Dana 35 Posi?

[Ben-88Comanche]

Ok, so this april I was planning on doing a lot of work on my comanche. I have a parts comanche and was told when buying it that it had a posi rear end. I didnt care at the time, I was just happy with getting a full 4.0 5speed comanche for 400 dollars. But now I'm wondering what he meant by that, don't think a strait up posi rear end was ever offered?

 

So I'm wondering if theres a simple way to check if the rear end has a locker or not without removing the cover. I think its a dana 35, ill be able to see it i wednesday to make sure(parts truck isnt at my house atm) Yea I know you guys would probably suggest getting a 44, but I don't have a lot of spare money and if this has a locker I might as well take advantage of it.

 

Also I was wondering how hard the axle swap would be, if my main truck already has a dana 35 in it. Would there be a way to just take the diff covers off both and swap the locker? (hopefully it actually has one and the guy wasnt lying) Any insight would be apreciated

Thanks in advance

[maddzz1]

I think he meant a limited slip.

[Ben-88Comanche]

yea thats probably what he did but i hope not lol

[aemsee]

Jack the rear wheels off the ground. With it in gear (so the drive shaft won't turn) spin one rear wheel. If it is open, the other wheel will spin in the opposite direction. If it is limited slip, the wheel won't turn.

 

I did a moderate amount of wheeling with a D35 and limited slip in my 93ZJ, with 31x10.5's. If you keep the tire size down, and are not insane with the gas pedal, you'll be OK. People make it sound like D35's just explode as soon as you drive off the pavement.

 

It can be a weak link, but there always is one of those, isn't there? :D

[CWLONGSHOT]

Jack the rear wheels off the ground. With it in gear (so the drive shaft won't turn) spin one rear wheel. If it is open, the other wheel will spin in the opposite direction. If it is limited slip, the wheel won't turn.

 

I did a moderate amount of wheeling with a D35 and limited slip in my 93ZJ, with 31x10.5's. If you keep the tire size down, and are not insane with the gas pedal, you'll be OK. People make it sound like D35's just explode as soon as you drive off the pavement.

 

It can be a weak link, but there always is one of those, isn't there? :D

 

EXACTLY.

 

Look at it this way, This crap about drive it like you stole it certainly WILL break a D35 right quick!!

 

Posi, Limited slip, traction loc, power loc are the same animal. Clutch type traction assist devices. Chevy used one name, Ford and Jeep another and Chrysler/ Dodge still another. Apples to apples.

 

It wasn't until recently manufacturers started offering true lockers to there vehicles.

 

CW

[86FUBAR]

 

EXACTLY.

 

Look at it this way, This crap about drive it like you stole it certainly WILL break a D35 right quick!!

 

CW

 

i had a lockright in my 35 for 4 years and i broke the cross pin with in the first month and fixed it , then the last year it was in i broke the pins in the lock right and so i just welded it up and figured id run it till it broke and it never did but then i was runing the 2.8 v6 and i drove the piss out of it .

now if it had the 4.0 in it it would be a different storie because my rubicon LJ 6 speed gets it like no other

[Eagle]

I have a parts comanche and was told when buying it that it had a posi rear end. I didnt care at the time, I was just happy with getting a full 4.0 5speed comanche for 400 dollars. But now I'm wondering what he meant by that, don't think a strait up posi rear end was ever offered?

 

So I'm wondering if theres a simple way to check if the rear end has a locker or not without removing the cover.

I think some clarification is called for, because you are mixing up terms.

 

As CWlongshot already noted, "posi" was short for "Positraction," which actually a GM trade name for their limited slip differential. Over the years, "posi" was sort of hijacked to refer to any limited slip differential. But, whether you call it a "posi," a "Trac-Lok," or any of a variety of other trade names, it is a limited slip differential, it is not a "locker." Jeep did offer a limited slip in both the Cherokee and the Comanche. It was a Dana-Spicer unit which both Jeep and Dana called Trac-Lok. Jeep never offered a true locker until the air locker they put in the Wrangler Rubicon a few years back ... and they put that unit ONLY in the Wrangler Rubicon.

 

Your parts truck could have a Trac-Lok even if it's a Dana 35. The usual test is to jack up one rear wheel, with the parking brake off and the tranny in neutral, and see if you can spin the wheel by hand. If it doesn't spin, you have Trac-Lok.

 

The catch-22 is that if the wheel does spin, it doesn't completely prove that the diff doesn't have Trac-Lok. The system uses clutches, and they usually last only 75,000 to 100,000 miles. Once they wear out, the diff acts like a normal, open differential. So the only positive way to know if there's a Trac-Lok in there is to remove the diff cover and look.

[Ben-88Comanche]

oo so you could say posi and limited slip are the same thing? I always thought that posi was strait up both wheels spinning all the time... shows how much I know haha.

 

Thanks for clearing that up. So is there a functioning difference between the posi/track lock and one of the lockers you install yourself?

 

And would the limited slip device, if still functioning, be something I could transfer from the parts dana 35 into the one on my truck? or would a whole axle swap be nessesary?

[Eagle]

So is there a functioning difference between the posi/track lock and one of the lockers you install yourself?

Yes, there's a difference. A limited slip is a limited slip. It isn't a locker. Put too much torque to it and the clutches slip. It also wears out, and the clutches require a special additive for the gear oil.

 

And would the limited slip device, if still functioning, be something I could transfer from the parts dana 35 into the one on my truck? or would a whole axle swap be nessesary?

You could transfer a Trac-Lok from one axle to another, but you would have to know enough about setting up gears to be able to measure the lash on your original setup and then match it exactly with the Trac-Lok. If you don't match the existing gear pattern, you'll have a noisy diff and possible early failure.

