Rear diff... Help!!!!
7th Gear
Joined: Mar 2010
Posts: 7
Likes: 0
From: Reno NV
The diffs are pretty tough, but your done. If you have been driving it like that, remove the diff and fix it right or you will be buying a new R&P and paying someone like me to build a diff for you. I don't even know what you have is worth fixing now, but you can try. You will need a new crush sleeve and you will have to remove the diff from the car. Once you have the new crush sleeve in place, you can start tightening the nut with your impact until you feel a very small amount of play. Once you have done this then you just want to bump the impact and check the torque with a ROLLING TORQUE wrench. You need to tighten the nut until you have 15in/lbs of rolling torque. Once you get this, stake the nut and you are done, reinstall the diff. Don't forget install the oil seal, and pack the back of the seal with grease.
Justin
Justin
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
I am not angry, but you did quote me and say I was wrong, and told me to look at the diagram. I have a bunch of experience with these things and I know what they look like. I agree that it should be checked and adjusted as soon as possible, but at the same time, just hitting it with an air wrench for a few seconds is not going to crush the sleeve that much. It may tighten up too much on the bearing, and it may make the bearing unserviceable, but the described noise is not a symptom of a tight bearing or a forward pinion. A loose pinion will pull on the drive side with absolutely no noise assuming that the shim is correct in the first place, but will howl like a stuck hog on the coast side. That is the symptom that was described.
More then likely that is a damaged pinion from his drive with it loose. Can it be tightened and go down the road, sure it can, is that the right thing to do, NO. It could only possibly cause further damage resulting in the complete loss of the core itself vs. just fixing it the right way now. I understand the gentleman does not want to spend allot of money on this, however you have to look at the bigger picture, you could save yourself the cost of a rebuilt one which from us would be $599 or he can just hope he fixes it the right way now, if not he could cost him $1249 because he cracked the carrier when the pinon made contact with it, which is usually what breaks them. So it depends on what your definition of saving money is. He can save $650 right now and just have it fixed properly or he can risk it and get 100 miles down the road and spend $1249.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
Do yourself a favor and don't have him fix it. bump the impact? I remember my first diff rebuild. lmao The torque wrench he's referring to is a dial type. the turning torque (amount of torque required to turn it) should be ten to fifteen inch-pounds. You do need to remove the housing and the carrier but it's not so bad. When you install the new crush sleeve, crush it until it takes ten to fifteen inch pounds of torque to turn the pinion, then reassemble the diff putting the shims back where they came from. check that your backlash is between five and ten thousandths of an inch, torque on the cap bolts is fifly-five foot-lbs, rear cover is the same. I use Loctite on everything. hope this helps.
themetalman03886 make sure you check the grease at least evey 1000 miles for any particles. if you get through 2 or 3 of these and it seems to fairly clean fluid then let her rip. Like I said in my first post these are tough diffs, but the they will not hold up to a loose pinion making contact with the carrier. If it is possible pull the rear cove and inspect the carrier, if it made contact you will see some nice contact patterns on it. Check the access holes of the carrier for cracks at the center line, you will need to clean it with some brakleen. The carrier is cast with two molds and where the molds cometogether in the center is where they tend to crack if anything hits them. If it looks good then you are probably good to go until you are ready for a gear swap or just plain wear it out.
Justin
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Actually you quoted me saying I was wrong. I have rebuilt a couple of hundred of these myself.
More then likely that is a damaged pinion from his drive with it loose. Can it be tightened and go down the road, sure it can, is that the right thing to do, NO. It could only possibly cause further damage resulting in the complete loss of the core itself vs. just fixing it the right way now. I understand the gentleman does not want to spend allot of money on this, however you have to look at the bigger picture, you could save yourself the cost of a rebuilt one which from us would be $599 or he can just hope he fixes it the right way now, if not he could cost him $1249 because he cracked the carrier when the pinon made contact with it, which is usually what breaks them. So it depends on what your definition of saving money is. He can save $650 right now and just have it fixed properly or he can risk it and get 100 miles down the road and spend $1249.
More then likely that is a damaged pinion from his drive with it loose. Can it be tightened and go down the road, sure it can, is that the right thing to do, NO. It could only possibly cause further damage resulting in the complete loss of the core itself vs. just fixing it the right way now. I understand the gentleman does not want to spend allot of money on this, however you have to look at the bigger picture, you could save yourself the cost of a rebuilt one which from us would be $599 or he can just hope he fixes it the right way now, if not he could cost him $1249 because he cracked the carrier when the pinon made contact with it, which is usually what breaks them. So it depends on what your definition of saving money is. He can save $650 right now and just have it fixed properly or he can risk it and get 100 miles down the road and spend $1249.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
Not being fatalistic, I did say that the diff can take a ton of abuse. I have seen many of the carriers with pinion contact patterns in them that were ok, but I have seen more that had cracks develop from them. I am pointing out what he needs to look for, and I also explained what he had to do to fix it. My advice was to fix it now and not risk spend twice the amount later, my recommendation just as yours was to run it now. Neither is wrong, but I am not being fatalistic by being realistic.
Wayne is doing well, he restores military Hummvee's they way he used to do Corvette's.
Wayne is doing well, he restores military Hummvee's they way he used to do Corvette's.
