TOM - I think Harry is making this stuff up as he goes along. Not only have I never broke a pressure spring, I don't remember ANYBODY here ever saying they did. I won't say it can't happen, but a big heavy spring like that only compressing a half inch should have a life expectancy of millions of cycles. Springs by their nature fatigue in operation, whether coil, leaf or torsion, they sag, they can break, the more they compress, the bigger chance they will break. My '78 F150 I over-loaded a lot, never broke a leaf in the rear springs. My '87 F150 I never over-loaded, in fact, never carried much at all. I broke two of the four leaves in the left rear spring. Stuff happens!
JEFF - When I refurbished the 70 this spring, I had a new teaser spring, pressure spring, & T/O bearing for it already, also a used but good friction disk. When I got the clutch and drive shaft out, the area where the T/o brg & teaser spring looked good,only very slight wear, the rear hole for the coupler was still tight, so I reused the 48 yr old driveshaft. Clutch works like new. I'm sure the parts I replaced were factory original. That tractor had worn out 5 or 6 K161/181 engines so it had a LOT of hours on it. Most of it's use was mowing, never had any weights on it, and with the Pizza cutter GY turfs, couldn't pull much, plus there were always bigger tractors around to do the heavy pulling.
The drive shafts in the 72, (It's on #3 since new) all seem to wear at the roll pin hole on the very back. That's due to a combination of more HP and the way I use it, heavy draft loads, plowing, aerating my yard, pulling my lawn vac, etc. Not sure why IH LVL didn't add another roll pin on a longer coupler like I wanted to do, or use tougher steel than the 1018 CRS they used, but at least ONE engineer @ FARMALL knew about the problem with the rear of the driveshaft on higher HP GD CC's. We were tallking CC's one day at the water cooler and he mentioned the problem on his 10 or 12 HP GD CC. On 7 & 8 HP GD's they last forever. Factory DS on my 72 was 13 yrs old when I got it, had a 10 HP engine installed 4 yrs later, wallowed out the hole in the DS and broke the roll pin in five more years. I replaced the roll pins with 1/4" dia A2 TOOL Steel pins in a brand new OEM DS & coupler, they lasted till about 14 yrs all with 10 HP. I'll let you know in another 10-15 yrs how the MWSC 4140 pre-hardeden steel DS & Grd 8 bolts work. They've got 6-7 yrs & 200 hrs on them already.
