So I recently scored an lsd out of an 88 gl-10 but the gearing is 3.70 and I want it with my 3.90 d/r. I've read a few writeups but I just want to clear things up. Is it really as simple as unbolting the 3.70 ring and bolt on the 3.90? I've never messed with a rear diff before so I'm not too educated on these things and somebody told me swapping the rings will screw up the backlash or something. 

http://www.ultimatesubaru.org/forum/topic/63821-pics-of-lsd-conversion/

 

http://www.ultimatesubaru.org/forum/topic/47527-lsd-swap/

 

 

this should get you heading in the right direction.

next time try searching. most of the guys here will just ignore a post like this.

I've already searched and found these, I just wanted to clear things up. as far as I'm concerned it's just bolt off and on. But I want to make sure.

Use locktite on the bolts for the ring gear......and get them TIGHT.....

 

Make sure after reassembly that there is not excessive backlash or no backlash......you want it to be just a red hair's width of backlash.

I've already searched and found these, I just wanted to clear things up. as far as I'm concerned it's just bolt off and on. But I want to make sure.

some you have to grind the case to make clearance for the larger LSD chunk.  look at where the LSD case is ground and copy that.

Well...since you didn't bother to tell us what vehicle this is going in....I can't tell you for sure.

 

 

 

But I will say, just to be clear. The ring and pinion gear have to match. And the pinion gear is fairly difficult to swap into a different case. So you swap the ring gear to the LSD carrier, and then put the whole assembly back in your 3.9 housing.

 

 

 

All the EA82 housings I've had apart were clearanced such that the LSD could be installed without grinding. I did have to grind on an EJ housing once.

Oh it's going into a loyale. Thanks for the info guys I'll give it a shot.