I developed a leaky butt a few months ago, and without examining the problem very closely, I just popped off the diff cover and put on a new gasket. It became immediately obvious that I still had a leak! I've tried to photograph where the leak is coming from; it's basically where the driveshaft goes into the rear end. Is this something I can get to relatively easily and fix myself? Or am I going to have to remove/rebuild the rear end? Thanks in advance for any help! Ben
It appears to be the pinion seal, never done one but I think when you put it back together you have to get it right. the ring and pinion seat can be messed up if not tightened right.
its a pinion seal , depending on how the axle is built , you can change it yourself , but you have to be carefull when tightening down the pinion nut ( NO IMPACT GUN) , as if there is a crush sleeve you can screw up the bearing preload if you crush it more . IMO I would take it to a shop that specializes in axles and have them do it . as a normal shop might just screw it up thinking you can just zap the nut off replace the seal then Zap the nut back on when the crush sleeve might have to be replaced .
Not all that hard to replace, but DO follow the factory service manual procedure when reinstalling the yoke/nut...
Some say you can mark the pinion nut so that you tighten back to the same spot. Make sure you check the vent.
^^^This is smart.^^^ Spin the yoke by hand to get a feel for it and drag a paint marker up one flat of the pinion nut onto the exposed threads tighten until the yoke feels the same as it id and the lines match up.
As said above you could take a center punch and mark the pinion and nut and then count the threads taking it off,then when you put it back feel out the free play (backlash) you want to feel a very slight drag.If you put it back together and hear a hum on Deceleration you didn't go tight enough (only if there was none before)
Make sure the vent tube is not clogged. When the rear gets warm, it will push oil out when it builds pressure.
You will have no problem if you follow the directions for replacing the pinion seal. Repair manuals will give you the proper torque on the pinion nut. Other than that it is a straight forward repair.
There is usually a rotational torque spec for the pinion nut in assembly. It is usually specified for either new bearings or used bearings in IN-Lbs. The post about leaking along the pinion splines is a real deal possibility; it happened on my buddys 9 in., but it's probably the seal.
It's not that hard to do,I replaced the seal in my Ford 9" recently,,I also use the punch method. HRP
What Stimpy said in #3; It takes some know-how, and experience. You could DIY, but first read thru the shop manual, to get the proceedure down pat. Happy Roddin' 4TTRUK
It is a good idea to Loctite the threads on the pinion and the nut (everything spotlessly clean). Tighten nut to achieve a slight rotational drag on the pinion U-joint yoke (difficult to determine accurately because of carrier bearing drag and/or brake drag). You do NOT WANT THE NUT TO BACK OFF WHILE DRIVING DOWN THE ROAD! I would pop that rear cover off and inspect the axle 'C' clips for wear. With age, they have a tendency to wear out to the point where they fall out and allow the axle shaft to leave the axle housing. A complete rear axle tear-down, inspection and re-build is not a bad idea at all.
You probably will need a impact wrench. I have done a few of these and its not as big a deal as you would think. I couldn't have done them without the impact wrench.
I have had this happen more than once. Muddobbers, bad vent hose, one even had the vent hose fitting replaced with a bolt to hold the brake line tee in place. Part of my regular maintenance program to check this out.
Maybe I missed it; but I don't think anyone mentioned that you should check the seal area on the yoke and install a speedy sleeve if it has a too deep a groove worn into it. Not fun to repeat the repair in the near future if the new seal is cut by the wear groove.
Some are more difficult to do than others. My 10-bolt in my beater I've just let leak because the last time I changed one, I ended up having to buy another yoke for it - twisted off bolts on the existing one. Plus I'd have to get it on a 4-post lift to change it. Bottom line, look up the procedure in a factory service manual and go from there. But if the leak's not bad, you may be able to get away with just topping it off every six months until either it gets worse or you get tired of the truck marking it's territory everywhere.
I work at a parts counter at a Ford dealer. I love it when a customer asks if he can fix it himself, like I know what his mechanical skills are.
That rear end uses a crush sleeve to set the pinion bearing preload. Replacing the seal without putting a new crush sleeve in and thus, setting the pinion preload, is risky but can be done. You will NEVER be sure you have set the proper bearing preload( which directly effects bearing longevity and oiling) without using a new crush sleeve. Unfortunately, to do it right you need to completely disassemble the third member which is why people generally opt to "fudge it" and mark the threads. Doing the latter can produce acceptable results but, think of it this way, by taking the time to disassemble it and do it right, you set yourself up for another 100,000 miles(or more) of knowing its right and everything else in there is right too. Your call.
The only concern with marking the pinion and nut is if the nut has backed off than putting it back in the same position would leave it loose and not to spec. Or if the pinion bearings have play. If you have access to an inch pound torque wrench, remove the brake drums and measure the rotating torque of the whole rear end assembly while turning the pinion nut clockwise. Than just as simple setting it back to that. Usually most used pinion bearings have a spec of 6-15 in lbs and adding in the carrier preload should add another 10 in lbs or so of rotating torque to that to give you some kind of idea on how much torque it should be.