Lee21490 Posted July 27, 2014 Posted July 27, 2014 Okay, so this is driving me insane. Whenever i stop the truck from 15mph+ And keep my foot on the brake, There's a hefty clunk from the rear. It ONLY does it in gear, If i shift to neutral it doesnt.Seems its when it downshifts while braking. Thought maybe it was the tranny mount as it was pretty worn looking, So i just swapped it out & it didnt change anything. I've checked the ujoints and they look/feel fine. There's no slack in them. Any ideas? '86 comanche 95 4.0l & tranny SOA rear (doubt its wrap)
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 Failing differential would be my guess. Very possible. But wouldnt that cause issues when accelerating?
Jeep Driver Posted July 27, 2014 Posted July 27, 2014 I won't explain it very well......... You are applying power to both sides of the ring gear. You are going from the drive side to the coast side then back to drive side. Pressure on the components is changing. If the spider gears or RnP or bearings or.....are failing, the change in the direction of pressure is causing the 'clunk'.
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 I won't explain it very well......... You are applying power to both sides of the ring gear. You are going from the drive side to the coast side then back to drive side. Pressure on the components is changing. If the spider gears or RnP or bearings or.....are failing, the change in the direction of pressure is causing the 'clunk'. Alright, That makes sense. Guess its time i start looking for a 44
Incommando Posted July 27, 2014 Posted July 27, 2014 Look into an XJ 8.25 or Explorer 8.8. XJ/MJ D44's are way over priced
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 Look into an XJ 8.25 or Explorer 8.8. XJ/MJ D44's are way over priced Kay, Noob question. http://seattle.craigslist.org/sno/pts/4568213137.html Assuming that would work? Not sure what the average price for these are. Wtf is posi. I'm young and still learning, Go easy on me. haha
Jeep Driver Posted July 27, 2014 Posted July 27, 2014 Yes it will work.........little pricey......but..........it's got discs and if you need 4.10........... You'll need to have it set up though, spring perches welded.
Jeep Driver Posted July 27, 2014 Posted July 27, 2014 BTW....... You'll easily have $600 in it, if not more. You'll need wheel spacers with the 8.8, and you'll need parking brake cables and you'll need to adapt your DS yoke....etc.........oil, brake pads, perches, and the like. And you'll need to eliminate the prop valve to go with discs. It is not a 3 hour bolt and go endeavor. You'll also need new Ubolts.......yeah, you'll have $700 in it.
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 BTW....... You'll easily have $600 in it, if not more. You'll need wheel spacers with the 8.8, and you'll need parking brake cables and you'll need to adapt your DS yoke....etc.........oil, brake pads, perches, and the like. And you'll need to eliminate the prop valve to go with discs. It is not a 3 hour bolt and go endeavor. You'll also need new Ubolts.......yeah, you'll have $700 in it. Yea, I'm aware. Prop valve was eliminated awhile ago. I'll check the local P&P First. Not in a rush, I just like to reasearch stuff in advance.
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 Would a 8.25 be an easier swap? or pretty much the same?
Eagle Posted July 27, 2014 Posted July 27, 2014 Alright, That makes sense. Guess its time i start looking for a 44 First, pull your drive shaft and grease the slip splines where the yoke goes into the transfer case. See if that helps.
Incommando Posted July 27, 2014 Posted July 27, 2014 Around here such an 8.8 goes for around $125-$150. The typical 8.8 swap here is around $350-$400 when you are done if you refresh the brakes at the same time. For the price of spring perches and an 8.25 you can have a rear that is ready to go. It may need a 1" shorter drive shaft. Get a pair perches for $20. The local price for an XJ 8.25 is about $100. If you or a buddy can weld you have a new & much stronger rear for $150 or so. Finding a bolt-in MJ D44 is difficult,expensive, and it gives you no advantage over an 8.25 in my mind and is considered weaker than an '97-up Explorer 8.8. The 8.8 gets you rear discs...although nice they are not a requirement. An MJ D44 will most likely be $400-$500. An XJ D44 is the same price and requires all of the same things to install as an 8.25.
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 Alright, That makes sense. Guess its time i start looking for a 44 First, pull your drive shaft and grease the slip splines where the yoke goes into the transfer case. See if that helps. I keep reading that, But isn't that only for newer model Xj's that have the external yoke with the boot? Doesnt my tranny fluid lube my yoke?
