Hey guys I'm recently been trying to install a powertrax lockrite locker into a 3.42 rear I picked up from a junkyard. Everything was going along smooth until I was about done with the installation. It appears that there is too much gap between the drivers (the pieces withthe semi circular hole for the pinion shaft).

The shear pins that go from one driver to the next have enough clearance to go to the other side and don't even set with the springs on the other side.

Here's some pics so you can get the idea of the gap I'm talking about:




Please help!!!

 

Check the side gears that you removed from the carrier. There are shims with them that need to be used with the PowerTrax. They may be stuck to the side gear via the lube.

If you used those shims then need to get some more to set the proper gap.

Oh, and once you start driving the car be prepared for folks to come up to you and tell you there is something wrong with it. It will click like crazy when pulling into a packing spot. I even had folks coming up to the car and start shaking the rear tires while telling me something was loose.

The look on their face was priceless when I just said, "no, it has a locker in it", and walked away.

RBob.

 

^ hahaha I'm prepared for all the random noises! Lol

Yeah, I used the thrust washers from both the side gears but it appears to not be enough. Do you know where I can buy these shims??? I've already looked on napa's website and rockauto, but haven't found anything :/

 

I'm not sure where to get them. Try places such as drive train specialties (DTS) and such. I recall getting them for 12 bolt clutch type posi units. Used them to shim up the clutch packs as they wore or were replaced.

RBob.

 

is this a 28 spline axle or 26? because the 26 spline axles have 2 different part numbers.

You may be able to use carrier bearing shims between the powertrax and the case if all else fails to make up the difference. I did that years ago to fit a 7.5" powertrax into a 7.625 axle, that was 26 spline though

 

Damn I guarantee that's my problem, it's a 26 spline axle with a 7.625 ring. Only thought I saw one part number on summit's site. Glad it's an easy fix tho!!

 

You need to get the correct kit for the differential that you are using. Shims are not designed to be used as thrust washers and they may wad or wear quickly. You also may run into porblems with the c clips.

 

But are not the thrust washers in a stock differential a shim? They are used to set the backlash between the spider gears and side gears.

RBob.

 

therobot, give PowerTrax a call and see what they say. IIRC, they state to do that in the instructions if there is too much of a gap.

RBob.

 

No, thrust washers are heat treated to resist wear. They are not in there to take up space, they are in there to keep the axle gears from wearing out the differential case. They are more of a bearing than anyuthing else.


If Summit will not exchange this for the correct kit you can contact Power Trax and see if they will exchange the couplers for the correct ones. The drivers are probably the same for both kits with the couplers being a different thickness.

 

I understand what you are saying with thrust washers versus shims. Some of this is terminology, thrust washer versus shim and what it actually is.

I would have thought that the thrust washers for an open carrier were available in different thicknesses. As this is what sets the spider gear to side gear backlash. When setting the backlash I refer to it as shimming. Although, it is done using different thickness thrust washers. Not a stack of 'shims.'

Anyway, with a clutch type posi, there are different thickness thrust washers available.

RBob.

 

Yea mine makes some noises but not to bad. Sometimes it makes a big clunk but for the most part it is fairly quiet after you get use to driving it. It also seems to get a little quieter as it gets older.

I also hear an auto is quieter.

 

The standard differentials all get the same .030 thrust washers. They don't set backlash in them. The machining tolerances are tight enough that they just use the same thickness thrust washers in all of them. The Auburn cone type limited slip differentials don't get shims in them either. As they wear the backlash becomes greater until they stop working. The Eaton Posi and Traction Lock use clutch plates, which do get shimmed. This is to set the preload on the clutches, not the backlash on the gears. The shims in these units don't see any friction because they are placed between the clutch pack and the case where there is no movement.

 

Yes sir when I installed mine I thought it was to tight so I called powertrac and they where very helpful. All I had to do was pull each tire out a little.

 

You know, it seems that we can argue forever. As you post info that is the opposite of your previous posts. Which doesn't mesh with your current posts.

I never mentioned Auburn type posi, as they are not the same as a clutch type posi that I referred too. So why do you mention it?

Dang, so "shims" are used. However, I never mentioned "shimming" the carrier bearings, only mentioned "shimming" the clutch packs. Which is exactly what you just stated.

See, I stated that the side gear "shims" are to set the spider gear to side gear backlash. Which is how the clutch pack pre-load is set. Not how the ring & pinon is set up.

Why is it you not only try to prove me wrong, but at the same time prove me correct.

RBob.

 

Not trying to prove you wrong about anything. I was just trying to tie up loose ends. Shims are used in clutch type differentials, but not in standard differentials. I may have misunderstood what you were saying. I mentioned the Auburn because that is what was used in the 3rd gen, not clutch type. That wasn't meant to correct you, it was for anyone else that might read this and think that they could shim an Auburn. I'm not on your case, just trying to clear up a few things for anyone who doesn't know. If you look closer at what I posted you will see that I didn't post anything that was opposite of anything that I had already posted. I also never mentioned shimming bearings or the ring and pinion. I think you misunderstood what I was saying.

 

I got it. But I've had my hands on every single one of the diffs mentioned thus far in this thread. We need to clarify that some diffs have shims inside the differential carrier assembly, but all use shims between the carrier bearings and the case. Very different shims. Internal shims may turn or be worn-against, but carrier shims just sit there, static.

 

Truthfully man, i would toss that locker across a field and get an Eaton. I had the same locker in my car for about 6 years and I couldn't stand the damn thing. The popping and noises just drove me crazy, I trully felt like I couldn't push the car as hard as I wanted to ( i like going in the twisties, not just a straight line). When I finally took it out of the car one of the springs fell out and got smashed through the gears a few times. Luckily it didn't damage anything. I'm loving my Eaton. I really feel like I can put the power down without breaking anything.

 

Robert, not to disagree with you, but lockers are extremely tq sensitive. A little too much throttle at the wrong time in the turn and that open diff will lock right up. IMO, an Eaton clutch posi slips too much. So to me the happy middle ground is the TruTrac/TORSEN style diffs.

 

True, I've heard very good things about the trutrac and I was going to get one but the deal I got on my Eaton I couldn't pass up. I love mine, I haven't had any slippage issues with mine and the good thing is is that it's rebuildable when the time comes.

 

The locker in mine works great of coarse I like to drive straight a lot.