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Broken Belt

wbird

Member
I broke my belt this weekend and need some advice.

The belt I broke was a HPPD Plus. I am considering the Blackhawk belt as a replacement mainly b/c I have heard that it is tougher and stronger. The belt failed at the worst possible time - in the marsh with 9 hunters scattered out and no other way to get to them except in an airboat. I don't want this to happen again. This is the second belt I have broken in the last 100hrs.

The belt was tight and there was nothing lodged between the upper and lower assemblies. What are the possible reasons for the belt breaking and how can I prevent this in the future?

FYI - I have a chevy 502/502 with a CH3 2:1 reduction unit.

Thanks in advance.
 
How cold was it maybe the belt you used was temp sensitive things get brittel when they get real cold or you have somthing rubbing on it you have not seen yet
 
I thought you might be in a real cold area so I guess that not it I had 120 hrs on my belt drive when I changed to a gearbox never had a problem have you checked to see if fuel is getting on the belt so how that could have a bad effect on it.
 
Wbird,

Talk to Faron.. There is something drastically wrong (i.e. too tight, too loose, mis-alingment) if you're only getting 100 hours on a belt. I've got over 1350 hours on mine and it looks like new. (502/502 with a ch-3, 2:1)
Hope you fine the culprit....
Brian.
 
Made a call today to AA. Farron and Stan are out until next week and I am not sure if I will get in touch with them until then. I need to make the order today or tomorrow for the belt so I can get back up and running. Any comments on the Blackhawk belt? I plan to identify and fix the problem when I replace the belt and hopefully it will not be to mush of an issue $$$$. Thanks for your response.
 
id go with the black hawk tougher than oem just change mine the original belkt was 7 years old to tight is a killer needs to flex some should rumble a little when you step on the peddle
 
My boys CH3 was bought way used but still had the original belt. He painted it up and has had it on his boat now for I guess 5 years. I'd guess it has over a thousand hours on it anyway.

One of my first instructions when I went to work in the Seismic fields was ya don't just stab the throttle and ya don't just take yer foot off from wide-open. I took it to heart and never had a problem with them but those who thought they knew better were called belt-wrappers. The name implys it all. Ya can tear one up but ya don't have to.

I'm guessing you may have had a factory defect or infant failure kind of thing. I'd go with the newer toughter belt to, just in case. There is a tension standard for the belts and I'm sure Frnklin is willing to share info. Too tight and they heat up and snap too lose and they will stretch and either snap or over run themselves. The two slack sides must run true with no waves in them.

Jus thinking out loud on this one. Never saw one break with that little service on it.

Scotty
 
Something to consider about the Blackhawk belt ...... it's stiffer, so it will steal some horsepower.

You should be able to easily get a thousand hours out of the standard belt, so I'd look for other causes.

olf
 
I appreciate your input. The black hawk sounds a little more labor intensive but worth the $40 extra dollars. Whats a fair labor estimate in hours that a knowledgeable airboat mechanic could replace the belt n?
 
Got mine done in about 2 hrs with help from jdotson franklin will send a step by step pretty simple.
 
I think it is. A stiffer belt will be harder to turn.

When you go to install the new one, you'll diassemble the whole drive and come all the way back up with it. There are several things that are real important to look for ....

1) Check the outer case bolts and make sure they're still tight.
2) Check the bolts at the crankshaft where the flexplate bolts on and make sure they're still tight, and that none of the holes in the flexplate have cracked out, which would let the lower drum wobble.
3) Check for any play between the lower drum and the pilot into the crankshaft. Any at all is too much.
4) Check to see that none of the bolts between the lower drum and the flexplate have loosened up, or if any of the bolt holes there have cracked out.
5) When you install the new belt, a little too tight is better than too loose. A new belt will stretch just a little.

PM me if I can help.

olf
 
All the things Olf Said are right on 100%

When tightening the concentric adjustment remember NEVR use a long handle to make it tighter. Turn it with your hands only til it is tight and lign up the nearest bolt holes. If you have to use an extender bar to make that next set of holes line up, thats too tight.

I'm guessing the stiffer belt will warm up from its own stuffness and NOT be a LOT more power robber than the OEM belts. Maybe just a bit. If you were having a problem and didn't know it you may still yet see a performance increase when its all said and done.

Any wave in the slack side of the belt path will steal HP like crazy. Be good to check that belt after a few minutes of idling then again at the end of the first run. Readjust as necessary.

Keep us posted on developements, lot of us are interested.

Scotty
 
Bear, you may be right about the stiffer belt. I got six years out of the old one though and saw no reason to change.

The Lord looks out for dumb ol' folks like me. When I was changing my old drive to the new motor I found two holes cracked out in the old flexplate. :shock:
I ordered a new TCI flexplate from Summit for $68.00 which is approved for drag racing. That should be the end of that problem.

olf
 
Olf we saw a lot of cracked flex plaqtes. We put the drag rasing ones on and they seemed to do better but still need to be inspected periodically.

I have heard a lot of specualtion on flex plate cracking and it seems to be a factor inherrent in this drive. Obviously the thin stock and OEM plates crack but so to may the heavier ones. Having said that my boy hasn't had any cracks in his yet and its old now. His is just the stock 'Vette plate.

I know that substituting washers instead of the proper spacers will cause it to crack right away though. Seen that done and it was a disaster.

Scotty
 
Would it make sense to order a flex plate and ???? when I order the belt, anticipating problems. Anything else you recommend doing once the unit is broken down?

Thanks for all the input guys. I appreciate your help!
 
Yes it would, its the perfect time to get the heavier one.

Just inspect your bearings closely. They aint much fun to tear down and have to replace better to find anything wrong all at once.

Thats a good redrive unit, they have a super history for work boats where they are run all day every day all day long.

Scotty
 
wbird, when you get the new flexplate remember that you'll probably need to re-shim your starter, which won't cost but $3-4 bucks for shims at any good autoparts store. The new flexplate won't be worn down like the old one was. Just a thought.

Post up if you have any problems ..... there are a bunch of folks on here that run the belt drives. Any one of 'em will try to help.

olf
 
Olf & WB,

Good stuff...I think ya'll are onto something here!

UncleBubba and I saw a CH-3 grenade a few months ago :shock:

Notice the flexplate, (or what's left of it). He was hard on the gas when it blew apart but I think the inspection of the bolt holes mighta been a factor here)?

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