Rear end noise -with video-

**Customta98** · 08-14-2009, 04:01 PM

Whats up everyone just got back from getting my car towed. Well I went to the S OF S to get my new plate ordered (BRDOPRY) and I was driving back on back roads and it started makeing this noise then it slowly got worse and you could feel it in the floor.
Now I was thinking it was the trany mount but when I got back I lifted it and got under the car when it was in gear at idle and the sound is comeing from the rear end / driveshaft connecting points.
I just got the new motor back in and replaced the driveshafts rear U-joint I also bought new U-joint straps. I was thinking at first that it was hiting something (the driveshaft) like the tourq arm but its not put my hand inbetween it and everything but its not hiting anything.
So here is where the video comes in, I got my camera out and took it under the car with me to show everyone what it is doing now im thinking that its probably just that the stock 10 bolt is a POS and cant handel the new motors power, so im thinking an upgrade is in my near future.

Well here is the video on youtube
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**Silver Streak** · 08-14-2009, 04:16 PM

Wow.. kinda sounds like mine before it granaded... except mine wasn't a constant banging like that.. I would pop the cover and take a look to see if there are any metal shavings in there...

**Customta98** · 08-14-2009, 04:19 PM

oh there probably is I drove it a good 5-7 miles before it got really bad and I pulled over and called a tow truck.

**Customta98** · 08-14-2009, 05:06 PM

also dose anyone know where I can buy a nice Rearend possibly a 12 bolt or maybe somthing better.

**Silver Streak** · 08-14-2009, 05:08 PM

Originally Posted by Customta98

also dose anyone know where I can buy a nice Rearend possibly a 12 bolt or maybe somthing better.

Moser...

**Smittro** · 08-14-2009, 05:12 PM

Call me crazy, but sounded like the universal knuckle, or one of the universal saddles was slightly hitting/tapping on the torque arm maybe even the head of one of the saddle bolts. Sounded more like tapping on steel to me. IMHO Looked like there was shinney spots on the saddles too as it was spinning..

**Customta98** · 08-14-2009, 05:22 PM

Originally Posted by Smittro

Call me crazy, but sounded like the universal knuckle, or one of the universal saddles was slightly hitting/tapping on the torque arm maybe even the head of one of the saddle bolts. Sounded more like tapping on steel to me. IMHO Looked like there was shinney spots on the saddles too as it was spinning..

yeah when I put everything back together I had my friend put in a new rear U-joint on the drive shaft and I also used new U-Joint straps and bolts (probably the shiny thing you saw) and it was tourqed down right. Yeah I also thought it was hitting the tourq arm but I checked it all around there its not hitting anything.

**35th-ANV-SS** · 08-14-2009, 05:32 PM

I was going to say see if you see any shiny spots on the torque arm or drive shaft. This would be an indication that there was metal to metal contact. It looks like you have already checked for clearances though. Never heard a bad rear-end first-hand. Good luck man.

I'd go with the Moser 9" if you are indeed thinking about spending the money on a new rear.

**Smittro** · 08-14-2009, 05:32 PM

Originally Posted by Customta98

yeah when I put everything back together I had my friend put in a new rear U-joint on the drive shaft and I also used new U-Joint straps and bolts (probably the shiny thing you saw) and it was tourqed down right. Yeah I also thought it was hitting the tourq arm but I checked it all around there its not hitting anything.

Dam that sucks man, good luck with it.

**Silver Streak** · 08-14-2009, 05:33 PM

Originally Posted by 35th-ANV-SS

I was going to say see if you see any shiny spots on the torque arm or drive shaft. This would be an indication that there was metal to metal contact. It looks like you have already checked for clearances though. Never heard a bad rear-end first-hand. Good luck man.

I'd go with the Moser 9" if you are indeed thinking about spending the money on a new rear.

I've heard the 9" is better for the manuals.. and the 12bolt was better for the auto.. but I don't know what the OP has...

**35th-ANV-SS** · 08-14-2009, 05:44 PM

Originally Posted by Silver Streak

I've heard the 9" is better for the manuals.. and the 12bolt was better for the auto.. but I don't know what the OP has...

