Shudder when accelerating uphill on curve

[TexasExcursion]

Need a little advice before heading in for service--

I'm getting a shudder in the rear end when accelerating up a steeper hill on curves...sounds pretty specific, but it doesn't do it accelerating up a hill on a straight road. I'm thinking something in the rear end given the whole curve thing.

Thoughts??

 

[Scot]

Try adding friction modifier to the rear diff.

 

[Kleetus]

I'd live with it before I'd EVER add friction modifier... I've got 27k on the clock and the LS has been absent for the last 10...

Does it make a difference turning left to right or only one way? what about the same hill under light accel?

 

[Yellowsub1962]

like Scot said, if it's got a posi in the back then it needs friction modifier or the clutches will chatter and eventually glaze themselves and/or self destruct

 

[Kleetus]

no way man... they will not glaze themselves and or self destruct without friction modifier. They will glaze if you DO use it.They will not self destruct either... the worst they can do is just provide so little friction that they are basically useless. If you break a friction or steel disk, you've got something else going wrong in there. The only reason the modifier is in there in the first place is for little old ladies in their lincolns that don't like noise in the car.

Go talk to any autocross person who still has a factory LS rear (decent ones scrapped the LS for Auburns or Detroits)


Still, we need to figure out if it's direction sensitive, or if it does it coasting too... if it's truly the clutches, then it should do it with or without power, left or right. If it only does it one way, then something else is going on. Think about it... why would the diff care if it's up hill or down hill? The chatter if it's the clutches is them sticking together then slipping and what you feel is the torsional energy release of the axles. That action is direction independent.

 

[Zookie400]

FRICTION ADDITIVE
not invented for little old ladies, but to keep the static friction coefficient as close as possible to the sliding friction coefficient, thus "eliminating" clutch disc chatter.
i would recommend doing 15-20 slow, tight circles in a parking lot after you add it. (or 30-40 figure 8's to keep from getting dizzy )

 

[Kleetus]

Whatever man... ask any performance shop they'll tell you the same thing. I wonder why it voids the warranty on any Auburn if it's used in there... Hmmm?

TxEx... it's your rearend. do what you want. What's odd on this is this apparently just started this behavior?

 

[TexasExcursion]

Whatever man... ask any performance shop they'll tell you the same thing. I wonder why it voids the warranty on any Auburn if it's used in there... Hmmm?

TxEx... it's your rearend. do what you want. What's odd on this is this apparently just started this behavior?

Sorry guys, been out of the net this week. Had the truck into the dealership while I was on a bizniss trip and they said it was the clutches in the rear end that are starting to go. My concern is that they'd go out on me and leave me stranded while out with our travel trailer. Service guy said if they did go out it'd be like driving a normal limited slip rear end. I didn't have them fix it....said it'd be $700 parts and labor.

As for you alls questions, i get the shudder when going up a hill to the left and right--direction doesn't matter. It doesn't do it if I'm not accelerating. I haven't tried it in a flat parking lot, though. Guess I've got some homework to do tomorrow.

It started doing it recently, and the only other event that lines up with when it started was when the dealership I had problems with replaced the fluid in the rear end. Hmm.....

 

[Kleetus]

Wow.. seven bills for clutches? Yikes... I'm going to try to get them to put in a Detroit tru-track for me as I'm still under warranty, and my LS is toast. it's about $435, I'll buy it if they put it in... I suspect I'll never have to screw with it again.

Odd though that them chattering is a sign of them going... it just means their actually working. I wish mine would chatter! lol.

 

[Zookie400]

when they drained and refilled the fluid in your diff, they didnt put the additive in...i get problems like this all of the time at work. chattering is NOT a sign of them being smoked. put the additive in and the chatter will go away.