Two months ago on vacation, I was parked briefly on a moderate slope, pointed downhill with right wheels on grass and wet dirt and left wheels on pavement. To get to my campsite I had to back up about 20 feet, then go forward and make a hard right turn. OK, put 'er in reverse, eased the clutch out and the right rear wheel spun on the grass, so reached down and slipped it back into 4H and drove out of there. Got a little way and thought, "wait a minute, that's a limited slip rear end," so went back and looked. Yup, right rear wheel dug a good trench with that big mud and snow grabber tire.

Seems like in the past, that rear end would've locked up and pulled me outa there in 2H.

So, home now, took it to my regular shop and among a couple of other things, told him about the rear end. He nodded and said, "yup, that's common with Dana 80 and you've got 150,000 miles on yours. It'll run a $1,000.00 or so to rebuild it."


Is this for real ?? He says it wears every time you go around a corner, but I thought it took a certain amount of wheel spin to lock it up ?? Is the price to fix it realistic ?? Hoo Boy...............

Lar.

 

That sounds about right, but there are also other clutchless units available also. http://eastcoastgearsupply.com/i-133...true-trac.html

 

you can buy a brand new carrier for 500 bucks, how is it going to cost 1000 to rebuild?

 

I don't understand what 150k has to do with it, unless you have never changed the oil. Mine is still working at nearly 700k! I use Royal Purple and change it every 50k.

 

I've done the factory recommended changes on schedule and used the recommended oil and friction modifier.

I'm not familiar with these units and so came to you guys for opinions. Glad I did........hope to get more responses. This is an education.

Lar.

 

Ever hear of labor charge and I"m sure new bearings, shim kit will be needed. On a Dana 80 those are not cheap parts. Add fluids and friction modifier and there you go, 1000 dollars plus. Did you ever rebuild a dana 80? I have rebuilt many of them and they are not that easy. Every adjustment is done using shims and without the proper tools and dummy bearings you will never get a proper gear mesh pattern. You can always just reuse the old shims and bearings and hope it doesn't sing to you going down the road.

 

The first couple of changes I used Mobil 1 synthetic and Dodge pantherpiss. The next two I used Mobil 1 and the aftermarket modifier from CarQuest. Since then I have used Royal Purple with no modifier, it is already mixed in. I have a Mag Hytec cover, so changes are 7 qts instead of 4. $$$$$$$$$$$

 

all you need is a set of clutches ...simple to change

 

I would start looking around for a more honest mechanic. Just because truck has 150,000 and a Dana 80 is no reason for a complete rebuild. If clutches are all that is bad, then replace clutches as johnh stated. Don't let mechanic take out a good set of bearings and gears. Taken care of these will last 100's of thousands of miles. Both trucks I drive have original gears and bearings.

 

I'll ask him about it and see what he says. Thanks

Lar.

 

Verify which LSD is in there. It could be a Powr-Lok or a Trak-Lok. The Tlok isn't worth touching....they are junk brand new. But if you feel compelled to rebuild it, figure on a $100 max for a clutch kit, $200 give or take in labour (easily done in a few hours at a properly equipped shop) and another $50 for shop supplies and oil or whatever.

I would highly recommend springing for the Plok - it is superior to the Tlok. It will cost around $500 and change. Figure on 4 hours for a properly equipped shop to do the job. It isn't rocket science to set up gears on a D80....it is no different than any other Dana axle. But again, if you don't know what you are doing, you could certainly turn it into an expensive mess. A case spreader, set up bearings, the properly sized bearing puller and press will make short work of it. Plus, you will be leaving the pinion alone....no need to set up depth and pre load again unless something is seriously wrong. Now, if you were going to re-bearing the ring and pinion at the same time, I'd add an hour of labour and another $125 for the bearing master kit. At that point, you could get closer to the $1K mark....

 

I would check the unit first myself.
Lift the rear end off the ground, release parking brake. Put transmission in Neutral. Turn one wheel. Is the other one turning the opposite way? You have an open differential. Is it turning the same way and it is hard to turn? You have a limited slip. Put tranny in Park or in gear (manual) and use a torque wrench on one of the lug nuts, set at 85 ft/lbs. Can you turn the wheel before it clicks? If yes, clutches are worn. If not, they are Ok.
P.S. Please do refer to FSM for this procedure, as I typed it up from memory after having done it myself a year ago.

 

OK, thanks all.......I'm just about ready to go on this. How do I tell whether I have a P Lock or T Lock ?? How would you compare them to the unit in the 2nd post above - http://eastcoastgearsupply.com/i-133...true-trac.html ?? For $150.00 difference on something like this I'd want to go with whichever is the better unit. Before I let him start, we'll do the tests that PaulDaisy recommends. Thanks.

Lar.

 

The parts are way more expensive for a Dana 80 than others have quoted here. The Master kit alone is $325.

The Stock L/S diff should be a TracLoc which is a strange breed when compared to the old skool T/L and P/L. This T/L resembles a P/L to the untrained eye. It has a 2 piece case and 4 spiders just like the P/L. The clutches are expensive too.....$220.

Both Dodge Dana 80 T/L's I had apart today had the clutches stacked in such a way that would make the very weak in tranfering torque. I stacked them in a different way to make them as stiff as possible. Too much? Won't know till this weekend when the truck hits the strip and sledpulls. 770HP will tell us what it needs.

Bottom line is.....you may be able to just pull the carrier and restack the clutches to get the bias you want. Assuming the rest of your axle is in good shapeand you have some skills/tools.

The Truetrac is a great diff, but you will have the same issues with spinning one tire on slippery surfaces. That style of diff, much like the 11.5" TracRite needs torque to multiply before it will apply any "Extra" torque to the wheel with traction. Just apply the brake a little and you'll pull right outta that jam you are in. I do it all the time in my Jeep on Rubicon.

$1000 is a fair price for Labor, synthetic oil, and clutches, assuming you need all that.

 

It is still hard to believe you need a complete rebuild with only 150,000 miles. Unless you do a lot of mud running or just run without oil, I can't imgine it. My '01 has over 276,000 on original gears, bearings, seals and u-joints. The only thing done is change oil. I have seen gears changed on vehicles and use old bearings, just set them up for new gears.