Jargon Posted July 27, 2014 Posted July 27, 2014 Okay, so this is driving me insane. Whenever i stop the truck from 15mph+ And keep my foot on the brake, There's a hefty clunk from the rear. It ONLY does it in gear, If i shift to neutral it doesnt.Seems its when it downshifts while braking. Thought maybe it was the tranny mount as it was pretty worn looking, So i just swapped it out & it didnt change anything. I've checked the ujoints and they look/feel fine. There's no slack in them. Any ideas? I know this won't make much sense... I'm not trying to prove anything or say "this is your issue", I'm just sharing my experience: I had this exact same symptome on my 1998 XJ. It was very annoying and lasted about 1 year. I checked just about everything I thought it would be (then I was thinking rear brakes, suspension components). I just put up with it for the longest time... Then, I changed my differential fluid. The old fluid was filled with metal debris. With fresh fluid, the clunking noise went away. About 1 year later, still no noise and my fluid is clean. When I saw the debris in the old fluid, I expected I would need to replace the gears eventually, but so far so good. Like I said, I don't understand it really, but, it doesn't clunk anymore, so I won't argue with it :thumbsup:
Jargon Posted July 27, 2014 Posted July 27, 2014 Hmmm... although, I just thought about something: My XJ has a manual tranny, so I would be in neutral while braking and the clunking noise would exist. I assume your MJ is an automatic, and you said you don't get the clunking while braking in neutral, so perhaps our issues are not the same. :doh: Still, I know that new differential fluid fixed my XJ... it might be worth a shot for you.
Lee21490 Posted July 27, 2014 Author Posted July 27, 2014 I actually flyshed and replaced the tranny filter not long ago. And when I did the old fluid still looked new and no shavings Also; Would i need a longer, Or shorter drive shaft for the 8.8 compared to a d35?
Eagle Posted July 28, 2014 Posted July 28, 2014 Alright, That makes sense. Guess its time i start looking for a 44 First, pull your drive shaft and grease the slip splines where the yoke goes into the transfer case. See if that helps. I keep reading that, But isn't that only for newer model Xj's that have the external yoke with the boot? Doesnt my tranny fluid lube my yoke? Good point. I had that clunk symptom with a '99 WJ and lubing the splines helped, but you're correct -- that was the new style, external slip yoke.
Lee21490 Posted July 28, 2014 Author Posted July 28, 2014 Alright, That makes sense. Guess its time i start looking for a 44 First, pull your drive shaft and grease the slip splines where the yoke goes into the transfer case. See if that helps. I keep reading that, But isn't that only for newer model Xj's that have the external yoke with the boot? Doesnt my tranny fluid lube my yoke? Good point. I had that clunk symptom with a '99 WJ and lubing the splines helped, but you're correct -- that was the new style, external slip yoke. Noticed today if i REALLY feather the brakes while stopping, I can make it clunk AFTER i let go of the brakes. So I'm going to have a buddy look under & see wtf is going on.
nitroxsteve Posted July 28, 2014 Posted July 28, 2014 Make sure you don't have the exhaust banging on something.
Jargon Posted July 29, 2014 Posted July 29, 2014 I actually flyshed and replaced the tranny filter not long ago. And when I did the old fluid still looked new and no shavings Did you do rear differential fluid? That's what fixed it for me; not the tranny fluid.
Lee21490 Posted July 30, 2014 Author Posted July 30, 2014 I actually flyshed and replaced the tranny filter not long ago. And when I did the old fluid still looked new and no shavings Did you do rear differential fluid? That's what fixed it for me; not the tranny fluid. Ah missread you on my phone. Yea, The diff fluid is new too. Had a buddy climb under & managed to make it clunk a few times, you can't find where it comes from though. Seems to be the transmission?
Lee21490 Posted August 14, 2014 Author Posted August 14, 2014 Update; So there's about half a turn of play in the rear diff. 99% sure thats what's causing everything. Picked up a 8.8 with 4.10 gears & LSD from c'list today, Put new brakes/calipers/rotors on it. Ordered everything i need for the swap, Just have to wait a week~ for it to come in the mail. Thanks again for the help.
8valvehero Posted August 14, 2014 Posted August 14, 2014 Update; So there's about half a turn of play in the rear diff. 99% sure thats what's causing everything. Picked up a 8.8 with 4.10 gears & LSD from c'list today, Put new brakes/calipers/rotors on it. Ordered everything i need for the swap, Just have to wait a week~ for it to come in the mail. Thanks again for the help. RAD! You should get that Cheromanche guy to do your perches.
Lee21490 Posted August 14, 2014 Author Posted August 14, 2014 Update; So there's about half a turn of play in the rear diff. 99% sure thats what's causing everything. Picked up a 8.8 with 4.10 gears & LSD from c'list today, Put new brakes/calipers/rotors on it. Ordered everything i need for the swap, Just have to wait a week~ for it to come in the mail. Thanks again for the help. RAD! You should get that Cheromanche guy to do your perches. Was thinking about giving him a call, If my brother inlaw is out of town when i get all my parts in, I'll probably call him.
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