View Full Version : 8.8 clutch pack wore out?

04-01-2006, 05:50 PM
I have been hearing a clank every time I take off in a turn. I think it my be the diff. I had one side of the car jacked up and and I could rotate one wheel while the other was on the ground(kinda easy). I think it may be time to put new clutch pac in. I done a new clutch pac about 4 yrs ago, but I think they are shot again.

When you rebuild it cant you add a clutch to each side and get a F-150 S-spring to make the clutches tighter?

Kerry M.

04-01-2006, 10:01 PM
Here's some great tips from MFE at CC.com. 4 years isn't bad if you drive hard. I think most people don't even know when the disc go bad.

It helps if you have a good manual but the instructions that come with
the kit are pretty good. The part number is F5AZ-4947-BA and itís generally around $70 or so at Ford dealers. You may be able to find it cheaper on the net. Get about 3 quarts of 80w-90 gear oil. If you use synthetic you probably shouldn't use much friction modifier. If you want absolute max trak-lok action and are willing to put up
with some unsettling noises from the rear end, don't use any modifier at all. It just makes the clutches more slippery so they don't chatter. I chose to use half a bottle the last couple times and I'm glad I did since this is my daily driver, autocrossed and dragraced for fun. Anyway, here goes.

1) Jack up the rear end and support with stands.
2) Loosen the diff cover bolts, removing all but the top two so you don't take a gear-oil bath
3) Pry the cover loose and drain the rear into a pan.
4) When threat of bathing is gone remove the top bolts and pull the cover off
5) Scrape/wipe out the bottom of the diff.
6) Now is a good time to soak the new clutch discs in friction modifier, the need to soak for 20 minutes at least. If not friction
modifier, at least gear oil -- you don't want to put them in dry
7) The shaft going through the center of the diff is called the pinion shaft. It's got a lockbolt on one end. Undo the lockbolt and push the shaft out. Youíll only want to push it in a little bit so you can still rotate the assembly and pull it out toward you. There isnít enough clearance to push it all the way through or to turn the assembly if youíve tried.
8) Remove the wheels and brake drums, leave the other brake hardware alone. Push the axles inward, and you'll see the c-clips that hold them in place. Remove the clips and pull the axles out gently -- don't torque the bearings on the way out and don't let the axles hang, just remove them.
9) Get a grip on the s-spring and pull it out. You may need to punch it with a hammer to get it started, and keep a damn good grip on it when you remove it you don't want it zinging around.
10) The gears you see are the pinion gears and the side gears, called spider gears. Rotate things until the spider gears pop out, then pull the pinion gears out too. Inspect for damage.
11) Now you can simply slide the clutch packs out, use the tabs on the plates if necessary. Make sure you get them all out including the shims.
12) Reinstall the clutches and steels in the proper order, using a shim at least as thick as the ones you removed. You want to use the thickest shim you can while still being able to get the spider gears back in. Forget about using the set-up tool and all the special measurements, if you can get the spider gears back in you're all set. Note: Each clutch pack is made up of a series of Frictions and Steels and in the factory order they go F-S-S-F-S-S-F. However, if you re-use the best two of your old Frictions in place of one of the new Steels you can re-stack them in an order that makes the diff lock better, which is F-S-F-S-F-S-F, which is the same number of total elements. You may have to trial assemble it a couple times to get the right shim so it's just loose enough to get back together, barely.
13) To get the gears in, it helps to have a helper turn the now-temporarily-installed driver's side axle while you lock the passenger-side pinion gear in place. The spider gears will squeze into place. They are perfectly aligned when you can get the pinion shaft back in.
14) Re-install the s-spring. Or donít. Itís only there to help in really really low-traction situations. Leaving it out will not hurt the locking power of the unit under normal conditions. Getting it in, if you choose, can be a *****. Try holding it against its slot with a pair of channel-locks to get it squeezed down a bit while prying it in with a piece of 2X4 using the swaybar as a fulcrum. Alternately, do the same but whack it with a mallet. It should pop in. If it doesn't, try using a 1-1/2 inch hose clamp to squeeze the spring so you can insert it. Then cut the clamp and slide it out.
15) Re-install the axles by pushing them all the way in, installing the c-clips, and pulling the axles back out against the clips which are now recessed in the housing and locked in place.
16) Reinstall the pinion shaft and make damn sure you put it in the right way so the new lockbolt can be installed. And do not use the old lockbolt.
17) Use gasket maker on the diff housing and reinstall the cover.
18) efi85gt posted a terrific tip for filling the diff. Forget the fill plug. Let the rear end drop as low as you can and remove the little vent cap on the top of the right side axle tube. Clean the area around it carefully and youíll be able to fill it through this hole with a fraction of the stinky mess you get when you use the ďfill holeĒ. Looks like this: http://www.corral.net/photopost/dat...baer024-med.jpg

But you should still remove the fill hole bolt so you know when to stop filling, which is as soon as it starts to come out that hole. Wipe the tip of the bolt off, it's magnetic and the silvery paste is metal shavings.
19) Fill the housing until it comes out the fill hole and replace the plug.

04-02-2006, 12:52 PM
If the spider gear pin is worn out can you buy a new one some where?

Thanks Kerry