I have just purchased a set of Iroc wheels (see picture for the type), for my 88 Iroc with front and rear disc brakes.
I was wondering if I need spacers?
I noticed in the parts manual that they show a spacer.

Thanks

 

The spacers were stock on my IROC.

JamesC

 

Some came with them and some didn't, depending on year and model etc... No you don't 'need' them. They are only 1/8 inch.

 

Why did GM put them on the cars?

 

they went on cars with 16" wheels and rear drum brakes.

If you have drum brakes, it's probably not a bad idea to get them.

 

According to Chilton's, TheWraith is correct. However, many cars--including my IROC which came with rear discs--had the spacers as well. The General strikes again.

JamesC

 

What cars got them and what ones didn't varies alot. I'm running drums with 87 Iroc wheels without the spacers and I can't see any reason to get spacers--I don't want them to stick out any farther.

 

If you are not the original owner, the wheel spacers were probably
lost or misplaced over the years. I would get them if youi are using 16" wheels and iron drum brakes.

 

If the IROC rear wheels have the 16mm offset, you will probably need the spacer if you have drums. I still can't figure out why some Fbodies have the seperate offset wheels. I know for a fact that all Trans Ams, base Firebirds, and Formulas have equal offset wheels, but the GTA doesn't.

 

correction: Formulas have 0 offset front/16mm offset rear combo with the 16" wheels.

 

This is an extremely old thread, but it was the only one I found that covered the factory GM wheel spacer issue. My '92 RS w/factory 16x8 aluminum wheels had this same spacer on the rear. I have since upgraded to 17x9.5 ROH ZS wheels, but now I really need a spacer on the front (not just the rear) because my tie rod end is too close to the inside edge of the rim. I currently have a pair of Mr. Gasket 7/32" (0.219") spacers on the front (thinnest I could find @ summit racing), but I KNOW that is way too thick. I don't see how I could be getting proper thread engagement, so I was wondering if any of you have a pair of factory GM .125" spacers laying around that you'd like to donate to a good cause...any takers?

I thought about just moving the rear spacers to the front, but then the front wheels would stick out further than the rear...