(800) 853-2651
SHOP NOW

Need machinist / metallurgist opinion

F

Fritz Maurer

Well-known Member
I need to repair the threads for a spanner nut (retains two large tapered bearings). Had the idea I could weld up the thread area and re-cut them. Can I do this without messing up the integrity of the pinion? Is there another way to handle this repair? Diameter 2-15/16", 12 T.P.I. Thanks, Fritz
a70724.jpg
 

Fritz,

The two options I see are fusible spray
weld or submerged arc crankshaft welder . Both
would work ,but I think the crank welder would
be less likely to warp the shaft as it welds
around the shaft.
I have a friend that has a crank welder ,he
does what I need until I get my crank welder
wired and running, I have done several shafts
like that with the fusible spray weld and they
have worked well.

george
 
I've got to agree with George, the ways he has mentioned are the best ways to get it done. That said, as heavy as the shaft is, and as short of an area as you need to built up, and the diameter of the shaft, I don't see whay you can't do it by hand if all else fails. Personally I'd be more worried about taking the hardness out of it, as I assume the splined area is at least case hardened, than I would warping anything. That being the case, I think with a proper preheat and cool down you could lay a series of overlapping beads, parallel with the length of the shaft, and get the required buildup. If your worried about warping it start in two places, on opposite sides, and work back and forth until both build up areas meet.

One thing I will caution about, from experience, is that rehardless of what you do machine the area your repairing a bit undersized before you build it up. If you don't do that you'll be attemping to cut the new threads into the root of the weld. I have seen that cause problems, especially when cutting finer threads, if any hard spots happend to develop between the base metal and the weld at the fusion point.
 
If you are set up to remachine the threads, could you machine a custom set of smaller diameter threads in the shaft, and machine a new custom nut. Or, even weld the ID of the existing nut and ramachine it. Welding on the nut has much less risk since the stress is much less of a concern in the nut and the distortion much less critical.

RND
 
If you have enough room to go ahead and cut new threads without getting into the spline diameter, that is what I would do.

You would have to make the nut for your newfound thread size.
 
George has the best answer. I wouldn't try to cut smaller dia threads on the shaft, you need a better surface than that to thread it.
 
You realize if you would post a little sooner I would not have to type as much! LOL

I obviously like your idea.
 
THe left shaft seems to be different than the right one. It appears to be hl=eld on with a snap ring. The thread areas look very different.
If the one with threads is the one being repaired, I would index it in a lathe, and retouch the existing threads, I am sure if I could do it others could as well. If the shafts measure the same, and the left shaft is in need of threads, Metal deposit welding is probably a best practice. If the spline is holding up people, or it it a highway operated device, I would be worried about safety and re heat treat the shafts. Jim
 
machine old thread about .030 under minor diameter of thread . a good tig welder can build up diameter without touching the other parts then re-machine threads . it will be soft afterwards .
 
Looking at the worn gears on the shaft I would say it was scrap iron and the best thing would be to scrap it an start out with a new one for safety. Welding on a shaft like this can only cause more trouble than it is worth.
If it can not be replaced then take it to a good machine shop an have then cut it back an put a pressed on ring then weld it in place then cut new threads on the ring. Make sure that the ring is made from the Same material for strength.
But my guess is to replace it.
Walt
 
How much is a new shaft and is it available? The edges of the gear look like they have alot of wear. I have had a few shafts fixed at work where they actually spray a thin layer of metal over the damaged area to build it up. Then turn down to the right diameter, then heat treat. It just takes a few days to get it done because the shops are in different locations, at least it is free.
 
If the nut isn't too loose and you just need to straighten up the threads to get the nut on, a thread file might work.
 
I should have clarified that the shaft on the right was just to show what it was supposed to look like. Yes, the teeth are barked up a little, from jamming in and out of mesh with the turntable bearing. The bottom bearing failed and started dropping rollers between the gear teeth. The shaft is available, for $2775, but I didn't really want to spend that (who does?) to put back in a semi-retired machine, where the one on the right came from. Thanks for all your help. I'm just going to turn it over to a professional; if I have to begin by turning the old threads off, I'm already beyond my capabilities. That sucker is hard! Thanks guys
 
It is common to "Spray Weld" worn out crankshafts
oversize and then grind them down to "Standard".
That process should work in your application,but
cost has to be considered.
 
You must log in or register to reply here.

Similar threads

M
New-to-me JD-A and JD-B Repair Tips
Replies
13
Views
859
Fixingfarmer
Fixingfarmer
R
Where do I find a Rear Axle for a TO-30?
Replies
9
Views
2K
warbaby
W
0
Second hand parts
2
Replies
22
Views
794
07AKU
0
K
D239 Pulley Removal
Replies
2
Views
486
JimB2
J
G
Rear axle nuts won't stay tight.
Replies
14
Views
2K
JMOR
J
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top