D17 power steering - governor driven pump

[Termite]

Evening all, having power steering woes with my D17 with single front wheel. I'll preface this with I've not experienced the issue and working on vague secondhand information and a service manual.

Symptoms: Started with assist on left turns and loss of assist on right turns (including return to center). Progressed to no assist in either direction before returning to the barn. Full of oil that does show water contamination.

Diagnosis and remedial options:

1- Flush the contaminated oil and replace with new trans/hydro oil. Go from there if symptoms persist?

2- Drain oil and open pump for inspection/rebuild? New oil on fill.

3- Possible ram issue?

4- Control valve issue?

Options 3 and 4 both appear to require pulling front support off which is a challenge at the in-laws place.

Appreciate any advice and experience you all can share. Maybe tomorrow I'll have the time to check it out firsthand and see what its doing.

 

[DrAllis]

I think you better drive it for at least 30 minutes and down the road always to get some good information.

 

[Termite]

I think you better drive it for at least 30 minutes and down the road always to get some good information.

I went over and moved it to the barn yesterday afternoon. Turns right with some resistance and no power assist returning to center or left.

From looking at service manual and parts diagram, I'm expecting to disassemble the gearbox to at least inspect and clean everything.

 

[DrAllis]

Remove the steering box fill vent tube. Oil level should be just above the gear inside. Start the engine and throttle it up to half or more. Look inside with a flashlite and see if the oil is moving around. If the oil isn't moving, I'd say the pump has issues. Start with some diagnosis instead of just tearing things apart.

 

[Termite]

Remove the steering box fill vent tube. Oil level should be just above the gear inside. Start the engine and throttle it up to half or more. Look inside with a flashlite and see if the oil is moving around. If the oil isn't moving, I'd say the pump has issues. Start with some diagnosis instead of just tearing things apart.

I'll check fluid flow before disassembly as advised and report back. We head out of town today and won't have time to do anything with this project for a few weeks.

It has some leaks that need to be addressed and this will serve as motivation to deal with those as well. Haven't gotten to cleaning everything up to truly identify source of the leaks, whether they are control valve area or main housing/wheel support intersection.

 

[Termite]

Going to be back out at the barn tomorrow and will do some diagnosis on this. Assuming pump moves fluid, what would be next most likely cause or diagnostic step?

 

[DrAllis]

Complete and ACCURATE diagnosis is key to figuring out what's the next step. On June 5th I suggested for you to drive it around for 30 minutes to gather info. That hasn't happened yet, so there is no info to work with.

 

[Termite]

Complete and ACCURATE diagnosis is key to figuring out what's the next step. On June 5th I suggested for you to drive it around for 30 minutes to gather info. That hasn't happened yet, so there is no info to work with.

On the agenda for today is to do so, I was requesting next steps on the basis of the below as I won't be online while at the barn and don't expect yourself or others would be waiting with anticipation to reply immediately. Regardless, I'm putting the time in over there this afternoon and will report back.

1. Is fluid movement within gearbox observed following approximately 30 minutes of operation?
1a. Fluid movement is observed and responds proportional to increased engine speed. Go to step 2.
1b. Fluid movement is not observed or is minimal. Pump issues or restrictions likely. Go to step 3.

2......

3......

Many thanks and don't take my responses as disrespectful. I try to look a step or two ahead to maximize the effectiveness and productivity when I get the chance to dedicate time to diagnosis and repairs.

 

[DrAllis]

There should be fluid movement of some kind anytime the engine is running. The faster the engine speed, the faster the fluid should move. If there is no fluid movement at any engine speed and no power assisted steering during right or left turns, I would be removing the pump.

 

[Termite]

Drove it around the barn yard for a spell, long enough to get up to operating temperature then parked it. Significant fluid movement was observed with filler cap removed at idle, as well as at increased engine speed. Went ahead and dropped the fluid to remove the water contamination and gave a fresh fill. No change in lack of power assist.

Right turns are easier in comparison to left but more resistance than typical. Left turns are a serious challenge.

 

[DrAllis]

Left turns not-power assisted ?? Right turns more normal ?? There is probably a sheared off pin that connects the power steering cylinder rod end to the steering gear rack. With this pin sheared it is manual steering only when turning left and still a more normal power assist to the right. Requires the removal of the radiator and slide forward or removal of the front support/steering gear to disassemble.

 

[Termite]

Finally got back to the tractor after dealing with vehicle repairs and other more pressing matters. Pulled the front wheel and spindle, slid steering gear forward, then pulled completely off the tractor and brought it home for cleaning and inspection.

After cleaning, pulled the hydraulic ram to find the pin intact, glands intact, and nothing obviously amiss. Proceeded to pull the control valve and worm gear out. Upon removing the front cover from control valve, I discovered the nut holding the bearings on worm gear was barely engaged with the threads and not staked to the shaft. I suspect the nut worked its way loose enough the valve spool wouldn’t shift adequately when turning left. Cleaning and reassembly will proceed evenings this week or next weekend, if I don’t head to the national forest with the kids to camp out.

 

[DrAllis]

OK. That does happen occasionally. That nut cannot be TIGHT. Basically, you just snug it up to contain the Orings on each side of the spool. So, too tight will make the steering assist less and too loose will allow the Orings to blow out. The front support still had to be pulled to get to where you are now at.

 

[Termite]

OK. That does happen occasionally. That nut cannot be TIGHT. Basically, you just snug it up to contain the Orings on each side of the spool. So, too tight will make the steering assist less and too loose will allow the Orings to blow out. The front support still had to be pulled to get to where you are now at.

Understood. Service manual specs 5 ft-pounds. No complaints about pulling front support, it definitely needed a thorough cleaning.

 

[DrAllis]

Stake the nut good.

 

[Termite]

Continued cleaning and inspecting over the past two weeks. Aside from sludge build up in the front support housing, nothing amiss in that area. Did go ahead and drop main gear and bearing assembly (retainer) out to allow for more thorough cleaning.

Now to locate a source for the 0.005 vellum gasket replacement between the bearing retainer and front support. Is the .005 critical or can a 1/64 gasket (0.015-0.016) replacement serve without issue? Does not appear to impact preload unless my support has been missing a bearing for who knows how long.

In essence, what I see on the bench doesn’t match the service manual.

 

[DrAllis]

Well yeah !! A tapered roller bearing and cups top and bottom !!! Set your bearings to a slight pre-load. Do NOT make a gasket !! be careful with what you have and smear a layer of RTV in place of a .005" gasket. IF THIS IS A SINGLE FRONT WHEEL I'VE NEVER SEEN ONE BEFORE !!! AND THAT MAY BE HOW THEY ARE !!!

 

[Termite]

Well yeah !! A tapered roller bearing and cups top and bottom !!! Set your bearings to a slight pre-load. Do NOT make a gasket !! be careful with what you have and smear a layer of RTV in place of a .005" gasket. IF THIS IS A SINGLE FRONT WHEEL I'VE NEVER SEEN ONE BEFORE !!! AND THAT MAY BE HOW THEY ARE !!!

It is a single front wheel unit. I suspect the manual is written for wide front axle units or mine is a Frankenstein.

The retainer assembly has a tapered roller bearing below the main steering gear that appears to be the upper bearing. I’m assuming there is another lower in the housing but haven’t disassembled that portion, just flushed out with brake cleaner followed by a light oil.

Honest question:
Do you have an aversion to making gaskets? History of them failing or incompatible material? Or not recommended as you’re unacquainted with my skill level? I’ve made numerous and never had an issue in the past.