Belt tensioner and serpentine belt problem
 

Have a couple issues with the z. First I know the tensioner has been discontinued but did not know if there is another GM part that you can cross reference for the whole assembly. Replaced the pulley because bearing were going out, and replaced alternator because lights where starting to dim when running accessories. Replaced alternator with a high output 170 powermaster, had to put delco remy pulley on it, plus gates 80 3/8 belt. Everything was tight and running great until a couple days ago. Belt jumped off when accelerating( down shift). Eased it back to garage and there was coolant all in engine bay. Just did a complete flush when adding knew parts, well tightened everything up again and jacked passenger side up to make sure the pump was streaming coolant for the block, looked fine. Tighted everything up and last night on acceleration same thing happened, was thinking maybe the spring in tensioner? Belt does not go on easy!! So I know it’s tight, no crazy noises like it’s not aligned, in limbo. Any advice would be great, thanks, Shaun. 1990 c4 Lt5

Just wanted to add I wish I got the pulley for the tensioner that had the lips on the sides(I am ordering one today) but that should not matter when it’s aligned

These can be rebuilt,Dave Hetrick? has got a great write up on the parts needed. This reminds me;I need to rebuild my spare. Dave is over on the ZR-1 Registry site.

Marc Haibeck also offers rebuilts and a rebuilding service I believe.

Thanks for the information, my concern is that the belt never came off before changing the parts.

Check the pulley diameter on the new alternator to OEM alternator pulley. Most CS144 replacements show up with smaller diameter pulley. If so, replace the pulley with the old one.

Your belt is way too long. 80.5 is standard and even those tend to be on the loose side. You need an 80 inch belt. Check this out.
H
:cheers:

http://www.zr1.net/forum/showthread....Belt+tensioner

. Thanks for the info, still don’t think it should have Came off that easy, Going to order a 80 inch then, and check alignment as well, because I did have to put the delco remy pulley on the PM alternator, ( had to shave the rear screw on the new alternator so the bracket would fit right, pretty much straight forward on install other then those two things

Was going to see if anyone has reference # for the serpentine belt, wonder why all the belts are 80.5 on every website that I’ve looked at, so is the listed belt 80 and 5/16 or is 80.5 meaning 80 in a 1/2

There are a million belts out there. All I can tell you is the 80 inch Dayco 5060800 is what worked for me and is recommended by Haibeck.
H
:cheers:

Thanks for the part number:cheers:

:iagree:

I replaced my pulley with a new one for an LT1 that doesn't have the ridges. NO problem in 8 years and almost 30k miles running+.

That’s great Paul!! well I’ve had the new pulley and belt on for a week now and no problems, after comparing the two pulleys the one without the lips is smaller than the one I just received from rock auto, and the new belt that is 80 and a 1/8 length looked to have solved the problem. Thanks, Shaun