Rear wheels keep coming loose

[jack benny 12]

79 C-161, 8 speed 16 Kohler

Have had tractor for almost 30 years and this year i am having problems with rear spindle falling off of axle shafts. Woodruff keys and keyways appear to be good. Just not sure why now i am havi g problems. It does only have one set screw to hold onto woodruff key. I am thinking i may need to add 1 or 2 more set screws in hub.

Thanks

[ebinmaine 67,106]

 

 

Have you removed the wheel hubs and cleaned the axle and inner hub bore? 

 

Are the set screws new?

 

 

[wallfish 16,955]

New set screws would help. Don't use regular bolts

The cup on the end of the set screw is what digs in and holds.

https://www.mcmaster.com/products/set-screws/alloy-steel-square-head-cup-point-set-screws/?s=square+head+set+screw

Edited August 6 by wallfish

[jack benny 12]

14 minutes ago, ebinmaine said:

 

 

Have you removed the wheel hubs and cleaned the axle and inner hub bore? 

 

Are the set screws new?

 

 

I have not. I do have an axle seal that needs replacing so i am going to do both and i guess i will get new set screws also. Thank you

[jack benny 12]

8 minutes ago, wallfish said:

New set screws would help. Don't use regular bolts

The cup on the end of the set screw is what digs in and holds.

https://www.mcmaster.com/products/set-screws/alloy-steel-square-head-cup-point-set-screws/?s=square+head+set+screw

Thank you for the link. I am going to replace both set screws guess i thought they wouldnt go bad. My bad on that. Also have a leaky axle seal so will be doing both of them also.

Thanks

[wallfish 16,955]

Just now, jack benny said:

Thank you for the link. I am going to replace both set screws guess i thought they wouldnt go bad. My bad on that. Also have a leaky axle seal so will be doing both of them also.

Thanks

Yup, that added lubrication ain't helping to keep them on either

[ebinmaine 67,106]

4 minutes ago, jack benny said:

Thank you for the link. I am going to replace both set screws guess i thought they wouldnt go bad. My bad on that. Also have a leaky axle seal so will be doing both of them also.

Thanks

 

 

Set screws are a "limited use" fastener. 

 

I've known techs over the years that would toss a set screw after ONE use. 

 

I inspect mine when they're outfor whatever reason. 

Almost always replace them so they're part of our parts department.  

 

 

Get new set screws, new Woodruff keys, new set of four seals.

 

When you remove the hubs be aware...

DO NOT USE A 3 JAW PULLER 

 

 

[WHX?? 48,696]

Try and not operate the tractor too heavy to avoid further possible damage to hubs or keyways.

Absolutely use new hardware.

Edited August 6 by WHX??

[lynnmor 7,294]

If you have only one set screw per hub, add a second one as shown above.

[ri702bill 8,236]

13 minutes ago, lynnmor said:

If you have only one set screw per hub, add a second one as shown above.

A word of caution on adding a second retaining screw and nut. This is best done in a drill press or milling machine. Why?? To get the tapped hole centered and at 90 degrees to the original - and to be able to add a flat on the OD for the jamnut to seat. Not a place for a hand drill....

 

Do consider grinding a small flat on the axle where the new screw contacts it. The cup point WILL raise a burr (desired), but without the recess, hub removal in the future is much more difficult.

[jack benny 12]

1 hour ago, lynnmor said:

If you have only one set screw per hub, add a second one as shown above.

Will look into. Thanks

[jack benny 12]

1 hour ago, ri702bill said:

A word of caution on adding a second retaining screw and nut. This is best done in a drill press or milling machine. Why?? To get the tapped hole centered and at 90 degrees to the original - and to be able to add a flat on the OD for the jamnut to seat. Not a place for a hand drill....

 

Do consider grinding a small flat on the axle where the new screw contacts it. The cup point WILL raise a burr (desired), but without the recess, hub removal in the future is much more difficult.

I do have a drill press so will look into this. Thank you

[Achto 27,474]

 

Looks like the gang has you covered. 

[JimSraj 412]

Remember to clean up the edges of the woodruff key slot to remove any burrs. Also, put a layer of tape over it before sliding the new seal on. 

[rmaynard 15,393]

Since you've never had this problem before, and now have leaky seals, this is probably the reason why your hubs are moving. After the seals are replaced, even if you don't add another setscrew, be sure to use a new Woodruff key and a new setscrew. I believe there is a torque recommendation of 28-32 ft.lbs. 

[gwest_ca-(File Mod) 11,018]

From the 1978-79 service manual. 

After a few minutes of driving retorque the set screws.

Again after a 1/2 hour of driving

Again after an hour.

Again after 2 hours until you are confident the torque sticks. Gives the parts time to settle in and stabilize.

The lock nut should be just snugged up, Any tighter tends to pull the set screw back out and you lose the applied torque.

[Wild Bill 633 845]

FYI, A-Z fabricates wheel hubs using a tapered hub which acts like a collet to grip the axle shaft.

For 1" axles:

https://www.ebay.com/itm/265931240640?itmmeta=01J4V9K2TYPAFN5F12GFTGQ2Y3&hash=item3deabcb4c0:g:OpwAAOSwlIxfmse0

For 1-1/8" axles:

https://www.ebay.com/itm/266239705030?itmmeta=01J4V9K2TY99NKDQSB9055RAEF&hash=item3dfd1f7fc6:g:OpwAAOSwlIxfmse0

 

Edited August 9 by Wild Bill 633

[Lagersolut 645]

I've had new grade 5 cup points move on the axle - so I started using the Alloy -available at  Mcmaster and Carr

Edited August 9 by Lagersolut

[Tonyp 284]

Do yourself huge favor , replace  the hub lockdown screws and keyways on both hubs with factory standards.    I had the same issue not too long ago with my 1979 C81. I fooled with it and fooled with it, then got the new parts.

 

Problem solved.   It really was that easy ! , 

[jack benny 12]

On 8/9/2024 at 12:54 PM, Tonyp said:

Do yourself huge favor , replace  the hub lockdown screws and keyways on both hubs with factory standards.    I had the same issue not too long ago with my 1979 C81. I fooled with it and fooled with it, then got the new parts.

 

Problem solved.   It really was that easy ! , 

Thanks for the info. I have the parts ordered and am awaiting their arrival