Recommendation for best course of action. Jack shaft.

[emudryj]

So I'm working on this cart I bought for $100, that has a jack shaft and the main problem with it was that the bearings on it were completely gone...

I pulled it today to follow the advice about switching the sprockets on the jack shaft to bring the ratio higher, and it was like opening the worst can of worms ever...

Since this is my first time dealing with a jack shaft I would really appreciate your advice.

Some of the problems:
#1- (and probably the worst) Somebody decided to WELD the sprockets to the shaft!!!! so now I have no way (that I know of) to remove shaft to turn it around and change the ratio. Short of grinding the shaft to save the bracket, i do not know what to do.


#2- As you can probably see, the previous owner (PO) blew the bearings but for some reason thought it would be OK to keep going. The shaft ran for some time bare naked against the bracket, which in turn "ate" a good chunk of the shaft.


#3- The situation above, also caused the bracket hole where the bearing should seat to be deformed.


So, in conclusion:
- I cant remove the shaft without cutting it.
- Even if I leave the sprockets the way it is, I would till not be able to put one of the bearings because the sprockets and locking collars are welded to the shaft...
- Lets say I cut the shaft and get a new one with new sprockets, is the bracket still usable with the deformed hole?

So... what would you guys do?
Start from scratch with a new jack shaft?
Salvage the bracket?

 

[Denny]

That whole mess is fubar. I would start over from scratch.

Denny

 

[crazykart]

Ya, you need new everything. You may be able to save the sprocket by grinding the tack welds off, but if you're going to go with a different ratio then there really isn't too much of a point to it.

 

[DHC]

Not sure of your setup... but I would definitely recommend replacing everything. Only item I see salvageable (maybe) is the gear, after grinding it off. As far as the bracket... it may be able to be salvaged by enlarging the opening enough for a metal pipe/sleeve of proper ID for the bearing, and JBWelding the sleeve in place... but that is ONLY if you cannot replace it... plus it would be a royal pain to line it up w/ the other bearing, determine the depth of the sleeve, cut the hole to 'just' slide the pipe/sleeve into, etc... and it may/maynot work, depending on the torque applied.

... best bet is get/make all new!

 

[landuse]

I would buy a new kit or make your own

 

[emudryj]

Ya, you need new everything. You may be able to save the sprocket by grinding the tack welds off, but if you're going to go with a different ratio then there really isn't too much of a point to it.

Yep... that is what I thought... I was hoping you, more experienced guys, would see it different...

Really not too concerned about saving the sprockets. Those are readily available and somehow cheap. Just order online, sit and wait.

The bracket on the other hand would be a little bit trickier but I'll see what I can do about it..

I'm looking at this as an opportunity to set the ratio I wanted...

with the ones I had, I was going with 14t in to 10t out for a 6.4 ratio. I've noticed that is kind of the standard for most jack shaft kits out there, but if I would have to go wit new ones... what sprockets should I look for? more teeth on the input side? what is the next step above 14t?

---------- Post added at 09:34 AM ---------- Previous post was at 09:24 AM ----------

Not sure of your setup... but I would definitely recommend replacing everything. Only item I see salvageable (maybe) is the gear, after grinding it off. As far as the bracket... it may be able to be salvaged by enlarging the opening enough for a metal pipe/sleeve of proper ID for the bearing, and JBWelding the sleeve in place... but that is ONLY if you cannot replace it... plus it would be a royal pain to line it up w/ the other bearing, determine the depth of the sleeve, cut the hole to 'just' slide the pipe/sleeve into, etc... and it may/maynot work, depending on the torque applied.

... best bet is get/make all new!

That is a REALLY GOOD idea!!!! but what if I do the small sleeve thing on both sides and use 4 bearings instead of 2???
I bet that if I can find the right size pipe and my small Harbor Freigth core flux welder would be good enough I could pull it off. I may be able to use the old shaft to line up the pipes...
Cutting the hole could be the most challenging part.

 

[mckutzy]

If you have the welder, weld in a new hanger. Don't rig up a fix. It will be less hassle later on.

 

[crazykart]

Yup, just weld on a new hanger, or get pillow blocks. Now that I look at it again, if it's just the end that's chewed up, and you have a way to cleanly cut the end off you might be able to reuse the shaft itself.

That would depend on the length vs the area it is to be mounted in though. I can see chopping a few inches off the end if you can move the bearing hanger placement in to compensate, but that's just me.

 

[emudryj]

If you have the welder, weld in a new hanger. Don't rig up a fix. It will be less hassle later on.

After a quick cleaning the bracket is looking much better already, the shaft is looking much worse.

I'm sure that I can grind the bad hanger clean, easily, now... the shaft is beyond repair... I could give it a try but it will end up with too many weaker points.
I already ordered the kit.

