Trak Lok Installation

Hi Guys,

My '95 Sport has a Chrysler 8.25"/27 spline 3.55 with an open diff. (has the tow package, but not an LSD - go figure). I'm thinking of installing a factory Trak Lok unit, but am wondering what's involved regarding the installation. I've never messed with rear ends before, and don't want to get in over my head. Are we talking dial indicators, gear mesh patterns, etc., or is it more or less a bolt in?

Thanks

A Trak-Lok is a full case limited slip differential. To set one up is at least a partial gear setup as you are changing the carrier. I don't think you have to reset the pinion depth. It is definitely NOT a bolt in.

A Trak-Lock has the advantage that you can rebuild it for about $50. If you want a more aggressive limited slip, look at an Auburn (but it is more money.)

Wait a minute....... are you *SURE* it doesn't have a limited slip? Have you opened up the diff cover and made sure? It may just need a dose of friction modifier, or a rebuild kit.

I'm pretty sure it doesn't have a limited-slip. I'm basing that on three things:

1) I got the window sticker from the original owner, and it's not listed as an option.
2) I jacked up the right rear and spun the tire - figured if it had a limited-slip, it would lock up (right?), and it didn't.
3) From what I've read, a limited-slip would have a tag attached to the rear cover bolts identifying it as such (in addition to the gear ratio tag). It didn't have that tag.

I understand what you said about it not being a "bolt-in", but is it a job for the uninitiated (I do most of my own mechanical stuff).

Incidentally, what would be an example of a good, economical, bolt-in unit (if any)?

Thanks

Hmmmmm......

Always thought that tow packages came with the l/s, but I may be wrong. Take the VIN to a dealer, or run a request through the Jeep.com website for a full list of factory equipment.

Your test will fail if the friction modifier was put back in, or if the clutches are just plain worn out.

If the diff cover was taken off, no guarantee that it would be put back on.

I don't know of any bolt-in limited slips. There are a couple of lunchbox lockers that will replace the side and spider gears, but I'm not sure if you want to go the locker route.

No, the tow package does not include limited slip. Up Country does, but not the tow package.

As Jeff noted, the Trac-Lok is a full case unit. Assuming you're not changing gear ratio at the same time, the pinion doesn't get touched. What you have to set up, therefore, is only the carrier bearing preload and the backlash. A dial indicator is ideal because you can check the backlash before removing the old carrier, than just set the new unit to give you the same.

I've never worked on an 8-1/4 diff, but I recall someone writing something about setting the backlash with an adjusting screw -- is this correct? If so, installing a Trac-Lok in an 8-1/4 should be easy.

The 8.25 backlash is set with a pair of adjusters under the bearing caps. It's a bunch easier (so I'm told anyway) than a Dana because you don't have to count shims, and press the bearings on and off to change the thickness. The tool I've seen for turning the adjuster is a long job that goes in the axle tube from the wheel end. I don't know off the top of my head if you can turn the adjusters through the diff cover opening.

You'll still need a good dial indicator and probably gear marking compound.