I have a 97 f-150 4.6L. I have a problem with my rear differintial 8.8 ford. It was clunking loudly when I turn both ways, and did it occasionally stop and go traffic. I took the cover off and the two side by side smaller internal gears were some what chewed up. What would I be looking at, and what other damage could be done. The internal casing looks good no visible damage.

 

Is it a limited slip?

 

I dont know if it is a limited slip. How do I find out.

 

Look at the tag you took off, if there is an "L" where the dot is in the 3.55 in the image then it is limit slip.

 

It said 3L55 so it looks as though it is a limited slip. Thanks. Also I looked in my diff. case and the 4 internal gears are worn and cracked. Are these the spider gears and side bearings.

 

Yes you have a Limited Slip Rear End.
Some people call them spider gears but they are the side gears (axle goes into) and the pinion gears.

Description

The limited slip axle assembly is identical to the conventional rear axle (4001) except for the differential (4026).

The limited slip differential employs two sets of differential clutch packs (4947) to control differential action. The mounting distance of the differential side gear (4236) is controlled by seven plates on each side: four steel, three friction, and one steel rear axle differential clutch shim (4A324). This steel rear axle differential clutch shim is of the selective type to control the position of the differential side gear.

The plates are stacked on the side gear hub and are housed in the differential case (4204). Also located in the differential case, between the differential side gears, is a differential clutch spring (4214), which applies an initial force to the differential clutch pack. Additional clutch capacity is delivered from the thrust loads of the differential side gear. Splined plates are splined to the side gear hubs which, in turn, are splined to the axle shaft (4234). The friction plate ears are keyed to the case so the differential clutch packs are always engaged.

LS Rear End:
http://i54.photobucket.com/albums/g9.../LSrearend.gif

http://i54.photobucket.com/albums/g9...ar%20End/8.jpg

 

you will have to pull the limit slip assembly in the above photo and probably replace the unit. the bevel pinion set gears outside taht might look o.k. and be reusable-- MAYBE. with all that trash going thru the oil, i would guess you will be replacing the bearing on each end of the LS unit, and also the outboard end at the wheel. minor trash has gone thru them and will eventually take its tole. you might be further ahead to replace the entire axle with a jused unit. if you have 4 x 4 you need the same gear ratio as now. you may not need the LS unit if you want to go cheaper.