Clutch repair on the 73

[mfrade]

This will be a second attempt at getting a thread started on the repairs to the clutch mechanism on the Model 73.
I replaced everything that was worn or could be worn when I received the tractor back in the winter of 88 / 89.
So after 42 years the throwout bearing let go. Ordered new parts from CCS and maybe we can start reassembly this weekend.

 

[dfrisk]

MIKE - I was told by a VERY reliable source that MWSC has a healthy supply of throw-out bearings made by IH's OEM supplier, That was a few years ago but it's worth a phone call.
I used to drive by MWSC's shops about once a month until just over a year ago, but always in a hurry, no time to stop and say HI to Julian. Then SON moved.
I've had the new T/O bearings fail in what seems like too short a time. I went COMPLETELY back to a stock clutch in my #72 in spite of over doubling it's stock HP. The stock bearing failed in such a fantastic fashion I saved it.

 

[mfrade]

Thanks Denny. Parts were already ordered and shipped from CCS. So we'll see what arrives.
When I did the last overhaul (1988/1989) I replaced with new all the normal wear items. The main spring I stepped up to an item we used in the mold shop I was working at back then. Just raised the application pressure slightly, barely noticed any change in the operation but the clutch disc is still like new even after all these years. Plus I had added the creeper gearbox so I never had to ride or "slide" the clutch when using the snow thrower so it all adds up to less wear. On my final mowing for the season, I was putting the tractor away and driving into the shed the clutch pedal suddenly "fell" as the bearing came apart. I could still operate the clutch but the lever (pedal) height was almost zero. So it really was the final mowing for the season!

Again, thanks for the info.. I'll keep it in the back of my mind, just in case.

 

[PACub100]

The stock bearing failed in such a fantastic fashion I saved it.

 

[mfrade]

Been awhile since any updates so, here we go. After getting the ordered parts in hand I finished the disassembly of the clutch and driveshaft. It was then that I discovered that the shaft was also beat up pretty good. No matter, I've had some stock in hand and now a reason to spin it into something.. Pics in no order..

 

[mfrade]

And these are pretty much where I left off today.. Tomorrow I hope to actually start putting it all back together.

 

[dschwandt]

Way to go Mike!!
Thinking about the same thing for my 882 as the couplers are worn and have a lot of wobble.
Maybe a length of 11/16" CRS turned enough on each end to fit and snug up the worn couplers.

 

[mgonitzke]

Way to go Mike!!
Thinking about the same thing for my 882 as the couplers are worn and have a lot of wobble.
Maybe a length of 11/16" CRS turned enough on each end to fit and snug up the worn couplers.

For that particular case, I'd upgrade to the later 2000 series or CV joint driveshafts. The flex coupling driveshafts don't live long in a diesel.

 

[mfrade]

Thanks Dave. It was a fun project and I'd agree with Matt. I'd upgrade to a CV joint system, but this 8 horse tractor ran for 42 years on the last rebuild, so if that remains true... I'll never take it apart again. At least this system doesn't have any rubber flex parts in it.

 

[dschwandt]

WE parted one of those this fall and I believe we saved the driveshaft.
Will have to take that in to consideration for sure.
Weak part will still be the pinned connection to the hydro pump though, not?

 

[dfrisk]

I've found the rear driveshaft hole to the front coupler sleeve hole is what wears the most. I've had drive shafts that would easily accept 5/16" bolts or pins, and a 3/8" would start into the driveshaft hole. I tried to explain what I wanted for my #72 to Julian at MWSC last time I rebuilt my clutch. I wanted a longer coupler sleeve with TWO 1/4" cross holes for spirol roll pins, doubling the surface area being hammered. Maybe even make it long enough for 3 or 4.
I had a red die spring in my 72 for a while, till the catastrophic failure of the throw-out bearing. Then I went completely back to all stock parts. And I'm running 14+ HP in my 72, a "small flywheel" K321. The stronger pressure spring REALLY cuts throw-out bearing life. If your running a heavily modified pulling tractor with DON VOGT caliber HP you need a stronger clutch. If your pulling a lawn sprayer, or fertilizer spreader, or aerator a stock clutch is fine.
MIKE - Glad you got your Cubbie running. I have some work to do to my 3 and I can't even get near them in my shop! I have ALL MY stuff plus SON's wood shop in my shop!

 

[mfrade]

I reassembled the driveshaft, haven't installed it yet. I was thinking about the rear coupler and the next steps.. I'm thinking I can bore & bush the coupler then rebore to a shrink fit. At least the coupler to the creeper connection would be just about bulletproof. The driveshaft side would become sacrificial which wouldn't be a huge deal as they are easily replaced. Here's what's left of the T.O. Bearing.

 

[mgonitzke]

WE parted one of those this fall and I believe we saved the driveshaft.
Will have to take that in to consideration for sure.
Weak part will still be the pinned connection to the hydro pump though, not?

In my opinion, as long as the input shaft and the coupler are in good condition, it shouldn't be an issue. I think a lot of those got badly worn when run too long with a worn driveshaft flopping around. Those cast couplers are also pretty soft compared to the machined steel versions needed to use the newer driveshaft.

 

[dschwandt]

MIke, Sure did not mean to hi-jack your thread!!
So, I owe you a beer or two should we ever meet up at show sometime!!

 

[mfrade]

MIke, Sure did not mean to hi-jack your thread!!
So, I owe you a beer or two should we ever meet up at show sometime!!

I don't care about a hijack.... but now.. You did mention BEER? Right??? LOL. Be proud to share a beer or 2.. maybe 3 with you! OH, I meant "Adult Beverage"... wink wink.....

 

[PACub100]

"Wobble Pop"
"Barley Soda"