foot? I would be happy to remove one before you stub your toe...

 

(I'd really like an LSD, put the empty mounts under my car tell me that beggars can't be choosers! And it is an automatic, so why bother (almost)?)

Hey RX (or do I have to call you Dr.?:-\), if you do this all of the time does that mean you have a complete non-LSD 3.7 (or two) kicking around and under foot? I would be happy to remove one before you stub your toe...

 

(I'd really like an LSD, put the empty mounts under my car tell me that beggars can't be choosers! And it is an automatic, so why bother (almost)?)

I have one out of my 88 s/r 5spd turbo?? WIll this one help you out??

Hey RX (or do I have to call you Dr.?:-\), if you do this all of the time does that mean you have a complete non-LSD 3.7 (or two) kicking around and under foot? I would be happy to remove one before you stub your toe...

 

(I'd really like an LSD, put the empty mounts under my car tell me that beggars can't be choosers! And it is an automatic, so why bother (almost)?)

Once I pull them apart, I only put the LSD back together. I recycled a bunch of them about 6 months ago.

Once I pull them apart, I only put the LSD back together. I recycled a bunch of them about 6 months ago.

Sortof a side note for DR. RX here, or anyone else who knows. Is there any particular reason you put the LSD diffy in the 3.9 case, rather than put the 3.9 gears in the LSD case?

Sortof a side note for DR. RX here, or anyone else who knows. Is there any particular reason you put the LSD diffy in the 3.9 case, rather than put the 3.9 gears in the LSD case?

The main reason is that the ring and pinion gears in the 3.90 are already matched and shimmed. Just putting the 39 tooth ring gear into the LSD case will not work since the pinion gear isn't matched to that ring gear.