Write-Up: Replacing Supercharger Belt Tensioner

38351 is a Gates part #. If you type it in the search, it brings up both the Gates 38351 @ 65.79, and the AC Delco under 38351 but with the ACD part # in the description @ $74.79. If you type in the GM part # it only brings up the 38351 under AC Delco. I wonder if they are really different mfgrs? I'd think the AC Delco would fall under it's own part # instead of Gates' #.

I.m thinking one uses different materials than the other. There has to be a difference. They wouldn't sell the same part at 2 different prices, I hope.

I did some part # interchange searching, and it looks like a few mfgrs use the 38351 part # to identify this tensioner. Gates and ACD call them DriveAlign auto belt tensioners. I think they are identical.

Don't know when an answer might come, but I emailed RockAuto and asked about these 2 options.

Thanks for the help, Dave. I'll stand by in case they shed some light on things.

No reply yet.

Replied overnight. Pulleys are the same, plastic ribbed, and steel smooth. But DUH, that info is already stated online. I replied and asked about the tensioners themselves. Will let you know what they say. I'm sure the Gates is fine, but for $9 I'd just go with ACD.

Ok, they replied already. But they don't really answer the question. I'm assuming they don't have physical access to the parts to check it out.

... as I suspected. No parts there to compare. Either choice is probably going to be fine. Buy both and you can compare them for us.

I have a new one in the shop I can take a photo of but it won't be until Saturday

New, but from who? Gates? AC Delco? Dayco? NAPA?

Thanks for the diggin, Dave. Eric, what's your price?

I bought mine from NAPA approx $99.00. It came with a metal pulley. I don't think it looks like the one pictured earlier in this thread but I might be wrong.

The one I posted earlier was incorrectly spec'd by Dayco and RockAuto. Dayco doesn't offer one for the Riv, it turns out.

Your NAPA piece has a steel smooth, and plastic ribbed pulleys, right?

I am pretty sure it just has one steel smooth pulley.

Really? Gates and AC Delco units have the ribbed pulley included.

http://198.208.187.182/internet/PartImage.jsp?mfgname=&prodlinecd=&acpartnbr=38351

Sounds to me like they may have sold you the tensioner unit by itself, instead of the complete assembly. That's what RockAuto tried to give me as a repl for the Riv, until we found out it was not the correct app(see pic on pg 1) and the tensioner could only be purchased as a whole assembly. I could not figure out a way to remove the tensioner only, from the complete assy, on my car. Because you can't replace it.

The one in the link is the one I have. I know the smooth pulley is metal and I will have to check on the ribbed. It's been a while since I have had it out of the box.

Ok, you should be good to go then

Selling price, Eric?

It's not for sale... sorry. I bought it to put on my car but haven't gotten around to it yet.

I cannot get the bolt (rev thread) off my s/c tensioner pulley. The bolt is stripped and wont accept a torx bit. Im about to drill it out but need to get another bolt like this. Can anyone help me out? Have one lying around? GM will try to sell me the entire assembly. Im not sure how else to get that bolt out. Advice appreciated.
It's the bolt that goes here:

I believe that bolt is reversed thread.

That's what his post says.

Maybe you could try heating it a bit then try again?