L3710 gst no power steering once shifted into gear

[Lakelife]

I’ve been trying to diagnose if the tractor needs to be split for gst hydraulic clutch pack seal repair/ replacement. Today I was able to get a copy of the wsm and started doing the pressure readings of the gst system, relief valve settings, pilot pressure and clutch pack pressure.

gst system pressure was 370

Relief valve setting pressure was a little low at 400 but trying to turn the adjuster didn’t seem to increase.. seemed to already be bottomed out so didn’t want to force it so moved on.

Pilot pressure I can get about 350 as soon as you shuttle shift into gear but then pressures fall to around 200. (This is also when the power steering stops working)

I stopped testing at this point as clearly there is an issue with the pilot pressure circuit.

guessing I need to look at the pilot orifice or modulating valve next or is this looking like the clutch pack issue??

 

[North Idaho Wolfman]

What is the pressure at the pump before anything?
Because what your explaining sounds like the pump is going out and that's why you can't get the pressure up.
I had the clutch pack seals go completely south and it never effected the steering on mine.

I've also had issues with a bad suction line causing issues and a bad filter causing issues.
I would look into those before you even consider a tear down.

To do the GST clutch pack it requires the transmission to be completely torn down, it's quite a task.
No for the faint at heart.

 

[Lakelife]

What is the pressure at the pump before anything?
Because what your explaining sounds like the pump is going out and that's why you can't get the pressure up.
I had the clutch pack seals go completely south and it never effected the steering on mine.

I've also had issues with a bad suction line causing issues and a bad filter causing issues.
I would look into those before you even consider a tear down.

To do the GST clutch pack it requires the transmission to be completely torn down, it's quite a task.
No for the faint at heart.

What is the pressure at the pump before anything?
Because what your explaining sounds like the pump is going out and that's why you can't get the pressure up.
I had the clutch pack seals go completely south and it never effected the steering on mine.

I've also had issues with a bad suction line causing issues and a bad filter causing issues.
I would look into those before you even consider a tear down.

To do the GST clutch pack it requires the transmission to be completely torn down, it's quite a task.
No for the faint at heart.

Thanks for the reply, I really hope you’re right as I’d rather not tear it down. The tractor does seem to have a lot of power in gear still. Takes a second or maybe 2 to start moving when you shuttle theft it but doesn’t seem out of the normal. The only test as far as the pump goes was the relief valve test that I did by hooking my gauge to the test port on the pump and got the 400psi. Is there something else I can do to test it as well?
The rubber part of the pickup tube does look original which I’ll order a new one and change the filter to begin with since it sounds like it could be an issue.

 

[Lakelife]

Thanks for the reply, I really hope you’re right as I’d rather not tear it down. The tractor does seem to have a lot of power in gear still. Takes a second or maybe 2 to start moving when you shuttle theft it but doesn’t seem out of the normal. The only test as far as the pump goes was the relief valve test that I did by hooking my gauge to the test port on the pump and got the 400psi. Is there something else I can do to test it as well?
The rubber part of the pickup tube does look original which I’ll order a new one and change the filter to begin with since it sounds like it could be an issue.

 

[Lakelife]

Changed fluid /filters/ rubber hose In suction tube, no change. Power steering works great in neutral, soon as it’s put in gear it losses steering. Checked pressures at ports and it’s the gst clutch pack. Long as it’s only the rubber seals it’s only a $75 repair

Tearing into it, couple hours at a time.

 

[Lakelife]

Looks like we found the problem, the big clip is broken and caused the seals to leak. New parts on order should go back together this week. Spent the extra $225 and replaced the clutches and rubber seals. $300 repair and we should be back in business. I have 5-6 hours into it so far breaking it all apart. Probably another 6 hours putting it all back together I’d guess. Been pretty simple so far, nothing that wasn’t called out in the wsm manual.

 

[Lakelife]

Found a broken retainer plate and broken springs along with the ripped outer d ring seal causing my hydraulic pressure drop in my power steering. I can’t believe this tractor was moving and shifting fine. That’s what made it so hard to believe the seal was bad but it’s obviously destroyed. I guess I’ll be ordering another $60 in parts tomorrow.

 

[North Idaho Wolfman]

Found a broken retainer plate and broken springs along with the ripped outer d ring seal causing my hydraulic pressure drop in my power steering. I can’t believe this tractor was moving and shifting fine. That’s what made it so hard to believe the seal was bad but it’s obviously destroyed. I guess I’ll be ordering another $60 in parts tomorrow.

Ok now that makes a lot more since, the seal will cause all the issues.

 

[D2Cat]

Looks like we found the problem, the big clip is broken and caused the seals to leak. New parts on order should go back together this week. Spent the extra $225 and replaced the clutches and rubber seals. $300 repair and we should be back in business. I have 5-6 hours into it so far breaking it all apart. Probably another 6 hours putting it all back together I’d guess. Been pretty simple so far, nothing that wasn’t called out in the wsm manual.

I complement you on cleaning the machine before you start the dis-assembly. See a lot of folks just start removing components and soon the internals are exposed to a lot of filth. Seems silly to worry about the correct fluids, filters and cost of parts if that's how it gets tore into.

 

[Lakelife]

I complement you on cleaning the machine before you start the dis-assembly. See a lot of folks just start removing components and soon the internals are exposed to a lot of filth. Seems silly to worry about the correct fluids, filters and cost of parts if that's how it gets tore into.

Thank you, helps when the labor is cheap and willing to learn!

 

[Chanceywd]

Thank you, helps when the labor is cheap and willing to learn!

That takes me back 60 years when I was 11. My dad didn't work on vehicles but my next door neighbor did.
Anytime I see he had a hood up I was his second set of hands. He taught me so much that has been with me all the years working on my stuff and others. Love it when my son and I work on a project together too.
So good to see the youngster in there helping!

Bill

 

[BAP]

Great job undertaking this project and better still, your write up with pictures about your repairs.