B7100 steering shaft too long?

[seanbarr]

Despite my best effort to rebuild the steering box after reading the articles here and looking at different posts, I still got the annoying "snap" in the steering and decided to replace the shaft. I ordered one from eBay and when I tried reinstalling it carefully, it just wouldn't sit in all the way. After closely comparing it, the top ball bearing race sits a little taller than the original. Getting extra shims would be out of the question because it's approximately a good 1/8" of an inch! Is this to be expected or should I be expecting a good fit?

The top bearing raceway is on the left, notice the difference in thickness of the last worm groove and the ball bearing raceway. That was the only difference. What options do I have? Anyone had the same experience?

Sean

 

[kubotasam]

Sorry to hear of your trouble with parts. I would think you could have the shaft turned on a lathe. It would need to be an exact radius cut because the rounded area acts as the bearing race. Another thought is to make a spacer plate from 1/8" steel using one of your shims as a pattern.

 

[Apogee]

Send it back to the supplier and have them ship you another one. Obviously shouldn't be like that. Perhaps a mistake was made while it was being machined. Otherwise, I second either having the shaft machined so it is dimensionally correct or creating a spacer plate. Both will be more expensive than returning it to the seller for a replacement.

Only other option I can think of would be to go to a bearing shop and see if they have a thinner bearing that will fit for the top and bottom bearings. Or, have the case machined so the bearings sit deeper in the top and bottom of the steering box.

Kubota must have made a design change as the new replacement shaft definitely looks more robust. Now I'm nervous, as I've had a new replacement shaft sitting in the box for about a year. Haven't closely compared it to the original and I'm wondering if I'm going to run into the same thing...

I'm assuming you have the correct bearings. Have you double checked the part numbers you have against the Kubota parts list?

Finally, if you are forced to have the new shaft machined anyway, have you considered having a machine shop just clean up the original? For likely the same $$$ as fiddling around with the new shaft, they could clean yours up enough to make it usable and you could just return the new shaft to the seller.

Just my $.02,

Steve

 

[Apogee]

Sean,

Just had another thought about this problem.

I have seen complete aftermarket replacement boxes available. Perhaps the seller also carries those? If you're going to end up spending ~$200 at the machine shop, it might just make more sense to return the shaft and grab the entire replacement box instead.

The other thought I had is the same manufacturer is also selling the box housings. I would bet they are dimensioned correctly to fit the shaft you bought. Again for ~$200, you can buy the aftermarket housing and I bet it would fit correctly.

Hope this helps!

Steve

 

[skeets]

I have looked at these pics for a couple min now and I ll be danged if I can see what you guys are talking about

 

[seanbarr]

I contacted the seller and he simply offered the opportunity for me to return it for a full refund. None of that "let me double-check my stock and offer to replace it". Kinda not the route I wanted to take.

The older steering shaft turns fine but I just get this "klunk" every now & then and I know it ain't right. The "box" (ball bearing enclosed, borg looking thing I assume?) turns perfectly fine on the shaft and is very smooth. The "klunk" only happens under load so that's why I took the replacement route. I wish I knew where that came from.

I paid a tad over $150 for this unit on eBay. If I can't source another unit from another seller, I may have to try some other ideas. I'm concerned that they all were made by the same manufacturer so I'd be SOL. The spacer route may be one of them as I'd hate to have someone try to lathe it and mess it up. With the shims being very, very thin, it must be a nightmare trying to get the exact same length and the tolerance would be as thin as those shims.

 

[seanbarr]

I have looked at these pics for a couple min now and I ll be danged if I can see what you guys are talking about

 

[lsmurphy]

The old one look warn to me.

Have you tried to put it all together yet?

 

[Stumpy]

Just experienced something similar with the aftermarket reverse gear I bought for my machine. They either made the fork groove on my gear to the wrong dimensions or have very poor quality control. Unfortunately all the options I can think of have been mentioned. It's been too long since I took mine apart but I think I'd probably opt for making a shim plate were that in my barn because the bearing race is hardened, machining it would be difficult. If that doesn't sound appealing, get your refund and buy one from someone else though I'd bet most of these parts come from the same source.