[aemsee]

May also depend on gear ratios. There is a break/change in carrier sizes. I THINK it is 3.55 down and 3.73 and up are different size carriers

[CWLONGSHOT]

So is there a functioning difference between the posi/track lock and one of the lockers you install yourself?

Yes, there's a difference. A limited slip is a limited slip. It isn't a locker. Put too much torque to it and the clutches slip. It also wears out, and the clutches require a special additive for the gear oil.

 

Just to ad a bit more... On the street there is no advantage to a locker. the limited slip will do you perfect. Keep both tires on pavement and you will spin or not spin both. Yet, go around a corner easy on the throttle and the inside tire is allowed to spin just a bit faster. But lift a tire like you do off-road and you have just defeated 98% of all limited slip units manufactured today. Because as Eagle pointed out, its a LIMITED SLIP or better named off-road, LIMITED TRACTION. All the power WILL go to which ever tire is moved the easiest. That's the one in the air.

 

With a LOCKED axle, BOTH rear wheels are solidly connected and one CANNOT spin with out the other, NO MATTER WHAT. (Short of breaking) Go around a corner with a LOCKED axle and even crawling will result if "chirping" a tire. that's because when you do a circle the tires on the inside are making a smaller circle than the tires on the outside. But because they are locked and CANNOT spin at different speeds, one has to "give" and "chirps". Don't be confused, I said that that axle was LOCKED, as in a spool, not that it has a locker in it. I don't mean to be confusing, but some lockers WILL allow one tire to rotate independent of the other. the Detroit Locker, Loc-rite and EZ-locker are but three that will do this. the key is throttle, more throttle forces the locking action. get off the gas, like in a corner and one tire or side will "ratchet" and spin differently than the other. LOCKED axles on the street are harsh and hard on tires and drive trains.

 

That's why selectable lockers are so popular for vehicles that need to drive near factory normal on the street. Diffs like ARB and OX are two examples. Both of these allow fully locked spool like traction on one end and completely open for the street.

 

Hope this explains more than confuses...

 

CW

[comanche87]

speakn of dana 35s, i have a open rear end. what would be the most cheap effishent way to make it a limited slip?

[Mitch]

speakn of dana 35s, i have a open rear end. what would be the most cheap effishent way to make it a limited slip?

 

Pull an 8.8 from a junk yard that has limited slip from the factory and install it your self.

[CWLONGSHOT]

speakn of dana 35s, i have a open rear end. what would be the most cheap effishent way to make it a limited slip?

 

Sorry dude, there is no "easy or cheap" LS you can add to yours.

 

The way I see it, you have to choices. Buy another complete rear with the correct ratio and a LS.

 

OR, just throw in a Loc-Rite in the junk you have and don't drive it like you stole it...

 

CW

[Eagle]

Something like a Lock Rite is the cheapest way to lock a Dana 35, but that isn't a limited slip -- it's a locker. If you want a limited slip, the cheapest way is to buy a Dana Trac-Lok unit and install it. I haven't priced them for awhile, but I think they run about $225 to $250. If you're not changing gear ratios, you won't have to reset the pinion depth, so all you need to worry about is matching the ring gear backlash.

 

The idea of the Exploder 8.8 is a good one, if you can buy it for the right price out of a junkyard. Keep in mind, though, that the 8,8 doesn't work with stock Jeep tires and wheels. The Exploder axle is slightly narrower than the MJ axle, so you need to run rims with less backspacing, or spacers (which are expensive) to keep the tires away from the inner fenders.

 

Unless you plan to beat on it, I'd go with the Trac-Lok. I'm sure that's a minority view, however.

[87manche]

Something like a Lock Rite is the cheapest way to lock a Dana 35, but that isn't a limited slip -- it's a locker. If you want a limited slip, the cheapest way is to buy a Dana Trac-Lok unit and install it. I haven't priced them for awhile, but I think they run about $225 to $250. If you're not changing gear ratios, you won't have to reset the pinion depth, so all you need to worry about is matching the ring gear backlash.

 

The idea of the Exploder 8.8 is a good one, if you can buy it for the right price out of a junkyard. Keep in mind, though, that the 8,8 doesn't work with stock Jeep tires and wheels. The Exploder axle is slightly narrower than the MJ axle, so you need to run rims with less backspacing, or spacers (which are expensive) to keep the tires away from the inner fenders.

 

Unless you plan to beat on it, I'd go with the Trac-Lok. I'm sure that's a minority view, however.

a stock width 8.8 will clear the frame rails with stock rims as long as you don't have wide tires.

On stock rims with 31x10.5's the inner sidewall rubbed just a touch when I had stuff in the bed.

A 1/4" wheel spacer would have alleviated the problem.

stock rims with 30x9.5's would have cleared just fine.

[Eagle]

a stock width 8.8 will clear the frame rails with stock rims as long as you don't have wide tires.

On stock rims with 31x10.5's the inner sidewall rubbed just a touch when I had stuff in the bed.

A 1/4" wheel spacer would have alleviated the problem.

stock rims with 30x9.5's would have cleared just fine.

It may clear, but not "just fine."

 

With factory Jeep rims, 31x10.50-15s rub the inside shoulder against the inner wheel well on even non-aggressive trail rides. The Exploder axle may clear with stock tires if you ONLY use it on pavement and both rear wheels always move up and down together, but get it even slightly crossed up and you have an interference fit.

 

I'm not saying don't do the 8.8 swap -- but if you're going to do it, be sure you understand the limitations and compromises that come with the narrower track width.