SMTA Lift-All

Well I finished up the SMTA last week. Drove it over to a small town homecoming parade Friday afternoon. I noticed a little vibration at mid idle, which seemed to go away when I pulled the lift all rod all the way back. SO I locked it back with the little tab.

When I got home the fluid resevoir was HOT!
Yesterday I checked the resevoir and added 4 quarts of fluid, my bad.

Now I still have the vibration at low idle a little less when I pull the rod back. Engine rpm drops about 200 when I pull and hold the rod.

Questions: What is happening in the system when you lock the lever back with the tab on the resevoir? Why would the fluid get very hot?
Not many moving parts in that pump, can I rebuild it, are more than just the seal kit available for parts?
Is there a way to just bypass the whole affair. I don't think I will ever need the hydraulics.

Gordo

If all outlet ports are pluged on liftall thats dead heading the pressure and the relief valve opens to keep from overloading system. With lever pulled back all the time its building heat as fluid circulates under pressure. Valving works the same as a belley pump but with a constant pump feed.
Doubt if its causing the vibration.

As D Slater points out, that tactic is going to ruin parts in the hydraulic system. The vibration must be coming from other sources, as the drive for the live pump, and the internals of it are pretty much shafts, and are not reciprocating. There could be many things unbalanced in the moving parts. If the vibration is present even when the clutch is in, and the drive train is stopped, then from the fly wheel to the front pulley is the primary place to look.
A improperly milled flywheel
A flywheel with a chip of metal under it on the crank flange
A cylinder that is low on compression causing power imbalance. (possible valve adjustment issue)
A flat cam lobe (not usual on IH stuff)
Any of the four pistons that are not identical to the others (weight or style)
One wrong length rod
A front pulley with massive runout (unlikely)
Those are about it.
If it is operated by a seasoned IH driver, and s/he thinks it is normal, it probably is.

All of that series has no balance weights on the crank, they depend on the rods and pistons moving in opposite directions(one and four moving up, 2 and 3 moving down), and the firing order to make it operationally balanced. The pistons and rods must be all the same weight and type. They can be any weight, from cast iron to forged, but they must be the same. Good luck, JimN

The vibration is there with the clutch disengaged. It is less at about 1200 rpm. But as I say it is a very hi-speed vibe, much higher than piston speeds. Maybe flywheel speed. If it's out of balance, or not running true that could be it. My H and SH certainly don't have it. But of course a nice running 283 Chev was like an electric motor compared to the 454
I also noted that when you turn off the fuel with the engine running that SMTA dies in about 25 seconds. The SH runs for about two minutes before stalling. Quite a difference in fuel consumption I'd say.

Gordo

On our MTA, to use the loader, you have to have the "remote cylinder" valve locked in the forward position.
To use the remote valve for trailing implements,the "loader" valve lever has to be locked in the "raise" position.
Sounds like you might have a loose flywheel. You might check the bolts on that or pressure plate bolts. Alternatively, check for worn bearings/ shafts at the clutch/ TA input shafts going into the trans. Something is doing a dance number in there to get vibration like you are talking about. Better find what is causing it.

Was just thinking,, Have you looked into the valve lash adjustment?? Might be the valve adjustment is too narrow or wide on one cylinder---could cause problems???

fan blade or water pump?

karl f