peedeerooster

iTrader: (1)

I have a 2005 CTSV. I had a H/C full exhaust LS6 for around 18 months. Around 8 months ago the AC belt started coming off at more than 4000 rpm. I changed the harmonic balancer and it didn't help. Put a 408 stroker in about 4 months ago. The belt still jumped. replaced the tensioner with a brand new one. Put on an underdrive with the correct belt. It still won't stay on. The AC compressor pulley looks great and the alignment of the pulleys looks good. Could the compressor cause this or something else. Any ideas would be appreciated. This is an awesome car with the 408, but I am about ready to drop it off a cliff over a belt not staying on. Almost forgot, the AC cools great until the belt jumps off.

Larry

iTrader: (4)

Without looking at the car it's hard to tell the problem but do you have any pulleys that do not have a high shoulder? Also check the pulleys are parallel to each other. If one is not seated flush it can run the belt off. Worn bearings will allow the pulley to become angled.

I had 98 Camaro had a belt problem until I had ASP make me a taller shoulder idler pulley.

davidws6

iTrader: (36)

+ 1 on an idler with a shoulder. When I went to a larger stroker, the main belt would keep popping off. I grabbed an idler with a high shoulder and it's been on since.

peedeerooster

iTrader: (1)

This started when the heads/cam LS6 was still in the car.

scatillac

iTrader: (12)

The CTS-V A/C idler pulley tensions on the outside of the belt. There is no shoulder.

Since this is a very uncommon event, it's most likely related to belt sizing, pulley alignment, pulley runout (on the crank or compressor) or possibly a weak tensioner spring.

I would recheck everything (again).
Are you in the Pee Dee area of SC or NC?

peedeerooster

iTrader: (1)

Yes. I am in Marion.

peedeerooster

iTrader: (1)

I have swapped crank pulley twice and replaced the pensioners with a new one. Guess its time to go after the compressor.