making 4.11 LSD

[206er]

out of an old school LSD 3.7 type in RX and GL-10 that is.
can you just swap the diff guts into the 4.11 case to avoid a gear set up or tdo you have to use the LSD case?
I read cipers thread but it seems he was using a 4.44 diff which I have heard is different than the old school type.
tristan, what did you do?

[BAC5.2]

What are you trying to do?

Use a 4.11 LSD? You want to use the actual diff from the RX and bolt the ring to it and swap the pinion?

I guess you COULD do that... but why? A vicious diff that old has probably broken down to the point of near death. I doubt you'd have any advantage over an open diff.

That said, the 4.11:1 final drive will bolt into an R160 housing. There isn't any difference between the LSD and the non LSD case. I believe it's allll internal. Considering the rings are interchangeable, physical size is the same, but the internals of the diff are different (and they require different axles sometimes...)

[evolutionmovement]

Can the fluid in an VLSD just be replaced?

[206er]

hmm, then which is the better subaru limited slip and why?
I dont see why you couldnt change the fluid. also from what I have been reading on USMB there are ways to tighten up old LSD's such as flipping the cone washers.

[BAC5.2]

The vicious units are sealed. While I'm sure they could be opened, I doubt they could be effectively resealed.

I don't think it's really worth it, to tell you the truth. Flip the cone washers, and you might be good for a few thousand miles, but then you'll have a totally loose unit.

If it's a VLSD, there is no factory service proceedure.

I'd try to source a VLSD from a 91SS.

[206er]

I have heard about the VLSD having kind of abrupt action compared with the early clutch type.
who is to say I cant find a decent shape LSD anyway, and if not, hell I would rebuild it. what I am hoping is to be able to swap the guts to avoid having to set up a gear pattern although I really should learn to do that eventually.
stub axles are a non issue, they swap over.

[BAC5.2]

I seem to remember the axles being different between the LSD and the non-LSD cars. I may be mistaken though.

Clutch type diff's are generally more violent than VLSD's. Having driven several VLSD equipped Subaru's, I haven't noticed any violent behavior. I have also driven aftermarket clutch type rear diffs, and they ARE somewhat violent if you aren't expecting the results that they produce.

[Legacy777]

I seem to remember the axles being different between the LSD and the non-LSD cars. I may be mistaken though.

On the first gen legacies.....they're all the same. On the newer ones....I think they're the same, but can't confirm for sure.

[BAC5.2]

I wonder where I got that they were different from? I may have picked it up, and it wasn't for Subaru's.

Either way, I seem to remember there being some difference.

If they are the same, then that's all the better.

[tris91ricer]

Mine just has a swapped ring and pinion gear, IIRC.

Its housed in a 3.90 case, but the internals are 4.111 from a viscous-type LSD. Probably from a 98 GT, which, if there's one in a jy near you, would have this. (It might not be labeled, even!) Might as well get the drivetrain, too, eh?

[206er]

well it is this easy:
http://www.usmb.net/repair/?CurrentDire ... 667516.art
I am going to start looking for an LSD of either kind and throw it in a spare 4.11 case.

[Blackbart]

The axle stubs that go into the LSD diff are different than the stubs on the open diff, the LSD stubs have a right and left, the open stubs are the same for both sides. The open stubs will fit right into the LSD diff but it will not work as an LSD.
I have also come across a difference in ring gears from one R160 open diff to another. All the LSD diffs I have had apart have eight 11 mm holes but SOME of the open diffs have eight 10 mm holes instead of 11 mm.
If both rings have the 11 mm holes the swap will work (you also have to have the LSD stubs.)

[BAC5.2]

I knew I remembered some difference. Thanks Frank!

[Blackbart]

well it is this easy:
http://www.usmb.net/repair/?CurrentDire ... 667516.art
I am going to start looking for an LSD of either kind and throw it in a spare 4.11 case.

I just read the article in this link, there is more to it than this. You need adjust the lash, heel, toe, etc. this is done with the shims (reuse a combination of the shims you have from the diffs) blue marking dye and feeler gauges. I will try to find the specs for you.

[Legacy777]

Yeah you're right frank. I noticed that when I was looking at replacing the seals on my rear diff

[tris91ricer]

How do the open diff axles inhibit the lsd action?

[Blackbart]

The LSD stubs that conect the axles to the diff are longer and one side is stepped down to go into the diff deeper, the stubs almost touch each other inside.

[206er]

the way I understand ring and pinion set ups is that every case is a few thousandths different, requiring you have to play with spacers to get the gear pattern right. that is why I wanted to put the LSD unit itself into a diff that was already set up with 4.11 to avoid having to set a new gear pattern. unless of course there are crush washers or something that would have to be new for the gear install.
questions:
is all the adjustment for the R&P in the pinion or are there spacers on the ring gear to carrier surface which putting in a LSD carrier would change the tolerances? or maybe even changing the carrier AT ALL would require resetting the pinion depth due to changed tolerances.

are LSD stubs interchangeable viscous to clutch type?

are the older stub axles the same as the ones on my car?

the difference in stub axles that I was able to get from teh datsun guy's article is that the older style bolts into the carrier and the newer style (VLSD) have retainer C clips.
I think I am starting to understand...