92 ZR-1 bearing chatter

[Richard F.]

I have a 1992 ZR-1 and have a "bearing chatter" coming from the idler pulley area. I removed and changed the belt to a new one and there was no change in the chatter. While the belt was off, I turned the pulleys by hand on the idler, the water pump, and the alternator, and they all seemed OK. Also, while the belt was off I started the car, thinking that the chatter may be coming from somewhere in the motor. The result was that the bearing chatter was gone, so I guess its somewhere either in one of those three accessories above, or possibly the air conditioning compressor. Has anyone out there with a ZR-1 had this experience or possibly have some thoughts as to which direction to go in next.

[Joe R.]

Re: 92 ZR-1 bearing chatter

Richard,

The noise is usually coming from the tensioners for the camshafts. There were revised tensioners introduced a few years ago. Check with the guys on the ZR-1 Registry. They are the most informed people on the LT-5 engine. Very helpful and eager to solve problems for the ZR-1.

JR

[Edward J.]

Re: 92 ZR-1 bearing chatter

Rich, When I suspect a idler or tensioner pulley bearing noise I like to have the pulley in hand and spin, you can sometimes with limited space you cannot spin the pulley fast enough to hear. these pulley bearings can be a common failure. as can anything with a free wheeling pulley such as the alternator and water pump, A/C compressor pulley.

[Joe L.]

Re: 92 ZR-1 bearing chatter

Richard,

The noise is usually coming from the tensioners for the camshafts. There were revised tensioners introduced a few years ago. Check with the guys on the ZR-1 Registry. They are the most informed people on the LT-5 engine. Very helpful and eager to solve problems for the ZR-1.

JR

JR-------


If it was the timing chain tensioners the noise would not stop when the serpentine belt was removed and the engine started.

[Joe L.]

Re: 92 ZR-1 bearing chatter

I have a 1992 ZR-1 and have a "bearing chatter" coming from the idler pulley area. I removed and changed the belt to a new one and there was no change in the chatter. While the belt was off, I turned the pulleys by hand on the idler, the water pump, and the alternator, and they all seemed OK. Also, while the belt was off I started the car, thinking that the chatter may be coming from somewhere in the motor. The result was that the bearing chatter was gone, so I guess its somewhere either in one of those three accessories above, or possibly the air conditioning compressor. Has anyone out there with a ZR-1 had this experience or possibly have some thoughts as to which direction to go in next.

Richard------


I think you need a new belt tensioner. Tensioners are life-limited parts. The problem is that the LT5 tensioner, GM #10067479, is discontinued and hard-to-find. I don't know of any replacement that's available but it's possible there is one.

[Edward J.]

Re: 92 ZR-1 bearing chatter

Richard------I think you need a new belt tensioner. Tensioners are life-limited parts. The problem is that the LT5 tensioner, GM #10067479, is discontinued and hard-to-find. I don't know of any replacement that's available but it's possible there is one.

Joe, The pulleys are available at the local parts stores from Gates, Dayco. some of the time the tensioners them selfs can live a while longer if its just the bearing is gone, And also if you really want to thrifty, Just the bearing it self can be brought and removed as long as the pulley is made of metal. The bearing is the same as a front Alternator on the older 70/80's early cars.

[Joe L.]

Re: 92 ZR-1 bearing chatter

Joe, The pulleys are available at the local parts stores from Gates, Dayco. some of the time the tensioners them selfs can live a while longer if its just the bearing is gone, And also if you really want to thrifty, Just the bearing it self can be brought and removed as long as the pulley is made of metal. The bearing is the same as a front Alternator on the older 70/80's early cars.

Edward-----


Yes, the pulley is available. If the problem is the pulley bearing, a new pulley will solve it. However, I would not expect a bad bearing to cause a "chattering". That sounds more like a tensioner that's not applying the proper amount of tension. Nevertheless, replacing the pulley is worth a try.

[Edward J.]

Re: 92 ZR-1 bearing chatter

Edward-----Yes, the pulley is available. If the problem is the pulley bearing, a new pulley will solve it. However, I would not expect a bad bearing to cause a "chattering". That sounds more like a tensioner that's not applying the proper amount of tension. Nevertheless, replacing the pulley is worth a try.

Yes Joe there is no fix if the bronze bushing in the tensioner worn or the spring has loss it tension, and is flapping(chattering) around, I have seen this.

[Joe L.]

Re: 92 ZR-1 bearing chatter

Yes Joe there is no fix if the bronze bushing in the tensioner worn or the spring has loss it tension, and is flapping(chattering) around, I have seen this.

Edward------

At some point (if they have not already) someone is going to have to come up with a repair solution for these LT5 tensioners.

[Dan A.]

Re: 92 ZR-1 bearing chatter

Richard,
I used to have the same issue with my 90 ZR1. I found that different brands of belts, while all supposedly the same, were different lengths. I found that the Goodyear Gatorback belts worked best as far as eliminating the chatter was concerned. They can be found on EBay for cheap. Ultimately I agree with others in that the tensioner is the culprit but a different belt may be worth a try. They are tough to find but show up on the ZR1 forum from time to time. They can also be rebuilt by Marc Haibeck, I believe. He lists them on his website under "Products".

[Edward J.]

Re: 92 ZR-1 bearing chatter

I will never say never, As I had never heard of anyone rebuilding Fan clutches , Who would of thought.