Differential Spider Inspection

A

A-Man

Senior Member
Other than the obvious, i.e., broken, worn &/or pitted teeth, how does one determine whether the three(3) pinion spider gears need to be replaced? I read that excessive end play of the axles in the carrier assemby can be caused by worn spider gears. On that note, I am seriously considering replacing the spider gears. I have the rear end torn down to replace the pinion and ring gear. Two(2) teeth knocked out of the pinion.

Also, I observed that there are some nicks and grooves on some of the differential spider shafts. How crutial is this? Appears that there is no reproduction differential spider units available. How much play should there be when a new spider gear is placed on the shaft? Does one need to consider having the shafts built up and milled down? Is that feasible?

Thanks.
 
If the faces of the gear teeth are smooth and shiny they are very worn.

The NOS teeth and the less worn teeth will have lines running the length of the teeth from the broaching process used to create them. They will not be nice and smooth.

Look at the diff two halves. You can see how far the gears have worn into the housing.

All these factors come down to end play. How much the axle can move in and out along its axis.

It is all pretty low speed stuff and you can get away with worn parts.
How do you plan on driving the car? If you plan on putting around at 45 mph for a couple of hundred miles a year then you can use just about anything.

Keep in mind that the new parts you can buy might not be the best fit. I have not worked with the new stuff. Ask others before you buy.
 
Go to the orange county model a ford club web site, and look for the technical articles. Tom Endy has made his rear end rebuilding information public record. It has helped me rebuild several differentials. You should be able to see excessive wear on the carrier where the axles rub against the spider housing. The spider gear sets are not outlandishly expensive if new ones will give you piece of mind, but the differentials are forgiving.
A rule of thumb is if you rebuild and there is noise, then take it apart and redo it. Bob
 
You must log in or register to reply here.
Back
Top