Need advice: New carrier and axles?

Tripoli

Member
Mar 30, 2005
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16
Dallas, TX
Well, the clutch packs in my stock differential are completely hosed. I can do a wonderful 1-wheel burnout now, and right turns are interesting. I'm thinking I might finally get a pair of slicks for my car soon, so I'm looking to take this opportunity to upgrade my rear end, but I don't want to replace the whole thing right now because I don't want to fork over $2,000 for it.

What I have in mind is replacing the carrier and the axles. They're currently stock. I'm told that you can easily upgrade to 31-spline axles, but I'm not sure what all my options are for carriers and axles. I'm currently putting down 289 RWHP and 313 torque, but I'd like this setup to be good for significantly more with slicks. Basically, I want to know what my best options are while retaining the stock housing, and my FRPP 4.10s.

The car is daily driven, so I need a carrier that'll allow me to take tight turns relatively smoothly, but will still lock up nicely for burnouts, etc.
 
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For occasional 1/4 mile and mainly DD I would just go with a Ford 31 spline Trak-Loc out of an Explorer and moser 31 spline axles. Also while installing those I would have the axle tubes welded and the torque boxed welded also.
 
For occasional 1/4 mile and mainly DD I would just go with a Ford 31 spline Trak-Loc out of an Explorer and moser 31 spline axles. Also while installing those I would have the axle tubes welded and the torque boxed welded also.
The car is steadily seeing more and more track use, and may cease to be a daily driver in a year or so. I'm curious what other carrier options you might recommend if I wanted to go with something other than a Ford part.

I hadn't thought about welding the axle tubes and torque boxes now. Probably a good time. :nice:

I was just poking around on Moser's website and came across the Auburn Differentials. They have "High Performance" and "Pro" models. It says that the Pro series offers a 33-spline setup for the Ford 8.8". Sounds interesting to me, but I don't know if the Pro series would be too track-only for me.
 
If you wanted to go with a non ford carrier you could look into detroit tru-track, or auburn, it really depends on how much hp you plan on running down the road and also if price is an option. There are carriers out there that are limited slip and with a switch can be fully locked, those would be best for a weekend warrior type car, but your also going to pay a premium for it.
 
I've had a number of people recommend the Auburn pro now. I think the 33-spline option is out, because I'd have to go with C-clip eliminators. 31 spline axles should be plenty strong for my needs anyways.

I just got off the phone with Moser, who recommended the Eaton Detroit Trutrac. I really wish I understood how the hell that thing worked. Anyone have any experiences with them or heard anything about them?

I called Reider Racing for their opinion and they recommended the Eaton Posi. They said the Trutrac didn't like the shock load of launching on slicks with a manual transmission.
 
Hold up on the "c" clip eliminators. If you're on the street and drive the car routinely, eliminators is not the way to go. The reason is the bearing size , most if not all eliminators use a smaller bearing that will fit in the axle end (sort of) these eliminators are great for the drags, and are safer as well, but they will not hold up under street use. some of these eliminators use a bearing that is sealed, which makes the problem worse, these wear out about 5 times the rate of the stock bearings. One of the mags, (5.0 or musatngs & fords) had a real good article on this.
BTW, Moser is a good choice as well
Most Detroit locker stuff snaps, pops and raises cane on the street, the clutch type posi si a much better choice. If your car is a GT, it should already have a posi, somewhere around here is a great tech article on adding an additional disc. Everybody that has done that has been real happy with it, plus it's a lot cheaper than buying a whole new unit.
I found this: under "search" but I could not find the tech article on adding another disc to your 8.8

Positraction and TracLoc(k) are simply the brand names that companies - GM and Ford respectively - have chosen to describe their limited slip differentials. There are lots of different types of limited slip differentials. However, both positraction and tracloc limited slips operate in the same manner. Contrasted with a simple open differential which sends power only to one tire and allows the other to freewheel (when turning), limited slip differentials send power to BOTH rear tires. However, there are spring loaded clutches in the differential which, when they sense a speed differential between the two rear tires (as when turning), allow some 'limited slip' in the clutches. This allows the outside tire to turn faster than the inside tire eliminating any scrub or 'chirping'. There are other ways to achieve this limited slip effect besides with clutch packs. Torsen-type LSD's and the TrueTrac brand use a series of worm gears and sliders to achieve a similar effect - but in the case of the Torsen - more power is sent to the tire with the MOST traction. Whether clutch-type or gear-type -- LSD's generally work completely unobtrusively. You don't know they're there -- you just know the car corners quietly, but when you get on it - you have traction to both tires. However, the TrueTrac and Torsen units have nothing to wear out; unlike clutch-type LSD's which have to have springs/plates replaced when they wear out. I run a TrueTrac unit in the Dana rear end in my Volvo.

