Spindle rebuilding- John Deere 72 inch mmm

[MGADon]

Hi,
I've just mounted a used 72 inch mmm on my Deere 870. I'm
really pleased with this setup. However, the deck (located on Ebay) must have a gazillion hours on it. Two of the three spindles have noticable play when rocked by hand. They are not noisy or rough. Should I rebuild? Entire rotating assemblies are $214 from Deere. I went for the two bearings, seal and circlip to do one spindle for an outlay of about $30.
However, she doesn't want to come apart very easily.
Once the big 38mm nut is off the top, should I be able to tap/hammer the spindle down and out the bottom? Maybe I need to start with a puller for the pulley first. Any advice is appreciated.
Don

 

[DavidJ]

I'm sure someone here has more experience with the JD unit than I but here's a go.

Lots of those spindles use a snap ring against the bearings. You'll have to take the sheave off to access it. Once that's done you may be able to tap it out but in some cases you have to press them out of the bearings.

 

[MGADon]

Thanks David,
I will work to get the sheave off first. Two big snap rings are called for in the drawing, yet the position for these is not clear.
It's quite possible one is at the top. This would protect the spindle from dropping out if the nut were to come loose.
Don

 

[5030]

I would presume that a JD deck would be like most other large decks.

You have an upper and lower bearing with a external snap ring on each end and either a snap ring or spacer to provide preload. The shaft itself is pressed in to the bearings, so you will have to press the shaft down from the sheave side. The sheave will be held on by the top nut and driven with a woodruff key. Remove the sheave and then remove the spindle assembly. Either use a hydraulic press to remove the shaft or lay a block of wood on the top of the shaft and pound it out. A brass drift will work too. When you get the assembly apart, it will probably have a light knurl applied to it to retain the bearings.

 

[MGADon]

Thanks Daryl. I'll post my progress.
Don

 

[5030]

Don:

One note of caution, don't damage the threads at the top of the spindle. That's a fine thread and if you deform them, you will never get the nut back on.

I just rebuilt a spindle on an Woods bat wing for a guy and after I dis-assembled the unit, I drilled and tapped the housing for a grease fitting. Then I used a prick punch and popped the grease retainers off the inner sides of the bearings. That way, you can grease the bearings on a regular basis.

 

[MGADon]

Good advice Daryl. I plan to hit the spindle with a block of aluminum. I also use a big brass drift. Do you think I need to unbolt the entire housing from the deck? By the way, the Deere deck does have grease fiittings on the spindles. That probably provided for a pretty long service life to get to this amount of wear. All in all, I think it is a robust design in that there is a lot of wear showing everywhere- clevis pins, bushings and j- hooks, blades are ground way back, etc. - but he whole thing still functions well.
Don

 

[5030]

Don:

Though you probably already have taken it apart, it would be easier to remove the housing from the deck and put the housing in a vise and work on it.

The lower bearing will come out with the spindle. When you re-assemble the unit, just make sure before you do that, the inner seals on the bearings are removed so they will take grease. If you have a bearing packer, pack them in fresh grease before you install them. Lisle makes a nice bearing packer if you don't have one. NAPA stores sells them. It's 2 cones shaped plastic disc's with a hollow threaded stud between them. Place the bearing between the cones, tighten the top one down and pump in some grease until you see grease coming out of the bearing.

As far as hitting it with an aluminum block, I'd lay the block on the top of the spindle and whack it with a good sized hammer. One or two hits should do it.