my 84 c4 ring an pinion is out...ive got a complete rotor to rotor diff. is it easier to change punkin an bat wing or complete diff??? thanks for any advise

 

Just do the batwing and dif. If you do the whole thing you have more work. Including shocks and brake bleeding.

 

Unless you purchased another 3.07 differential you'll need to do some changes in the speedo drive/driven gears. You might as well sort that before hand and do it all at one time. Also if you purchased an '88+ then the hardware that attaches the camber brackets to the differential are 12mm so you will need to use either the bracket and hardware or drill your brackets for the 12mm hardware.

If you have purchased an '88+ you could mistakenly use your brackets and 10mm hardware assuming you were fine but you would actually create a very bad situation. I believe this is done more frequently than one would think.

 

mine is 84 an the diff I have is out of an 85 so should be r & r

 

You may need to do some speedo gear changes unless the one from the '85 is a 3.07 ratio also. All '84 were 3.07 with just a couple hundred exceptions. It's very doubtful that you have one of those.

Change only the differential with cover still attached, everything else unless you find other problems would be a waste.

Rotate one of the axle yokes one complete rotation and count the rotations of the pinion yoke. It will be either 3+ very little or something closer to 2 3/4 turns. You could look on the bottom for some information etched into the housing but it's not there on all of them. Some yes so it's worth looking.

 

I recently removed the whole diff assembly, Been waiting for my new transmission so have been looking for things to do.

Removing the whole diff assembly is very easy as long as you have a good trolley jack, tools mechanic's gloves and overalls.

First remove spare tire and tire support.

You do not even have to bleed the brakes!! I unbolted the caliper bracket and hung the calipers up out the way with wire to keep tension of the hoses. That way you do not have to bleed the brakes.

unbolt the sway bar from the link to the knuckle.

Remove the shock's from knuckle's, no need to remove from car they swing out the way and unclip the handbrake cables.

Unbolt the "spindle" (dog bones) control rods at the bracket that attaches them to the car two bolts each side, then you can remove the two batwing bolts that hold the diff assembly to the car.

Then slowly lower the whole assembly, keep an eye out for anything you may have forgotten to unbolt. Then put the other diff assembly in the car. I recommend you check the half shaft universal joints, pull a cap off and check for any wear they get badly worn very quickly.
While the diff is out the car it is easy.

I had a slight oil leak from my diff, i decided to remove the whole rear end and took it to a car wash. The high pressure spray really works great leaving the whole diff assembly spotless, any dirt would ruin the diff if it got inside when i opened it up.

To re install, jack the diff assembly up and put the bolts in to secure the batwing to the car. Then fit the sway bar link, brake calipers and handbrake cables.

You will need a crow bar to "massage" the dog bones into position and fit the bolts, now you can refit the shock absorbers to the knuckle. you will need to jack the lower control arm on each side to raise the suspension to fit the sway bar.

I did it all by myself, no help needed.
The only hard part was lifting the whole diff assembly into the trailer to pressure clean it, but boy it was worth it getting the years of grime off. The diff and batwing etc are spotless now

No more oil leaks after i fitted a new gasket between diff and batwing, i even found the 2 year old universal joints worn so replaced them as well. Also replaced the old worn dog bone bushes with polyurethane ones.

The rear end is in tip top shape now, and looks great.