8.8" rear differential choices?

[Joe Walsh]

Hi guys,
I am finally going to upgrade my OEM 3.55 gears to a set of Motive 3.90s.....
that, like many other modding parts, have been sitting in a box for way too long!...:o
I am going to have a local shop do the install after I have the axle tubes welded to the center housing.
I also have a set of 31 spline axles from the group buy...way back when.
The local shop is "Horsepower by Hermann"...who is well known and respected in the Mustang community.
www.hbh.org
He has been around a long time, and anyone who reads Mustang magazines will remember some of his SICK rides.

Now I have to make an important decision...what differential should I use?

Here are my options:

1: Use a 31 spline Auburn that I already have. (I bought it for my 85 Mustang GT's 8.8 rear)

Hermann says that the Auburn is NOT a good unit and DO NOT use it.
He has had many problems with Auburn differentials.

2: Use a (31 spline) Detroit TrueTrac (Torque sensing unit). This is my first choice for a differential.

Hermann says that it is a great street & road course differential, but will not last very long in a drag raced 4400lb sedan.

3: Use a (31 spline) FRPP Carbon Fiber Traction-Lok.

Hermann recommends this over all other differentials, including the Eaton differential.
He adds extra carbon fiber discs and runs them in 1,000 HP Mustangs all the time, with great results.

I was a little suprised by his recommendation of the FRPP CF Traction-Lok differential. I never really considered this differential, although it is used in the '03/'04 Terminator Cobras.

What have been your experiences?

[TooManyFords]

I really like my Auburn ECTED diff. With a flick of the switch it turns into a spool and I've never had a problem with it. Turn it off and it is a normal LS differential.

I've raced mine plenty and it has held up to these beefy Mickey Thompson's I run.

A little on the $$ side for what it is. Having said that and to do it all over again, I would run an inexpensive spool and be done with it. LOL!

In fact, I'll make you a deal on my ECTED if you're interested...

John

[merc]

Sherman & I run the same rear.

Ford CVPI 31 spline axles Shaft (6W1Z-4234-A)
Detroit TrueTrac limited slip 31 spline

[ctrlraven]

Hermann would choice that because if you look at the abuse the 03/04 Cobra's take while still having a stock rear it just goes to show.

A friend of mine has a 04 Cobra that makes 677rwhp 652tq and that's on 60k miles of hard driving and racing with a stock rear.

[merc]

Hermann would choice that because if you look at the abuse the 03/04 Cobra's take while still having a stock rear it just goes to show.

A friend of mine has a 04 Cobra that makes 677rwhp 652tq and that's on 60k miles of hard driving and racing with a stock rear.

I have seen a ton of stock gears with broke teeth. The fact is you race it , you break it. I love the Electronic locking rears. Martyo has one of those also.

[John Nero]

had a Auburn rear in the car(burned it up in 1 day at the track)went with Detroit True Trac we will see how long this will last

[FordNut]

I really like my Auburn ECTED diff. With a flick of the switch it turns into a spool and I've never had a problem with it. Turn it off and it is a normal LS differential.

I've raced mine plenty and it has held up to these beefy Mickey Thompson's I run.

A little on the $$ side for what it is. Having said that and to do it all over again, I would run an inexpensive spool and be done with it. LOL!

In fact, I'll make you a deal on my ECTED if you're interested...

John


I seen a ton of stock gears with broke teeth. The fact is you race it , you break it. I love the Electronic locking rears. Martyo has one of those also.

I'm also running the ECTED. I'm happy with it.

[ctrlraven]

I have seen a ton of stock gears with broke teeth. The fact is you race it , you break it. I love the Electronic locking rears. Martyo has one of those also.

I see more F-bodys though lol.

[bigmerc'03]

so why does herman not like the EATONS?

[2ndMDRebel]

Sherman & I run the same rear.

Ford CVPI 31 spline axles Shaft (6W1Z-4234-A)
Detroit TrueTrac limited slip 31 spline

How do the Ford CVPI 31 spline axles rate vs the Moser 31 spline axles?

[merc]

How do the Ford CVPI 31 spline axles rate vs the Moser 31 spline axles?

I sold my Moser 31's to Sherman. I can't tell you there is any real difference. The ford version is plug and play. Martyo broke his axle 31's at SSHS6.

[High-C]

I read in the lastest MMFF update on project "Stolen Goods" that Hermann was coming back to the metro area from Tampa... I have heard nothing but possitive things about him. Good luck with the mods...

[mpearce]

I have the Moser 31 spline axles, with the Eaton 31 spline posi, with the rear end stud girdle kit.

