Who's running a 31 spline differential?

Venom351R

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#1

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Pretty simple, what brand are you running and how do you like it? I figured Eaton and Auburn are the two main ones to choose from but any input is welcome.

 

1slow95

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May 16, 2002

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#2

• Sep 4, 2007

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I just rebuilt mine with these parts.

03 Cobra 31-spline diff
Superior 31-spline axles
Summit diff cover
Summit install kit

Total came to around $800 with tax/shipping, but the diff cover was around $150 so you can knock that off the total if you don't need it. I've only had it installed about a week and I really like it so far. I haven't noticed any one-wheel peel since I installed it. I also ran several low 12/high 11 passes this weekend and it seemed to hold up just fine.

 

Killercanary

The car that set the bar.

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#3

• Sep 4, 2007

• #3

I run an eaton, and so far I like it. I've heard of a lot of guys exploding them with hard dead hook launches, but I've luckily not had an issue. I was going to run a 31 spline ford T-lock, but I got the eaton for only a few dollars more than the ford unit. My dad has run the ford t-lock in his '91GT for YEARS with no issues, and the car launches and hooks hard. If I had to do it all over again I'd get the ford 31 spline differential.

 

Venom351R

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Killercanary said:

I run an eaton, and so far I like it. I've heard of a lot of guys exploding them with hard dead hook launches, but I've luckily not had an issue. I was going to run a 31 spline ford T-lock, but I got the eaton for only a few dollars more than the ford unit. My dad has run the ford t-lock in his '91GT for YEARS with no issues, and the car launches and hooks hard. If I had to do it all over again I'd get the ford 31 spline differential.

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Whats the difference between the Track Lok Ford and the Limited slip Eaton and Auburn? Are they all pretty much the same b/c the Eaton/auburn pro are $400+ while the Ford 31's seem to be cheaper.

 

OrangeMustangGt

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#5

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I have a locker on my bronco and i WOULDENT want that on my car...make sure its limited slip.

I was debating that issue also, and the best way IMO to switch splines would be with the 31 spline spider gear set from summit...for the 8.8 carrier, or just find a set from a bronco, they came stock with 31 spline axles.

you will get better grip with an aftermarket L/s, BUT the cost is a lot more than a rebuilt trac-loc

 

Venom351R

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Ive already got Moser 31 Splines on order that are coming soon, I just need a rear and to put them in now.

 

SublimeRT

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#7

• Sep 4, 2007

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I would suggest picking up a used 31 spline T-lok. You can get them for under $100. Then just rebuild it with the '03 Cobra rebuild kit and you'll have a very good diff for cheap. Just my 2 cents.

 

Killercanary

The car that set the bar.

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#8

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Redline_351R said:

Whats the difference between the Track Lok Ford and the Limited slip Eaton and Auburn? Are they all pretty much the same b/c the Eaton/auburn pro are $400+ while the Ford 31's seem to be cheaper.

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Well, its been a long time since I looked into this stuff, so this information may not apply to what is offered today. Having said that, the auburn was a cone style differential which is completely different than the "clutch pack" style used in the t-lok and the eaton. I do not think that the aburn is rebuildable, but I could very well be wrong about that. I heard enough bad things about that design that I decided to stay with the clutch pack style. The eaton and ford differentials are very similiar in their design, I only got the eaton because Mark Williams was having a killer sale on them and it was practically the same price as the ford unit. After I bought the eaton I started hearing about the case shattering on hard launches, I actually saw one that shattered and it was a horrific site. Basically it looks like the main pin cuts right through the center section of the differential. I've never heard of the ford unit failing like this. My dad runs the stock style one that came in the (I think) 1986 f-250. I hear the one that came in the '03-up cobras has better clutches than the one my dad has. The 28 spline differential has a substantially smaller center pin than the 31 spline does JFYI.

 

blksn955.o

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#9

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any f150 that does not have a 9in will have a 31 spline tloc. Broncos and exploders do as well (not 100% on the sploders).

A F250 should have had a dana rear IIRC like a 60 or 70 and not an 8.8. I would stick with the f150's as there are TONS of them out there.

I plan on going with a 31spline tloc with either a rebuild (with extra clutches) or 03-04 cobra setup and superior axles. Even if you pay 100$ for a junk diff and spend another 200 getting it rebuilt and installed its cheaper and just as strong as an eaton or auburn.

 

parchisi

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Sep 5, 2007

#10

• Sep 5, 2007

• #10

31 spline Eaton here with mosier axles. no complaints, but then again I'm just running street tires so far.

 

4Jenna

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#11

• Sep 5, 2007

• #11

04 Cobra Diff here...works great

 

Venom351R

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#12

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Thanks for all the info guys, I bought a Ford T-Lock Limited slipp from summit for $255 .

Paul I believe you are right about the Auburns not being rebuildable. If I blow this one up at least I can rebuild it and not be out $400+. Even though what I want has been bought feel free for input on anything anyone else is running or opinions on different rear ends

 

S351Saleen77

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Sep 5, 2007

#13

• Sep 5, 2007

• #13

I have a Torsen T2-R and love it! The T2-R is a high bias diff. Meaning it is around 4:1 vs 2:1 for a T-lock. So in a corner before the inside tire spins it will put 4 times the torque to the outside tire. So if you had 400ft lbs of torqe it would put 1600ft lbs vs. 800 of a standard diff. It is supposed to be faster in corners because you can put more power down before spinning.

All the Torsens and the Detroit True trac use worm gears so there are NO clutch packs or cones to wear out!!

The standard torsen is not a high Bias and the Detroit true trac is not high bias either.

You won't be getting a T2-R for $255 though....I think it was $700. The standard Torsens and Detroit True tracs are around $450 I think.

 

W

wytstang

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#14

• Sep 5, 2007

• #14

03/04 Cobra diff M4204F318C $244.20
this is at johnbleakleyford.com
8.8" differential Fits 31 spline axles Fits solid or independent rear suspension Carbon fiber clutch plates for increased durability Will accept anti-lock exciter ring.
This is were I'm getting mine.

 

1slow95

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#15

• Sep 5, 2007

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S351Saleen77 said:

I have a Torsen T2-R...

Click to expand...

That's what I want. The price is just way too high for me.

 

Venom351R

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#16

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Yeah thats a little more then what I would have wanted to spend. I didnt want to spend the money on an Eaton Pro being in the $430ish range b/c I already spent so much on the 31 Splines, 3.73's, Weld Pro-Stars, MT ET Streets. Im confident that the Ford 31 Spline differential will be just fine.