16.5 wheel hitting rear brake drums
 

So I had a bright idea to put some 16.5 x 8.25 wheels on one of my Blazers. While I was tightening the rear wheels they did not seem to be tightening down soon enough. I thought maybe they were tight on the center of the axle. Anyway I went for a ride and could hear grinding noises coming from the rear end. I crawled under to investigate and it appears that the outer edge of the drum is in contact with the wheel. This is deforming the drum pushing it into the backing plate. I am just interested if anyone has experienced this before.
Thanks, Paul

Re: 16.5 wheel hitting rear brake drums
 

I'm guessing that your new rims have too much back spacing.

Re: 16.5 wheel hitting rear brake drums
 

never heard of such a thing. I have run 15" wheels on a K/20 with HO52 as well as on Dana 60s and they cleared those larger brakes. They even cleared the front calipers once I took the casting ridge out of the center radius

Re: 16.5 wheel hitting rear brake drums
 

It does seem odd -- I also ran 15s for a few years on my K20 with HO52 and big finned drums, with no interference at all.

Re: 16.5 wheel hitting rear brake drums
 

These wheels have about 4 1/2" of back space. The wheel is hitting the edge of the brake drum. It seems to be more of a problem of the shape of the wheel. Hopefully you be able to see where the wheel was contacting the drum in the attached picture.

Re: 16.5 wheel hitting rear brake drums
 

I ended up radiusing the edge of the drum about 1/4"-3/8". Just curious as to why the drums where hitting the wheels. As far as I know the 16.5 wheels were optional for this year of Blazer. The drums could be from a 73 or newer truck that still shouldn't really be an issue though.
Thanks for the replies, Paul

Re: 16.5 wheel hitting rear brake drums
 

I know Blazers had the bigger finned drums and there were smaller ones on C/10s. Maybe the drum profile changed when disc brakes came out