Siezed drive shaft.

Mercury · 28 May 2009, 19:08

Hi. I have a 50hp. Merc Four cylinder, circa. 1985. With the drive shaft well and truly seized in the end of the crankshaft. I have tried brute force ie walloping it with a hammer etc. but it wont budge. I am toying with the idea of cutting it off leaving maybe an inch proud then try and drill it out, then chiselling the resulting shell out. the drive shaft has already been cut down to about Six inches. Has anyone had any similar problems, and got a result. If so how was it achieved. Anxiously awaiting any advice. thank you..

m chappelow · 28 May 2009, 19:30

how about warming it or get it hot,

Nos4r2 · 28 May 2009, 19:55

Have you taken the powerhead off? If you haven't, that's your next move.

Mercury · 28 May 2009, 20:03

Quote:

Originally Posted by m chappelow

how about warming it or get it hot,

Many thanks for replying. I have thought about heating it, but I would need to heat the crankshaft end round the splines to expand it. Trouble is I cant get any heat round the crankshaft without destroying the bearing and carrier, thus adding to my woes. Heating the drive shaft would only expand it where heat is applied. It's really jammed/corroded where it's splined in the crankshaft.

Nos4r2 · 28 May 2009, 20:10

Quote:

Originally Posted by Mercury

Many thanks for replying. I have thought about heating it, but I would need to heat the crankshaft end round the splines to expand it. Trouble is I cant get any heat round the crankshaft without destroying the bearing and carrier, thus adding to my woes. Heating the drive shaft would only expand it where heat is applied. It's really jammed/corroded where it's splined in the crankshaft.

Warm the joint with a rag soaked in boiling water then freeze the driveshaft with freezing spray.

Mercury · 28 May 2009, 20:12

Quote:

Originally Posted by Nos4r2

Have you taken the powerhead off? If you haven't, that's your next move.

Thank you for replying. The power head is off. That's how I bought it, I am having trouble with mine so I need this one. It's got good compression but the trouble is the drive shaft wont come out. The previous owner had to cut a hole in the mid section to get a gas torch in, so he could cut the drive shaft, enabling him to remove the power head.

Davie · 28 May 2009, 21:47

Cut the shaft as short as possible. Drill and tap it. put a long bolt in the hole and tighten it up. The bolt will press out the seized spline. you could weld on a large nut/bolt that fits a slide hammer but there is a risk of pulling the crank out the bottom of the engine. Hope this helps.

Mercury · 29 May 2009, 09:44

Quote:

Originally Posted by Davie

Cut the shaft as short as possible. Drill and tap it. put a long bolt in the hole and tighten it up. The bolt will press out the seized spline. you could weld on a large nut/bolt that fits a slide hammer but there is a risk of pulling the crank out the bottom of the engine. Hope this helps.

Cheers Davie, Drill & Tap is a good idea, I have taken it down to a local engineering shop with a few ideas such as drill & Tap. He says he can do the job. I will know on Tues.

Davie · 30 May 2009, 07:35

Drill the pilot hole to a size that you can tap a thread that a grease nipple will fit. Screw in the grease nipple and stick the grease gun on it! Stand well clear it might come out like a bullet!

Mercury · 02 June 2009, 20:26

Quote:

Originally Posted by Mercury

Cheers Davie, Drill & Tap is a good idea, I have taken it down to a local engineering shop with a few ideas such as drill & Tap. He says he can do the job. I will know on Tues.

It's done, A local engineering shop cut the shaft just above the splines them milled it out just inside the splines, the resulting shell then came out. No damage to the splines in the crankshaft at all. I have just cleaned it up and greased it, ready for service once again. I will take some pic's and post them on here if I ever find out how to do it.