There are also automatic and manual locking differentials, and spools. A spool basically LOCKS the two axles together -- THERE IS NO DIFFERENTIAL. The term differential exists because that unit allows a SPEED differential between inner and outer tires when turning -- a spool doesn't allow this. A spool-piece usually slides into the female ends of the axle splines in the gutted differential between the axle ends. The cheapest and least elegant version of a 'spool' is simply welding the spyder gears together -- done by MANY racers.

Lockers -- automatic and manually locked rear ends -- have a series of dog clutches that are either locked or they're not. The automatic units lock both axles together UNLESS they sense a speed differential between inner and outer tires -- when they sense that they unlock. They are typically quite noisy as they 'ratchet' in and out of locked position, although newer models have gotten better. Manual locking units work the same way (dog clutches) however - you choose whether and when they are locked. This can be done a number of ways - usually you'll see them electronically or pneumaticallly operated.

For street cars limited slip diffs seem to offer the best compromise, although some like lockers and are willing to live with the noise compromise. For drag racers and some oval track cars a spool is all that's needed. For road racers and autocrossers, a good LSD is usually preferred since they have to negotiate turns. However, you'll see some spools there as well. In my road race car, we simply welded the spyder gears together to 'lock' the rear end up - worked just like a spool. Made for interesting noises and tire scuffing in the pits -- but on the track, the radius of the turns was so big you didn't notice it.
 
Well, from the input I've received here, and from what I've read on other forums and websites, makes me lean towards the Eaton Posi LSD. The idea of not being able to rebuild the Auburn is a turn-off, and since they seem to be similar in performance, the Eaton seems to be the better choice. To further add to that, you can adjust the pre-load on the Eaton. I'm also steering away from the TruTrac. While I'm sure it'd be fine for my present setup and daily driving, I'm looking for something that's going to be able to handle punishment from slicks and with a lot more power than I currently have.

Any other input y'all may have is appreciated. You've probably got a couple weeks to make up my mind before I fork over the cash.
 
You do not need any of this crap. Just have your f'n trac lock rebuilt... Damn...

You will know when you need 31 spline. How? Because you will have destroyed your 28 spline stockers :shrug:

Do not be distracted by bright and shiny objects, just fix your car already.
 
You do not need any of this crap. Just have your f'n trac lock rebuilt... Damn...

You will know when you need 31 spline. How? Because you will have destroyed your 26 spline stockers :shrug:

Do not be distracted by bright and shiny objects, just fix your car already.


Stock is 28 spline, and it should have been done at the same time as gears. Why pay for labor twice?

And people have been known to snap the axles with nothing more than sticky tires.

Think of this as preventive maintenance ;).
 
You do not need any of this crap. Just have your f'n trac lock rebuilt... Damn...

You will know when you need 31 spline. How? Because you will have destroyed your 28 spline stockers :shrug:

Do not be distracted by bright and shiny objects, just fix your car already.
One of these days you're going to have something useful to say, Kilgore. Thus far, just about every post of yours I've ever seen has been completely worthless.

Some of us prefer to drive away from the track every time, you know. I'm pretty sure that with my stock rear end and 28 spline stock axles, I wouldn't be doing that with the slicks I'm planning on getting soon.

I feel sorry for your Cobra. :nonono:
 
One of these days you're going to have something useful to say, Kilgore. Thus far, just about every post of yours I've ever seen has been completely worthless.

Some of us prefer to drive away from the track every time, you know. I'm pretty sure that with my stock rear end and 28 spline stock axles, I wouldn't be doing that with the slicks I'm planning on getting soon.

I feel sorry for your Cobra. :nonono:
I tried to make myself care about your vaginal discomfort about my comments being worthwhile or not. Unfortunately I was unable to do so... Sorry :shrug:

Thanks for your concern about my Cobra. BTW it is much faster and better looking than your car ever, EVER will be :nice:

I was just trying to provide a counter point to the typical "whoopee lets make the rear strong enough to handle double the power and be totally unstreetable with some annoying f'n locker" :shrug:

Its your car,do what you f'n have to do. :nice: