At a Loss (driveshaft will not fit into pilot bearing)

[krazzyman]

I have been working on the transmission (replacing a bearing and the driveshaft itself) and went to recouple the front and the rear. We wrestled with it all afternoon thinking it just wasn't lining up right but this morning I took the clutch apart and tried fitting the old driveshaft in just to double check the fit. It won't go into the clutch pilot bearing...??? I did an engine rebuild just a month ago and I split the tractor and I don't even remember having issues with the drive shaft fitting. The rear has the new driveshaft but it just wont fit into the clutch pilot bushing. What could have possibly changed? what am I missing?

In the pictures it shows that the drive shaft wont even begin to slide into the bearing. I didn't change it or even touch it. did it get bigger some how??

Apologies for the terrible photo quality.

[tst]

bushing needs to be reamed to fit the shaft

[krazzyman]

What is the best way to do that and what is the safest way to remove the bushing?

[brewzalot]

What is the best way to do that

From a previous post-

I used a make shift "hone" by sawing a slit in the end of a 6-8" rod , about the length of the bushing. A steel or wood rod will work- it just needs to fit in your drill chuck. Insert the end of a strip of sandpaper(120-150 grit) in the slot and wrap it around the rod as much as needed to get close to the bushing ID size. The tighter you can wrap it the better. Chuck the other end in your drill ( you have to hold the paper tight until its in the bushing) and hone as much as necessary. Make sure your drill direction is correct (so the paper gets tighter as it spins.) This depends on which way it was wrapped around.

I would recommend getting the bushing close to size before putting it in (which it should be) and then finish as needed after installing it.
The bushing is fairly soft so make sure you check size often-it doesn't take much. Clean all abrasive material out when done and before lubricating.

edit- if you don't have a dial caliper you should get one. Very handy for this type of work, you can measure the bushing ID and shaft size accurately.
hope this helps
tim

[Glen]

Hi,
You don't remove the bushing to hone the ID of it, it is honed in place.
Boss Hog, one of the experts, has said on here that if the pilot bushing looks in good condition, and measures ok, it doesn't need replacing.

Usually what you describe only happens when someone replaces a pilot bushing, some of them are too small an ID when installed in the crankshaft hole. Then they need honing so they have the right clearance with the shaft.

Below is a page from the Cub service manual showing the running clearance for the pilot bushing and the shaft, at Spline and clutch shaft. Measure the end of the shaft, and the ID of the bushing.

http://farmallcub.com/rudi_cub/www.clea ... -05-02.jpg

[Clownfish]

Ammon
Are you saying that the same old driveshaft that you once slid into the bushing will not now fit? You haven’t changed either the shaft or the bushing?
Glenn

[Barnyard]

The problem is not the bushing since he didn’t say he replaced it. He said he replaced th shaft. Therefore he has a shaft problem that needs attention, not a bushing problem.

[Clownfish]

He also said he tried the old shaft and it wouldn’t fit. Sounds like the bushing has been damaged while trying to put the tractor back together.

[Gary Dotson]

That's my take on it, as well, Glenn. I think he has damaged the bushing.

[krazzyman]

Hey Everybody thanks for the discussion. Have been away for a little while. I realized something else as well. I replaced the crankshaft in a rebuild this summer so the bearing was slightly oversized. I got the old crankshaft out to check and both the new and the old driveshaft fit snugly into it.... I honed down the bushing in the *new* crankshaft that is installed right now and it slid together easy. I have no idea how I got the tractor together before and even ran it briefly when the new crank never fit either drive shaft. I know that is a twist and turn sorry for the confusion. got it figured out though.

[Matt Kirsch]

It was a matter of "close but not quite," right? Then, as previously suggested, it is very likely you inadvertently put a burr on the end of the bushing while pushing the tractor back together. Just a little off, and *BONK* there's your burr.

[BigBill]

I have a bux mag base drill to ream it to the correct size. Very handy portable drill press.

[NJ Farmer]

Measure the end of the transmission shaft with a digital caliper and the go online and buy a straight reamer that is close to the measurement you made....and make that measurement SEVERAL TIMES. Ream out the bushing with a little bit of light oil.....blow out the bushing with compressed air and finally the most important apply a thin film of your favorite wheel bearing grease on the end of the transmission shaft and the bushing. Put it all together and you will be happy at the ease of installation!

NJ Farmer