I don't know that the 12" is better for the auto's or not. However, for a M6 car, the 9" is preferred because

1) The 9-inch locates its pinion gear lower on the ring gear to improve tooth contact. This strengthens the rear-end assembly.

2) 9-inch has an internal rear-pinion support that also supports the gear end of the pinion to limit gear deflection under high torque loads.

M6 cars, when launched, put a lot more stress on the rear than an A4. All I know is I have read in here and on LS1tech about people breaking 12 bolts. Not to say that the 9" is 100% bulletproof, but it's as close as you can get IMO.

**35th-ANV-SS** · 08-14-2009, 05:45 PM

I guess it all boils down to what his plans are for the car and how much power he plans on putting to the ground.

**pajeff02** · 08-14-2009, 06:36 PM

Originally Posted by Smittro

Call me crazy, but sounded like the universal knuckle, or one of the universal saddles was slightly hitting/tapping on the torque arm maybe even the head of one of the saddle bolts. Sounded more like tapping on steel to me. IMHO Looked like there was shinney spots on the saddles too as it was spinning..

I agree. Sounds too high pitched and regular to be junk banging around inside the rear. You might luck out on this one... Let us know.

**Customta98** · 08-14-2009, 10:07 PM

Originally Posted by 35th-ANV-SS

I guess it all boils down to what his plans are for the car and how much power he plans on putting to the ground.

Well right now im gonna keep this engine that I just built but, after a little bit I plan on building a 454 LSX block or 427 and I plan on supercharging (roots style not centrifugal) it so im sure its going to make a fair amount.

**Customta98** · 08-14-2009, 10:33 PM

I took another look at the rearend houseing and checked just about everything around the driveshaft area again, nothing was hitting the driveshaft or any thing elce no marks or anything, then I looked at the bottom of the houseing and its really dirty and looks kinda shiny so I whiped some away and realized that its gear oil from the rear but its not coming from the cover its coming from the yoke to the houseing seal so im pretty sure that it is the rear end that is gone, so im going to open it up tomarrow and see what is going on i'll take some pics so you guys can see, im guessing there is going to be lots and lots of shaveings.
Also im thinking of getting a moser 9" but will it work well with my built 4L60E (Stage 5 4L60E built by Century Automotive & Transmission) and when I get the other motor built im going to put in a 4L80E thats built up will it work well with the 9"? and how much will it cost (rough estimate)?

**1998 T/A** · 08-15-2009, 07:22 AM

i had the same exact noise before my rear end took a shit...i popped the cover and the posi unit was fucked as well as the ring and pinion

**Customta98** · 08-15-2009, 01:19 PM

Well I went through and got the cover off and saw what I expected mostly. Well I expected to see everything fucked but I was kinda happy to see what I did. My pinion gear has three missing teeth. so thats not so bad guess im gonna go with 3.73's again also this is the fourth set of gears I have gone through about 2 years each set the only set that did not brake was the stock 2.88 (I think thats what it was). Well as promised I took some pics so everyone could see instead of just having me explain everything. Here ya go.

If you look to the left there is the 2 of the 3 teeth that broke off and on the right is the magnet with a crap load of shavings.

**Smittro** · 08-15-2009, 01:24 PM

Originally Posted by Customta98

Well I went through and got the cover off and saw what I expected mostly. Well I expected to see everything fucked but I was kinda happy to see what I did. My pinion gear has three missing teeth. so thats not so bad guess im gonna go with 3.73's again also this is the fourth set of gears I have gone through about 2 years each set the only set that did not brake was the stock 2.88 (I think thats what it was). Well as promised I took some pics so everyone could see instead of just having me explain everything. Here ya go.

If you look to the left there is the 2 of the 3 teeth that broke off and on the right is the magnet with a crap load of shavings.

Daammmm! Well I guess it aint the drive shaft...lol

**pajeff02** · 08-15-2009, 01:42 PM

I guess that is the sound I do not want to hear then. Thanks for the pics and good luck with the repairs.

**Customta98** · 08-15-2009, 02:43 PM

Originally Posted by pajeff02

I guess that is the sound I do not want to hear then. Thanks for the pics and good luck with the repairs.

the funny thing is that when I broke my 3.73's (about two - three years ago) it did the same thing but not the same noise but that only broke off two teeth here is a couple of pics of the old 3.73's pinion gear.