LSD locked up?

[Emeraldage]

So a fellow member here sold me a 373 LSD rear end for my 89. After I got the engine all in I started driving, hearing some skipping or bouncing noise, Oh shit we did the clutch wrong... But then I took another sharp turn I noticed the inner wheel would be locked up and skipping or skidding on the road..

TLDR Rear axel locked up, inner wheel skids on tight turns, wat do?

 

[AbsoluteSpeed]

Replace the diff fluid. It is a clutch type LSD you'll need to add a friction modifier or it will lockup.
Everyone seems to use ford diff additive. Add a little and test it, repeat until you can make tight turns without it locking up but not so much that it spins one wheel durning a launch.

http://www.supramania.com/forums/showthread.php?91845-Rear-end-LSD.

 

[Emeraldage]

Well we got it in the mail with on fluid because he had to ship it empty. I put about 2 in a half of these in it http://www.autozone.com/autozone/ac...-90-32-oz/_/N-25t1?itemIdentifier=991558_0_0_

Just filled it until it started to spill out a bit. From what I've seen it's just the left wheel locked up but then again I didn't really experiment much. But there is tire marks from my left tire all the way th rough my drive. Maybe I should try to jack it up and brake the clutch in it loose with the bear bolt or something? I don't know much about rear ends.

 

[AbsoluteSpeed]

Close, but you'll want to use 75W-90. I'd try the ford oil and additive like suggested in the link. Seems it has had the best results.

I've got to do the same soon. Mine will only spin one wheel.

 

[Silver MK3]

I put the ford oil and ford additive in my car about a month and a half ago. I think I put a little less than 2 ounces of the additive in. My LSD seems to be working perfectly, I haven't noticed anything strange. I assume it still spins both wheels, but I don't really do burnouts or anything so I can't say 100%. Also if you put 2 and a half of those bottles in your rear diff then you have a massive leak somewhere. The rear diff is only supposed to take 1.4 quarts.

 

[Emeraldage]

I guess I'll drain it into a separate container to see how much comes out again. My friend is the one who put most of it together. By Ford you mean Motorcraft 7590 and additive at dealer?

 

[Emeraldage]

I called a ford dealer and dear god the 75 90 is about 18 dollars a quart.. Thinkin just get the friction modifier and use whats in mine right now.. or one quart and mix it lol. I feel like I've already wasted so much money.

 

[Silver MK3]

I called a ford dealer and dear god the 75 90 is about 18 dollars a quart.. Thinkin just get the friction modifier and use whats in mine right now.. or one quart and mix it lol. I feel like I've already wasted so much money.

That's what they told me when I called as well, but when I went down there and actually bought it it was something like $18 for 2 quarts. I believe it was 75w-90 and the additive.

 

[Backlash2032]

$18 bucks for something you'll l likely only do once? You gotta be kidding me...

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[Emeraldage]

Lol 43 dollars for 2 quarts and a modifier. I wouldn't mind spending that in the first place but I already paid for 3 quarts of Castrol 8090. Sucks for me I didn't think it would make a difference. I bought all redline trans oil and that only ran me 23$.

 

[Backlash2032]

I have some whatever fluid from Napa or walmart or something.. with ford modifier. It's not the fluid so much as the modifier. Run redline over the ford stuff if it's cheaper.

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[hvyman]

can use reline 90. not mt90 just regular 90. Its made for lsd diffs. iirc diff holds 1.75 qts.

 

[Emeraldage]

Well I Have the shop manual it calls for 8090 at 1.4qt so I'll just take the Motorcraft oil back. Will the diff break lose after I try to drive it a bit with the modifier in it? I really hope so!

Also does anyone know the bolt pattern on the afm? Mine did not have any filter on it and don't have the factory one either need a cone adapter.

 

[AbsoluteSpeed]

That castrol stuff you used is made for lsd's so it will likely already have the friction modifier in it so adding the ford stuff (or anyother) isn't going to help. I'm guessing the issue is that you used the wrong weight of oil.

 

[hvyman]

Would have to be a major wrong weight.

If not enough friction modifier the diff will be locked or slip very little. I would add a little modifier at a time till it starts un locking.

 

[Emeraldage]

The tsrm literally says sae 90 for above 0c and 80w90 for under 0c. I thought it did as well bit I don't remember it saying 'clutch type' on the bottle last time I got it I swear it did but my memory is terrible. I'll update once I get it in maybe tonight or Wednesday. School :v

Then it's off to tensioning power steering better, getting a smoother non heavy cam loping sounding idle and hoping my water temp Guage works after soldering the wire back together..

 

[Emeraldage]

Well poured like more than half the bottle in, it's definitely better than when I first got it but it's still skipping a bit more slippery surfaces. Hoping just driving on it more and more will help get the fluid through?

 

[Emeraldage]

Damn... Whole bottle of ford friction modifier and it's still sticking..

One time I jacked up my car and my left tire kind of turned back as it was lifting like something was even twisted or something.

 

[jake8790]

Something is wrong with the LSD. Drop the diff, open it up, and see what's wrong.

 

[Emeraldage]

I'm not sure if I would trust myself to open it up, and the hassle of taking it apart again is a ridiculous amount of work. It's gotten a lot better it's smoother but still locked up harder than it should be. I mean it did spend like 2 weeks with absolutely no oil in it.