1967 water pump belt headaches

[Gary S.]

Good afternoon to all. My neighbor has a 67 427 tri-power and decided to (finally) add a water pump belt after driving the car for a year with only the alternator-water pump-crank pulley belt. I cannot figure out how to get the water pump to crank pulley belt on since there isn't a tensioning brace like there is on his alternator. A search (I think it was for a 70-72 454 however) here turned up that some just pull the fan, clutch and water pump pulley, install the belt and then force the water pump pulley back into position. Is that the approved technique or is there an alternative? This technique isn't working since the pulley needs to come up about 3/8" to get the bolts started.

In lieu of the Quanta restoration belt does anyone have an aftermarket belt from the local auto parts store that works ?

Thank you.
Gary Schisler

[Joe L.]

Good afternoon to all. My neighbor has a 67 427 tri-power and decided to (finally) add a water pump belt after driving the car for a year with only the alternator-water pump-crank pulley belt. I cannot figure out how to get the water pump to crank pulley belt on since there isn't a tensioning brace like there is on his alternator. A search (I think it was for a 70-72 454 however) here turned up that some just pull the fan, clutch and water pump pulley, install the belt and then force the water pump pulley back into position. Is that the approved technique or is there an alternative? This technique isn't working since the pulley needs to come up about 3/8" to get the bolts started.

In lieu of the Quanta restoration belt does anyone have an aftermarket belt from the local auto parts store that works ?

Thank you.
Gary Schisler

Gary------


The problem is that this CAPTIVE belt application with no adjustment possible requires a belt of a specific, exact length. The original PRODUCTION and SERVICE belt was GM #3837810 which was 34-3/8" in length. It's difficult or impossible to find an aftermarket belt of this, exact length.

GM #3837810 was discontinued in September, 1974 and replaced by GM #9433722. That belt is supposed to be of the same length but I don't think it is. I think it's slightly different but it might work. It's also been discontinued but you might be able to find one.

As far as installing this captive belt, I have found that it's best to remove the balancer pulley, install the belt and pull down enough to allow the balancer pulley to snap into place.

[Gary B.]

Gary,

For my L79, I ended up trying 4 different captive belts from Quanta before I got one to fit. Quanta offers a short version (34.4") and a long version (34.8") of belt # 3837810. The first two belts from Quanta measured 34-1/8" and 34-3/16"; both didn't fit; the long version measured 34-5/8" and was clearly too big. The 4th one fit nicely. It’s a Goldilocks thing.

I recently had a similar issue with the crank-water pump-alternator belt. The first Quanta belt was so short it placed the adjusting bolt for the alternator brace at the extreme engine side of the slot. I called Quanta and they went thru their inventory belt by belt based on my belt length measurement and found me one with their same part number, but it was enough longer that my adjustment bolt is now much closer to center. Obviously there is variability in the lengths of the “same” belts from their supplier.

I installed my captive belt as you tried to do, by removing the water pump pulley, then pulling up with the belt in place. Maybe Joe is right that it’s easier to remove the crank pulley and then be pushing down, but I had little difficulty pulling up on the water pump pulley. If you have a belt of proper length either approach will work.

Gary

[Thomas N.]

Quanta has two part numbers for the BBC secondary water pump belt. I bought both of them, and it was the larger one that went on, still hard to do. I looked for the sleeve for the part number that the belt came in, but couldn't find it. I removed the pulley on the waterpump, installed the belt and put a brass drift between the hole in the pulley and the threaded hole in the water pump to give some leverage. If I remember correctly installing this belt before the small hose that goes from the top of the water pump to the intake manifold helps also.

[Gary B.]

Tom,

As I tried to say, I bought both a short and a long version from Quanta. There is no guarantee that either will work, which was my initial experience. It’s better to tell Quanta the length of what you have and the length of what you want, as I did with my alternator belt and Quanta was able to go thru multiple belts of their same part number in their inventory and find a length that is closest to what you want. At least that approach worked for me, without going back and forth just buying more belts and having me try them.

Gary

[Gary S.]

Thank you for the comments. I did search the GM part number from Quanta and from that got the length of 34.4". In addition I had a previous email from them saying "most choose the short version". Unfortunately we will have to send this one back and get the longer one. The only good out of all this is that the weather in Pittsburgh area is far too cold to have to rush out and buy something/buy anything! Quanta's website is no longer showing both short and long but we will call them tomorrow and order the long one, hoping that they actually have it. I will have my friend ask them to measure it because this one clearly isn't going on.

[Patrick H.]

