How to verify a locking rear differential?

[WCPoe]

I stumbled on a low mile, (32,000), 2006 Inferno Red SLT Quad Cab 4X4 on a local dealers lot. Very nice unmodifed truck but I was wondering how to tell if the rear differential was the locking type.



I looked in the glovebox but there wasn't a sticker showing the options added. Any one got any clues on the differential ID?



I think they're asking too much at $29k, but it was an intersting find as I haven't seen that many decent on the lots around here. I thought around $26k would be more in line with the way the economy is. Anyone care to comment?

 

[AMcCormick]

I dont think that a true "locking" diff was an option as oem. Limited slip yes and it would say on the glove box sticker. There are now aftermarket lockers avalible for the 3rd gen front and rear ends. "ARB" and I think "Detroit"?

 

[p-Bar]

The dealer can run the VIN and give you that info

 

[Matt400]

jack up the rear with both wheels off the ground, trans in neutral and rotate one wheel by hand. If the other wheel turns the opposite way then its a standard diff. If the other wheel turns the same direction then its limited slip.



It was an unusual case the other day but I got stuck with my 4x4 and had one front and one rear that would spin, limited slip would have been nice.

 

[SRadke]

It will have a stamped steel tag under the differential cover bolts that will tell you if it is. Easiest way is to take it for a test drive and get on it around a corner. You'll know... .

-Scott

 

[sag2]

jack up the rear with both wheels off the ground, trans in neutral and rotate one wheel by hand. If the other wheel turns the opposite way then its a standard diff. If the other wheel turns the same direction then its limited slip.



It was an unusual case the other day but I got stuck with my 4x4 and had one front and one rear that would spin, limited slip would have been nice.

Does not work that way with an American axle. I think I posted a couple of times the correct way to verify an AAM, but didn't see it in a quick search. Easiest way is to PM the last eight of the VIN and we can verify it.

 

[Jefff929]

It will have a stamped steel tag under the differential cover bolts that will tell you if it is. Easiest way is to take it for a test drive and get on it around a corner. You'll know... .



-Scott

Hey Scott,



That was my thought too :-laf



jeff

 

[WCPoe]

Does not work that way with an American axle. I think I posted a couple of times the correct way to verify an AAM, but didn't see it in a quick search. Easiest way is to PM the last eight of the VIN and we can verify it.

I was under the same impression. Aren't these AAM axles the torque sensing type and do not have the typical clutch packs?



Sag2 if you get a chance the VIN is 6J144299. Thanks for your effort.



I still haven't had a chance to get back to the dealer and scope it out a little better. I have been having the urge to step up to a 4X4 but I just don't know if I can part with my 2004. 5 since I have it pretty much set up like I want it.

Mines a Laramie as well and the one on the lot is a SLT. Heck they won't give any more on trade for all my mods and it would be a pain to remove the built transmission, turbo and full MBRP T304 SS exhaust. The other stuff could be removed fairy easily. Even though my truck is 2 years older and has a few more miles, (52,000 vs 32,000), my truck has been a garage queen since I retired 4 years ago and looks better both inside and outside.

What to do?

 

[Matt400]

Does not work that way with an American axle.

Didn't know that, thanks for pointing that out.

 

[sag2]

It has 3. 73, 11. 50, and anti spin (DSA). For some reason could not get the full report to open for print, using my wife's new computer.

 

[Matt400]

I was interested to learn a little more and found this:

American Axle & Manufacturing (AAM) - TracRite® Axle Differentials

#ad


I am guessing this is the style were talking about. Interesting that it's listed for use in front axles too.

 

[SRadke]

The are a very impressive carrier. The more torque you put to them the better they lock up. The downside compared to a friction style carrier is a low torque application like ice or slick mud. Sometimes you have to drag the brakes to get it to hook.

-Scott

 

[Matt400]

Sometimes you have to drag the brakes to get it to hook.

Would be cool if the trucks had traction control like my Charger, open diff but one wheel starts to spin and the caliper grabs it.

 

[WCPoe]

The are a very impressive carrier. The more torque you put to them the better they lock up. The downside compared to a friction style carrier is a low torque application like ice or slick mud. Sometimes you have to drag the brakes to get it to hook.



-Scott

Thanks for the info Sag2, SRadke and Matt400. ------> I 'll think I'll swing by the dealer and pester them a bit.



What's your idea for a good deal? They're asking $28,995 for this one which is an SLT QC 4x4 48RE, drop in bedliner, Michelin tires, (about 60% left), is very clean and is unmodified with 32,000 miles . I noticed it has the manual lever for selecting 4WD and low range, (Isn't that preferred over the electronic unit?) I think between $25k and $26K would be a decent price range but may never happen.



On another note they also have a 2007 Inferno Red QC 4X4 Lamarie with 63,000 miles with the new drivetrain for $29,500 but it doesn't seem in as nice as condition as the 2006. I feel more at home with the old tried and true 5. 9 Cummins and don't like the idea of the PDF.

 

[Matt400]

I noticed it has the manual lever for selecting 4WD and low range, (Isn't that preferred over the electronic unit?)

It is for me. Much more trouble free and cost to own is lower. Not much to go wrong with a lever but the other has the switch module that requests 4x4 from the 4x4 control module which in turn operates the transfer case motor and those systems do go bad.

I think between $25k and $26K would be a decent price range but may never happen.

I would run the numbers at http://www.kbb.com/ and print out what you find for negotiations.

 

[SRadke]

They used the 5. 9 through mid 07 so check it to be sure it is a 5. 9 or 6. 7

My 06 is basically what you describe with a 6 spd rather than an auto. It was 33. 5k new.

-Scott

 

[Newf Limo]

Would be cool if the trucks had traction control like my Charger, open diff but one wheel starts to spin and the caliper grabs it.

My wife has an 01 Dakota with a limited slip. I have suspected that it does not work correctly and seems overly grabby.



On two different occasions, I would be driving on a straight fairly flat but icy road, careful to not "upset the flow of things" and suddenly had the back end try to snap around me! I is almost like I have been hit. Have to react real fast to get ahead of it. I am guessing that the power tire lost grip and the diff kicked in the other side and both tires end up breaking traction. The tires that spin, are the tires that lead. Sometimes I think the thing is locked unnecesarrily as well. Sounds like it is time to get it it's own credit card so it can go to the spa for some treatments.



Don't trust that truck an further than I can throw it. I like the 7500 lb version.

 

[Bubba7492]

Would be cool if the trucks had traction control like my Charger, open diff but one wheel starts to spin and the caliper grabs it.

That's how Caterpillar does it on the larger trucks.

 

[SNGLESHOT]

Hey Sag,
Was in the dealer the other day getting my EGR cleaned out (shocker there huh?) and I told them my truck was 'binding up' while in 4WD even on the snow and ice. They (technician) told me it was because of me having a limited slip diff's front and rear. Does that sound logical to you? I can see the rig binding up on dry ground or ashpalt... but on snow and ice too? This is first time truck has seen snow and ice as it spent its first year down in Arizona way.

 

[Bubba7492]

No limited slip in front. Yes you will feel some bind, even inice and snow. Bind will be excessive if there is a bad u joint. Bind is because of different wheel speeds when not going straight.