Intermediate sprocket install

4sd911 · 05:28 PM

Trying to heat up the sprockets to install to the intermediate shaft. Using a propane torch I'm having a tough time getting it hotter than about 250f, would using a mapp torch damage the sprocket? Or will that even get it hot enough? I guess the question would be is using a torch to heat the sprocket going to damage it?

ETA: I should add that the mapp gas torch did turn spots on the sprocket blue.

dtw · 03-24-2010, 06:00 PM

I always toss the jackshaft in the freezer overnight. Then I simmer the sprockets in oil to about 200. Quickly pull the shaft from freezer w/tongs, not hands. Throw the shaft in a vice, bring the saucepan out to the garage with tongs, drop them on the shaft, done. Requires a certain 'rhythm' but it is really not that hard.

cgarr · cgarr's Garage

Toss it in the oven to about 400 and as Dave said cool the shaft, be aware you only get one shot to get it on square before your advantage goes away, a bit of oil will help.

4sd911 · 06:31 AM

OK, so should the sprocket itself be 200 or 400 deg.

Did I damage it by heating with the torch, should I get another one.

Eta: If heating sprocket in oil do I need to use motor oil or can cooking oil be used? I don't like using motor oil in the kitchen.

dtw · 03-25-2010, 07:02 AM

You can't heat motor oil to 400, it will scorch. So if you do it in a pan of oil, just go to 200 or 250 if you're feeling froggy (but things happen fast if the temp goes any higher...ask me how I know

). If you put 'em in the oven dry, you can get to 400. Then just make sure you have plenty of oil on the shaft when you go to drop the sprocket on. Just a matter of preference on how you want to proceed.

If I had to guess I'd say any distempering of the steel from the torch was just on the surface, but that's only a guess.

4sd911 · 03-25-2010, 02:17 PM

It's done. Used the freezer and oven method dry no oil (only oil on the shaft), my temp gun even after over 1 hour, only showed the sprocket over 200 deg. f. First try I used a 1 1/2" pipe to send it down (as the sprocket would not slide on without help) the key slid out and had to use the puller to get it back off, it was still hot and came off easy but did leave marks on the inner face of sprocket, not near the teeth. Next two tries worked for both sprockets but I did have to use the pipe and hammer to drive it home. The oven did turn them a bit blue anyway.