Merc63

Any have issues with their factory LSD? I was at the track last night and after on the drive home, the car pulls to the left when I give it throttle.

If I hammer it through 3rd and 4th it doesn't seem to track straight, kind of pulls left and right some.

I think the stock LSD has a clutch?? Maybe mine is toast...


What's the best LSD, wave track?

zibby43

It seems to me that less people have had problems with the Wavetrac, as opposed to the Quaife.

Critter

Merc63 recheck the tire pressure on all tires, especially the rear.

glennhl

I agree. I've never heard of a bad posi making a car pull. If the clutches are bad the rearend will act like an open (non LSD) differential and the car should drive straight.

Ingenieur

Tire pressures?
Are the tires shot?
Any off track excursions?.alignment?
Bent sway bar link

Could be many things
But not likely the lsd

JimmyR

Did the track have a lot of tight Right hand bends?? I wonder if you have worn the front LEFT tyre outer tread and now it is drifting/pulling to the left as you describe.

Jacob-63

Maybe your tie rod has a problem

Merc63

I'll check tire pressure.

Drag strip, not road course.

mr747

Merc63 honestly the wave trac is probably one of the best upgrades
Since I've put the diff in the car just drives 20 times better with more feeling in the *** end and is so much more controllable

Merc63

Me so stupid, I only had 15lbs in the left tire. Fail

No tire pressure monitors in canada...

Jasonoff

You should have individual wheel speed sensors that detect a differential. Not sure how sensitive they should be but when I was around 5psi lower in a rear that picked up a screw the indicator notified me.

Critter

Now that you have run the tire at high speeds with 15 psi in it, you should be made aware that damage could have occurred inside of the tire on the sidewall, where excess heat will bubble a line around the inside where the car was running on the wider footprint. Sometimes you can see the bubbles on the outside but not very often. Use caution as this is now a weak area and the tire could blow without prior indication and also usually at the least opportune time. Dismantle the tire from the rim and check the inside for damage. Good Luck

kgmuse

and you shouldn't rely on sensors. anyone should who tracks should check before, during, and after. running that low around corners and at temps has ruined the tire. if you see any rubber strips, excess pieces it's toast.

Merc63

I had my drag tires on and switched back. Tire didn't appear to be low, 30 sidewall. Seems fine now. It's almost toast anyways.

Critter

I keep a small pressure gauge with a magnet on the inside of the gas door, check tires every two weeks as part of a walk around the car. Yes sensors are nice but sensors fail , old school methods are tired and true. Could you not see where the tire had been contacting the road on the sidewall, that would be the darker ring up the sidewall from the tread, this is where the damage would be on the inside of the wall.

Ingenieur

Check mine monthly
Just did it
Car sitting 12 hours 70 deg
40.5...40.5
45,,,..,,,45

I use a accutire digital el cheapo
My gas flap is plastic?
I keep mine in the center console

Critter

Ingenieur, those pressures you state, on my E is for 5 people with 5 pieces of luggage, in other words fully loaded. For 3 people with 3 pieces of luggage the pressures are 36 front 36 rear, I run 35 on a mechanical pressure gauge. Plastic gas door?, is that for weight reduction, even the lowly CLK63 has a metal door.

Ingenieur

Plastic for whatever reason

The door sticker only lists 41/45
Manual says reference door sticker lol
But I remembered that my Audi had it on the gas flap, sure enough
Reduced load 39/39
Full load 41/45
I will set at 40/42
Thanks for the brain jog
I am running 245/265 and when you look up pressure vs load in the spec book wider tires of the same type (xl, speed rating, etc) are usually a few psi lower for the same load rating
And I assume MB selected the psi based on load
Having said that 39/41 might be better

Critter

I believe with the higher pressure and wide tires you are more prone to wear the center of the tread as opposed to the edges. But you should notice improved ride comfort with the reduced settings.

Ingenieur

Over inflation will wear the centers more
Wished I would have caught it sooner
Thanks

Can't believe the door sticker doesn't list normal and full load pressures

Edit: set 39/41 and tpms reset

whoover

Mine lists 41/41 for normal loading and 44/46 for full load.

But my TPMS is calibrated for 39/39. When I inflate to 41/41 with a very accurate gauge and reset the TPMS, it reads 39/39, meaning it thinks that's the nominal pressure. (The TPMS is very sensitive to pressure changes, but useless as an absolute pressure gauge, so the nominal pressure is encoded.)

To get my TPMS reading properly I had to deflate the tires to 39/39 and then do the TPMS reset, followed by reinflating to 41/41. When I take it in for the 2,000 mile service, I'll see if the TPMS calibration is something the dealer can change.

Critter

Not sure about 39 being the calibrated PSI, but if you reduce the pressure on one tire, I am sure the TMPS will pick up the pressure lose and register the reduced PSI. The TMPS system is open circuit what is- is what is, not it is compared to what it should be. IMO
Also the car should be running to get the system to operate on changes.

Ingenieur

Door sticker

Ingenieur

Gas flap

whoover

They tweaked it for some reason. But forget to tell the TPMS. Door pillar is consistent with this.