Calling all Quaife ATB LSD guys

[Dmacc]

I know that ATB diffs aren't usually supposed to be abused upon for events such as road racing, but I just wanted to see if you guys could give me some input on a strange noise I'm having post install.

When I took the car up and down mountain road going solidly fast, I noticed that whenever I was pulling a lot of G's making a hard left, still on the throttle that the more throttle I would give it, a vibration coming from the rear of the car would start to get more and more troublesome, depending on how hard I was taking the turn and how much throttle I was applying. The shimmering and vibration would only be more apparent with the more throttle I gave it. Wouldn't happen when I was making hard right hand turns, only more so on the left hand turns.

Just wanted to see if anyone with a quaife is experiencing or has experienced the same thing? All input welcome, thank you!

[int2str]

I have completed various auto-x events and a few track days, including blasting through a banked oval turn yesterday at 120+mph (Auto Club Speedway). No noise, no problems....

Something may be wrong with your install or diff...

[Dmacc]

Originally Posted by int2str

I have completed various auto-x events and a few track days, including blasting through a banked oval turn yesterday at 120+mph (Auto Club Speedway). No noise, no problems....

Something may be wrong with your install or diff...

Thanks for the input, just as I suspected

I'm going to go to the shop that installed it and replicate the noise for one of the techs, hopefully it was just an install problem and not the unit itself :/

[Eyeman]

I've had my LSD for 30k miles now on my tuned, step transmission car. I probably don't drive hard as long as both of you do but I do like to occasionally drift/power spin my car, etc and I never get any vibration type issues other than traction control kicking in, etc. Unfortunately my LSD does whine in the 65mph range due to shimming issues, but otherwise I love it.

[loesch]

It's not the same problem others have had with the JB4 is it? Some say spark plugs need to be replaced. Others think it's the flywheel. Mine does it too. Like a vibration under WOT at low RPMs. I'm trying to be optimistic for you. Hope it's something simple like that.

[IGoFast1589]

Who did the install? Did you buy a pre-assembled rear end and just swap the pumpkins or did you install the Quaife into your factory housing and remove the OEM differential? Any fluid leaks near the axel seals?

Also check to make sure you lug studs are tight and when the car is in the air try and grab and shake the wheel to see if the wheel bearing has play in it.

[Dmacc]

Originally Posted by IGoFast1589

Who did the install? Did you buy a pre-assembled rear end and just swap the pumpkins or did you install the Quaife into your factory housing and remove the OEM differential? Any fluid leaks near the axel seals?

Also check to make sure you lug studs are tight and when the car is in the air try and grab and shake the wheel to see if the wheel bearing has play in it.

great advice, I'll try to see if anything is loose. I bought a full assembly from VAC, they put the differential in a used pumpkin and sent the whole pumpkin for a direct swap with my old one. Thanks for the advice! I'll update you guys when I have a definitive answer as to what exactly is going on, again I appreciate all the help thus far

[fboutlaw]

Originally Posted by Dmacc

great advice, I'll try to see if anything is loose. I bought a full assembly from VAC, they put the differential in a used pumpkin and sent the whole pumpkin for a direct swap with my old one. Thanks for the advice! I'll update you guys when I have a definitive answer as to what exactly is going on, again I appreciate all the help thus far

Before doing any of that crazy work, look for rubbing in your wheelwell. I've had issues before and it's always loose suspension parts or poor alignment causing contact that shouldn't happen or joint slop that shouldn't happen. Also Jack up the car and check for any bolts that are loose in the suspension. The torque spec's are really funky for our cars on some of the bolts (like 72ft-lbs + 90deg, meaning way higher than 72)

Never had an issue with the quaife though and I do track/autox and beat it up pretty bad.

[IGoFast1589]

Originally Posted by fboutlaw

Before doing any of that crazy work, look for rubbing in your wheelwell. I've had issues before and it's always loose suspension parts or poor alignment causing contact that shouldn't happen or joint slop that shouldn't happen. Also Jack up the car and check for any bolts that are loose in the suspension. The torque spec's are really funky for our cars on some of the bolts (like 72ft-lbs + 90deg, meaning way higher than 72)

Never had an issue with the quaife though and I do track/autox and beat it up pretty bad.

Agreed. If VAC did the install I would suspect it's something else first most likely. I have a Wavetrac and I never have any issues with it.

It's hard to diagnose these things over the internet, but try and isolate the sound. Ask yourself questions like when is it happening? When did it start? Get the car up in the air and poke your head around for anything that looks funny. It's all about finding the little gremlin first...