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Hoping for help with material spec on John Deere pinion shaft

Joe Miranda

Titanium
Joined
Oct 19, 2004
Location
Elyria Ohio
I have a business neighbor that has asked us to help him repair a pinion shaft off of a late '80s vintage John Deere 310C Backhoe Loader. The part number in question is AT114686.

We need to recreate one of the splined portions on the shaft. I am guessing we will have to anneal it back a bit after welding in order to re-machine the splines because it is going to require about .125" build up per side. But my guess is that the beveled spiral gear on the end of the shaft needs to be @60Rc so we will have to re-heat treat to get the appropriate hardness back.

I am hoping someone here has knowledge of what material was used for that shaft or would be able to give me a contact for how to find that info.

Recommendation for welding would be appreciated too.

Thanks - Joe

View attachment 303281
 
I have a business neighbor that has asked us to help him repair a pinion shaft off of a late '80s vintage John Deere 310C Backhoe Loader. The part number in question is AT114686.

We need to recreate one of the splined portions on the shaft. I am guessing we will have to anneal it back a bit after welding in order to re-machine the splines because it is going to require about .125" build up per side. But my guess is that the beveled spiral gear on the end of the shaft needs to be @60Rc so we will have to re-heat treat to get the appropriate hardness back.

I am hoping someone here has knowledge of what material was used for that shaft or would be able to give me a contact for how to find that info.

Recommendation for welding would be appreciated too.

Thanks - Joe

View attachment 303281

I would not attempt to do this repair as you have several things going against you.

Can't tell from the picture you attached but there is a sliding gear that goes onto the pinion shaft, correct?

If the splines are worn and you weld everything up and do a proper heat treat, your pinion gear is going to have a terrible miter fit on the ring gear. The gear end is going to move.

John Deere does two heat treat operations on this part. One is to case harden the splines right after the splines are cut with an induction heat treat. The second heat treat op does the pinion gear itself.

The pinion gear is then ground and fitted to its matching ring gear.

The 310C tractor is fairly common and you can probably find a whole rear end assembly in a tractor bone yard for at lot less work and cost then to go down the path that you are looking at.

I am also concerned that your weld repair might not hold up. The issue is that this tractor has a shuttle shift and sees frequent shock loads from forward to reverse and that is why the splines are worn to begin with.

How much other damage is down on the rest of the gear train? Usually when the sliding gear spline is shot, the associated other gears are showing signs of severe wear.

I know this is not the specific answer you are asking but I think you are going down a path with too many pitfalls for a relatively common used part(s).
 
The only one we have found is $1700 - too much to make it worth it for the customer at this time.

Yes, there is a sliding gear that goes onto that shaft and it had been damaged. The neighbor got a new one (used) one of those and we checked for cracks and it looks good.

Most of the shaft is intact. It is only the small portion of the spline nearest the beveled pinion gear. It does not appear that that portion has that much engagement. I am not sure why the mating gear spun there and sheared off some of the splines - didn't actually shear them but damaged them pretty bad.

The threaded end was damaged too but we welded that and re-cut the threads and all is well with that portion.

If you know of the heat treatment, could it be that you also know of the material spec? That would be awesome! Thanks.
 
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I used to do lots of "repairs" like this to earthmoving machine parts for a big used tractor dealership......you can preheat gear hard steel enough for welding without significantly affecting the hardness of the gear teeth.In general ,you can repair the unit to practical ,reliable operation for a fraction of new part prices.Dont even attempt to harden/reharden gear teeth....wasted money ,ruined part.
 
This search thread may help (or may not): gear and shaft repair welding rod - Google Search

I'm far from an expert in this area, but I think I've read of using high nickel or stainless fillers to build up unknown gear teeth alloys and the like. As to what risk of embrittlement you might face, I'd guess that a good pre- and post-heat will help with that, perhaps around 500-600F?

Like I said, no expert...

I have built up hundreds of splined shafts for ag equipment over the last 35yr, the best rod to use is 312-16 stainless. It is sold as Super Missile rod, Perma Max, Golden Rod, Eutectic 680, etc. Preheat to 400F and do not try to weld it all up at once. Slow and easy. HS cutters will have trouble unless you have good coolant running and use 50 SFM or less. Carbide about double. Lots of feed, it is SS.

Ed.
 
Does it look like the sewage pointed to at the bottom right of the image snatched below from the Utube?

ASM gives examples of pinions made from a bunch of stuff with some differences in “CE” (carbon equivalent). Likely (since it’s solid) a 4140ish parent would be my target & you can actually buy that filler (rod). It’s not much fun to work with, interpass @ 600°F & post heat. Re-hardening by flame or induction isn’t something I’d recommend a repair shop trying.