-Mat

[Joe Walsh]

Sherman & I run the same rear.

Ford CVPI 31 spline axles Shaft (6W1Z-4234-A)
Detroit TrueTrac limited slip 31 spline

Knowing how hard and how often both of you run at the track, that says A LOT!


had a Auburn rear in the car(burned it up in 1 day at the track)went with Detroit True Trac we will see how long this will last

That is exactly what Hermann said; "That I would burn it up in 1 day at the track."


so why does herman not like the EATONS?

He said that he has had some bad experiences with the Eaton spider gears in high HP applications.
Again, this is his experiences.
My brother has an Eaton in his modded CV and it has been bullet-proof.

I know that the ECTED's are great, but I'm leaning towards the TrueTrac because I want a Posi that works all the time for street driving.

[Joe Walsh]

I read in the lastest MMFF update on project "Stolen Goods" that Hermann was coming back to the metro area from Tampa... I have heard nothing but possitive things about him. Good luck with the mods...


Yep, That's how I found out about him coming back to the Wash. DC area.
He welded in the subframe connectors on my 84 Mustang GT convertible years ago when he had his shop in Crofton, Md.
He did a great job on the subframes!

He now has set up a shop in Beltsville, Md.

[FordNut]

I know that the ECTED's are great, but I'm leaning towards the TrueTrac because I want a Posi that works all the time for street driving.

The ECTED is limited slip when off, spool when on.

The Eaton version of the electric locker is open when off, spool when on.

[Joe Walsh]

The ECTED is limited slip when off, spool when on.

The Eaton version of the electric locker is open when off, spool when on.

Interesting...I didn't know that.

A spool would be sweet at the drags!

[bigmerc'03]

go with the eaton posi limited slip
www.rearendparts.com- (http://www.rearendparts.com-)

[blazen71]

What's up Joe? You must have come into some money recently to start modding yor car again ;)!

[Joe Walsh]

Well?
What's the word!?!?

How is that bad-boy running?.....:banana2:

[blazen71]

Well?
What's the word!?!?

How is that bad-boy running?.....:banana2:


Runs really good....too good. I was screwing around and an intercooler pipe blew off. Now the car will sit in the garage until the dyno tune. I'm going back to Florida tomorrow for 2-3 weeks. I'll get it tuned when I get back!

[Joe Walsh]

Well, I have to get my gears in for some Spring racing...so I 'bit the bullet' and ordered a Detroit TrueTrac 31 spline differential.

I ordered it from Summit Racing because I had a $50 off coupon for Summit.
That put the whole deal, including shipping at $411.90.

Next I am going to pull the entire rear to have the axle tubes welded to the center housing and then get a nice gloss black powdercoat on the axle.

Then I'll have the TrueTrac & Moser axle goodies installed and set-up.

Last I'll re-install the axle with the Metco rear arms/Watts link.

Oh!
And that set off Todd's/TCE rear brakes!!

:banana:

P.S. Jake...You still got the engine bling...but my undercarriage will be super SHINY!

[ctrlraven]

Booooo go with FRPP 4.10 gears! lol

Are you going to be running a 16" drag radial setup again?

[Blk Mamba]

Auburn is a road race rear end, made to direct power to the opposite side to help pull the car through the turns, it's a patented system, having to do with the side shift in the corner, these are the reasons I looked in to them.

[RR|Suki]

I'm still on my stock rear end... we'll see how that works when I get some grip :lol:

[Joe Walsh]

Yesterday I got a box from Summit Racing!!

Time to get my butt in gear and pull the Marauder's rear to install some go-fast goodies!

I'll post pictures of the entire rebuild.

BTW: What is the best/easiest way to post FULL SIZE pictures in my thread??
I always end up with 'thumbnails' that you must click on to expand...
I am a computer illiterate...so be gentle!

[merc]

Yesterday I got a box from Summit Racing!!

Time to get my butt in gear and pull the Marauder's rear to install some go-fast goodies!

I'll post pictures of the entire rebuild.

BTW: What is the best/easiest way to post FULL SIZE pictures in my thread??
I always end up with 'thumbnails' that you must click on to expand...
I am a computer illiterate...so be gentle!

Send them to me and I will link them on my site. :burnout:

[lincolnpimp]

31 spline cvpi axles, with Detroit Truetrac, and 4.30 gears. Nitto 255 55 18's and a custom drive shaft similar to the one DR sells (only much better, higher terminal velocity). This set up is freaking incredible!!!! Have never had so much fun with Pather platform EVER.

GO DETROIT TRUETRAC!!!!!