2nd Gen Non-Engine/Transmission My trac loc slips, now what?

[CFast]

went to the snow yesterday, thought I had a LSD, but only one tire spun. I just bought the truck a month ago. I was hoping it was just the wrong fluid. I pulled the rear diff pan today, it's a Trac Loc. I drained out as much fluid as possible. then i raised one tire, leaving the other on the ground. I can turn the tire by hand, no where near 90ftlbs torque like the manual says. So now what? Can i get a power lock for this Dana 80? should i just get new clutches for this TracLoc? Will changing the fluid help any? It's still up on jack stands, i haven't added the new fluid yet, i doubt it will help. How hard is it to set up the rear end in these dana's? ANY suggestions?

 

[SpicyJam]

I noticed my 80 does the same thing, I called the dealer and they said they could rebuild it. I said OK but then what?, is it going to do it again soon? Kind of not happy with the ole rear end.



I just changed fulid, didn't help me. Rear end has a mind of its own. Works sometimes, and sometimes not.

 

[Gary - K7GLD]

DON'T panic - threads like this come up frequently - and there's one or 2 active here now...



Former owner probably put in a non-standard lube - possibly a synthetic - in some units, if not checked for proper operation after a fluid switch, the LS function no longer works - but the owner, since no chattering is evident, ASSUMES all is hunky-dory in the differential...



Drain the differential, pick up the DC recommended lube and install it - drive the truck for a few days to allow the proper lube to circulate and penetrate the LS clutches - do a few tight figure 8's to force the LS to operate. If/when you detect chattering or slippage from the rearend on sharp turns, get some DC Friction modifier and add half a bottle at a time, drive truck until you are satisfied with the LS action...



BUT, if the LS still won't function properly, you may have badly worn or contaminated LS clutches that must be replaced...



Good luck...

 

[Straight6Jeff]

I too had a non functioning trac-loc in my 3500. I rebuilt the unit with new frictions/steels, restacking hte unit so it had max active surfaces. From the factory, there are only two or three active plates, the rest are stacked as spacers. I have a total of 6 actives on each side. Now it is a spool. I will be trying osme different friction modifier/fluids to try to loosen it up a bit. If it doesn't loosen, I will be restacking ot decrease the active surfaces.



Now one might wonder why I would want to decrease the action. I have smoked througha set of rear tires in about 3500 miles. I fully understood that htre would be some experimenting with the stack order til I got it to where I want it.

 

[Gary - K7GLD]

JEFF - I sorta wanted to comment over in the "other" thread on the subject, I really think your situation SHOULD be fixable with addition of Friction Modifier or different lube - I would far rather do a little experimenting with lubes and get the benefit of spreading wear and control of LS action over a larger number of clutches and the added wear surface they provide - I realy think all it takes is a bit of patience ib balancing the lube characteristics against your particular LS unit...

 

[CFast]

The old stuff was regular gear oil, stunk like it anyway, looked like it too. The stuff I got is from my work. Syn 75-90. We put it in all the freightliner trucks rear ends. EATONs and rockwells I can't remember who makes it since we get it out of 500gal barrels. I want to say it's quaker state, but that's just the name on the barrel. What does DC recommend. I would call my local dodge dealer but they're jerks. thanks. By the way, can I put a powerloc in this instead? This truck has 125,000 miles on it and i've got a feeling the previous owner used it to 4x4 quite a bit. If i'm going to pull this to rebuild it,i'd rather put in a power loc.

 

[CFast]

Maybe i won't put in a power loc, just looked at some prices, $530! How long will a rebuilt trac loc last

 

[Wheaties]

CFast,



I think what StraightSix means by a 'rebuild' is more of a 're-org'. You mostl likely haven't worn out the limited slip. It comes from the factory stacked in such a way that it isn't doing much. This gives it a smooth ride with almost no chatter.



By taking it apart and re-stacking the components, you can actually increase the number of active surfaces, effectively turning more of the limited slip on, and tightening things up.



StraightSix has his set to 'maximum' and when he says it is a "spool" he means both wheels are turning at the same rate at all times, there is no differential action at all.



I agree with Gary that some combination of re-stacking and friction modifier should work, I suppose it is cheaper to try friction modifier first?