Before going further down the rabbit hole I’d determine just how hard that particular area actually is. As I understand how the stuff slides back & forth over the top of that area it may not need to be really hard like the pinion end mating the ring gear. The parts above it really do need to be hard

Pretty sure I still have 4130 in 3/32” but from there all I’d have is some hot work TS rod that prolly wouldn’t be cool for cold weather applications.

Good luck
Matt
 

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You ve got me and Atex 57 saying austenitic stainless 310/312.....both of us have rebuilt splines......Ive even done broken teeth on a truck diff (for myself),and in 3 rd world countries rebuilding broken gear teeth and splines is the only way to keep moving.......One thing I have noticed,is where the weld metal fuses to a high carbon case,the join will eventually crack......consequently ,I grind away to expose the low carbon core ,and fuse to that..........Note these repairs wont give new part service,but neither will a 30 year old backhoe.........As Guiseppy Serafin used to say..."I done want him to be perfeck---I jus want him to go!"
 
My pinion in my 510c John Deere backhoe was bad when I bought it. I found a good used one at a salvage yard for a whole lot less than $1700, but that was 10 years ago. 310c‘s were a lot more popular than 510c‘s, I would think you could find a used pinion. In my opinion a used one would be better than trying to rebuild your old one. I am all for saving a buck but this is not the place.
I am an old JD industrial mechanic, I have forgot a lot but will help if I can.
 
You usually find that particular parts fail,and are very difficult to source as used spares......if you are well connected ,you will know the locations of hundreds of broken down machines to source spares.......buying off dealers and salvagers is a different ballgame .....lots of these guys want 70%+ of new price for spares that are in demand ........they would rather scrap something than sell cheap ....Yep,Ive been one of them...just a game really .Big bucks from something you paid scrap price for.
 
The thing is that these backhoes are still fetching $20k plus. If they were in the minus $10k range we could probably find the shaft for a few hundred bucks.

Just in case someone has one, or knows of one that is being parted out, the part we need is actually called a "housing" and is part number AT114686. If we can't find one under a grand we are going to repair this one and return it to service. The owner will probably get his lifetime's service out of the repair. We're not looking for another 40 years - only half that :)
 
i did weld repairs on heavy equip for 40 yrs and agree 100 percent with using Eutectic 680
just skip around on the spline don't get it too hot less than 450F built it up machine it off put it back to work
I did a Backhoe swing shaft on a International 3616 kept it cool welded up remachined the teeth that were broken as far as I know it is STILL running
hey what the hell it's useless now right
 
i did weld repairs on heavy equip for 40 yrs and agree 100 percent with using Eutectic 680
just skip around on the spline don't get it too hot less than 450F built it up machine it off put it back to work
I did a Backhoe swing shaft on a International 3616 kept it cool welded up remachined the teeth that were broken as far as I know it is STILL running
hey what the hell it's useless now right

You're generally totally missing the point. If the part can be found in a TLB boneyard it will be cheaper than doing the repair, it will be faster to obtain than doing the repair and it is guaranteed to work.

If the part can't be found or costs a lot more to obtain than repairing the old one, that's when to repair the old one.

Pretty much everyone here with any experience knows that anything can be repaired... If it needs to be.
 
You're generally totally missing the point. If the part can be found in a TLB boneyard it will be cheaper than doing the repair, it will be faster to obtain than doing the repair and it is guaranteed to work.

If the part can't be found or costs a lot more to obtain than repairing the old one, that's when to repair the old one.

Pretty much everyone here with any experience knows that anything can be repaired... If it needs to be.

Add to this that the pinion shaft is the very first part that goes into assembling the rear drive housing assembly. In addition you have to split the tractor between the transmission and the rear drive housing. You couldn't ask for anymore work to get this part in and out.

This is not a part I would be cheap on.

The root cause of the original gear failing is that the sliding gear which slides on the pinion shaft has too narrow of a hub. The spline on the pinion shaft and the sliding gear is an involute spline. When the shuttle shift goes between forward and reverse, the sliding gear walks on the splines. If you tighten up the spline clearance between the shaft and the gear, then you can't shift the sliding gear. Too loose and it won't last long before it fails again.
 
I believe the 310‘c have a tran axel with a short driveshaft between torque converter, making them MUCH easier to pull out than the old ones. Still its no fun doing it twice. No prices listed on the salvage yard parts, it will be interesting to see what they want for them. Seems like for my 510c was $500.00 but that was 10 years ago.
Frist gear was out on mine when I bought it the lube line inside of transmission was damaged, ruining 1‘st gear and pinion.
 
The part number I listed is a good part number. Also, the guy I'm fixing it for is a heavy equipment mechanic and has been attempting to source a used part - hence the reason he came to us. It is not worth it to him to put $2k into this particular machine. If he can get it running for a few hundred bucks he will take a chance on it. He doesn't want to put another $2k into it.
 








 
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