Trying to sort out a very nasty vibration/grinding happening lately for the last year or so.
Last year I had a local shop service the TJ. They 'forgot' to put rear diff fluid back in.
10 miles down the interstate outside town, I came to a halt - and immediately knew what went wrong - not the first time I've seen a shop forget to replace fluids. Gears welded themselves together, broke, all kinds fun. Because covid, and because times are weird the only gears they could source were used. Dana 44 3.73's. Not even randy ring and pinyon or Yukon or anyone had any readily available. I couldn't wait 3 months for gears, so used it was with all new bearings (supposedly).
Since then less than 5K miles has been put on the TJ. Over the last couple months I have developed a very bad noise. With only one ear I cannot echolocate and can't 100% identify the source. Rear DS went in for a rebuild and straighten last month, along with the front. So I took it on the highway with only the front DS. The noise subsided, but not 100%, it was still heard/felt a little. With the rear DS back in it was obviously worse and removing the front DR ruled out the front diff. Starts at 45, and gets real bad at 60-65 and somewhat lessens at 70. I have driven it a few thousand miles and nothing has blown up yet. When off the throttle, it mostly goes away, as typical with rear end problems, but is sill there although significantly reduced. It is not the typical 'whine' noise from a poorly set rear-end. It has that too of course, but this is not the sound I'm talking about. It really sounds like something is about to give up and go ka-boom. Front wheel hubs were replaced along with the DS rebuilds as they were bad. I also used a laser temp gun to see if there are any abnormal temperatures at all bearing locations, trans, transfer, etc... Nothing is wildly higher than would be expected.
The fact that the noise still can be heard/felt with the rear drive shaft removed is throwing me off, and I just don't hear noises that well anymore. Pinyon does not have excessive play. The clutch, flywheel, pilot and throwout bearings need replacing but I dont think that is necessarily the source. Trans and transfer fluids are also new and no signs of obviously bad wear. The sound almost mimics an impact somewhere, like if the rear end or transfer was pushed right up against the tub, or if a t-case mount fell apart. I see no signs of that however. The only common dominator in this event is the recent replacement of the rear diff gears. The only other obvious issue is it's been so darn hot wheel weights to balance whee/tires are literally falling off. But, this is not a 'shake' kinda feel conducive to out of balance tires. Although I suppose that is a possibility but I think highly unlikely.
I am fairly confident the rear end is totally jacked, that it needs all new bearings, actual new gears, and even a carrier - maybe it bent from the heat of destruction. I am suspecting the bearings and races didnt actually get replaced. But I wanted to pose this situation here to see if any other suggestions are out there before I spend 2500 on something that doesnt fix it. TJ goes to the main 4x4 shop in town on Tuesday.
However, I would like to rule out if possible the transfer case. It has an advance adapters SYE, and teraflex 2-lo kit. It's never had issues, fluids were changed but looked fine no obvious problems. I've been seeing plenty of threads on transfer case failures last few days, serious enough that the housing totally busted apart. But I have only come across one thread that mildly talked about a gnarly grinding noise before failure.
Last year I had a local shop service the TJ. They 'forgot' to put rear diff fluid back in.
10 miles down the interstate outside town, I came to a halt - and immediately knew what went wrong - not the first time I've seen a shop forget to replace fluids. Gears welded themselves together, broke, all kinds fun. Because covid, and because times are weird the only gears they could source were used. Dana 44 3.73's. Not even randy ring and pinyon or Yukon or anyone had any readily available. I couldn't wait 3 months for gears, so used it was with all new bearings (supposedly).Since then less than 5K miles has been put on the TJ. Over the last couple months I have developed a very bad noise. With only one ear I cannot echolocate and can't 100% identify the source. Rear DS went in for a rebuild and straighten last month, along with the front. So I took it on the highway with only the front DS. The noise subsided, but not 100%, it was still heard/felt a little. With the rear DS back in it was obviously worse and removing the front DR ruled out the front diff. Starts at 45, and gets real bad at 60-65 and somewhat lessens at 70. I have driven it a few thousand miles and nothing has blown up yet. When off the throttle, it mostly goes away, as typical with rear end problems, but is sill there although significantly reduced. It is not the typical 'whine' noise from a poorly set rear-end. It has that too of course, but this is not the sound I'm talking about. It really sounds like something is about to give up and go ka-boom. Front wheel hubs were replaced along with the DS rebuilds as they were bad. I also used a laser temp gun to see if there are any abnormal temperatures at all bearing locations, trans, transfer, etc... Nothing is wildly higher than would be expected.
The fact that the noise still can be heard/felt with the rear drive shaft removed is throwing me off, and I just don't hear noises that well anymore. Pinyon does not have excessive play. The clutch, flywheel, pilot and throwout bearings need replacing but I dont think that is necessarily the source. Trans and transfer fluids are also new and no signs of obviously bad wear. The sound almost mimics an impact somewhere, like if the rear end or transfer was pushed right up against the tub, or if a t-case mount fell apart. I see no signs of that however. The only common dominator in this event is the recent replacement of the rear diff gears. The only other obvious issue is it's been so darn hot wheel weights to balance whee/tires are literally falling off. But, this is not a 'shake' kinda feel conducive to out of balance tires. Although I suppose that is a possibility but I think highly unlikely.
I am fairly confident the rear end is totally jacked, that it needs all new bearings, actual new gears, and even a carrier - maybe it bent from the heat of destruction. I am suspecting the bearings and races didnt actually get replaced. But I wanted to pose this situation here to see if any other suggestions are out there before I spend 2500 on something that doesnt fix it. TJ goes to the main 4x4 shop in town on Tuesday.
However, I would like to rule out if possible the transfer case. It has an advance adapters SYE, and teraflex 2-lo kit. It's never had issues, fluids were changed but looked fine no obvious problems. I've been seeing plenty of threads on transfer case failures last few days, serious enough that the housing totally busted apart. But I have only come across one thread that mildly talked about a gnarly grinding noise before failure.
