I was posting this in the tranny section until I figured out it was rear end issue. My son broke his car and through this forum I was able to determine it was a broken pinion shaft(?). When opened the diff cover, it was evident that the pin was broken in two. I assumed it was an 8.2 open rear and ordered the pin through Randy's ring & pinion. The pin arrived today and it is slightly smaller in diameter and length than the broken pin. Does this mean he has an 8.5? How can I be sure? Does anyone have an exploded view of this type of rear end for assembly purposes? Many thanks. Bill
It is a 70 Skylark custom, it is the big straight pin in the housing that hold the two gears. There is a hole in one end, I assume to pin it in place. I don't know exactly what it is called. Make sense?
The part I think you're referring to is the cross pin (sometimes called cross shaft). There's a retaining pin that you unscrew from the carrier that allows you to remove the pin itself. This pic should help but I don't know if the 5/16" callout is correct: For what its worth, these parts usually fail due to long and frequent peg-leg burnouts. :laugh: Devon
Cross pins seldom break. Occasionally they may gall under the spiders & then the spiders can seize to the cross pin, then crosspin will spin, breaking the pin bolt & chewing up the machined holes in the case. Unfortunately, in GM 10 bolts there are all different lengths & diameters of these crosspins, depending on which style carrier & design of 10 bolt the pin was originally in. In parts bins, I have prob a hundred lbs of such cross pins, occasionally will dig hrough the bins looking for an odd sized crossed pin. Pin bolts retain the cross pin. Pin bolts (esp 7.5's & 8.5's) break all the time during disassembly, esp by folks who do not know how to propperly remove them. Use a long wrench & a hammer to jar the seated bolt loose & the head, typcally won't break off. Try & just remove the small headed bolt by hand with just a wrench, & the bolt will often stretch & the head will break off Broken headed pin bolts can be removed with cross pin bolt removal tool kit. Matco makes just such a tool for under $25, or one an do as I do & make their own with correct threaded cap screw, a lathe to center drill, then will need long drill bit, & a small square headed screw extractor. Got Posi :3gears: Roger
Look at the pinion yoke where it connects to the rear U-joint. The 8.2 uses U-bolts and nuts. The 8.5 uses straps and cap screws like in the picture.
Larry - That picture is what he has. It is the cross shaft(pin) that snapped in half. I ordered the 8.5 and a new retaining bolt. I hope nothing else is broken in there that I couldn't see. Thanks for all the help and advice.
Got the replacement pin and it is the same size. However, the retaining bolt pin(?) hole is bigger on the new one. Do I have the wrong replacement again, or is there a simple fix to this. I did check the housing again and the old pin was held in with roll pin, not a bolt. Can I just drill out the housing to accomodate the appropriate sized roll pin?? Also, what weight gear lube should I put back in it?
Can you give me more info on the tool you made to remove the retainer bolt ? They can present major problems especially if you are in a hurry . so I want to make one to have just in case I break a bolt . Thanks in advance
I cannot get the axles out to remove the housing so I can pin in the new cross shaft. I do not see any C clips holding in the axles, is there something I am missing??? Please HELP -
HAAAA! I had this same problem...which is not a problem at all. You have bolt in axles. Pull off your brake drums and look for holes between your lug studs. Look through the holes and you will see 4 nuts to remove. After you remove those you will need an axle puller to get the axles out. I went to Advance Auto Parts and used theirs. It's like a slide hammer. You use it to pull the axles out and tap them back in. You have to pay $129 to rent it but you get it all back when you return it. Good luck!
I took my 72 axels out like this. remove the rear drums, and in between the lugs there are 3 holes, use a deep socket to reach the 4 bolts behind it that keep the axle in just like stated above. I however didnt need an axle puller, never even thought of it. I just pulled them out with a little persuasion. didnt take much. Good luck!!
I didn't rent a tool either. I used a long punch to go from behind the backing plate through the bolt holes and onto the hub itself. A couple of taps rotating though all four bolt holes and they came right out. I posted the same question in here under HELP! and got the answer.
Wow, mine would have never come off that easily. It took about 10-12 thumps from the slide hammer to losen it. Then about 5 or 6 to get them back in. We're you changing to a posi while you have it all out? MARK
