I just placed 18" rims on a 07 HHR LT2 2.4L Automatic and having some issues. I have lost traction control and the transmission is hardshifting anyone else having this problem. If so how did you correct this situation. Chevy Dealer states that the HHR is not able to run a 18". Anybody able to help me would be appreciated.

 

I doubt this is from the 18" wheels if you have the same size on all four corners. A lot of guys are running 18's on their HHR and the SS comes with them stock. (your dealer doesn't want your business by the answer they gave you so look elsewhere) Stop by an Advanced Auto and see if there's any stored codes. Loss of T/C and hard shifting could be several different faults and none are tire size related. You can do a search on the forum for "hard shifting" or something like that and see what I mean.... lots of threads going.


Welcome to the forum

 

If your tires are more than 3%-5% taller than stock, if the air pressure is unbalanced between the tires, this can happen.

 

There is an idiot of a dealer. Doesn't even know that the SS they have been selling come stock with 18's/

Best deep dealer voice impression: "Oh, no, it's your wheels. The HHR can not run 18's. You just voided your warranty"

 

Since you did not mention the offset or rims you are using, could they be rubbing inside ?

And what size 18"s you using ?

 

What size tires and are you sure you have the same air pressure all around? If you get too far outside the parameters programmed in the pcm it can react like that. The speed sensor sends info to the pcm based on factory tire sizes, there are many other factors involved with shifting functions but they all are dependent on getting correct info, so if the tires are outside the window and the pcm isn't reprogrammed to compensate, that's a common reaction. Erratic shifts and abs function can result.

 

I just put some 5 spoke chrome 18in wheels off a pontiac soulas prob spelled wrong but the look n ride with no problems 235/45/18 run 40 pounds in all tires no problems.

 

What code(s) are being set?

 

IIRC even though the bolt pattern's the same, the Pontiac Solstice wheels have a different offset than the HHR's. If you're running Solstice wheels it may be the offset that's throwing everything off since those are RWD vs our FWD setup. Someone correct me if I'm wrong?

Later
Allex

 

Before i got my ss i had a 07 2lt and put 18's on it idk why but had problems after i put them on. Of course it rode rough but seem to have some other issues.