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Post Mortem: Jeep axle u-joints

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  • Post Mortem: Jeep axle u-joints

    I've just replaced the u-joints on the front axles of my '97 Jeep Grand Cherokee. There was nothing particularly difficult about it except my physical condition which makes working under the car difficult and painful, but the factory makes a big issue of replacing the entire axle assembly rather than doing the rather simple repair. The u-joints are not very different from drive shaft joints - not CV, in other words, and the operation is one I've done dozens of times on drive lines in my life.

    And wow, what a difference. We've had a very wet year and those bearings take a beating at the best of times. On both axles neither bearing had any grease left, and the rollers were broken or turned to dust. Oddly they began getting noisy while turning just a few weeks ago but weather, still being very wet, prevented my doing the work.

    I chose to do the work because the dealer wouldn't replace just the bearings, and I didn't want to replace the shafts. Either way the labor is only slightly different and the effort is approximately the same, and very expensive to boot, so I saved a lot of money in the deal and got what I wanted.

    One concern was balance after the new parts were in place, but I marked the two pieces and put them back the way they were just the same as I do drive shafts. There is no vibration at all.

    This seems to be a common operation for off-road Jeep owners who even do it while still off road if something breaks. My question to the group is, has anyone done this or seen it done or heard of it being done and where there were complications as a result of not replacing the axles? I just can't imagine something this simple being a big deal for the dealers, but we are a very litigious society.

  • #2
    I used to do all of them at the Chevy dealer I worked at...And then when I took the fleet job at the County, I got Jeeps to mess with...constantly.

    I seriously doubt if the factory recommended replacing the whole front axle just because the U-joints were bad. The Service Adviser was telling you that because all of his "gomers" in the service department didn't know how to perform the simple replacement of the hub U-joints. I'm afraid it's coming to that. All of the experienced guys are leaving the trade, mainly because of the pay, and the shoddy politics that go on in the shop. Managers actually prefer to drive off experienced people, so they don't have to pay them. Unfortunately, (for you) the turd burglars that they keep couldn't make a sandwich even if the directions were printed on the loaf of bread.
    Trade School graduates will work for a whole lot less than an experienced mechanic....It's all about money, dp. They could care less if you were dumb enough to buy a whole front axle assembly, instead of a couple of U-joints.

    As far as balance is concerned, as long as you put everything back together like it was, with new joints, balance isn't going to be an issue. Whenever I did front joints on a 4 X 4, I used to make a punch mark on corresponding parts so I could get them back together properly....not a big deal.
    No good deed goes unpunished.

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    • #3
      Dennis I've just done the same job on a nieghbor's 5.2 L 93 Grand Cherokee lately. I'm somewhat surprised that yours were non-cv type joints as from all that I've seen listed they were all cv jointed at the spindle end.

      Simple job as you noted, other than trying to get a 12 point socket to fit the three 12 bolts for the hub/bearing mounts after almost 20 years of salt exposure.

      Although in my case even though the CV joint is serviceable, the entire shaft/CV joint was available for approx. $75 so I decided to go that route. Only becuase it's more cost effective in that case.

      However if a simple U-joint were in need of replacement I certainly would not hesitate to do only that. The axle shaft itself unless badly abused will not need replacement. The only thing that wears is the U-joint. The only exception, and this is rare, is a grooved shaft due to the axle housing oil seal. And like i said this is rare...and serviceable. U-joints are cheap and simple to replace.
      No need to mark the the pieces for a single U-joint. If there are multiple U-joints on a driveshaft or axle with a splined slip yoke, and the yoke is without a master spline, then the U-joint will have to be brought into phase to preclude any vibrations.
      Home, down in the valley behind the Red Angus
      Bad Decisions Make Good Stories​

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      • #4
        Originally posted by saltmine
        It's all about money, dp. They could care less if you were dumb enough to buy a whole front axle assembly, instead of a couple of U-joints.
        I worked at several dealers from 1965 to 1971 when I was going to school doing everything over time from the lube rack to transmission overhaul, to tune-up and AC. And lots of electrical as that seemed to confuse a lot of people and I was working towards being an electronics engineer. Not much has changed since then. It was a real eye opener when I became a service writer in 71 - lots of crooked rules we were to play by to get service sales. I didn't last long in that role because I wouldn't steal, but it was time to get out of the business anyway.

