Doctor Diff's 8 3/4" Helical Gear Sure-Grip ("Sure-Trac") LSD

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JoesEdge

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I have a spare 489 case with 2.76 gears and an open diff that I'm planning on rebuilding but with some sort of "positive" traction device (I put that in quotes because I'm using the term loosely) such as a Sure-Grip LSD or maybe a Tru-Trac LSD.

But, now I see that there is a new-kid-on-the-block in the form of Doctor Diff's "Sure-Trac" LSD.

Has anyone here had any experience running this? Should be similar to a Eaton Tru-Trac, but better/stronger since it uses two more helical gears.

If you're not sure what I'm talking about, then here's the link:

8 3/4" Helical Gear Sure-Grip ("Sure-Trac")
 
I have a spare 489 case with 2.76 gears and an open diff that I'm planning on rebuilding but with some sort of "positive" traction device (I put that in quotes because I'm using the term loosely) such as a Sure-Grip LSD or maybe a Tru-Trac LSD.

But, now I see that there is a new-kid-on-the-block in the form of Doctor Diff's "Sure-Trac" LSD.

Has anyone here had any experience running this? Should be similar to a Eaton Tru-Trac, but better/stronger since it uses two more helical gears.

If you're not sure what I'm talking about, then here's the link:

8 3/4" Helical Gear Sure-Grip ("Sure-Trac")


I'm anxiously awaiting a response to this question too. I have a 489/open diff/3:23's that I was considering for this upgrade as well.
 
I have the strange version in the S60 in the Demon. Big block auto car. Turning 28-12/15 Sportsman S/R’s. It’s smooth and no noise when turning etc. But when you mash it both tires turn immediately. I have abused it from time to time. Doesn’t have to engage and so on. With that being said Cass doesn’t sell, in my opinion, anything that’s inferior. On top of that he’s excellent to deal with. If I had an 8 3/4 I would not have any issue running one. Call and talk to him.
 
I just put that in my 489 rear, but I'm waiting on having the ring and pinion set up. Should be done by Friday plus with the temp. in the 30*'s I'll wait till next week to put it in. I did get mine from Dr. Diff.
 
I run a Eaton Tru Trac in my truck and it works great.
been in there 3 years and no complaints.
 
When I built my 489 case I put a spool in it. All brand new stuff from dr.dif. but as you can see where there's a will there's a way! LOL one more call to Dr diff for Dana Parts LOL as you can see if you have a will this is the way, they're much bigger.. along with bigger main caps..
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Had $1,200 in each...
Dana is still happy...
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I've actually talked to Cass about this differential, but that was way back before it even came out. Maybe a year or two ago. It was still in the development phase.

I originally was inquiring about the Sure-Grip and the Tru-Trac. He had mentioned something regarding some issues with the Tru-Trac, which is what inspired him to come out with something similar, but better. So I waited. Besides, other things came up which ate up "diff funds". Now I'm revisiting it again.

I've bought brake stuff from Doctor Diff and I'll tell you he has AWESOME customer service. I wouldn't hesitate to spend money with him again. But...I also tend to shy away from being and early adopter, so that's why I wondered if anyone has run this diff and what their thoughts were about it. Aside from the two extra helical gears for strength, not having to run friction modifier is a plus too!
 
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I hate to burst your bubble but he recommends 1 bottle of "FORD" friction modifier additive beside conventional 85-140 gear oil.
 
I hate to burst your bubble but he recommends 1 bottle of "FORD" friction modifier additive beside conventional 85-140 gear oil.

Are you sure? The item description states that it is not required. Has there been a change?

Sure-Trac.png
 
It's a sticker placed on the box about the Ford additive. I ordered it in Sept. of 2018, so it's probably the latest info on that sure grip, and he calls it sure trac. I tried to get a photo of the box, but nothing is working right today. I guess the global warming here at 31* is the problem.
 
If it makes my car go faster I'm all for it. But if the guy that sells it, tells me it needs that additive I will definitely put it in. A bottle of that is a lot cheaper than a new sure trac.
 
I'm just wondering if you guys are confusing it with a Sure-Grip which is a different animal. Sure-Grip uses clutches and Sure-Trac uses helical gears.
 
Right on the box that contained the sure trac from Dr. Diff it stated that a Ford modifier additive is to be used. It couldn't be more plainer. I have the unit and hopefully I'll put it in next week in the car.
 
@j par

See maybe if you had let a ford piss in your diff it would have survived?

Maybe that 8 1/4 just identified as a LSD?


:poke:

Stay well brother and dont let anyone touch your hat!
 
Absolutely not. With less rotational forces comes less stress. But it doesnt hurt u to inspect the assembly once in awhile. Or upgrade to something stronger or put in better parts, in this case the caps. Kim
 
I recommend Ford friction modifier for my clutch type Sure-Grip and NO friction modifier for my helical type Sure-Trac.

It is possible I put the wrong tag on the box, however.
 
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