GT-14 Hydro Gear Swop

[Herder 2,354]

I picked up this 69 GT-14 sometime back in the spring, some may remember.  I chased this tractor for a while before I purchased it and it turned out it has a weak hydro gear and I was aware that something with the drive unit was off.  Low on fluid, a little slow.    Fresh fluids and a filter didn't save it.  I believe the damage was caused by pulling it around.  Well that didn't stop me from buying it.   She made it back into the shop this weekend and it's time to get down to it!!

She is a good looking tractor and the more time I spend looking her over the more I like what I seek.  I always loved the big rear tires the long frame and hood with that giant cast-iron nose that leans forward just a bit.  Its got that hot rod look, well you know for a tractor.  Well here we go and I will do my best to provide pic and progress as I go.  

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Here's the hydro gear that's going in after I've swopped the drive gear.  I will be following the step by step tutorial from 953nut. 

[ebinmaine 63,231]

I'm in....

[953 nut 51,802]

        Nice looking GT-14.

Before you do the swap out have you checked the Acceleration springs and valves? @wheelhorseman now sells replacement springs if they are the problem. The one I did was so badly damaged that the valves couldn't even move so swapping out the drive unit was the only choice.

[Herder 2,354]

11 minutes ago, ebinmaine said:

I'm in....

Come along for the ride. There could be bumps, bruises, some swearing, it should be fun.  

[Herder 2,354]

6 minutes ago, 953 nut said:

        Nice looking GT-14.

Before you do the swap out have you checked the Acceleration springs and valves? @wheelhorseman now sells replacement springs if they are the problem. The one I did was so badly damaged that the valves couldn't even move so swapping out the drive unit was the only choice.

I will do that, thank you.

[pfrederi 17,155]

Have you opened up the [pump.  From What I have seen the pumps brass slippers and valvbe plate are more sensitive to damage than the hydro gear.  The slippers and valve plate can be resurfaced.

[953 nut 51,802]

               If your three point lift is strong the pump is working well.

[pfrederi 17,155]

A pressure test might be revealing...  but Richard is correct the charge pump is Ok if the 3 pt works...but the slippers and valve plate are still suspect....and can be fixed.  how sure are you about the new/replacement unit conditiojn???

[Herder 2,354]

6 minutes ago, 953 nut said:

               If your three point lift is strong the pump is working well.

I've stood on them to see if they would lift, I am 200 ponds and they struggled.  Without weight on them they are slow.  That's how I tested the lift.  

[Herder 2,354]

6 minutes ago, pfrederi said:

A pressure test might be revealing...  but Richard is correct the charge pump is Ok if the 3 pt works...but the slippers and valve plate are still suspect....and can be fixed.  how sure are you about the new/replacement unit conditiojn???

The pump came off a working unit (parts tractor) and seemed quite strong.  I haven't removed the pump from the GT yet.  I do plan on an inspection so that I can determine what has failed.   

[daveoman1966 3,612]

When power is lost with this Sundsrand Hydrogear, IMHO, you'll find the issue is with the hydro pump itself.  You can remove the pump from the hydrogear, but it may be easier to just remove the entire pump & hydrogear as one unit, then break it down.  Open the pump and inspect the 9 brass piston slippers and all other internal components.  I think you'll find conditions like in these pics.  If so, refinish the contact faces to remove gouges and scars...using 220 400  800 grit sandpaper on a surface plate.  Don't remove any more material than necessary to clear the imperfections. 

[953 nut 51,802]

Regardless of which unit you use I would replace the acceleration springs, $ 32.00 well spent. Lowell also has the gaskets and cam plate you will be needing. @daveoman1966 has a very good point, may as well freshen up either pumpso you will get several more decades of service from it.

https://www.wheelhorsepartsandmore.com/transmissions.html#!/TRANSMISSION-ACCELERATION-SPRINGS-2-7052-9215-&-2-7264-9858/p/155147886/category=23548039

[Herder 2,354]

I know this question has been asked before!!  where is the best place/vender to get a complete seal and o-ring kit for the pump & gear unit.  At one point I had done some research and wasn't sure if I was looking at the correct items.   Got confused

[pfrederi 17,155]

Like this thread pinned up top

 

 

[Herder 2,354]

23 hours ago, 953 nut said:

