Hi all,

I was wondering if there's any type of limited slip setup in our front axles, or if they're open? I did some stuff with my truck yesterday that had me spinning the tires on grass while pulling a chevy boat anchor. (chain between his rear bumper and mine) All 4 wheels spun, but I seem to remember that these trucks maybe had open front differentials from the factory.

 

An open diff will still supply power to both wheels as long as they both have the same traction, problems arise when one wheel leaves the ground or are on different surfaces, one wheel in the sand and one on pavement for an example...

Rick

 

True, that's why I'm still not sure if it's open or limited slip. Since it did spin both fronts, I have no way of knowing whether it did that due to a limited slip unit, or because the traction was equal between the two front tires.

 

I thought only the rear diff's got the LS.

 

I don't know about the LSD in the front axle, but it sounds like you have the factory tires? The factory tires are real slippery, mine were a bit scarry in wet and snowy conditions, and they spun on wet grass! The factory tires were the first thing to go.

If you are in snow country, I would replace your tires with something with a more aggressive tread. I went BF Goodrich AT KO's, night and day difference in the traction department, and it has traction on wet grass. I think the BFG's can still be had for around $115 ea. (the 315's). There are other tires out there, I just have had good luck with the BFG's, even run them on my semi.

Mike

 

I live in Montgomery, AL. No terrible snow problem. The tires spun because I was hitched to the back of a 1/2 ton 4wd chevrolet jerking him up a slight hill in grass. He was in 4wd trying to jerk me down the same hill. It ended badly for him.

In any case, does anyone know whether we have limited slip in our front axles?

 

My factory build sheet only shows LSD in my 11.5" rear diff. I've never heard of any modern factory putting an LSD in a fron axle, except for maybe the jeep rubicon. Obviously, you could put one in if you need the extra traction up front.

 

I think that the front axle is open, as a limited slip could cause steering problems as it automatically engages and disengages. The new Power Wagon is being offered with a selectable locker on the front 9.25in axle, so the parts should be available for our trucks. I think that a selectable locker is what you want on the front axle, and is something that I'll pick up if I upgrade the axles.

 

Sounds like a worthwhile upgrade to me.

 

No limited slip in the front axle is available from the factory. All front diffs are open differentials. They have only side gears and spider gears. The rear is actually not a limited slip either. All limited slip diffs have clutches, these don't. A better term would be a positive locking differential. You can see how they work on American Axle's site.

 

I don't follow it all that closely but I do not recall seeing a pickup with a limited slip front axle from the factory since the 80's or early 90's. I had an old Ford that had factory limited slips front and rear. I think it was about an '82, it was a great rock crawler.

 

Not all LSD are clutches, the Tru-Trak is a gear drive LSD.

The Rubicon has a selectable locker in the front and rear not an LSD, when it is locked in it is a spool, much like the ARB air locker, OX Lock, Eaton, and the Toyota E-Locker that come in the rear of the TRD Tacoma.

The best type of locker you can put in the front is a selectable locker, especially if you live in snow country and drive in four-wheel drive a lot. Full non-selectable lockers are very unpredictable in the snow and can cause a lot of driving problems. If you do not want to pay the cost associated with selectable type lockers then in my opinion I would look into a Detroit Tru-Trak LSD.

I am new to Dodges but I have been associated with heavy Rock-Crawling four-wheel drive rigs for a while and one of the first up-grades you make are some type of locker set-up for the front and rear diffs. There are a few pics of my Rock-Crawler in my pictures.

 

That is exactly why I stated a better name for the clutchless type units like in our trucks would be a positive locking differential instead of LSD.

 

No because a "clutchless LSD is biased to allow wheels to slip, whereas a Detroit basically has both wheels "locked together" but will ratchet when going around turns and the selectable lockers are "spools" when engaged, no racheting.

Here are the specs on the two types of LSD's that Detroit makes. There are other types of "clutchless LSD's" out there but this one is the only one I know about because I used one in the front of my Toyota when I first got it and it was my DD.

Differentials - Limited Slip Type (Torque - Sensitive)
Tractech’s limited slip differentials are the Detroit Truetrac® brand, and the Suretrac® and the brands. They provide a controlled amount of resistance to a one-wheel spinout, so that the other wheel (with traction) receives sufficient power to keep the vehicle moving

Detroit Truetrac®
Uses pairs of "Helical" gear sets
Gears only - no clutch packs.
Ideal for 4WD front axles or rear axles, as well as 2WD; light trucks, SUV’s, cars.
Rugged yet smooth and quiet.
Torque bias ratios of 2.5 to 3.5:1 range

Suretrac® /Detroit LSD
Heavy duty clutch pack type, for severe applications where limited slip type smoothness is preferred.
For larger (over 10,000 lb. capacity) axles
Two types, offering torque bias ratios of 2.5 to 4.0:1 or 1.5 to 3.0:1 ranges

 

factory usually will not put a limited slip in a front diff. The fact that if both front tires are spining you lose the ability to control the vehicle as well.

it is not like on snowy road you want locked diff's front and rear.

I would proably only use and air locker or e locker in th front do to this fact.