Qsb raw water belts.

[john]

The older qsb with a v belt is so simple and works great for tensioning. The flat serpentine belt is a just a crazy design. Anyone have tips to pit it on. I just did two and replaced a pump to a seaboard pump. I think the jabsco pump was easier than the seaboard pump. Had to loosen everything then pry the belt over. Seems to tight to me. The jabsco pump I put one bolt in and levered the pulley into place with a pry bar. Reguardless I think it’s a poor design

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[Tony Athens]

If you had a Sherwood QSB pump side but side with the SMX QSB pump and took them apart, with your experience, you immediately see why “Sherwood” left a lot of room for improvement………..
Actually, you might be impressed ..

Tony

[Fireisland1]

I have changed a lot of pump in 50 years. The v pulley QSB is about as easy as it gets. I suspect the problems with the Sherwood pumps came from lack of maintenance. They can be difficult to rebuild and I bet most owners just kept putting in impeller instead of a full rebuild. By design there is a lot of stress on the bearings. I’m sure it’s can lead to mechanical seal failure quickly. I can see not getting high hours out of them. I just did one of mine and it took an hour with the use of pullers and shop press. It’s not a back yard repair.

[Tony Athens]

Is the “stretchy belt” super high tech, or just a proprietary part “rip off”‘?….

I say the latter, so Ii am working on it………..

Tony

[David R Flamer]

I have to "old" style 3-pulley system

No, not the best, but it is pretty straightforward to R&R the single raw water pump belt. Oh the whole, the belts for the early design QSB 5.9 are pretty inexpensive. I always have 2-3 sets just in case.

[28Cuttyhunk]

Stretchy Belt

Its more difficult to get the old one off, maybe 2 minutes. You can roll a new one on in 60 seconds. Only thing not to like is the $160 price tag of the belt.

[john]

Yes it is the first time dealing with the as you say streachy belt. Not to streachy to me. I have three sets of qsbs that I work on. This is the first with that belt setup. I guess I’ll take this over the old b series gear driven pumps so its quite a bit if improvement. I will make a long pry bar into a spoon to get them on. I think that will help.

[Tony Athens]

John,

My guess is this is the first time you dealt with the “stretchy belt” and you went thru a frustrating “learning curve”..

Yes, it can be tricky., but once your “learn” how to deal with it, it is easier & way faster than the v-belt and really requires zero maintenance..

I am not saying I like it, but it seems to be a reliable system.

Tony

[john]

Yes I was getting things confused between sherwood and jabsco. To many pumps to remember. You do have to tension the v belts some but installing them in a engine room is much easier. I know the extra parts are a liability somewhat. I happened to work on both designs yesterday. Tensioned belts on a v belt and installed one of your pumps on the blizzard . Changed the flat water pump belts also. It is a very difficult job in a tight area like that. I know you don’t do it that often but design wise seem poor to me. Tension on that belt seems to much but it seems to work.

[Tony Athens]

John,

They never was a “Jabsco pump” on a QSB.. Not sure where you came up with that…How ever, Cummins did redesign the Sherwood pump drive system a few years after it came out..

Early designs were the 3-pulley v-belt system and then Cummins redesigned to to what we call a “stretchy belt system ( the small serpentine bet that needs to to “stretched” over the pulley when you do not understand how it’s done.. The 3-pulley drive did have some issues and I believe was one of the reasons for the redesign ( besides simplicity and cost). Between you and me, I am not a fan of either, but will say that the later design has be reliable

As to our pump, just a vastly improved version of the Sherwood design, nothing else– Either “pulley system” fits it, as that is a Cummins thing, not mine..

Tony

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