430

[DRussell]

On a 430 that leaks hydraulic fluid into the transmission can you over fill the transmission/rear-end to compensate for the leak or does the transmission take gear oil?

 

[flatpkr]

Transmission takes SAE 90. The torque tube takes hy-tran fluid. You need to replace the PTO shaft seal and 3 point piston O-ring accessible after removing the top transmission cover.
Jim

 

[DRussell]

How critical is it for the transmission on the 430 to have the 90 weight oil? My 1030 takes hydraulic oil in the transmission and rear-end. Is the 430 made with different components (compared to say the 1030 or other ones) and those components in particular require the heavier oil or were there other reasons such as it was cheaper?

 

[Joe (Wa)]

The hydraulic oil level at the full mark in the torque tube is very much higher than the normal full level in the transmission. To equalize the two oil levels will have the transmission oil level nearly up to the top of the housing with much more hydraulic oil than gear oil. The transmission was built with the intention of using 90 wt gear oil to maintain an adequate oil film between moving parts. To dilute it with very low viscosity (~10 wt?) hydraulic oil on a machine this old may provide adequate lubrication if not heavy, sustained loading but will almost certainly guarantee seal leaks at the axles and/or differential shafts onto the brake discs.

It is pretty much a case of changing the seals that are leaking now or change some more seals that will leak down the line as well as the original leakers.

Migration of hydraulic oil into the transmission occurs primarily in order of likelihood: the Eagle hitch piston seals, the pto shaft seal, and the transmission main shaft outer seals in the front of the transmission. There are other areas in the transmission front than can leak but I think it a very remote possibility. A leak at the transmission front obviously requires a split.

Check the Eagle hitch piston seals. With some weight on the draft arms lift the hitch to the highest position. With the engine not running does it leak down? If yes it is defective piston seals or the hydraulic interlock + the control valve leaking. The odds are it is the piston seals and it is the easiest think to check. That does not eliminate the other seals as leakers but it is the first thing to correct. The hitch does not leak down now or pretty much stays up overnight, the next thing to check is the pto shaft seal, Even if you are only replacing piston seals you will have clear access to the pto seal when you pull the rock shaft housing. Here is a pic of what the early 430 pto shaft seal looks like with the rock shaft housing removed. The later 430 pto shaft seal is similar but not identical.

To check the seal have the torque tube oil level at full. With carb cleaner/electrical cleaner or other, spray the seal and adjacent area dry of oil. Observe the seal for a oil weep. Seal leak usually is most visible immediately after engine shutdown, ok to run the engine for a minute or so.

Joe

 

[DRussell]

Thanks Joe, your response is helpful. I get that the torque tube level is higher than the transmission level and the transmission would have to be run overfull for my idea to work. I also understand the possibility of other leaks starting. The tractor is not mine and is leaking hydraulic oil into the transmission/rear-end from somewhere. It appears that the most likely place it is leaking is from the rockshaft seals as it will fill the transmission level with oil to the point it comes out the top at the gear shifter. Or at least the leak at the rockshaft appears to be the worst. If the PTO shaft seal was leaking as well, I would think it would equalize between the two reservoirs rather than come out the gear shift lever.

Despite this the tractor does not have other leaks on the outside, i.e., the axle seals are not leaking and the brake shaft seals are not leaking. This is not to say it won't start in the future, but...

The tractor is not used heavily. My original question was more related to whether hydraulic oil in the transmission/rear-end would provide sufficient lubrication.

The following may or may not apply to the discussion, but I spoke to a fuel oil supplier yesterday and was told that hydraulic oil can be purchased at weights up to 150 wt oil. I was thinking maybe getting heavier weight hydraulic oil than the standard 10 wt oil and filling both chambers with hydraulic oil and allow it to leak internally. I was thinking maybe a 30 or 40 wt hydraulic oil.

 

[John Saeli]

You are looking for the easy way out, and there isn't any. It isn't that big a job to replace the Piston Seals & PTO shaft seals. Yes, you can run thicker oil in the Torque Tube, and thinner oil in the Trans- Diff, but to properly lube the range shaft, gears & bearings in the Torque Tube would require WAY overfilling the Trans-Diff, to the point it will seep everywhere.

 

[DRussell]

You are right. I'm looking for an easy way out on what is a design flaw. Case should have made the entire compartment, rear-end transmission etc, use hydraulic fluid and be the hydraulic reservoir.

 

[John Saeli]

The fluid levels are the factor.

 

[d13series1]

The transmission will self-overfill.

This leak on my 430 has proven impossible to stop, including during a complete rebuild.

The biggest issue with mine is the overfill leaks thru the axle seals rendering the RH brake inoperable. But hey, a 55 year old tractor doesn't need much brake, right?

I have actually considered replacing the trans check plug with a nipple and allowing it to drain off constantly. But I do a lot of rough brush hogging and would tear it off. My second thought is just a valve and drain out every couple hours.

More likely I will just live with it.