I have one of those (Harbor Freight) Chicago core flux MIG-100 welder... nothing fancy but has serve me well in the past.

The bracket steel is 1/8 thick and I'm not really sure about the thickness of the hanger because I have not got it yet...

Do you guys think that my welder would be good enough for a job like this??? I have welded other things but I'm not sure about this one.... worst case scenario I would have to take it to a welder, the hardest part will be to make sure they align both hangers correctly..;

 

[utahoutdoors]

scrap it... Make your own via kit or buy some bearings and JS itself.

 

[landuse]

Your welder should be fine for what you need to do there. Just go slow on the thicker stuff

 

[emudryj]

Your welder should be fine for what you need to do there. Just go slow on the thicker stuff

Just read the really good thread about welding on the FAQs... Learned a lot!!!!
I was doing it very wrong....

Will grind old hanger this weekend and give it a try to weld the new one as soon as I get it...

 

[mckutzy]

Why not cut that worn out thing off, smooth out and redrill those old holes. Put in a self aligning bearing/hangers with the right shaft diameter, instead of re jigging that JS bracket.

This kinda begs the question of why it way kinda messed up like this in the first place... Your pics show it looks fine...at least to me.

 

[emudryj]

Why not cut that worn out thing off, smooth out and redrill those old holes. Put in a self aligning bearing/hangers with the right shaft diameter, instead of re jigging that JS bracket.

This kinda begs the question of why it way kinda messed up like this in the first place... Your pics show it looks fine...at least to me.

Well, that is kind of what I'm trying to do without the self aligning bearings... did not know that those even existed...LOL

I wondered the same... and I'll tell you what I think... The had it running and they needed to replace the jackshaft bearings. Whoever replaced them had a good welder machine and decided to go the extra mile and weld all the collars and sprockets in place. To make it worse they made placed the jackshaft as far as they could from the engine and axle leaving no play in the chains, kind of bungee cord tight...

The amount of oiled dirt on the whole jackshaft was disgusting, so I think that at some point all that dirt got to the internals on the bearing but they kept using it and going, and going.

The bearings finally failed, and you would think they would stop at that point, but no.. they kept going and going even when grinding metal against metal...

I'm sure that somebody looked into fixing it by replacing the bearings, but since the collars and sprockets were welded they could only change one, and it was not even the one on the worst shape.

But that is just me guessing...

Easiest plan was to sell...

 

[utahoutdoors]

what size is your JS?

 

[emudryj]

what size is your JS?

Mmmm not really sure to what measurement exactly you refer too, but, here is what I know

shaft is 3/4" thick by 10" long with a groove for a 3/16 (I believe) key

Sprockets are are 10T and 14t for 40# chain.

Bearings are 1-3/8 OD by 3/4ID,
Distance from sprocket to sprocket is 5-1/2

Bracket width is 5"

I hope I provided the info you requested... I can't think of any other size...

 

[utahoutdoors]

Looking at your pictures I think I would scrap it and start over. Some of your pictures I see some issues with the bearing hangers, etc.

I personally would hate to put $$ into something that may fail. Just my 2 cents.

 

[mckutzy]

It most likely failed by it not be able to be totally aligned with each other(maybe buddy couldn't find those bearing/hangers of right size). Tension on the chains compounded the issues and destruction occurred.

 

[chancer]

If you already ordered a "kit" It should come with new bearing hangars. They are really just GIANT washers. Here is what I would do, If I was doing what you are trying to do.

I would weld the new bearing hangars to the old bracket. Maybe even open up the old holes.
First put the bearing and shaft and hangars together. Then tack weld the hangars in place. This should help you get everything lined up straight and square. Be CAREFUL welding even tacking with the bearings in place. Then take it apart and securely weld the new hangars. Also since you are dealing with a jacked up bracket maybe add extra collars on each side of the bearing to keep everything in place.
In my opinion your Chicago welder should handle this job. If it is not working then stop before it looks like a bird pooped on it.

 

[emudryj]

Looking at your pictures I think I would scrap it and start over. Some of your pictures I see some issues with the bearing hangers, etc.

I personally would hate to put $$ into something that may fail. Just my 2 cents.

Would you tell me what you see wrong with the hangers on the pictures?... So I can avoid doing it...

---------- Post added at 09:05 PM ---------- Previous post was at 09:04 PM ----------

It most likely failed by it not be able to be totally aligned with each other(maybe buddy couldn't find those bearing/hangers of right size). Tension on the chains compounded the issues and destruction occurred.

I was thinking that could be and option too... bu any chance is there an instructional video that you guys know on the correct procedure to align a shaft???...