M670 Super PTO adjustment

[J.A.R]

My 68 super has a very weak engagement on the PTO lever. Wondering how 2 adjust it as my jensales book covers only the older low band tractors for some reason. When engaging the lever it pretty much just falls forward it takes no effort and there is no noiticable "snap" . And when it is forward and you push it even farther forward the lever vibrates and feels bumpy like some thing is rubbing. I haven't been able to hook it up to anything to c if it slips but it does turn. Can anyone point me in the right direction..thanks.[/code]
 

[molinegb]

Adjustment should be no different than early 670,M5 etc. It has a Twin Disc clutch. You
just push pin in and tighten clutch to setup snap on lever. Sounds like your lock nut has
come loose making setup impossible. To access just remove seat and hydraulic setup. Only
real way to see what is going on. Just did one last week. By the way all 670's after 1966
used the heads you have. There was no real A series in the 336 like the 504. Just different
head and copper rings for injectors are different.
 

[J.A.R]

Will I need any special tools to do this job? Sounds like it may be a little project and are parts available for this area of the tractor?
 

[molinegb]

No special tools. Parts should be easy to get if required.
 

[J.A.R]

I have everything loose on the pto main shaft the one I'm assuming that goes through the tractor clutch and tranny. My question is how does that shaft come out. My book dosent say anything but simple pull shaft out the rear of the case. From what I can see there is something either in the tranny or tractor clutch that is stopping it from pulling out. Please tell me how I can remove it. The tractor is not split....book said it didn't need to be.
 

[Alan K]

Here are a couple of pictures when I adjusted the one in my M5. Im betting the
670s are the same. The M602 I have I removed the shaft. You are supposedly
supposed to be able to bump the shaft out the rear by using a drift or punch on
the edge on the shaft just infront of the clutch assembly. There isnt much of an
edge lol. I used a slide hammer threaded into the shaft at the rear. The shaft
only has to be removed if you are removing the clutch assembly or parts
associated with it. For just adjusting or tightening up the nut that holds the
clutch to the shaft you dont have to remove it.


 

[J.A.R]

Thanks Alan but after draining fluid and looking it over more I found that it ate one of the clutch plates...found most of it in the bottom of the case. I have a slide hammer so maybe will give that a go tomorrow will let you know what becomes of it.
 

[molinegb]

M670 super has different shaft as there is no rear hydraulic pump. One way is to tap shaft to put in 3/8 bolt and make puller. I made one to lock onto the splines on M5.
 

[Alan K]

Ive often thought of making a clamp of some sort to clamp on the shaft to have
something to hit against. Might be something to try if it doesnt come loose.
 

[molinegb]

When pulling shaft you are pulling two tapered bearings on rear portion of shaft as well as
bushings in housing and spline in flywheel. I pulled two last week. They can be a tug. When
reinstalling make sure gap between the bearing is up. This is where oil is fed. If gap not
in position bearing will fail.

 

[molinegb]

Also there should be a shim on end of shaft to set endplay. There is an Allen screw with a cotter pin in midst of clutch that holds key in. When reassembled and clutch set. Shaft has to have 20 thou endplay. There is fair movement in shaft back and forth. The torque of locking clutch will move shaft. This is why it has to be done twice. The setscrew actually locks shaft.
 

[J.A.R]

Well thanks guy appreciate it I'm going to make a puller using 3/8 threaded rod and pull little then hit the set screw landing with my air hammer then just keep working back and forth. Would have been nice if the manuals would have mentioned something about how hard these things are in there lol would save a lot of time and confusion lol. But then again we got you guys thanks again.
 

[molinegb]

Best puller is take a 3/4 piece of flat iron 6 inches long by 2 wide. Drill center to
accept your 3/8 bolt. Dill two holes on each end and welds on couple 1/2 fine thread nuts.
Use 2- 4 inch fine thread 1/2 inch bolts. Turn them evenly and let them do the pulling.
 

[J.A.R]

I welded this together worked flawlessly.
 

[J.A.R]

Quick question I was wondering during install would I be better off pressing the two end bearings off the shaft and then get the shaft in and then press them back in after everything is back in the tractor?