VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 31 fan belt

Cool! Glad that you found the correct brace for your generator. On the new old stock belt.....be careful with those because I have had several and, due to their age, they were brittle and hard as a brick and not really that serviceable.

:( :( :(

i buy mine at the local tractor supply they are not cogged and made of kevilar probably may have to never replace . hope this helps

The kevlar belts from Tractor Supply are green color but can be lightly painted with flat black paint to make them look more original. I have run several fractional horsepower belts from the local hardware $ 4-7 and the kevlar belts without any problems. Eventually any belt will fail because of heat, light and atmospheric gas which causes them to harden.

Well, I spoke too soon. The 5L360 belt is too short, and the 5L370 is too long, and they don't come in half sizes. Maybe a kevilar belt is the answer. I'll be near a tractor supply house in the morning. Could it be that the bracket I found is too short? It is a total of 7" long, and slightly curved at the generator end. I mounted it as Junkyard Dog advised.

It sounds like you have the correct generator brace. The problem is that you probably don't have the correct length fan belt. The length of the belt should be approx. 38 1/2". See if you can find a Dayco 24380 fan belt. Those work great and they are the correct length as well.

Unfortunately I don't remember the number of the TSC belt but it is the wide 38" one that fits. The 36" belts fit the late four bangers.

Interesting belt...

ebay belt for sale

I don't know but I don't think it is original....maybe a later replacement belt? The experts will know.

Just checked the belt on one of my '31 engines. it is a 5L380 fractional hp belt. The length is just right putting the adjustment about 3/4 of way to the end of the slot in the brace.

Thanks for the help guys. I bought a 5L380 fractional hp belt yesterday (nice green color!), and it comes closer than anything so far, but still doesn't fit. When I put it on, I'm unable to tighten it. The adjustment brace is at the end of its run, and it needs another inch or so to tighten. As I said previously, the brace is 7" long and has a slight curve at the generator end. If it were one or two inches longer, it would work great. I mounted it as Junkyard Dog advised. It's kinda weird 'cause earlier I bought a 5L370 belt, and it was too long - it must have been labeled wrong. Could I have a larger pulley on the generator (3 1/4") or water pump (4 1/8") that would cause this? I'm considering asking a machinist friend to make me a slightly longer brace to solve the problem.

I don't understand why you are having a problem. Just measured two '31 engines with 7" long braces. The generator pulleys are ~ 3 5/16" diameter and the water pump pulleys ~4 1/8" dia. One has a 5L380 belt with generator bolt ~ 1" from the end of the slot. The other uses a Gates Powerated 6938 belt with a similar space on the brace. Do you have the correct generator? It should be a Delco-Remy Model 943J.

6wheel, have you measured the belts you have?

I don't know why you can't get the fan belt to fit either. The correct belt measures 38 1/2" and if your belt measures the same then it is correct.

A 39" belt on my '31 Sedan is barely tight enough not to slip with the adjustment out to the max. I could see it vibrating and it made a buzzing sound at driving speeds. I now have put on a NOS belt that is a perfect fit. It is a John Bull #55, made in England. It's NOS from the 50s or 60s so it may turn out to have a short life. Does anyone know what a John Bull #55 was made to fit?

I have a 38" to 38 1/2" (depending upon how you measure it) belt on my car and it fits like a dream! With this belt the adjustment bolt is right in the middle of the long slot at the end of the generator brace...just as it should be. d2d2....it sounds like your 39" belt is too long, and that is probably why you are at the end of the adjustment.

I have three different new old replacement stock belts, and they all measure 38" to 38 1/2" long as well.

By the way, the John Bull #55 belt is not a NOS belt. It is a "new old replacement stock" (NORS) belt and it is an aftermarket item. A new old stock belt would be an "OEM" item (original equipment manufacturer) which is new original belt from Chevrolet with the correct Chevrolet part number and etc.

I don't care if it's NOS, NORS, or whatever. John Bull #55 looks right and works right so maybe I can get some others if I find out what they fit.

Just trying to keep the terminology straight for the new dudes that don't know the difference between NOS and NORS since the terms are not the same.

Yep, any aftermarket belt will work great if it is the right length. Sounds like the John Bull #55 will work fine if you can locate more of them and find out what the application is.

:p

Thanks Chipper, I think you are on to something. The generator is a Delco-Remy. Tags from both generator and starter were removed by the rebuilder, but I saved them. One says 943R 227371, and I assume it is from the generator. The other tag says 714L 860809. What year is the 943R? Is it larger or are the ears located differently than on the 943J?

If I remember correctly the 943R is a '30-31 Chrysler generator. Also fits DeSoto, Dodge and Plymouth maybe others. I think I have one around here somewhere. Maybe the dogface can tell if the housing is different than the Chevy.

The housing is the same, and if you are using the correct dia. generator pulley on your 943-R generator then the 38" to 38 1/2" fan belt should fit just fine.

Do you have the correct harmonic balancer on your car or the correct engine?

Junkyard Dog, the # 2879918 is stamped on my engine behind the fuel pump. Casting # is 8364 9 and date code is H 10 1. So, it is a '31 engine, correct? The harmonic balancer is 5 7/8" in diameter.

Yep, you have a 1931 engine.

Louis C., I measured the new green belt, and it's 38 1/4" outside. It comes closer to fitting than any of the others, but I still need another inch or so of adjustment on the upper bracket to snug it. Dog, are the mounting ears in the same locations on my 943R generator as on the 943J?

I just checked my Delco-Remy parts book and while the generator housings and the comm. end frames are the same for the 943-J and the 943-R generators, the drive end frames are different. That is probably your problem.

You might want to check into getting the correct generator for your car.

Guess I need to find the 943R that I have stuffed somewhere and check it versus the 943J. I will look later this evening.

One of the '31 engines actually has a 943R generator on it. With the 7" brace mounted in the top large bolt in the timing cover and 5L380 belt the adjustment bolt is about 1" from the end of the slot. Now I assume that all the parts in the 943R are correct including the front plate. The front plate appears to be the same as the 943J generators so it might have been changed. If that is the case then it might still be the problem.