[josephl]

I recently replaced the OEM Michelin tires on my 2010 SRX at 40K miles. The tires were about half-worn and had always rodden fine and wore smoothly. The new tires are the identical Michelins. I immediately noticed a vibration in the car when cruising at 50mph and above. The vibration seemed to come and go. I returned to the tire dealer and had them rebalance the tires. The vibration persists. I've now been able to determine that the vibration only occurs when there is a load on the drivetrain, like going up a grade--even a slight one. I can feel the vibration in sixth or fifth gear, the car running in cruise control. The vibration stops when the extra load is gone. I talked with the local GM service manager and he said it might help to reflash the tranny/engine module(s), but we're not sure. It does seem that it could be an issue with transmission/torque converter not locking properly under these mild load situations. I'm wondering if a slight change in the diameter of the new tires could cause an issue? In any event, the vibration began with the tire change and has now been there for 2k miles. I'd like to know if anyone has had and, hopefully, solved a similar issue. Any suggestions would be appreciated. Thanks.

 

[adamjeeps]

Do you have AWD or front?

 

[josephl]

Sorry, I should have mentioned this. It's AWD.

 

[adamjeeps]

Did your tire shop road force balance with the Hunter GSP 9700? Most of the time, tire balance is the problem. They should be able to get them to less than 10 pounds of variance, although GM recommends 15 pounds or less. The tire can also slip when driving after its mounted and throw off the balance.

If you are sure it is not a tire balance problem, then I might try a transmission fluid flush. Does it vibrate when you are on heavy throttle or is it only certain rpm's?

 

[josephl]

The vibration is always low RPM cruising under slight load, no heavy acceleration. The tires were balanced and then checked again, but not load balanced. I don't really think it's a balance issue because cruising on level road there's no vibration until additional force is need from the engine. Then it will begin to vibrate and even continue if it dowshifts to fifth. Once the resistance is overcome, the vibration is gone. I can check on the tranny flush and what it might accomplish, though I think these cars don't call for any service until 100k. It's my understanding that the ECMs adjust to how the cars are driven, and that resetting them to factory defaults might solve the issue. That's just a guess. I had to drive the car 300 miles yesterday, and can now say the problem is always there and as described. Most of the time my wife drives the car and she doesn't notice such things. Enough said about that!

 

[calif phil]

If it was a tire balance issue it would be there regardless of engine load. My bet is you have a slight misfire Maybe time for spark plugs or a coil going bad. A scanner will show misfire history.

 

[Cadillac Customer Service]

Hello josephl,

I know how this vibration issue would be frustrating and I am glad to see that you’ve already received quite a bit of feedback from the rest of the forum. If you end up pursuing a resolution with the dealership, please feel free to send a PM my way if you would like an additional layer of assistance.

Have a great day,

Austin J.
Cadillac Customer Care

 

[bigdog9586]

Since you didn't have the problem before the tires take it back to where you got the tires and tell them the problem and have them rebalance.
I doubt it's plugs or tranny as no problem before tires, now problem after tires.

 

[Nice Ride]

It is your Drive Shaft / Shaft Mounts if it is a 2010. Google Transmission Vibration. GM is well aware of issue. In severe cases, the driveshaft will Separate and rip apart the wiring under the vehicle causing the air bags to deploy.

 

[retcad]

I'm assuming you had your front end aligned when the new tires were mounted? This is a must.

 

[Nice Ride]

If its only under load ( light load) there is a strong chance it is the Drive Shaft or tranny. The fact that it was noticed after the new tires can be pointing in the wrong direction and just a coincidence.

 

[josephl]

I'm off to the dealer tomorrow, hoping to learn what's really wrong. Thanks to all for suggestions.

 

[Nice Ride]

$5- on the Drive shaft / Shaft mounts...

 

[thetobins]

Steady bearing! Had this problem. Entire drive shaft has to be replaced if so. It's a complete unit. That was my case. I have AWD.

 

[Nice Ride]

Me too....

 

[josephl]

UPDATE. Had the tires load balanced, and still not happy with the results. I'm beginning to think it's an issue with the tires themselves. From the moment they were installed the vibration began and the ride has been terrible. As the Cadillac mechanic noted when riding in the car, "That Cadillac ride is sure gone!" Dropped the pressure from 35PSI to 32PSI and still very rough. I'll check the drive shaft mounts but my next call is to Michelin.

 

[MI-SRX]

It could be a tire that's out of round, not sure if load balancing would catch that or not. I had it happen a few years back myself and it took a few trips back to the tire shop to get it all ironed out.

 

[adamjeeps]

The road force machine should catch any out of round tire or wheel issues. But, it takes a competent tech to use it properly. Did they tell you how many pounds of variation each tire had? Should be less than 10 for best results.


Sent from AutoGuide.com Free App

 

[Nice Ride]

If the problem only surfaces when the drivetrain is under light load, I still think it is Drivetrain / Transmission related.
If it is the tires, can you get it to happen at a set speed? If so when it occurs, put the car in neutral, does problem still exist? Also try by putting the car in say 2nd or 3rd gear and keep it there, still a problem? Try rotating the tires front to rear just as a test, does the sound / vibration change? Increase the tire pressure to 45 as a test, any change?

 

[josephl]

Update Two

Had the car serviced at dealer. Checked everything on the driveshaft and said it's fine. Did front and back alignment; only slightly out. Reset to defaults on module that control vibration and suck for rear differential/axles. Still not a smooth as with the old tires and the new tires are definitely harder. Only thing left is to talk with Michelin.