Drive belts - ZR-1 Net Registry Forums

secondchance · 03-26-2016

I am having an issue with drive belts being too long causing tensioner to bottom out resulting in rattling at idle. I tried AC Delco and Dayco. Both slip on too easy. Anyone know of shorter drive belt?

Dynomite · 03-26-2016

Quote:

Originally Posted by secondchance

I am having an issue with drive belts being too long causing tensioner to bottom out resulting in rattling at idle. I tried AC Delco and Dayco. Both slip on too easy. Anyone know of shorter drive belt?

Remove your Belt and measure you belt length by holding the belt and tape measure in your hand and pulling the belt with tape on outside of belt through your fingers until you get to the mark you started on. I forget the lengths but I have NO standard length belt on any of my Zs. Anyway......for you......try a belt about a 1/4 inch or 3/8 inch shorter. Go to the counter at Autoparts with your belt and ask for the length you think will work from your measurements. And....when at the Autoparts (take your Tape Measure with you), measure the Belt they find to make sure of its length. You can also take the belt you now have with you and compare. Most Autoparts (I use Oreillys) will have Belts in lengths of 1/4 - 1/2 inch longer or shorter.

See Item #1 Alternator, AC Pump, Power Steering Pump

George Maz · 03-27-2016

Marc just yesterday found same problem with a car I sent him.
"Before test driving the car we noticed a clicking sound from the accessory belt tensioner. It was bouncing against the retracted travel stop. It was acting like the accessory belt was too long. The engine has a new OE size Dayco belt. The problem as that the alternator pulley was too small. 2.2" diameter. The correct pulley is 2.6". We installed the correct pulley and now the belt fits normally."
...perhaps it's worth checking.

secondchance · 03-27-2016

Quote:

Originally Posted by George Maz

Marc just yesterday found same problem with a car I sent him.
"Before test driving the car we noticed a clicking sound from the accessory belt tensioner. It was bouncing against the retracted travel stop. It was acting like the accessory belt was too long. The engine has a new OE size Dayco belt. The problem as that the alternator pulley was too small. 2.2" diameter. The correct pulley is 2.6". We installed the correct pulley and now the belt fits normally."
...perhaps it's worth checking.

I sent an email to Marc and he replied with the same info. Yes. I confirmed my alternator pulley is 2.2" diameter also. I'll be replacing my pulley with an aluminum billet piece I had been too lazy to install.

Also, learned another interesting info - Dayco belt model/length. Evidently correct LT5 belt is 5060805. Last 3 digits signify that it's 80.5" long. Next size down id 5060800 - 80.0" long. Evidently belts are available in .5" increments as Dynomite replied earlier.

secondchance · 03-27-2016

George,

Did Marc remove the pulley with the alternator on the car?

Scrrem · 03-28-2016

Yun,
I remember when I took my alternator apart, the nut on that thing was torqued pretty good....was a real bear to get loose. As I recalled I rigged up something to hold the fan blades and got a big socket with a breaker bar.
Rich

Tony Davila · 03-28-2016

Impact wrench will break it loose easy while on the car.

George Maz · 03-29-2016

Quote:

Originally Posted by secondchance

George,

Did Marc remove the pulley with the alternator on the car?

He didn't mention.
There's a list of things to be sorted on this car first, then hopefully we can modify & tune as planned.

secondchance · 04-23-2016

While at Dempsey's Evolution Motorsport last Saturday, removed the alternator nut with an electric impact and installed correct diameter alternator pulley. However, the belt was still too long and allowing the tensioner to bottom out at idle. I replaced 80.5" belt with 80" and all is well. Looks like my Z lost 1/2" somehow... Actually, 80" belt went on easier than standard AC Delco belt I remember putting on a few years ago. Strange...

Z51JEFF · 05-02-2016

2 differant size pulleys is something I've never heard of before. Is it possable because there might be 2 differant size pulleys there could be 2 different size belts for an LT5? The reason I ask this is because years ago I tried replacing the belt with an OEM GM belt,correct part number and it would not go on regardles of what I tried,the belt was too short.

03-27-2016	#3
George Maz Join Date: Dec 2014 Location: Long Island, NY Posts: 295	Re: Drive belts Marc just yesterday found same problem with a car I sent him. "Before test driving the car we noticed a clicking sound from the accessory belt tensioner. It was bouncing against the retracted travel stop. It was acting like the accessory belt was too long. The engine has a new OE size Dayco belt. The problem as that the alternator pulley was too small. 2.2" diameter. The correct pulley is 2.6". We installed the correct pulley and now the belt fits normally." ...perhaps it's worth checking. __________________ 1990 ZR-1 #1587 1990 ZR-1 #1727

03-27-2016	#5
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,721	Re: Drive belts George, Did Marc remove the pulley with the alternator on the car?

03-28-2016	#6
Scrrem Join Date: Feb 2009 Location: Alexandria, Virginia Posts: 1,467	Re: Drive belts Yun, I remember when I took my alternator apart, the nut on that thing was torqued pretty good....was a real bear to get loose. As I recalled I rigged up something to hold the fan blades and got a big socket with a breaker bar. Rich __________________ 1990 Bright Red Coupe #608 380 Stroker, Ported Heads/Intake/Housings/TB Haibeck Secondary Delete Chip / Pete's Cams George Braml Intake / FIC Injectors Coated SW Headers / Corsa Bill Boudreau B/B ZF6 / Viper 4.10 gears Ron Davis Radiator Pioneer AVIC-Z140BH NAV Fikse FM5's 285 / 335 / C6 Brakes WAZOO Member

03-28-2016	#7
Tony Davila Join Date: Jan 2004 Location: Enterprise, Alabama Posts: 349	Re: Drive belts Impact wrench will break it loose easy while on the car. __________________ Tony Davila (Projects) Water Meth: http://www.zr1.net/forum/showthread.php?t=19422 Exhaust cut outs: http://www.zr1.net/forum/showthread.php?t=22689 Auxiliary 12V install: http://www.zr1.net/forum/showthread.php?t=22878 Auxiliary pusher fan install: http://www.zr1.net/forum/showthread.php?t=22859 Oil Catch can Project: http://www.zr1.net/forum/showthread.php?t=20320

04-23-2016	#9
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,721	Re: Drive belts While at Dempsey's Evolution Motorsport last Saturday, removed the alternator nut with an electric impact and installed correct diameter alternator pulley. However, the belt was still too long and allowing the tensioner to bottom out at idle. I replaced 80.5" belt with 80" and all is well. Looks like my Z lost 1/2" somehow... Actually, 80" belt went on easier than standard AC Delco belt I remember putting on a few years ago. Strange...

03-26-2016	#1
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,721	Drive belts I am having an issue with drive belts being too long causing tensioner to bottom out resulting in rattling at idle. I tried AC Delco and Dayco. Both slip on too easy. Anyone know of shorter drive belt?

05-02-2016	#10
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,068	Re: Drive belts 2 differant size pulleys is something I've never heard of before. Is it possable because there might be 2 differant size pulleys there could be 2 different size belts for an LT5? The reason I ask this is because years ago I tried replacing the belt with an OEM GM belt,correct part number and it would not go on regardles of what I tried,the belt was too short.