        The tear-down was quick enough - I did have to go buy a socket for the axle nut but still have all my tools from when I was a wrench. What I don't have is a clean bench with a vise handy, so I used an anvil and two-socket method with a BFH to disassemble, and my arbor press to put the bits back together.

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        • #5
          Jeep U-Joints

          Prevent future headaches by using a really good grease designed for truck or auto suspensions. They provide better water washing characteristics than run of the mill greases. The driver side suspensions and drive parts suffer more water washing from the curb side wheel splashing water to the drivers' side. Doesn't apply if you're in a nice warm arid state ;-)

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          • #6
            I've driven Jeep Cherokees for many years, as have a couple of my kids also, many hundreds of thousands of miles. I've replaced plenty of front axle u-joints and never had any problem at all with balance or other issues except for the reduced life span of cheap joints.

            I don't recall any factory recommendation about replacing the whole axle. It certainly is not the case with Cherokees, for which the factory service manuals specify how to change the joints. Someone might have misread the text, which notes that "single cardan universal joints are not serviceable," to mean the whole axle, instead of the joint. I suppose it's possible that the dealers themselves will try to sell you a whole axle, and with labor costs so high it may be a wash, but it's more likely dealerese for "we're behind on our boat payments."

            If you followed the instructions properly you'll be fine. Make sure that you torqued down the axle nuts very very tight again. They hold the unit hub bearing together and you'll eat up bearings if that nut is not tightened to the specified 175 foot pounds. If you lack a big torque wrench, that translates into "big wrench and jump on it."

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            • #7
              Originally posted by bruto

              If you followed the instructions properly you'll be fine. Make sure that you torqued down the axle nuts very very tight again. They hold the unit hub bearing together and you'll eat up bearings if that nut is not tightened to the specified 175 foot pounds. If you lack a big torque wrench, that translates into "big wrench and jump on it."
              'Zactly what I did

              My t-wrench stops at 150 so I went there and a bit over with my foot on the breaker bar. That nut also preloads the bearing which is why they'll go TU in short order if not set right.

              It was the dealer, not the factory who pushed hard on the axle swap. for a '97 I doubt the factory cares much.

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              • #8
                If those UJ's have grease zerks - grease em monthly - makes a world of difference.

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                • #9
                  Originally posted by Willy
                  .............. I'm somewhat surprised that yours were non-cv type joints as from all that I've seen listed they were all cv jointed at the spindle end.
                  ..........
                  .................
                  I forgot that the part-time transfer cased Grand Cherokees used a conventional single cardan U-joint.
                  The last couple I've done were full-time all wheel drive transfer cased equipped Grand Cherokees which utilize a CV joint at the spindle end.


                  Originally Posted by Opa

                  The driver side suspensions and drive parts suffer more water washing from the curb side wheel splashing water to the drivers' side.
                  I believe the reason one finds more problems on the driver's side is due to another issue associated with winter weather.
                  During the winter months as highways maintenance crew apply salt most of the highly concentrated brine is in the center portion of the roadway.
                  The proper application of salt requires it to be applied in about a 1 yard wide strip on the centerline of the road. The crown inherent to most roads then allows the brine to slowly gravitate to the roadway's edge.
                  After looking at the concentration of not only body but suspension damage to the left side of vehicles over the years I believe it's mostly due to the stronger brine solution near the centerline.
                  Dryer weather high mileage vehicles usually sustain more suspension damage to the passenger side due to curbs and people driving onto the shoulders while cutting corners.
                  Home, down in the valley behind the Red Angus
                  Bad Decisions Make Good Stories​

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                  • #10
                    Agree with Willy, Damned road salt!!

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                    • #11
                      Originally posted by Limy Sami
                      If those UJ's have grease zerks - grease em monthly - makes a world of difference.
                      Serious off-roaders sometimes avoid the greaseable joints because the cross is hollow, thus a bit weaker, and they'd rather have it wear out early than break on the trail. But you can get premium joints with a little fitting in one end cap. It's easily overlooked, but it does indeed make a world of difference if you get one with a fitting and remember to use it.

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