[jgoodman]

I’m having trouble diagnosing an issue with the rockshaft on my 1978 316K. It seems to be weak in only one direction. I have the mower deck removed and don’t have any other attachments, so it’s a little difficult to say for sure, but it sticks/lags when I push the lever forward. No such problem when pulling the lever - the rockshaft action is quick and steady. It doesn’t look like there are any obstructions to the movement of the rockshaft, the fluid level is good, and this occurs with engine at full throttle. I haven’t had the tractor for long, but I believe the fluid and filter were changed recently. I plan on changing the filter anyway to rule that out. I also plan on getting a pressure gauge to help further diagnose, but was wondering if y’all had any ideas.

 

[rwmeyer]

Joe, I'm not really familiar with a 316, but the first thing I noticed was "1978"...the 316 didn't come out until 1984! Typo ???

Now, assuming it's a 316, the rockshaft cylinder is attached to a slotted bracket welded on a rotating shaft...the slotted bracket allows for "float" on whatever is mounted. Possibly the lag you're seeing is just the cylinder moving through the slotted shaft. With no weight/load, the shaft doesn't want to rotate freely.

Mount your deck (shouldn't need mule drive & belt, just draft arms & lift links) and raise fully. Push hyd lever fwd and see if deck immediately starts to lower. If not, repeat this standing on the side of the tractor with your foot on the deck applying some down pressure on the deck.

You may also want to crawl under and spray parts with parts cleaner, followed by some lube...plain oil or WD-40

Try and report back. Bob

 

[chuckv]

Bob,

The model 316 with a single cylinder Kohler engine was indeed made in the 70's. It is completely different tractor from the Onan powered 316 which is essentially a stripped down 318. The 316 Onan and the 318 are part of the lineup of open frame garden tractors of the 1980's and early 1990's -- while the 316 Kohler is part of the earlier closed frame series that includes the 300, 312, 314 and the 317.

Joe -- it sounds like the deck lift is binding someplace such that gravity does not lower it quickly and reliably. The hydraulics simply allows the deck to fall of its own weight, but does lift it without any provision for decoupling the hydraulics stroke from the deck motion. In other words it floats at whatever height you set with the mowing height stop adjustment, but lifts all the way up when you pull the lever. If you have a copy of the parts catalog or view it on-line you will find good exploded views of the mechanism that will help you visualize this and let you check all the linkage motions.

Chuck