 

[seanbarr]

The old one look warn to me.

Have you tried to put it all together yet?

I did, hence noticing that the outer tube/top wouldn't sit all the way on the gear housing.

I'm in the process of contacting other sellers to see if they can provide one that's similar to the older shaft. Hopefully they are not all from one manufacturing source.

 

[seanbarr]

Stumpy,

I'm leaning towards getting a spacer plate made as one option you suggested. The one thing that worries me is the tight tolerance. Grr.

 

[Stumpy]

I went and looked at mine again and I don't think a simple shim wouldn't work like I was picturing. On mine the flange at the bottom of the steering column has a circular boss which fits fairly tightly into a hole on the steering box. That boss provides a lot of the strength to support the steering column.

If yours is built the same way a shim as large as you're talking about would put any nonaxial stress entirely on the bolts and they might not take it. A shim with a boss that fits into the steering box and then a hole for the column's boss would work but you'd need a mill with a rotary table or a lathe with a faceplate head to make it.

Unless you're a glutton for punishment (or have access to some neat toys) I think the better course is to return the shaft and find a new one that fits or get a complete remanufactured box.

 

[Apogee]

Sean,

This might save you a few bucks...

https://www.tractorpartsasap.com/category_s/45324.htm

Don't know if it's any different than what you already have though.

Also, you might consider bringing your original shaft to a machine shop. A decent shop should be able to weld up the damaged area and re-machine it. It will get rid of the clunk under load. If you don't do it, it will simply eat up the ball bearings and you'll be doing this all over again.

Steve

 

[seanbarr]

Aww dammit Apogee!

Well, I went back out to see about changing the shaft and I was careful to count the balls. 54! I thought there was 52 as I counted 52 in my old shaft. What the... So after trying to swap the "borg" (ball bearings & housing), I couldn't, something about a tight fit so I decided to put the originals back together and reinstall the old steering shaft on the tractor. I noticed that the steering shaft moves up & down slightly whenever I turned the steering wheel, which tells me that the shaft IS worn down and it shouldn't be like this as the top & bottom bearing should be just holding the shaft at the right place, not allow it to move vertically. Perhaps I DID have the correct length out of the new shaft!

Off I went to put the new shaft in but with a twist, I put the old ball bearing races back with it (bought two new ball bearing assemblies a few weeks ago), thinking I could take advantage of it being "worn" a bit but hard to tell as the ball bearing races were perfectly smooth and doesn't look worn. Regardless, with it all together with the original ball bearings and the new shaft, it went together PRETTY close to perfect fitment. I'm gonna order a few thick shims and hope this will do the trick. I had it temporarily together without tightening down the top and everything works like a charm, no klunking!

I'd never imagine something like this would be a pain! Thanks for all the insight, feedback, suggestions, etc. I've seriously considered each of your opinion and just glad your responses got me to press on until I got pretty close to where I am now. All of you made me think and it's nice to always have inputs, always! Now that the experience has made me a little more knowledgeable, I'll be sure to watch the forums & return the favor!

 

[Apogee]

Maybe the problem with your old shaft is you were missing two balls....

(Sorry could not resist..)

Glad you're on the right track!!!!

Good for you for sticking with it!

Best,

Steve

 

[seanbarr]

Wise guy eh?

I'm now to the point of determining what shims are the thickest that is offered. Kubota parts list 5 different part numbers but gives no indication on how thick they are. Hopefully Messicks would have an answer in the morning or I'll just have to be creative somehow...

 

[kubotasam]

When I put mine back together I needed a shim. I took one of the metal shims, scanned it on a flat bed scanner. Then printed the image on thick card stock. Then cut the card stock to fit. It worked great.

 

[seanbarr]

When I put mine back together I needed a shim. I took one of the metal shims, scanned it on a flat bed scanner. Then printed the image on thick card stock. Then cut the card stock to fit. It worked great.

It worked??? Hmm, I'll give that a try!