T-Lok clutch packs bad

Turn in tight circles

What follows is IMO. Not my intent to offend. Just frank speaking.

From previous posts I gather this is a salvage yard rear end and a new install on your vehicle. Fresh oil and friction modifier was installed at that time. It is unreasonable to assume that a new batch of different weight oil and friction modifier will fix your problem.

More than likely, the T-LOK clutches are rusted/ruined from a long time of setting unused in the salvage yard. It is quite possible that the axle was stored in an odd orientation. Or just as likely, the clutch packs were partially submerged in gear oil. Some rain likely entered as well. This resulted rust/drying out on the parts not in the oil.

Before replacing the T-LOK clutches, try this. Go to a parking lot and turn slowly in tight circles. Do this both directions. The intent is to hyper exercise the T-LOK clutches in an effort to free them up and distribute the lubricant throughout.

I am afraid this is the down side of a salvage yard rear end. Where ever possible, rebuilding should be considered before replacing. Rebuilding will make it just as good as new without the risk associated with a salvage yard unit. The costs are about the same.

I am unsure the effects of continued operation. One would expect extra debris would end up in the gear oil. I could see some bad things if the clutch packs wore down enough to separate inside the carrier. However, if you want my best guess, it is OK to drive as long as it is not abused. Continue to monitor and be alert for changes.

Good luck.

I would not drive it if the rear-end is vibrating. Obviously something is NOT right and it needs to be fixed. Get it fixed before you are stranded somewhere, (tow jobs are not cheap).

a 00 rear is obviously almost 10 years old. A very good chance that the clutch paks are bad... BUT they will not likely be where your vibration is coming from. Odds are that one of the outer wheel bearings will be whats causing the vibration.

Replace both outer wheel bearings (cheap to do, under 30 bucks) and put in a new clutch pak. Your rear will be fixed for under 100 bucks and good to go for another 100k of abuse!

Did you add friction modifier? Plain gear oil could make the clutches chatter.

merc123 said:

I've got my other rear end that's broken so I'm going to practice on that with removing the clutches and installing them back in. That way I don't jack it up myself.

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That sounds like a great plan

I am currently rebuilding the rear end in my 2000 so I can offer some real world advise. I removed the entire rear end from the car. This gives full access without having to work underneath the car on axle stands. There are only a few more bolts to remove above what already has to be done. Of course this assumes that a lift is not available.

Removing the axle has made the project go so much easier. Measuring pinion pre-load, Installing/removing the pinion flange, and so forth is much easier out from under the car.

Are you planning on rebuilding the complete rear end? New gears? New bearings? New T-LOK?

In any case, here is a link to a good how to:

How to rebuild your 8.8 rear end - Ford Mustang Forums

I am using an inexpensive Harbor Freight dial micrometer and mag base. Works well enough for the home user. A 1/4" beam style torque wrench to measure pinion pre-load did the trick. Having the official Ford tool to hold the flange does help. Remember to put RTV silcone between the pinion nut and flange.

I went to a local machine shop to press off/on the pinion bearing and carrier bearings. Doing the reset of the work myself. Should have it done by 11-15.

Good luck.

I do not understand how you can use a beam torque wrench to measure rotational torque?

how to set pinion pre-load Ford 8.8

Kilgore Trout said:

I do not understand how you can use a beam torque wrench to measure rotational torque?

Click to expand...

The pinion nut is not itself torqued to a specification. Instead, it is tightened until there is a slight "pre-load" on the pinion bearings. The crush sleeve provides the tension to keep everything in place. The rotational resistance within the bearings offers a way to measure the pre-load.

The specification is 16-29 inch pounds for new bearings and 8-14 inch pounds for used bearings.

Basically place a socket on the pinion nut. In all likelihood the socket will be a half inch drive. Get two converters to step down to ¼” drive. Get a beam style torque wrench such as the following:

KD Tools 2955 1/4" Dr Fixed Beam-Type Torque Wrench 0 to 60 In/Lb KDT2955

Use the torque wrench to rotate the pinion in the normal direction of travel (clock wise) and watch the torque required to maintain rotation. Do not use the initial break away value. This is the pre-load.

Tighten the pinion nut until the pre-load is within specification. Be warned. When it is close, it does not take much turning to raise the pre-load. Do not back off of the pinion nut to reduce pre-load. The factory crush sleeve is a one use device. Get a new one. Even from Ford they are not expensive.

If the pre-load is too high, it will wear out the pinion bearings prematurely. If the pre-load is too low, the rear-end will make noise. It will also wear the contact surfaces of the ring/pinion gears as well as shot pen the bearing surfaces from the constant in/out every time the driveline goes from power to coast.

Therefore, if the pinion can be moved in and out by hand, there is NO pre-load. Note, the pre-load should be measured with the brakes removed.

I found it very difficult to measure pre-load while the axle was on the car (no service lift). At best, only 180 degrees of rotation is possible. This is where having the rear end off of the car helps. It is very easy to spin the pinion around several turns and get a good reading from the torque wrench.

I was also suprised to experience what 20 inch pounds feels like. With new bearings, the pinion feels harder to turn by hand than I would have expected. I would have gotten wrong without a torque wrench. I suspect, it will feel more normal after the bearings wear in a little.

If your intent is to re-use a crush sleeve (such as replacing only the pinion seal), the pinion pre-load needs to be measured before tear down. Reset the pre-load to the recorded value or GREATER (within the spec).

My first attempt to do this job did not go so well. I couldn't get a good reading working under the car. I don't believe I got the pre-load correct. A few months later, the rear-end started making noise. During a 2nd tear down, I could not find what was wrong. Ended up taking to a pro for rebuild. I am hoping to have better results on this attempt (different car).

I have not tried to rebuild the T-LOK clutches.