1077 Transmission issues

[Stepney 2,325]

Hello, all. Well, my newly acquired 1077 has been doing quite nicely. Just changed the filter and refilled with Type A. When I drained it I did get a few cupfulls worth of brown sludge-gunk.. It does drive a little better now.. but not much better. It'll climb a hill or run on that flat at full speed in reverse with no issues, actually, aren't these supposed to just go 3mph backwards?? It goes just as fast backwards as it does forward, which in both directions is abut 6-7mph, just like my Electro 12. (Which barely has reverse anymore, incidentally) But anyway, forward, it can get up speed on the flat, but any kind of a hill and it slows right down. So far it hasn't completely stopped but at 'full speed' on the lever it doesn't want to. I skimmed the manuals it came with didn't see much about adjustments.. so I'm just going to assume forward is worn out, and reverse, since it was probably lightly used, is still OK. Or am I missing something? Is there anything I should check or try? 

[Achto 27,820]

If you got some sludge out of the tranny. I would try running it around for a while to get things good & warm. Then while it is still warm I would drain the tranny again and change the fluid and filter one more time. This should help flush any remaining gunk out. If it is working properly, you should be able to hook to an immovable object & be able to spin the back wheels. 

[pfrederi 17,895]

A warm  fluid/filter change can't hurt.

 

Have you done a neutral adjustment??  covered in the operators manula shown at Fig 2. 

I am afraid however your issues may be more serious.  Hydros do not do well with sludge.  it may have damaged the slippers and valve plates as well a possibly the hydro motor gears.

 

One other less negative thought.  The sludge may have stopped up the suction screen (#38 in the tranny parts page) thus starving the pump for fluid.  You have to pull the hydro unit to get to it.

[953 nut 55,873]

As you say reverse is fine and forward is the problem child I feel that an adjustment as Paul suggested is the first thing to do. If that isn't the problem you may have to replace the acceleration valve springs on the forward valve (located at the back ).

[Stepney 2,325]

Well I ran it today for a good long while, did two yards with it. For the first 10 minutes it wasn't too happy, but now it seems to be doing quite better. Right now 90% of the time a full advancement of the drive lever will shoot it forward briskly, but sometimes it lags for a few moments then it gets going. Perhaps it's the screen? But besides the first few minutes it did great on the hills. 

[Sarge 3,463]

That sludge is probably sticking the acceleration valves pretty good - it will need several flushes of fluid changed as hot as possible to get it clean again . I'd run it up and down some hills for awhile and change the oil/filter at least twice more - my 1277 was the same way when I first got it from sitting for so long .

 

Another thing - on that '67 model there is one item known for wear on those that causes belt drive slippage to the pump - it's the vertical arm that engages the drive/park mechanism . See if the slot in it is severely worn - that's a common issue with those models and will keep the tensioner pulley from working correctly on the belt drive to the pump . Download or find the manual for your model - most likely that arm needs some welding repairs and get that slot straight and true to size again . I've had to rebuild 3 of them now....

 

Sarge

[Stepney 2,325]

Well, the tensioner setup is actually fine. I went through a guide from a great fellow Redsquare member on the valves, checked and cleaned everything, flushed it with a new filter.. and honestly it seems a bit worse. Still climbs in reverse very well, but it'll still lug the engine and try to stall forward on grades. 

[Sarge 3,463]

Sounds like a fairly serious issue in the hydraulic motor itself , might be time to tear it down with the manual in hand and start repairing anything that is worn or out of spec .

 

Sarge

[953 nut 55,873]

On 5/23/2017 at 11:26 PM, Stepney said:

went through a guide from a great fellow Redsquare member on the valves, checked and cleaned everything

Did you remove the acceleration valves and found the springs and valves to be clean and in good order?

7 hours ago, Sarge said:

serious issue in the hydraulic motor itsel

Not too sure that the motor would care what direction it is turning, have you found this to be true before? Always eager to learn something new.

[Stepney 2,325]

I'll check her over one more time.. but I did it once before, had it all apart, and honestly nothing looked that dirty (Granted I cleaned it anyway) and I couldn't find anything wrong.. I'll check it out again this afternoon just for the shot though. 

[pfrederi 17,895]

OK  Has this always been a problem or was it sudden onset?

 

You say she will not go up hills forward but will backwards. On the 15 may you said you mowed two yards and after the first few minutes she worked OK.  Has it regressed?

 

  You also say the engine bogs down when you put the motion control in full forward does it bog down at all when you try full reverse? 

 

I am a bit flumoxed if she has power in reverse and doesn't drag the engine down it sounds like the pump and the hydro gear motor are OK which comes back to the acceleration valve and spring.  These valves have incredibly small  holes.  That it ran OK for awhile in the 15th and now is acting up again says to me some more sludge got into the valves.  Also while you have it apart take a picture please of the acceleration valve springs and measure them.