Author Topic: Harrison M250 Lathe - Gearbox  (Read 418 times)

Offline GWRdriver

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Harrison M250 Lathe - Gearbox
« on: September 05, 2018, 09:44:29 PM »
A shot in the dark here, but one never knows . . .
I have an M250 and after a few years of non-use (of that side) the left-side gearbox change lever (knob in this case) is stuck fast and won't budge.  I'm sure the gear cluster is stuck to the spline shaft, and all reasonable mechanical encouragement has been applied to the problem, but there's been no joy so my guess is the gearbox will need to come off.
One thing I haven't tried is to drain the gearbox and fill it with a penetrating oil and that might be worth a last try.

Has anyone pulled the gearbox on an M250, and if so how much of a mess was it?

Harry
« Last Edit: September 05, 2018, 10:37:46 PM by GWRdriver »
Cheers,
Harry

Offline gbritnell

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Re: Harrison M250 Gearbox
« Reply #1 on: September 05, 2018, 10:10:31 PM »
I'd like to help but have no idea what it is.
gbritnell
Talent unshared is talent wasted.

Offline Ye-Ole Steam Dude

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Re: Harrison M250 Lathe - Gearbox
« Reply #2 on: September 05, 2018, 10:50:20 PM »
Hello Harry,

I have found that Kerosene works really well to clean and loosen stuck parts. I know it works in old engines, it might work in your case.

Good luck and have a great day,
Thomas

Offline GWRdriver

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Re: Harrison M250 Lathe - Gearbox
« Reply #3 on: September 06, 2018, 12:12:09 AM »
Thomas,
That's an excellent suggestion.  I'd begun thinking of what I could use to penetrate and dissolve, but not pose a danger to what might be attacked by something highly volatile . . . the plastic oil sight glass for instance.  I always have kerosene (Paraffin to our UK friends) on hand so I'll start the treatment tonight and give it a few days of working time.
« Last Edit: September 06, 2018, 12:17:24 AM by GWRdriver »
Cheers,
Harry

Offline Ye-Ole Steam Dude

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Re: Harrison M250 Lathe - Gearbox
« Reply #4 on: September 06, 2018, 12:17:30 AM »
That's an excellent suggestion.  I'd begun thinking of what I could use to penetrate and dissolve, but not pose a danger to what might be attacked by something highly volatile . . . the plastic oil sight glass for instance.  I'll give this a try tonight and give it a few days.

Harry


Hey again Harry,

I forgot to say that it might take more than one soaking. I have taken Ford Model A engines apart that has sat up for 30-plus years, in a barn, lying on their side and after several good soaking every part came loose without any damage.

Have a great day,
Thomas

Offline b.lindsey

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Re: Harrison M250 Lathe - Gearbox
« Reply #5 on: September 06, 2018, 01:48:09 AM »
If that doesn't work try PB Blaster, available widely at Walmart or the big box stores.

Bill

Offline GWRdriver

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Re: Harrison M250 Lathe - Gearbox
« Reply #6 on: September 08, 2018, 08:20:22 PM »
SUCCESS!    :cheers:
After a 3-day soak in fresh kerosene, daily runnings, and a wee bit of extra torque on the selector shaft, the reluctant cluster gear freed up and the gearbox is now running sweetly on all feeds.
How VERY glad I am that I don't have to open up that gearbox.
(Note to Self:  Cut more threads!)
Cheers,
Harry

Offline Ye-Ole Steam Dude

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Re: Harrison M250 Lathe - Gearbox
« Reply #7 on: September 08, 2018, 09:49:59 PM »
SUCCESS!    :cheers:
After a 3-day soak in fresh kerosene, daily runnings, and a wee bit of extra torque on the selector shaft, the reluctant cluster gear freed up and the gearbox is now running sweetly on all feeds.
How VERY glad I am that I don't have to open up that gearbox.
(Note to Self:  Cut more threads!)


That is good news Harry.

Have a great day,
Thomas