Noise in rear end

Islandcat

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My car is making a clunking noise for lack of better word when I decelerate ( most noticeable in lower gears like 4th to 1st) and it makes the same noise upon light acceleration but not quite as much as decel. It is coming from rear of car. I thought it was a bad ujoint on backend of driveshaft, but when I got under my car earlier i seen it’s what I would call cv joint I guess. Anyway I played with the driveshaft and I can rotate it a good 2-3 inches each way and whenever it stops I hear a clunk in rear end. Could something in my rear ended be going out and what would it be? I am not the most mechanically inclined but since the noise seems to come from rearend, I have no idea what it could be.
 

nxhappy

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yes it sounds like the issue is the differential. Usually they will make noise on take off or decel. Either way dont drive it or you might cause way more damage.
 

merkyworks

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That amount of driveshaft rotation isn't un-normal, your gear backlash is probably on the loose side. You could also have a worn out UCA bushing that's allowing the rear end to pivot more than normal.
 

Islandcat

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It could be 1 to 2 inches. It definitely has a lot of play. And when the rotation stops, it makes the clunking sound in the rearend. Regardless it just started making this noise Saturday. Very noticeably too. My upper control arm was added 8-9 years ago so that could be a problem too.

I am bringing it to mechanic shop tomorrow and they will look at it Thursday.
 

merkyworks

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The clunk your hearing is all the slack being taken out of the gear set. I'm not saying it doesn't need to be looked at but your backlash could be on the high side at 0.012". That high of a backlash would allow the driveshaft to rotate a good amount before everything fully engages.
 

HKusp

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If it was backlash being set that high, wouldn't he have experienced the noise all along? This just started a few days ago, so something must have changed, ie: worn out, came loose, etc.
 

Islandcat

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I am sorry. I just reread my op and realize why merky thinks it’s the backlash. It doesn’t just just make the clunk noise one time upon deceleration or accelerating. It goes clunk clunk clunk until it isn’t under load anymore. Driving at 45 I don’t hear anything. Accelerate to 45 or decelerate from 45 in a lower gear and it clunk clunk clunk........ or maybe even a clack clack clack. Like I said I thought ujoint at first cause it kinda reminded me of that.
 

Islandcat

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Mechanic called today after lunch. Said he gonna have to tear down rear end. It’s something in there and he thinking 9 out of 10 he gonna have to rebuild it. He gonna let me know Monday. Said about 1700 to rebuild one. That sounds about right? He also asked if I just wanted to install a 9 inch lol
 

RedVenom48

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If thats FRPP parts and labor out the door I guess thats not too terrible. You could get an S197 9" from Strange for double that amount.
 

merkyworks

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I think it depends on what a "rebuild" covers as to if the $1700 is a fair price.

Is that all new wheel, carrier and pinion bearings, rebuild diff clutch pack, replace gear set and all the labor, if so $1700 see fair.

If it's just a new gear set and carrier and pinion bearings and installation that seems a bit high. Cause a FRPP gear set is under $200 and a complete install kit is under $100, add gear oil say $40, diff cover gasket sealer say $20. That's $360 in parts roughly so then the labor is around $1340 and that seems high to me. But I don't live in your area so maybe that just the going labor rate in your neck of the woods.
 

Islandcat

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They called me today. They changing out some carrier bearings, and pinion bearings, and maybe something else. It was about 5 things they listed. Can’t really remember exactly what it was. Gonna be about 1,100 but I got them to install my new tpms on my tires. Guess that’s 50-100 of the cost.

I am getting it done at dick Barker Lincoln in Houma. They have done a lot of my work before and always seemed cheap. This was the first time I thought that their price was a lil pricey. Whenever I pick it up I will let y’all know what exactly was changed on it.
 

Kenneth

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Lance’s guys do good work.
They’ll fix it right.


Sent from my iPhone using svtperformance.com
 

Islandcat

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They replaced my 2 carrier bearings, pinion seal, and both axle seal. Also replaced both pinion bearings, and crush sleeve. Was 1,100 dollars . 6 hours of labor they charged. I guess that was diagnosis, fix, and test drive.

Anyway it is crazy how quiet it is now. I didn’t realize how much noise it’s been making for a long time. Pretty happy with it. Now if only I could get rid of the lil bit of gear whine I got. Damn 3:73 gears! Lol
 

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