Do I need to replace the inner axle shaft? (1 Viewer)

[MTrun]

Apologies, I am sure this question has been asked before. Unfortunately I am midway through my first front knuckle job with a friend, and when I pulled out the passenger axle, there are clear signs of spline wear on the differential end.

My main problem is that if I do need to replace them, I am not eager to leave the car mid teardown in the driveway for a week waiting on parts...

Any advice is appreciated!

 

[clx16]

Check partsouq as they have a 4-5 day turn around however look to see if they have messages regarding holidays etc. I would also reach out to the usual players like cruiser outfitters and wits end etc... call them don't email and wait. You don't know how long it will be down if you don't know how long it will take to source.

 

[MTrun]

Thanks! Just called Cruiser Teq -- super impressed with their responsiveness. They said they could ship today, but even with expedited shipping looking at next week given the New Years holidays. Checking dealer prices now as well compared to Part Souq (ouch).

 

[clx16]

Also, you can get a lot of things done before you install the new one; install axle seal, mount the knuckle and wipes/gaskets on the back. install seals and bearings in hub, pack those with grease, even pack the cv joint so it is ready for the new inner shaft.

search your local area for online toyota parts. for example one of my local toyota dealers gives terrible prices over the counter, but if i order it online i get a very large discount, and i can choose order online pickup in person. I would expect them to not have it in stock though, but worth checking.

 

[Box Rocket]

Sounds like you're already on the hunt for a replacement, which I think is a good idea given the amount of wear on the splines. Hang onto the old one as a trail spare just in case. It will definitely work to get you off the trail and home again if need be.

 

[MTrun]

Thanks for the help guys. I would have loved to have heard "No it's fine -- just roll with it, it will make it another 300K miles" but I am working on the replacement.

 

[Kernal]

Never had worn splines so not an expert, but were you getting any grinding or slipping in the drivetrain before you pulled the axle shafts??

You could stuff it back into the axle housing/diff, you'll know it when it starts making noise or slipping, then pull it all back apart. Or, just replace it now.

How does the bearing surface of the shaft look (where the axle seal rides)?

 

[bhsdriller]

I'd run it but i'm cheap

 

[mudgudgeon]

You could button it back up with those shafts to get it back in action. They should probably be replaced, but you'd get a few more miles from them yet.
It just means removing hubs and spindles again to fit new ones down the track.
Its not a messy job if knuckles have been recently refreshed

 

[MTrun]

Never had worn splines so not an expert, but were you getting any grinding or slipping in the drivetrain before you pulled the axle shafts??

You could stuff it back into the axle housing/diff, you'll know it when it starts making noise or slipping, then pull it all back apart. Or, just replace it now.

How does the bearing surface of the shaft look (where the axle seal rides)?

I can definitely fee a subtle dip (and visually see) where the axle seal rides.

No grinding or slipping -- it was quite a surprise to see how worn the splines were as I did not expect to add that to my parts list when pulling all of the supplies together.

The local options did not pan out, so it looks like I am ordered regardless and buttoning it back up as is for replacement with the next round of parts. Thanks again for the rapid responses guys. Clx16 - you nailed it, getting on the horn and talking to people in person made a big difference. Websites did not exactly match inventory or shipping timelines advertised (i.e. one local dealer showed they could have them in 48 hours, but on calling they said 2 weeks minimum).

 

[clx16]

Since it isn't that common for them to be worn out, me personally, would have been happy to check junkyards and partouts that are local to me. Car-part.com and then there could be some cruiser shops close to you that have parts rigs. I just don't know what is near you. I live within a reasonable distance to @slow95z so he is my emergency parts guy. I think land cruiser heaven has a shop in Virginia but no idea where.

 

[Rifleman]

MTrun, factory axle splines are heat treated, and are hard. Seeing as how worn your axle splines are, the next question you might want to be asking. If your axle splines are that worn, then just what kind of shape are it's mating splines in, up inside your diff ????​

 

[MTrun]

MTrun, factory axle splines are heat treated, and are hard. Seeing as how worn your axle splines are, the next question you might want to be asking. If your axle splines are that worn, then just what kind of shape are it's mating splines in, up inside your diff ????​

Yeah -- fair question, afraid to know to the answer to that one.

 

[slow95z]

I have a set of inner front shafts. 20 per side plus the ride

 

[mudgudgeon]

MTrun, factory axle splines are heat treated, and are hard. Seeing as how worn your axle splines are, the next question you might want to be asking. If your axle splines are that worn, then just what kind of shape are it's mating splines in, up inside your diff ????​

Yeah -- fair question, afraid to know to the answer to that one.

I was thinking the same. What is the condition of diff gears?

I think gears would typically be quite a bit harder than axle shafts. I've filed burred splines damaged after a birf explosion, but a file won't typically touch a gear.

It's also possible that the shaft didn't meet hardness specs at the factory.

 

[Rifleman]

It's also possible that the shaft didn't meet hardness specs at the factory.

It's possible that Mr T's parts supplier may have missed the correct Rockwell hardness spec on this shaft.

I think gears would typically be quite a bit harder than axle shafts.

I hate to disagree with you but i use to machine gears and spline shafts for a living. In order for the parts to last, their "mating surfaces" need to be the same Rockwell hardness. Otherwise, if one part is softer then the harder part, the softer part will wear quickly, especially when placed under a heavy load.

In the case of axle shafts, the splines are heat treated to make them hard, but the inner core under the splines is still somewhat soft along with most of the rest of the axle shaft . That softness will allow the shaft to slightly twist under load, and then "snap back" without breaking kind of like a rubber band.

If you look at the photo below of his axle you can clearly see the heat discoloration rings from the induction heat treating processes that does not quite go all the way to the center of the shaft.

 

[mudgudgeon]

It's possible that Mr T's parts supplier may have missed the correct Rockwell hardness spec on this shaft.

I hate to disagree with you but i use to machine gears and spline shafts for a living. In order for the parts to last, their "mating surfaces" need to be the same Rockwell hardness. Otherwise, if one part is softer then the harder part, the softer part will wear quickly, especially when placed under a heavy load.

In the case of axle shafts, the splines are heat treated to make them hard, but the inner core under the splines is still somewhat soft along with most of the rest of the axle shaft . That softness will allow the shaft to slightly twist under load, and then "snap back" without breaking kind of like a rubber band.

If you look at the photo below of his axle you can clearly see the heat discoloration rings from the induction heat treating processes that does not quite go all the way to the center of the shaft.
View attachment 2879896

Quite happy for you to disagree with my uneducated observations
metallurgy and heat treating are things I only have rudimentary knowledge of, and personal observations to go by.