Hydro question

[meadowfield 2,595]

I am fairly certain my GT14 sundstrand transmission is in reasonable shape - pump will drive lift cylinder to lift 400lbs and the motor will almost stall or spin wheels if the tractor is trying to push something immovable...

My question is when the engine isn't running, should I be able to move the tractor at all with the control lever in neutral and the tow valve closed?

Just pushing the tractor by hand with the valve open or closed I feel the same resistance - which doesn't feel like a lot. Is this normal? Or am I paranoid....

[refracman 167]

You shouldn't be able to move it with the tow valve closed. How does does it respond fwd and rev while your running with the tow valve closed?

[meadowfield 2,595]

It's the first hydro I have had, so hard to judge... But pushing the lever slightly forward it seems to creep forward and gradually get faster as I push fully forward. Reverse is much the same, but a little slower (guess that's by design).

I have noted that running downhill it seems to run forward a bit then hold and drive ok - almost like maybe 1/4 turn backlash in the transmission.

The motion control linkage does seem worn but in reasonable shape, but again no prior knowledge...

Thanks

[Paul D. 26]

Does it drive the same with the tow valve open? If not then the valve may be faulty.

[meadowfield 2,595]

Does it drive the same with the tow valve open? If not then the valve may be faulty.

That is a good question... Should it drive at all with the valve open?

[Paul D. 26]

Not totally sure we will have to wait for one of the hydro experts to chime in but I would assume it shouldn't drive the same

[refracman 167]

It will gain speed down hill, so Ive heard, where i live its flat, so I cant comment on that.

You can drive it with the valve open, I have done it to mine with no ill effects,but your not supose to. It will not be very responsive or move very fast.

If when driving it forward should be about 10kmh and reverse should be about 4.5kmh.

Just wondering which trans do you have the Sundstrand hydrogear or the piston to piston? The hydrogear is one big cast piece and the piston to piston is a 2 peice assembly.

[can whlvr 993]

no it should not move if you open the tow valve,they do go faster down hill,they are totally different than the 8 speeds,the real question is does it stay strong after a good long warm up,then drive it up a hill,if it pulls up good then she should be ok,not suer what sundstrand you have,mine is from a c160 1975,but they should act similar,mine wont move 1 foot if its not running and the tow valve is closed

[meadowfield 2,595]

From what I can see it is the piston piston unit with the tow valve at the bottom where the pump joins the motor.

[can whlvr 993]

have you driven it enough to really warm it up,if it drives good after a warm up your ok

[shootinok 15]

Mine will move with some resistance - have not tried to push it very far, but it's not like it locks up. Mine is strong as an Ox.

[meadowfield 2,595]

hmmm,

so two opposing stories:

• With tow valve shut it wont move
  
• With tow valve shut it moves with resistance
  

Mine seems to move with resistance open or closed. Will see if i can get it warm this weekend, though the yard is small

[can whlvr 993]

as you have probally noticed that all these machines act different,some hydros wont move when cold some will,they are like people,all different,thats the one thing (and only thing)i dont like about my c160auto,you cant just give a push to move it in the shop,my new to me 312-h will roll without doing anything and i find that very handy when you just need to move it a bit and dont want to fill the shop with smoke from starting it up,good luck,hope its gonna be a runner for you,too many bad stories of hydros it seems(been there done that)

[JamesBe1 82]

as you have probally noticed that all these machines act different,some hydros wont move when cold some will,they are like people,all different,thats the one thing (and only thing)i dont like about my c160auto,you cant just give a push to move it in the shop,my new to me 312-h will roll without doing anything and i find that very handy when you just need to move it a bit and dont want to fill the shop with smoke from starting it up,good luck,hope its gonna be a runner for you,too many bad stories of hydros it seems(been there done that)

I can certainly agree with this. While my C-145 (hydro) will move a few feet, my D-180 would hardly move at all. The 8 speeds are much nicer in that respect as you can push them around easily on a level surface without having to start them.

[meadowfield 2,595]

it certainly seems good for the moment, as previously said, it will stall or skid under extreme load - but I haven't got the tranmission hot yet... Thats for the next weekend when I'm back home.

I'm actually more concerned about the fact the tractor has no brakes! and relies on the transmission to hold it - how do I go down hill without it running away?

[JamesBe1 82]

it certainly seems good for the moment, as previously said, it will stall or skid under extreme load - but I haven't got the tranmission hot yet... Thats for the next weekend when I'm back home.

I'm actually more concerned about the fact the tractor has no brakes! and relies on the transmission to hold it - how do I go down hill without it running away?

Yeah, no brakes is something that you have to get used too. Is there a brake pedal? Typically, the brake pedal moves the transmission into neutral.

I don't see why it should run away when you go downhill. How significant is the speed increase? I'm no expert on hydros, but in my humble experience, every tractor in the world speeds up a little bit. You shouldn't have to worry about it running away if it stalls. Without pump pressure to turn the hydro motor, you shouldn't be going less than a few feet at best.

Also, don't forget about the parking brake. Be careful thought. Most people (like myself) forget about it and try to drive away. Certain designs are know to sometimes brake under those circumstances.

[meadowfield 2,595]

Yeah, no brakes is something that you have to get used too. Is there a brake pedal? Typically, the brake pedal moves the transmission into neutral.

