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Front Axle U-Joint Replacement on Dana 44 Axles
Contributed By: Jay Quartuch
I had the fun task of replacing U-joints on my front Dana 44 axle when I purchased my beater Jeep J-10 pickup. I was lucky that the failed joints lost only the needles and the previous owner unlocked the front hubs to keep wear to a minimum. Since the Hubs and brakes are covered in a different section I'll outline the procedure to R&R from front hub removal. Whether drum like mine or disc equipped, the front procedure starts at the bare spindles.
Once the wheel flange is removed complete with the front bearings, you will be looking at the spindle assemblies. There are 6 nuts retaining the front spindles and backing plates/dust shields to the steering knuckles, these nuts are 9/16 and a 6-point socket with extension takes them loose nicely. Once the nuts are removed pull the backing plate/splash shield off and then secure a large hammer and a block of hardwood. Hold the hardwood against the spindle at the outer bearing threads and strike with the large hammer, this will need to be done several times working around the spindle to help break the rust bond loose between spindle, knuckle, and the studs in the general area. Healthy doses of penetrant will aid in spindle removal. DO NOT strike the spindle directly with the large hammer as this will damage it around the threads or bearing surfaces! The idea is to slowly work it loose with no damage, strike all around the spindle in the direction the wheel sits to get it loose. When it does come loose, remove it and place in a shallow bowl of muriatic acid, this will eat the rust off so it can be greased lightly to prevent future rust buildup. Muriatic acid can be purchased at hardware stores or pool supply stores, it's commonly used to clean concrete. Wear gloves and eye protection around the acid, and keep a lid on it or work in an area with fresh air, the fumes from it are quite nasty.
Once the spindles are de-rusted, rinse with fresh water and blow dry with compressed air. You'll notice a small needle bearing in the inboard end of the spindle, this should get a coat of wheel bearing grease worked into it or replaced if pitted or broken/missing. Now comes the fun part.
Grab the end of the stub axle shaft protruding from the knuckle and pull it straight out of the knuckle. Slight tapping may be needed to help the U-joint yokes out of the knuckle hole, a small hammer may be used but go easy on the yokes. Once the axle shaft is out soak the yoke area in the acid bath, this does a great job of removing rust from the bearing cups and yokes and makes removal/replacement much easier. Turn as necessary until all rust is gone and it looks new, then rinse with water and blow dry. 4 external snap ring clips hold the cups in the yokes, remove these and press/drive the cups out of the yokes to remove the old U-joint. At this point I give the yokes a good look-see for damage and even another acid bath to remove all rust traces. Also check the axle shafts and stub shafts for bends, twisting in the splines, spline damage, etc. Replace any bent or broken pieces.
To install the new joint, start by removing the cups and needle bearings complete from the cross. Insert the cross into the longer shaft and then put a fingertip-sized blob of grease CAREFULLY into one cup and assemble through the yoke and onto the cross. Push this one through the yoke almost all the way and be careful not to unseat the needles in it, then put on it's snapring. Another fingertip of grease in the other cup and hold the joint so the cross is halfway in the first cup and CAREFULLY guide the second cup onto the cross and into the yoke. Use a C-clamp to compress the cups together enough to squeeze excess grease out around the cup seals and bottom both cups on the cross, tap the yoke as needed to install the second snapring, if it does'nt fit check for displaced needles sitting in the bottom of the cups, the second snapring groove should show completely if they are right.
The other yoke assembles the same way onto the U-joint as the first one did, it may be difficult with the C-clamp and juggling it all together with extra grease coming out, but this ensures the joint is greased well, as the factory grease may be for assembly and packaging use only. Remember these joints have no grease fitting and this is the only way to ensure they are lubed right for long life, they should be re-lubricated this way after any major water immersion as well. Once the axle shaft is back together I like to use a squirt of brake cleaner around the joint to remove excess grease and then paint the joint and yokes with a spraybomb of Krylon to keep the rust from coming back. A thin coat works best, this also helps to spot cracks or whether a snapring may be coming loose. Replace the housing's outer oil seal at this time to help keep your axle lube inside where it belongs and prevent dirt and water from getting in. These should be replaced every time the axle shafts come out. Also clean all rust off the spindle mounting area at this time, also get the inside where the axle yokes pass through. Lightly grease the inner splines and slide the axle shaft back into the housing, try to jiggle the inner splines upwards to engage the spider gears in the diff, a slight turning motion helps get them lined up.
Once the axle shafts are back in place, take your cleaned spindles and coat the entire flange area with a thin coat of grease or anti-sieze to keep them from re-rusting to the knuckles, which should also get a thin coating of grease or anti-sieze. Slip the spindle onto the axle stub shaft and align the keyway to be as close to vertical as possible, this helps in installing the wheel bearing lock washers. Press onto the studs until it bottoms against the knuckle, then re-install the backing plate/splash shield and finally the 6 9/16 stud nuts, these should be held with a bit of Loctite blue and tightened firmly.
That's all there is to it!
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