877 hydraulic lift conversion

[Stubby 19]

I have an 877 and another model which have no id tag so it has been a guessing game. I am thinking on switching my 877 over to hydraulic lift. I would have to take the hydraulics off the unknown model and put it on the 877. These machines are very close to being the same model. Lots of similarities. I put unknown model and 877 on the pictures. It appears to me that switching the physical parts over should not be an issue. My main concern is the fluid in the trans will possibly be. Please advise with all information that could be an issue.

[squonk 41,474]

There are (is ) an internal valve on the pump you will need also.  @pfrederi ?

[pfrederi 17,913]

You will need to transfer the implement relief valve from the unknown donor to your 877.  Downlaod the sunstrand manual here.  It shows what you need to do in the hydro gear section.  The 877 was called Wheelamatic but it is basically same as the later models called hydro gears.

 

 

[pfrederi 17,913]

 You do not want to mix ATF and motor oil.  It will be easier to completely clean out the hoses, control valve and cylinder than the hydro pump motor and transaxle. So i would use ATF

 

 

[Stubby 19]

18 minutes ago, pfrederi said:

 You do not want to mix ATF and motor oil.  It will be easier to completely clean out the hoses, control valve and cylinder than the hydro pump motor and transaxle. So i would use ATF

 

 

The 877 has trans fluid in the trans already. At least that is a plus.

Edited May 2, 2021 by Stubby

[Stubby 19]

31 minutes ago, pfrederi said:

You will need to transfer the implement relief valve from the unknown donor to your 877.  Downlaod the sunstrand manual here.  It shows what you need to do in the hydro gear section.  The 877 was called Wheelamatic but it is basically same as the later models called hydro gears.

 

 

That looks like item number 64 part number 7266 But it is called the tow valve. Is that the correct one? Nope I see it now.

Edited May 2, 2021 by Stubby

[Stubby 19]

Stupid question but how do I get the roll pins out so I can take off the hydraulic? I dont want to destroy anything.

[pfrederi 17,913]

What roll pins are you looking at??

[Gregor 4,847]

5 hours ago, Stubby said:

I have an 877 and another model which have no id tag

For what it's worth, your ID tag is right there in the circle. You will have to take off the tool box to actually see it. Not sure what it will tell you though.

[Ed Kennell 38,814]

Might be less work to put the 877 hood, belt guard, engine, etc on the unknown and make it an 877.

[Stubby 19]

2 hours ago, pfrederi said:

What roll pins are you looking at??

I got it. The peddles to get the hydraulic off the peddle bar. Stupid is as stupid does. lol

[Stubby 19]

51 minutes ago, Ed Kennell said:

Might be less work to put the 877 hood, belt guard, engine, etc on the unknown and make it an 877.

No, the unknown has all kind of work needed. It is a challenge for sure.

[Gregor 4,847]

20 minutes ago, Stubby said:

No, the unknown has all kind of work needed. It is a challenge for sure.

[Stubby 19]

I have t all switched over, I had the hydraulic lift come out about an inch. It is like there is no pressure. I took off the pressure fitting and put it on the 877 on top of the trans then the hose on it. I am thinking it is the control possibly. I have trans fluid in the system and not 10-30.This one calls for trans fluid without the hydraulic. Will the hydraulic lift work with trans fluid? I wonder if it is just as simple as air in the system. Not sure how to get it out. Drivng it while holding the handle down?

[Stubby 19]

Looks like page 60 to 62 part 55, 56 and all other in that line is what I need to change from one to the other.

 

[Stubby 19]

These parts correct need to be swapped over? But I think it has a cone relief valve and I swapped that over. Or am thinking the relief valve is on the control? The only implement relief valve is in the newer model and not sure the location of the older model. If it is where the hose goes that is under the seat then there was not one.

 

Edited May 8, 2021 by Stubby
different file needed

[pfrederi 17,913]

You are looking at the wrong part of the manual.  Your picture is for a piston to piston unit .  you have a hydrogear.   pp54-56

[Stubby 19]

7 hours ago, pfrederi said:

You are looking at the wrong part of the manual.  Your picture is for a piston to piston unit .  you have a hydrogear.   pp54-56

You will need to transfer the implement relief valve . The only place I seen that was what i posted that is why I posted that. Unless you mean part 83. 

I am not sure if I have to bleed the air out but the only thing that I transferred was one part to that location and tightened the hydraulic line to that. 

[Stubby 19]

There is a part that I took off of the old one and put on the 877. Tomorrow I will post a picture of it. I am thinking I am missing something and it is hard to tell from the info I have been given on what  I need to do next. Sorry for the lack of experience regarding hydraulic lift.

[Stubby 19]

Not sure what to do here. In the parts list there is no implement relief valve. The only thing I have swapped over was the part the top hose is connected to in the picture.

Part 82, 83 cone relief valve, both trans have them.

Do I need to swap the charge pump relief valve?

Cone relief valve?

 

 

 

[pfrederi 17,913]

 

 

What parts list are you looking at???

 

If your donor tractor had a lift it has a implement relief valve.  part 16/17 in first pic.  you put it in the 877 Wheelamatic same way as in pic 2....

Edited May 15, 2021 by pfrederi

[Stubby 19]

HYDROGEAR
PARTS DRAWING
1965-73 page 4

 

 

Edited May 16, 2021 by Stubby

[Stubby 19]

pfrederi that was it. It is now working one way is fast and the other is much slower. Not sure why that is but thank you so much. Apparently I was looking at the wrong page or manual.

Edited May 16, 2021 by Stubby

[Stubby 19]

Any thoughts on why lowering it is very slow? But lifting it is quick.

[Handy Don 12,491]

41 minutes ago, Stubby said:

Any thoughts on why lowering it is very slow? But lifting it is quick.

Several thoughts....

Simple stuff:

Does the control lever fully move the valve spool in both directions (i.e. does the lever move the "piston" in the control valve the same distance in each direction)?

 

Has the system been cycled 10 or 20 times to be sure that all the air has been purged out of the lines, control valve, and both sides of the lift cylinder? And the oil level in the reservoir checked to be sure it is topped up?

 

When the cylinder has reached the end of its travel and you keep holding the control lever in lift/lower, do you hear the relief valve open up (it'll make a whistling/screeching sound)? (If not, then the pump may not be delivering enough pressure to the lift cylinder.)

 

Kinked or obstructed hose(s).

 

Bad seals or excessive wear on one side of the valve spool internally, allowing oil to bypass the valve instead of going to the lift cylinder.

 

Quirky thing: 

In which direction (lift/lower) is the rod moving out of the lift cylinder? It takes more oil to push the rod out of the cylinder than to push it back in (because the rod itself takes up space on one of the cylinder. If you have low fluid flow then extending will take longer than retracting.