128 Overhaul

[Aircomet]

I picked this 128 up in a deal with my 149 I just finished wrapping up mechanically. This has been a slow work in progress. It is in pretty rough condition and looks like it sat in the rain all its life. The hood has one or two pin holes in it and the fender pan was rusted out badly. Mechanically it needs quite a bit too. Clutch is shot and delaminated completely. The shifter was broken around the “cup” part where they normally do. And the engine had a blown governor gear.

I have made decent progress on it up to this point. I have already pulled the motor out and completely disassembled and cleaned it. I measured the bore and it is in spec so I honed it and lapped the valves in. I replaced the governor gear with a good used one. I have it pretty much ready to reassemble when my rebuild arrives.

The rest of the tractor I disassembled and cleaned up the worst of the grease and grim. I welded the shifter up and that works smoothly now. I cut out the rusted out portions of the seat pan and welded in patch panels. Then, I riveted new rubber mounts on the voltage regulator and added taillights. I also reupholstered the seat. I am trying to keep this low budget as it is pretty rough and would take a lot to be “restored” beautifully. I mainly want to get it reliable mechanically to play with.

That brings me to where I am now. I am waiting for my engine rebuild to arrive. I tried to save a few dollars and buy a cheaper rebuild for it from a different seller on eBay and paid for it. I received a rebuild for a K161 or k181 instead of my K301 and it was not near the quality of the rebuilds I normally get from the other seller. So after waiting for two weeks to get it I had to send it back anyways and ordered a rebuild from my trusted supplier this time. Sometimes it’s just better to spend the money and buy from a reputable, recommended seller.

The clutch I had originally just replaced the disk in it a few weeks ago. But, I have since reconsidered this decision to use the original throw out bearing and springs and have since ordered a full rebuild for it. I don’t want to have to do this job twice if the springs are weak. Are weak springs something that other members are seeing as a common issue with older clutches? I know my 108 needs a clutch as well soon and I am wondering if it is mainly the disk or springs too.

Here is what it looks like as a roller now.

[Aircomet]

Got the clutch rebuilt with new springs, throw out bearing, and disk this evening. Compressing that spring was a treat; but, I figured out a little trick to do it on my vise which seemed to work really well. I told my buddy it would either work or he would see the drive shaft go up through the roof of my shop like that water heater on the old Mythbusters episode.

[modcub72]

Your 128 is far from rough looking,
you should see my poor bastardized 72.
That 128 is in great shape,
and well worth putting time into it.
It'll do you good for many years to come.

[finsruskw]

Rest assured, the spring will not launch into outer space.

I do them all the time that way in a vice using a pair of thick aluminum spacers in the jaws and a heavy brass drift driven against the end of the shaft to compress the spring. It will only jump/bounce about an inch when the vice is released slowly.

Consider re bushing the holes in the hanger and throw out lever some way to eliminate excess play and tighten things up a bit and replace the clevis pin as well.

I always freshen up small parts and paint them before re-installing them in a Cub. Gives me incentive to do more for appearance sake!

You are gonna love that 128!
Mine is for plowing and really pulls good in tough soils like at the plow day in Roanoke, IL, which by the way will be THIS FALL once again!!

[Merk]

Originally Posted by Aircomet

Got the clutch rebuilt with new springs, throw out bearing, and disk this evening. Compressing that spring was a treat; but, I figured out a little trick to do it on my vise which seemed to work really well. I told my buddy it would either work or he would see the drive shaft go up through the roof of my shop like that water heater on the old Mythbusters episode.

Did you true the clutch plates on a lathe?

[Aircomet]

Originally Posted by Merk

Did you true the clutch plates on a lathe?

Unfortunately, I do not have access to a lathe at this point. And I have been having a difficult time finding a reputable machine shop around here for small jobs like this. So, I made do with lightly sanding the surface rust off of the plates and making them smooth again. It is in the back of my head that this might cause issue; but, I am confident enough to give it a shot. Worse case I’ll pull it back out.

Small progress today on it. I got the clutch assembly painted and installed in the 128 with new roll pins. I also took the time while it was decently warm out to degrease and pressure wash the tractor. My correct engine rebuild arrived this evening so hopefully I can put that together tomorrow.

[finsruskw]

Roll pins or spirol pins?
If split roll pins, don't expect them to last very long.

[Merk]

Originally Posted by Aircomet

Unfortunately, I do not have access to a lathe at this point. And I have been having a difficult time finding a reputable machine shop around here for small jobs like this. So, I made do with lightly sanding the surface rust off of the plates and making them smooth again. It is in the back of my head that this might cause issue; but, I am confident enough to give it a shot. Worse case I’ll pull it back out.

I would have made a post on this site looking for someone that trued clutch discs.

One of the reason(s) to turn your clutch plates on a lathe is to make sure the clutch plates are flat. There could be less contact area which will cause your clutch to slip. I had to rebuild a few clutch assemblies because the owner didn't do that step. Most times it does damage to clutch disc and in some cases they had to be replaced.

Your Cub
Your money
Your call

[Aircomet]

Originally Posted by finsruskw

Roll pins or spirol pins?
If split roll pins, don't expect them to last very long.

Spirol pins. My bad, I’m used to just referring to them as roll pins even though they technically aren’t.

I know I should probably have had the plates trued but I’m willing to give it a shot and see how long it lasts. It way work or it may not only time will tell.

[Aircomet]

Got the motor assembled today and installed. Had some minor issues with bad points; but, I got it sorted. After I changed them for some genuine Kohler points I cleaned up it fired right off first revolution. Runs like a top and sounds great. Pto works as it should since I took it apart and cleaned everything up. Clutch works great on it. No vibration and it is extremely smooth letting it out. Now I know how bad the one on my 108 really is. I ran it in 3rd up a 30 degree incline to where I had to lean forward to keep the front down and it didn’t slip. So, I hope it is good in that department.

I’ve got some odds and ends to finish up yet; but, I am very happy with it right now.