OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions on Greenfield Ride On Mower Frames Greenfield 12/32 Clutch Plates

Hello I Have a Greenfield 12/32 I am reassembling total nut and bolt restoration. With the clutch corks (New Corks) What is the gap to be set and how do you align these correctly. I have this assembled with new bearings corks in the frame. I just need to know the gap measurement and how to set it correctly.
Regards
Leshby

Hi Sorry I hardly get on here mate. To align/set the gap - you need to use shims to set the neutral position. Depending on wear on the drive plates, i usually use 1-2 shims per side, then assemble drive and check for clearance. From memory the greenfield part # is GT00520.

Hi 94zza, welcome to Outdoorking, and thank you for that information on shimming the Greenfield clutch shaft. I just have one question: when you say 1-2 shims, do you mean Part Number GT541 - Shim (long shaft models), or GT539 - Shim (short shaft models), or are they all the same thickness anyway?

We have been told in an earlier thread that Greenfield has two different thicknesses of shim. Can you tell us what thickness of shims you use, when you set them up with 1-2 shims per side? Also, how do you decide what total thickness of shims on each side, to try first or next?

Finding a simple process for setting up Greenfield shim stacks has been an objective at Outdoorking for some time. I hope your procedure will move us quite a way forward in this.

Hi Grumpy - thanks for the welcome!Hopefully i can be of some assistance around here!

Greenfield definately have two shims - they actuaaly have 3. GT00539 is 5thou thick, GT00541 is 10thou, and GT07303 is a thick 20thou shim. In my workshop i use a GT07303 on each large drive plate between bearing and shaft, and 2 GT00539 shims each side. That is how i was taught to rebuild them, and ive done countless numbers! As you may be aware - each drive can be different - so the amount of shims required can be different. But in my experience 1 x GT07303 shim followed by 2 x GT00539 shims each side works best.

Cheers

Gary

Thanks Gary, that puts us quite a way ahead of where we were. Can you show us where you put the shims specifically? Here is a clutch shaft:



I see the central thrust bearing and a drive plate each side of it. Are you saying that you use one GT07303 and two GT00539 shims, totalling 0.030" thick, between each side of the thrust bearing and each drive plate, - so altogether you use six shims on each clutch shaft you overhaul?



In that illustration from the manual, Item 27 is shown as GT07303, and Item 30 as GT00539. That is, if the diagram is actually correct, the standard set-up is assymetrical: it has one more shim on the non-sprocket side than it has on the sprocket side. Can you tell us why the thicker shim stack on the non-sprocket side? Or is the illustration just approximate and you are supposed to just use whatever shims you need?

Because the forward clutch usually wears more than the reverse clutch, I'd have expected most rebuild jobs to use more shims on the forward clutch side than the reverse clutch side, unless you replace the clutch linings at the same time.

Hello.
When assembling this unit with the shims in place how tight do you tighten the nuts to. Or other than the shims in the drawings used and shown you add extra shims to tighten the nuts. I am confused.

The nuts are tightened to hold the stationary inner bushes of the pulleys, tightly against the ends of the square part in the center of the clutch shaft. The inner bush is circled in red in this picture of aldot's:


Clamping the inner bushes in that way ensures that they are effectively locked to the shaft, and rotate with it. The pulleys rotate on the bushes when the clutches are disengaged, or rotate with the bushes when the clutches are engaged. Hence you tighten those nuts quite firmly, recognising the diameter of the threads involved. I'd probably use about 25 lb ft.

The shims set the clearance between the pulleys (driven by the engine) and the clutch disks (which can only rotate if the clutch shaft rotates. If the disks rotate, so does the chain drive to the rear wheels). The clutch disks slide freely along the square part of the clutch shaft, but are held away from the pulleys by compression springs in between:


You can see the spring in the red circle. The bush seems to have been removed from the center of the pulley in this picture (also from aldot, like the previous one).

The thrust bearing in the center of the shaft, between the clutch disks, is also free to slide along the square shaft in either direction, when pushed by the clutch linkage.

I am un sure when I have assembled mine as per the drawings with all the shims and springs. If I tighten the nuts in totally where they seats and are tight nothing moves. This is while I am confused I am using all new parts etc with it locking up tight why.

Let's see what the experts say, but on the face of it unless you've made an assembly error I'd say you have too many shims, so the clutch plate clearances are negative. I suggest you try it with no shims at all, verify that both clutches are free, then shim it up until both clutches are free, but only just. Usually the forward clutch wears considerably more than the reverse clutch, and so will require a slightly larger share of the required total amount of shims. I think you'll find the clutch on the right side facing forward (i.e. the sprocket side, not the battery side) is the forward clutch. aldot has invented a system whereby you hold the two ends of the axle and rest the outside of the pulleys on a flat surface. Push it back and forth so the pulleys rotate, noting how hard it tries to rotate the axle in your hands.

Be sure to put all the washers in the right places, or it will eat its own liver when it runs.