Regardless of which unit you use I would replace the acceleration springs, $ 32.00 well spent. Lowell also has the gaskets and cam plate you will be needing. @daveoman1966 has a very good point, may as well freshen up either pumpso you will get several more decades of service from it.

https://www.wheelhorsepartsandmore.com/transmissions.html#!/TRANSMISSION-ACCELERATION-SPRINGS-2-7052-9215-&-2-7264-9858/p/155147886/category=23548039

Do you know if someone has done a thread on the replacement of these springs?  I read through the manual and although I understand it, the info is a bit scattered between troubleshooting and rebuilding.  Looking for something a bit more direct. Larger pics. for failing eyesight. I removed the large plug in the top front of the hydro gear.  Should there have been spring pressure behind the plug? The acceleration valve stayed in place.   Sorry no pics. yesterday was way to cold and nasty to spend any extra time outdoors.  

[Herder 2,354]

Didn't get to far today, getting late, cold and it's time for dinner.  Breaded chicken thighs.  Removed the 3 point hitch and drained the trans.  Can't say I am to excited about all the meatal shaving in the bottom of the pan.  Tomorrows endeavor: build a wheeled cradle for the drive unit.  I am thinking it would be easer to work on if it was removed       

[953 nut 51,802]

3 hours ago, Herder said:

Can't say I am to excited about all the meatal shaving in the bottom of the pan.

Chances are they came from your parking brake, If the axle comes apart you can weld it back like new.

3 hours ago, Herder said:

build a wheeled cradle for the drive unit.

Here is one I built.

 

[daveoman1966 3,612]

As 953NUT suggested, those filings like came from the parking pawl( brake).  Tiny filings like that are what cause damage to the soft internal brass piston slippers as those filings circulate in the fluid and the filter doesn't catch all.  Here are a couple pics of valve & springs...   There are a number of ports on this Hydrogear, so try to follow my alpha-logic in identifying them.

I have SOME replacement parts....if needed.

 

Edited January 1, 2020 by daveoman1966

[Herder 2,354]

9 hours ago, 953 nut said:

Chances are they came from your parking brake, If the axle comes apart you can weld it back like new.

Here is one I built.

 

 The idea of a dolly came from you.  My back thanks you.  From some of things I've read I was thinking it may be the parking brake (?)  In it's current condition it still worked perfectly.

[Herder 2,354]

6 hours ago, daveoman1966 said:

As 953NUT suggested, those filings like came from the parking pawl( brake).  Tiny filings like that are what cause damage to the soft internal brass piston slippers as those filings circulate in the fluid and the filter doesn't catch all.  Here are a couple pics of valve & springs...   There are a number of ports on this Hydrogear, so try to follow my alpha-logic in identifying them.

I have SOME replacement parts....if needed.

 

 

 

 

 

 

 

 

 

 

 

 

 

Prefect, I was  trying to find something like this.  Big pics. for failing eyesight and it simplifies many paragraphs of reading from manual.     Thank you.

[953 nut 51,802]

7 hours ago, daveoman1966 said:

Here are a couple pics of valve & springs...

Thanks Dave, those are excellent pictures.        

When it is time to inspect the acceleration springs and valves ( B and E in @daveoman1966 pictures) be sure to not mix parts. The Reverse valve (located at the front) has smaller holes than the forward gear valve (mounted at the back)

This thread by @meadowfield has a wealth of GT-14 information in it.

 

Edited January 1, 2020 by 953 nut

[rjg854 10,757]

This is all so very interesting!   to all who are involved in this thread 

[N875ED 98]

Fantastic documentation of this effort with photos and labels on the photos. I know this is time consuming but very worthwhile for this type of technical subject.

[Herder 2,354]

2 hours ago, 953 nut said:

Thanks Dave, those are excellent pictures.        

When it is time to inspect the acceleration springs and valves ( B and E in @daveoman1966 pictures) be sure to not mix parts. The Reverse valve (located at the front) has smaller holes than the forward gear valve (mounted at the back)

This thread by @meadowfield has a wealth of GT-14 information in it.

 

I just read this thread, thanks for posting it!!   I see a very similar project I my near future.   

[Herder 2,354]

On ‎12‎/‎31‎/‎2019 at 8:25 PM, 953 nut said:

Chances are they came from your parking brake, If the axle comes apart you can weld it back like new.

Here is one I built.

 

Ready to go.