Detroit locker

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70Duster340

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I purchased a Detroit locker several years ago at the Chrysler Classic at Norwalk. I haven't installed it yet, and I need some information on this particular unit. I have located several numbers on the unit, but I don't know which one is the actual model number. I just want to get some information on it, and I also want to be sure that I wasn't scammed (I know, a little late). I have emailed Eaton requesting information, but they haven't responded as of yet. The photos of the numbers I was able to locate are attached.

Thanks in advance!

IMG_20230109_192218441.jpg


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Might be an old nascar unit.

I have no idea how to ID those not who made them.
 
Those are casting numbers for parts identification and not anything to do with a model number. The hand stamped numbers are for inventory control after it was produced.

You'll not hear anything back from Eaton on this request.

Having drilled bolt heads holding the halves together tells you someone seriously raced it in the past.

You basically have to know what you're looking at with any differential. Post some wider angle photos and I can tell you more about it.

Tom
 
Eaton has nothing to do with that piece. That is a Detroit Automotive Products company (DAPCO) locker, known as a Detroit locker..
Their logo follows the 81310 number.
If it's not broken inside, it's the strongest lsd you can get. Also, the noisier (around corners).
Edit: apparently Eaton bought DAPCO, and may not make that part any more. Can't find it at summit .
 
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33IMP said:
Eaton has nothing to do with that piece. That is a Detroit Automotive Products company (DAPCO) locker, known as a Detroit locker..
Their logo follows the 81310 number.
If it's not broken inside, it's the strongest lsd you can get. Also, the noisier (around corners).
Click to expand...
Just to clear this up, it AIN'T a limited slip differential. It's a locker. It has 2 positions. Locked or unlocked and nothing in between.
 
May be relative after you install it - I have a Detroit Locker in my 427 Cobra replica. I've noticed that if the air pressure in the rear tires is unequal side to side by as little as 3 pounds the rear will have a slight jerk to the right with every shift (Toploader 4 speed). Also, get ready for the little clunk as you go around corners and the locker unlocks and relocks. Other than that, you've got a great piece.
 
Being that it’s an older Detroit unit and it has wire tie/lock provisions on the bolts, chances are it was an old nascar unit.

Doesn’t really matter now though. I wonder if any or all the guts are shared with the common Ford Detroit lockers.

Might want to take it guy that does Circle Track rear ends. Or a 4x4 rear end guy. They use them too.

I believe the springs in them help determine how quick or hard it locks. So you should have it checked out to see if it fits what you want to use it for. It could be setup for a pretty brutal engagement.

Nowadays they offer “soft” lockers or different models of them.
 
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supertruck said:
May be relative after you install it - I have a Detroit Locker in my 427 Cobra replica. I've noticed that if the air pressure in the rear tires is unequal side to side by as little as 3 pounds the rear will have a slight jerk to the right with every shift (Toploader 4 speed). Also, get ready for the little clunk as you go around corners and the locker unlocks and relocks. Other than that, you've got a great piece.
Click to expand...
Thank you, sir! I still don't really know much about it. I tried researching it on the internet, but I couldn't find anything. I still don't know if it will work in my 489 case.
 
supertruck said:
May be relative after you install it - I have a Detroit Locker in my 427 Cobra replica. I've noticed that if the air pressure in the rear tires is unequal side to side by as little as 3 pounds the rear will have a slight jerk to the right with every shift (Toploader 4 speed). Also, get ready for the little clunk as you go around corners and the locker unlocks and relocks. Other than that, you've got a great piece.
Click to expand...
I had an older friend in Macon years ago who was a retired engineer from Ford. He had a really nice collection of Ford muscle and police cars. One was a 69 428 SCJ Mustang. Factory 4 speed and detroit locker with 4.11 gears. This was back when we were in school in the early 80s. Then, it STILL had the original Firestone Wide Ovals on it. He said the detroit locker with the Wide Ovals was a recipe for disaster on wet pavement. lol
 
Can anyone advise how I can determine if this will fit in my 489 case? Is there maybe something I could measure?
 
70Duster340 said:
Can anyone advise how I can determine if this will fit in my 489 case? Is there maybe something I could measure?
Click to expand...
All 8 3/4 carrier units are interchangeable. The only way it won't fit is if it's not for an 8 3/4.
 
The carrier bearings are the only difference. Unless it already has the correct bearings for the 489 case, you may have to swap on the right ones.
 
Well, I don't know if it's for an 8 3/4. That's what I want to be sure of. You see, when I bought this, we (my ex-wife and I) started to have some issues, which led to a divorce. I completely forgot about it with all that crap going on. Now I am trying to find out if it's really for an 8 3/4. Just want to be sure it's what it's supposed to be.
 
70Duster340 said:
Well, I don't know if it's for an 8 3/4. That's what I want to be sure of. You see, when I bought this, we (my ex-wife and I) started to have some issues, which led to a divorce. I completely forgot about it with all that crap going on. Now I am trying to find out if it's really for an 8 3/4. Just want to be sure it's what it's supposed to be.
Click to expand...
You'll probably just have to get an 8 3/4 case and see if it fits.
 
I do have a 489 case (empty) that I purchased at the swap meet, too. Also, Cass (Dr. Diff) advised that it will in fact fit. He says it is a '60's era unit.

What would be the best way to clean up the surface rust?
 
70Duster340 said:
I do have a 489 case (empty) that I purchased at the swap meet, too. Also, Cass (Dr. Diff) advised that it will in fact fit. He says it is a '60's era unit.

What would be the best way to clean up the surface rust?
Click to expand...
If it was mine, I'd blow it apart and soak it all in vinegar. They're VERY simple in design. But I don't know what your abilities are, so.......
 
Disassemble it, degrease throughly, wash and soak in Evaporust to clean it up.
 
Here's all that's in it. Look how simple it is. Just take pictures as you go.
DETROIT.jpg
 
Thanks folks. Do the springs create a lot of force on the case? I don't want to get injured, nor do I want parts to scatter.
 
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