I don't see why it should run away when you go downhill. How significant is the speed increase? I'm no expert on hydros, but in my humble experience, every tractor in the world speeds up a little bit. You shouldn't have to worry about it running away if it stalls. Without pump pressure to turn the hydro motor, you shouldn't be going less than a few feet at best.

Also, don't forget about the parking brake. Be careful thought. Most people (like myself) forget about it and try to drive away. Certain designs are know to sometimes brake under those circumstances.

the parking brake disengages the pump and dogs the final drive on the transmission... but it's broken and in the bottom somewhere....

A design fault if the tractor is rolling or moving and the parking brake is engaged. So until I fix it theres no parking brake and when I do fix it I might find myself using it in a panic and it breaking again!

[JamesBe1 82]

Yeah, no brakes is something that you have to get used too. Is there a brake pedal? Typically, the brake pedal moves the transmission into neutral.

I don't see why it should run away when you go downhill. How significant is the speed increase? I'm no expert on hydros, but in my humble experience, every tractor in the world speeds up a little bit. You shouldn't have to worry about it running away if it stalls. Without pump pressure to turn the hydro motor, you shouldn't be going less than a few feet at best.

Also, don't forget about the parking brake. Be careful thought. Most people (like myself) forget about it and try to drive away. Certain designs are know to sometimes brake under those circumstances.

the parking brake disengages the pump and dogs the final drive on the transmission... but it's broken and in the bottom somewhere....

A design fault if the tractor is rolling or moving and the parking brake is engaged. So until I fix it theres no parking brake and when I do fix it I might find myself using it in a panic and it breaking again!

So what happens when you step on the brake pedal? I may be wrong, but the linkage should move the control lever into neutral.

[Trouty56 567]

Meadow, I have 3 auto's and each one is very controllable down hill, in fact, I can creep so slow that the rear tires skid at times if the hill is too steep. As far as braking I just use the hydro and throw it into the next direction a little. It takes getting used to. Stops you quick so best lean into it. I always park parallel to the hill cause mine will coast ever so slightly it seems.

James, I think he is talking about the parking pawl that engages in some manner on all the older hydros. Another reason I park sideways. I don't trust them either although all mine do engage.

[wheeledhorseman 574]

I'll send a pm Mark

Andy

[can whlvr 993]

as trouty said you use the hydro to slow down,pull back on the lever to slow down,you have to be a little more hands on with a hydro and hills,the hydro will stop you unless its so steep the wheels slip,but an 8 speed would slide also,my 312 (which is completely different than yours)has a brake band on the brakes,yes the brakes return the lever to neutral,which my 160 does also,but the 312 actually has brakes too,but i never use it and i have hills too,just use the control lever

[meadowfield 2,595]

MeaJames, I think he is talking about the parking pawl that engages in some manner on all the older hydros. Another reason I park sideways. I don't trust them either although all mine do engage.

thats right ! mine is somewhere in the bottom of the tranny rattling about - might post some teardown pics this weekend.

and yes, the brake pushes the drive lever into neutral-ish (the linkage is very worn)

mark

[Trouty56 567]

You think the whole pawl is off the shaft?? Maybe just the teeth?? If the whole pawl is down there you've been lucky it did not get caught under the rear gearing and crack the case....lol.... Most likely the teeth are broke off.

I'm not familiar with a GT-14. Is there a separate lever for the park so that it is possible to engage the transmission while the pawl is holding? Some of the early D's are like that. Why so many are broke.

Post your pics...it will be cool!!

[JamesBe1 82]

MeaJames, I think he is talking about the parking pawl that engages in some manner on all the older hydros. Another reason I park sideways. I don't trust them either although all mine do engage.

thats right ! mine is somewhere in the bottom of the tranny rattling about - might post some teardown pics this weekend.

and yes, the brake pushes the drive lever into neutral-ish (the linkage is very worn)

mark

That's technically your brake. Both of my hydros operate on the same principal. Some models even have an additional brake band on the transmission. Not sure if my C-145 has it as I never bothered to check. If it does have it, I'm not going to bother with it as it seems an unnecessary redundancy. Neutraling (if that's even a word) is a perfectly acceptable braking method IMHO.

There should be an adjustment to set the hydro pump back to exactly neutral with the brake lever depressed. It probably consists of raising the real wheels and adjusting a cam with the control lever in neutral so that there is no movement in the wheels. At least that is how both of my hydros are done.

Sorry to hear about the worn linkage. I feel your pain in that regards, my D has the same problem. Too much slop in all the little cams/pinions/bushings/levers between the lever and the transmission. The sum of a bunch of sloppy connections really adds up. I've been pondering what to do about that in mine for a while. I think I will have to disassemble it all that bend or reshape or whatever I need to do to reduce it as much as possible.

Yes, defiantly post your pics. Hopefully there is no damage in your gear box.

[Trouty56 567]

Some models even have an additional brake band on the transmission. Not sure if my C-145 has it as I never bothered to check. If it does have it, I'm not going to bother with it as it seems an unnecessary redundancy. Neutraling (if that's even a word) is a perfectly acceptable braking method IMHO.

I believe the failed parking pawl was eliminated and the friction brake replaced it...not redundant but replacement. If you are in a situation where inches make a difference that friction brake could save...maybe a child's life. Adjusting neutral on these machines is very tricky. I've already been pushing snow and backed towards an object, hit the pedal,.......and still moving a bit. Gives you a hairy feeling. Might be the loosening linkage. Now with a brake band that would not have happened.

******Disclaimer.......I'm not positive on my first statement!!!! LOL