Broke jackshaft

[mikeatnight]

My daughters Streaker Kart broke the jackshaft, It has a 13hp Honda engine. Any idea what to do to get the shaft out and anyone know where to get one like this?

 

[OzFab]

...one like what? Without details, measurements &/or pics, we can't really help apart from giving you the names of websites.

We endeavour to help everyone as much as we can but you need to help us first

 

[mikeatnight]

The shaft is 3/4 inch diameter. Approx 11 1/5 inches long. It appears to be threaded on both ends except where the bearing is in the first picture. The sproket appears to be threaded on. Everything I have found so far shows a slip on or pressed on sprocket. Does the sprocket just screw off? and then the shaft slips out?

 

[mikeatnight]

Oh and it is a Comet 40

 

[r97]

I would get a 12" or so length of 3/4" keyed shaft, an identical sprocket but 3/4" bore with a key-way, some key stock, and possibly some locking collars. I think having the sprocket thread on like that might have contributed to the failure (which I still can't believe!). You might be looking at new bearings too, so make sure to check those. thebigbearingstore.com should have everything you need. I'm assuming the jack shaft isn't stuck inside the bore of the driven, correct?

 

[mikeatnight]

The broke shaft is still in it and Im not 100 % sure how to get it out

 

[r97]

I would get two sections of 4x4 wood, put them on the floor with a roughly 7/8" gap between them. Place the stationary sheave of the the driven on the two pieces of wood (The cam should be facing you.). Next align the driven so you can push the shaft out and it will go between the two pieces of wood. Finally get something like a 5/8" rod, place it over the end of the broken shaft, and tap the rod with a hammer. Don't go crazy with the hammering, if it obviously isn't going anywhere stop. You can try soaking oil around that part if just hammering it out doesn't work.

 

[mikeatnight]

Thanks.

 

[mikeatnight]

Well i finally got it apart. Here are some images of the broken part. Do you think it can be welded?

 

[OzFab]

That depends on how much of the keyway you need. To weld it properly you would need to "V" the ends (grind them at a 45* angle at least half way through the shaft) to ensure good penetration.

Then you would need to find a way of keeping the shaft absolutely straight while welding it; not as easy as it sounds.

Another way to attack it is to drill both halves along the centre, tap a thread into both & use a bolt to hold the two together (again, accuracy is the key) then weld it.

The easiest way is to buy a new shaft but, as toystory would say, we are DIY

 

[Wwalding]

Take it to a machine shops. They can either fix it or build you a new one..

 

[r_chez_08]

Do you think it can be welded

It snapped when not welded and stronger, so I would say no.
Would need a method of getting it true also. Not worth the hastle.
Get a new jackshaft and modify your setup slightly, e.g. Use lock collars instead of nuts.

 

[little billy]

You will not be able to weld this. for about 20-25bucks you can order a 1045 keyed shaft. thread the end of it, order a new sprocket, and buy a few shaft collars. thats what I did on mine and it works great.

 

[mikeatnight]

We tried welding but I knew it wouldnt work. It was a good straight weld but the guy didnt cut an angle on the end pieces. It held for about 10 minutes. We have a new shaft ordered. Gonna ditch the threaded end and just put a collar on it. Thanks for all the help and suggestions.

 

[Blazkowiez]

Any Azusa dealer can sell you a 14" 3/4" shaft, just use locking collars on each end.