52 8N Transmission Rebuild Question

maxazillion · Jan 29, 2020

I am considering rebuilding my 8N tractor transmission since it has a terrible whining/growling noise. I watched a U Tube video and a guy was rebuilding a 9N transmission. On the video it showed him replacing his bearings by heating with a propane torch and they just dropped onto the shafts. It is really this simple? I kind of have my doubts. Any suggestions would be appreciated.

Bob · Jan 29, 2020

(quoted from post at 20:27:57 01/29/20) I am considering rebuilding my 8N tractor transmission since it has a terrible whining/growling noise. I watched a U Tube video and a guy was rebuilding a 9N transmission. On the video it showed him replacing his bearings by heating with a propane torch and they just dropped onto the shafts. It is really this simple? I kind of have my doubts. Any suggestions would be appreciated.

Yes, a bearing warmed up a bit can be typically be installed just that easily.

It's a common shop procedure, suggested in many service manuals for various machines.

I don't recommend using a torch, though. Probably a propane torch would get things hot enough to affect the temper of the steel, but why take a chance?

Industry recommendation is to heat them to no more than 257 F.

Heating them in oil in an old deep fryer works well, and they get evenly heated all the way around. I also have an old kitchen "wall oven" in my shop mounted on a cart so I can wheel it close to where it's needed, works GREAT for heating flywheel ring gears to mount them, as well.

I plug it into the extension cord for my welder.

A note, though, your 8N transmission is a constant-mesh "collar shift" transmission, vs. the transmission in the video you watched, which is a "sliding gear" transmission, there's VERY little in common between the two models.

IowaSam · Jan 29, 2020

Yes,
Step 1: Clean new bearings & trans shafts in mineral spirits, air dry till all odor is gone.
Step 2: Put shafts in a plastic bag & into your freezer.
Step 3

lace bearings on alum covered cookie sheet in your oven @ 350* for 30 minutes.
Step 4: Assemble parts on kitchen table, clean-up & be gone before your wife gets home ! ! !

Honestly, heat will help as the diff is only a few thousands of an inch.

Sam.

flembo · Jan 30, 2020

I always set the bearing on top of a 100 watt light bulb for 10 or 15 minutes and the shaft in the freezer for the same.

52 8N Transmission Rebuild Question

maxazillion

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Bob

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IowaSam

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flembo

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