I bought 3 different belts thru Amazon to get one to work perfectly for this type of application. Cheaper than Quanta, but still painful.

[Joe L.]

Thank you for the comments. I did search the GM part number from Quanta and from that got the length of 34.4". In addition I had a previous email from them saying "most choose the short version". Unfortunately we will have to send this one back and get the longer one. The only good out of all this is that the weather in Pittsburgh area is far too cold to have to rush out and buy something/buy anything! Quanta's website is no longer showing both short and long but we will call them tomorrow and order the long one, hoping that they actually have it. I will have my friend ask them to measure it because this one clearly isn't going on.

Gary-----


I do not understand how there can be different lengths applicable to the GM #3837810 belt. Originally, they were all the same length.

However, something else that's critically important here: for the 3837810 belt to fit properly, the engine must also be fitted with the correct pulleys. The correct waterpump pulley is GM #3906656. This is a 2 groove, stamped steel pulley of 7-1/8" OD. Depending if the car was built very early in the model year, it's also possible that pulley GM #3864480 was used. This pulley is also 2 groove, 7-1/8" OD and should work with the GM #3837810 belt. Either of these pulleys should be stamped with their part number.

The crankshaft pulley should be GM #3863108. This is a 2 groove CAST IRON pulley of 6-3/4" OD. The part number is usually embossed on the pulley.

If this car does not have the above-referenced pulleys, all bets are off as far as the correct belt.

[Gary S.]

Joe,
When my friend approached me I first went to the F.L.A.P. stores hoping to find a Gates or similar belt to no avail. So I turned to Quanta whom I have done a little business with and been happy. They used to have a short & long belt with the 3837810 part number but with an "A" or "B" designation. Now they just show 3837810. Today i will go back over and measure the pulleys. The problem as I see it is that this car was bought from a well known online bidding website but was initially a 390 horse versus its current condition as a 435 horse car. My feeble research tells me that this particular fact shouldn't make a difference. regardless, I will look at the pulley, call Quanta and as them to measure their belts for me like Gary B. did.

thank you all again.

[Tim S.]

Good afternoon to all. My neighbor has a 67 427 tri-power and decided to (finally) add a water pump belt after driving the car for a year with only the alternator-water pump-crank pulley belt. I cannot figure out how to get the water pump to crank pulley belt on since there isn't a tensioning brace like there is on his alternator. A search (I think it was for a 70-72 454 however) here turned up that some just pull the fan, clutch and water pump pulley, install the belt and then force the water pump pulley back into position. Is that the approved technique or is there an alternative? This technique isn't working since the pulley needs to come up about 3/8" to get the bolts started.

In lieu of the Quanta restoration belt does anyone have an aftermarket belt from the local auto parts store that works ?

Thank you.
Gary Schisler

Depending on the authenticity of your pulley's, Gates number 7348 or 7350 should work

[Gary S.]

thank you Tim. I will be measuring as per Joe L.'s comment.

[Patrick H.]

thank you Tim. I will be measuring as per Joe L.'s comment.

Gary,

I took an old belt, cut it, made it the right length and then measured it.
Note that old style (Quanta) belts might be thinner than modern ones, resulting in a different belt length because of how it rides the pulley. I used a newer belt for my testing.

Good luck.

[Owen L.]

As far as installing this captive belt, I have found that it's best to remove the balancer pulley, install the belt and pull down enough to allow the balancer pulley to snap into place.

100% agree with Joe. Much easier to install it on the water pump pulley first and then mount the crank pulley with the belt on it. The problem with trying to lever it over the water pump snout is that the approach angle makes the belt "shorter" by a good bit — and the water pump shaft is rotating while you're trying to get the bolt holes aligned.

The crank pulley only has a small step to register into the balancer. Use a drift through a pulley hole into one of the bolt holes and you can easily lever it right into place. (Plus rather than trying to pull upwards you're pushing down, which provides more muscle.)

[Robert P.]

I have a gates captive belt that came off my 66 L36 engine , its a 7345 extra service made in USA and in great shape.
This info might help you , also i am not using this belt
Bob Peckham

[Gary S.]

And the story continues:
the pulley that is on his car is a two groove 3900434AB 7 1/8" diameter. A quick search says Camaro and Corvette big block but obviously not the numbers that Joe L. put out.

Thank you all for the comments. The short 3837810 is on its way back to Quanta and we are hoping that we don't suffer the same issues that some of you have had with irregular measurements. The one we got was 34 1/2". here's hoping that Gary B's "goldilocks thing" isn't happening.