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New Fan Belt Squeaks

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MichaelG

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Hi Folks,

I needed a new fan belt for my TR4A which is unmodified with generator and large belt.

Checked the forum archives and purchased the cogged belt from Moss
(834-025) as some had recommended. Looks like a quality belt. Made in Germany by Flennor, the size is 20 X 900.

After initial install it was not quiet, and when I checked it was pretty loose with 1.75 to 2 inches of "play" in the belt between the pulleys, and the manual calls for 1 " to avoid overtightening.

Re tightened, and now it is between 3/4 and 1 ". Unfortunately, the noise is much more pronounced. If does not sound like a bearing in the water pump or generator (which is new). Sounds more like the squeaking type noise my new boat shoes make on a hard wood floor in my house. I don't have a mechanics stethoscope but I put a long screw driver to each part and to my ear and bearings sounded okay. Also, its rhythmic and increases with engine speed vs. a constant metal to metal type of sound.

I might try making it tighter, But before that I wanted to see if anyone had recent experience with this part, or thoughts on how to diagnose. Has anyone had to reload and try another belt in this situation?

Thanks for your counsel.
 
Sounds to me like the belt is too loose. WITHOUT THE ENGINE RUNNING, grab a hold of the fan on the generator and try to turn it in both directions. If you can get any movement on the fan and pulley without the belt moving, the belt is too loose.

Edit: I know, I just looked and it's real tight down there and you may have trouble grabbing a hold of the fan. Maybe you should just tighten the belt up and see if that cures the squealing. To me, that 3/4"-1" just seems too loose. I would cut it down to 1/2".
 
Have you checked that the pulleys are lined up and running true ? The crank pulley in particular can be damaged by rocks thrown up from the road; and the water pump pulley sometimes comes loose on the shaft. Worth a quick look with the engine running, to see if the pulleys are running true.

"Rhythmic" sounds like a bad spot in either pulley or belt; loose belts normally shriek more-or-less constantly.

Don't recall if I got it from Moss, but the last 'German' belt I had was hard as a rock and didn't last very long. The Gates belts from NAPA work much better, IMO.

That's interesting about the 4A manual ... the TR2-3 manual calls for belt deflection of 1/2" to 3/4" in the longest run.
 
Sometimes you get an mystery metallic sound from a fanbelt, though more so when they get old and dried out. Belt dressing, available in a can from auto stores, and applied while the motor is running, will quieten it. Take great care though, and use the plastic tube extension supplied with the can to get in. Try and spray each tapered side of the belt where it's travelling downwards if possible. Goggles needed if spraying on the up travel.

The crank pulley is in two halves and of fairly thin metal, and a side of this can fatigue and fracture. Oddly, a piece of the pulley will depart, yet the belt stays on, so it's something to check.

Viv.
 
Sometimes fanbelts will squeek until they are paid for. Or was that shoes?
 
The angle of the "V"(belt) has to conform to the "V" in the pulley(s)If the belt DOESN'T sit correctly in the pulley its going to make a noise.My personal opinion?you have the wrong belt.Suggestion go to NAPA AUTO take your belt with you & have the clerk look up a belt for your car & compare them.If you tighten the belt TOO TIGHT IT WILL wear the bearings.ALSO the belts & pulleys have to run on the same parallel plain,if the belt is not riding straight it will squeek.GoodLuck :savewave:
Ken&Whitelightning
 
I have also just replaced mine, with the same belt, and also have a squealing sound, changing with engine speed. (My car has just been rebuilt, it was quiet before, but generator bracket may not be aligned as it was before.)
I have tried belt dressing, did not work, tried loosening and tightening, did not work, also removed belt and ran the engine for a few seconds, nice and quiet.

I have tried adjusting the bracket to improve alignment, which seemed to help, and tried spinning the water pump and generator pulleys by hand, but did not find them unduly noisy. The belt has not been getting loose, but the noise is driving me crazy.

I will look at the angles of the sides of the belt, thanks!
Simon.
 
I recall seeing TRF advertising that they'd located some very high quality belts, and hopefully they aren't the same brand as the noisy Moss ones.

Others wide belts suitable for 4 cyl TR's are-

Dayco Top Dog Gold Label cogged fan belt p/n 28380 (20 x 965)
Cummins Diesel cogged fan belt p/n 178539WRZ

Viv.
 
Simon, I have tried all the same fixes and also assured that my pulleys were aligned. I now believe it is the belt, which certainly had a different side profile than the one it replaced.

Randal, do you have the part number for the Gates belt that has worked for you? BTW, you were correct on belt tightness, I rechecked the manual and 1/2 to 1" is correct deflection for TR4

TRF does have a "high quality" smooth belt for sale, and I will try this if I can't get the Gates belt locally.

Thanks
 
Don Elliott said:
For my TR3A I use a Gates cogged belt 19mm by 970mm.

I don't know how you can install a 900mm belt.
Click to expand...

Don, I'm assuming you believe it would be to small. FWIW, with this 900mm belt from Moss, I am using 90% of the maximum adjustment...so I was thinking the 900 was a little on the large side,as I have little room to tighten any further. Go figure
 
Hi Don,

I have an older belt which is 970mm, (IIRC) and is too loose no matter the position of the generator on its bracket.
The shorter belt is either 900 or 930, I forget which, and fits correctly on my car, i.e. somewhere in the middle of the range of adjustment.
Simon.
 
That's weird, as like Don, I was wondering how a 900mm belt would fit. The metric conversion of the old imperial length belt was always very near 965mm. All I could figure was that it may have been a 17mm width belt that sat lower in the pulleys, and would therefore need to be shorter. Maybe its to do with measuring the inside or outside length, but I thought there would have been a worldwide standard spec.

Just another TR mystery, but inconvenient if you get caught out on the highway with the wrong belt, and then don't have a passenger wearing nylon stockings to swipe, so as to get to help without cooking the engine.(Stockings only work between the crank pulley and water pump. Don't include the generator loading... just run on the battery)

Viv.
 
Update on the situation.

Based on recommendations from Randall and others I installed a NAPA 25-28386 (Gates Number TR28386) This is a 7/8" X 39-1/8" cogged belt (22mm X 995mm)

Thought the belt would be to long given earlier comments in this topic, but when installed it's just right on my TR4A. Best of all the squeak is gone.

I would definitely recommend this one over the Moss 834-025 belt.

Cheers

Michael
 
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