Mower hanging down on left

[Tom Evans]

I've got a 1975 1650 with a 50GT model 359 mower deck. When I hook up the deck it hangs down on the left side. I've adjusted the adjustable lift link and still it hangs to the left. After a few days of messing with this, I noticed that the lift arms off the rock shaft aren't parallel. The left is about 1/2" lower than the right. Looking at the 1" shaft that they attach to, it looks like they're held on by roll pins through the shaft that goes through the frame. Is there any adjustment for this, or are the holes for the roll pins wallowed out? Thanks for any help, Tom.

[gitractorman]

My guess is that the roll pin is broken and the arm is spun a bit on the rockshaft. Since it's a hydraulic lift, it could actually be the one on the hydraulic cylinder side (right side) that's broken and spun, letting the left arm drop lower than the right arm that's spinning. I've seen it happen both ways. There's no real good way to check other than trying to drive out the roll pins and see which one moves. If one moves when trying to drive them out, it's aligned correctly, and you can work on the other side.

First, try to drive out the roll pin from the top, but I'm betting it wont' budge (because they're broken and not aligned). You'll probably have to drill out the ends of the roll pin that are in the lift arm. I'd start with drilling out the the top one, as you may be able to skip drilling the bottom and just drive it out from the top once it's re-aligned. Then, re-align the arm where it's supposed to be on the rockshaft and you should be able to drill straight through to get the middle section out of the rockshaft. Again, if you get it re-aligned, you may be able to drive out the middle and bottom pieces, but I've had to drill them out in the past.

If you get it drilled out and aligned, you can put in a new roll pin and it should fix the lift issue. If you decide to go with a bolt instead of a roll pin, get a Grade 5 or 8 bolt, as standard bolts are too soft and will just do the same thing.

I'll warn you, this isn't an easy job. It will take a lot of patients because those roll pins are hardened or spring steel, and they DON'T drill easy! That plus being a confined work area, make it a real PITA! Get some good drill bits and take your time.

[Tom Evans]

Gitractorman,
Thanks, you we're right on. I checked the roll pin on the left by inserting a drift pin through the center of the pin and it went all the way through, so I knew it was OK. The right rock shaft lift arm had a 5/16" bolt through it and it was sloppy and moving when lifted. I replaced it with a 3/8" bolt and all is well. If I hand hands the size of a child it would have been much easier. Thanks again, Tom.

[gitractorman]

Glad you found it. Yea, not an easy spot to work in. I can tell you one way that it gets broken on hydraulic lift Cub Cadets. When you adjust the lift stop (the oblong cam bolt on the right side of the frame) it acts as a stop for the lift, to set your height of cut for the mower deck. However, inside the frame, the way the rockshaft bolts to the hydraulic cylinder, there are two hookup options. One way lets the system float, where there is no down pressure, and the other hookup is direct to the cylinder so there is down pressure. If it's hooked up with down pressure, it's real easy to be forcing down pressure on the rockshaft while it's against the lift stop. At that point, the "weakest link" in the lift system is the bolt that you just replaced.

I would double check this hookup and fix it so it's in the floating setup. There's really no need for down pressure on anything unless you're trying to use a snow blade to grade dirt or gravel (which honestly, you don't even need down pressure for this as the snow blades will continue to dig until you hold them up). Otherwise, the down pressure just puts undue stress on the whole lift mechanism.