Matt

 

[DAWG-1]

L/S

These limited slips are a joke. I have 27000 miles on my truck and I have a none working L/S. I have done some research and with the torque are engines put out they just don't last. You can put an ARB (air locker) or a Detroit locker (not to good on icy roads). I think I will go with the ARB. The ARB is either locked or unlocked for normal driving. Sam

 

[Straight6Jeff]

Gary, I will be trying different fluids and modifiers first. Restack is the last option to me.



The ARB is only available in the D80 35 spline with 3. 73 and numerically lower gears. More than one Drivvetrain shop said that the ARB will not hold up to the torque that a highly modified Cummins will put out.



When I did my LSD, I orderd a friction/steel pack. I wanted to use new pieces as the old pieces had been slipping for 40k miles. The plates wear mate themselves to each other when slipping. The trac-loc in my 2500 truck was awesome. it always spun both wheels, and was just a touch grabby on the tight turns. Production variances seemed stacked against me on teh one in my current truck.

 

[tpruitt]

I just put a detroit in and love it. If you want something that you know is there i would get it. I can still make all the same turns with no noise if i am not on the throttle. So far it has been quiet and i would not have anything else. I just put it in on Saturday but so far i have been impressed. Well it might be more than some want but if you want something that works i would look into it. Also i dont know if it available but the true trac would work really well for the rear. It almost operates like a warn winch, the more of a load them more it splits the power. I wanted on of there for the front but they do not make it for our 32 spline axle shafts.



Trey

 

[Straight6Jeff]

I spoke with Tractech regarding the Truetrac. While they have a part number listed for the 4. 10 35 spl D80, they do not currently have any timelines for when it will be released.

 

[Straight6Jeff]

I spoke with Tractech regarding the Truetrac. While they have a part number listed for the 4. 10 35 spl D80, they do not currently have any timelines for when it will be released.

 

[Straight6Jeff]

Well, I am currently running the Royal purple 85-140 synthetic with 4 bottles of the Ford Motorsports friction modifier (the most foul smelling stuff ever), and the rear end still will not slip. Although I did get the thing to chatter a little bit. Next step, ordering a Detroit locker.



Detroit locker ordered, along with install kit and spare set of set up bearings. A big Thansk to Scott at MassDiesel for getting the parts ordered in a hurry!



Should be in this weekend.

 

[jkern]

just restack the clutch pack!!!

don't spend lots of $$$$ just take the factory diff out and notice how the stack of the friction material and the metal surfaces are. simply re-stack them making in friction surface then metal surface, etc. put it back together with the proper lube and you will have a limited slip that works very well... close to a locker but not quite. this will help your situation greatly... talk to some of the sled pullers and street racers, this is how they get theirs to put the power to the ground.

 

[Rman]

Personally I would never spend the money for the factory LS option. Get the open diff and put in a Detroit. If a a locked diff is what you want there really is no other answer in my opinion. Detroits are tough and can take some abuse.



Sounds to me like your trac loc is just worn out, it's common because it's just not a very good design, restacking is an option, but again my opinion, if you have to go through all that trouble just put in a detroit and forget about it.

 

[Wheaties]

Keep me posted Jeff, and I'll give you a hand. Just keep handing me the dumb end of the tool, and I 'll be fine.

 

[Straight6Jeff]

Thanks Matt. Setting up the diffs on Saturday was fun. I am still in amazment that the pinion gear was melted on that D80.

 

[CFast]

I've got a clutch type SureGrip in my Duster that works great, and a friend of mine has had one in his car for 10 years that still works great. What's so much better about the detroit? These LSD's in the dodge look pretty stout.

Jkern, what does the clutch pack look like in the TracLoc from the factory? Do you mean I don't have to buy a new clutch pack, just simply restack the ones that are already in there? Is there somewhere to get pics of this? I won't have time to pull it until next weekend. How hard is it to get the diff assembly back in the D80? I've heard you need to spread the case. Thanks

 

[Straight6Jeff]

The D80 cluthces are all steel. You can restack the factory ones, but they have taken a wear-mate to each other. Restacking worn clutches could wear the ridges and grooves down to a point where the LSD would slip too much, then again maybe not. the clutches are $105 for the entire set. I'm going with the detroit because I am tired of experimenting with fluid. Right now even with 4 botle of FM and full synthetic, it is still locked. I figure if I'm gonna pull the trac-loc out and restack for another experiment, I might as well slip in a detroit and know what I am gonna end up with.



A case spreader is highly recommended. , depending on how tight your case is, you might have to pound quite a bit to get the chuck in and out. I bought a spreader just to restack the trac loc, but It has proven a very valuable tool.