870 powershift, no power in 4th gear, hydro fluid burpin

[Lizer]

I just picked up an 1970 870 gasser recently with powershift. The other day I went to take it down the road to fill it up with gas. Starting out in 4th gear and the tractor had no power trying to go down the road. Even when shifting up, it wasn't changing speeds, in fact it actually started slowing down. It wouldn't even throttle up. Almost like the brakes are stuck and the tractor can't go. Except the brakes didn't smell nor were hot.

What I'm assuming to be the powershift hydro body in the rear of the tractor smelled hot, was smoking or steaming, and hydraulic fluid was burping out of the filler neck in the back (with the cap on). It was burping out enough that there was a trail of fluid down the road and in my driveway.

I had made it about 1/2 mile before turning around and heading back home. It does fine in 1-3rd gear.

Just wondering how bad the situation is for this tractor and what issue is indicated by these symptoms. Not sure if I should send it down the road or try to rejuvenate it. Tractor is in pretty decent condition.

This post was edited by Lizer on 07/19/2021 at 07:46 pm.

 

[1370rod]

Sounds like something is slipping badly. Do the 3 powershift speeds operate properly when in first, second and third gear? If they do I would suspect the torque limiter
is bad and slipping which would explain the hot oil smell. Tractor needs to be split if the torque limiter or power shift need servicing. Rod.

 

[mEl]

(quoted from post at 22:55:27 07/20/21) Sounds like something is slipping badly. Do the 3 powershift speeds operate properly when in first, second and third gear? If they do I would suspect the torque limiter
is bad and slipping which would explain the hot oil smell. Tractor needs to be split if the torque limiter or power shift need servicing. Rod.

That's where I was also on this problem, If he would put the tractor in 4 th gear, hold the brakes and make it slip while someone was watching the PTO run in gear, if the TL is slipping the PTO will stop, this only works on the first generation of PS tractors however but an 870 will be that.

 

[Lizer]

(quoted from post at 19:55:27 07/20/21) Sounds like something is slipping badly. Do the 3 powershift speeds operate properly when in first, second and third gear? If they do I would suspect the torque limiter
is bad and slipping which would explain the hot oil smell. Tractor needs to be split if the torque limiter or power shift need servicing. Rod.

The 3 powershift speeds do operate properly when in 1-3, though if it's been running for a while it will spit out a little bit of hydraulic fluid, but it doesn't smell hot.

 

[Lizer]

(quoted from post at 04:05:07 07/21/21)

(quoted from post at 22:55:27 07/20/21) Sounds like something is slipping badly. Do the 3 powershift speeds operate properly when in first, second and third gear? If they do I would suspect the torque limiter
is bad and slipping which would explain the hot oil smell. Tractor needs to be split if the torque limiter or power shift need servicing. Rod.

That's where I was also on this problem, If he would put the tractor in 4 th gear, hold the brakes and make it slip while someone was watching the PTO run in gear, if the TL is slipping the PTO will stop, this only works on the first generation of PS tractors however but an 870 will be that.

This made me think of something else. Sometimes I can't get the tractor in neutral. Even when the shifter is in the neutral position, the tractor is still in gear and you discover that when you lift the foot off the clutch! Not sure if that adds any depth.

 

[Determined]

(This made me think of something else. Sometimes I can't get the tractor in neutral. Even when the shifter is in the neutral position, the tractor is still in gear and you discover that when you lift the foot off the clutch! Not sure if that adds any depth.

Not uncommon with a worn shifter for it to not always come all the way out of gear.
Burn this into your mind so you always are aware it might happen when releasing the clutch pedal.

Is it possible the fluid is fuller than it should be as per the sight glasses on the side of the tractor?
Not saying this is the case here but I came across one where the owner thought the little piece of metal on the fill cap was a dipstick and added oil accordingly.

Last thought, I have an old tired 970 diesel, guessing it's probably making similar power as an 870 gas would be.

In 4th gear it is pretty gutless so if your 870 is showing it's age it's possible it just doesn't have enough umph left in it to do much in the 4th gear range.

 

[Lizer]

I looked for that site glass but I can't find it.

 

[Determined]

(quoted from post at 13:01:07 07/21/21)
I looked for that site glass but I can't find it.

There should be two of them on the drivers side of the tractor.
You kind of have to crawl between the front of the rear wheel and the tractor to see them well.

As far as I know an 870 should have them but I have seen a photo of a 70 series without them.

 

[mEl]

If the engine stays up to speed and the tractor does not accelerate when the shifts are made in 4 th the TL is most likely slipping, what you describe is a classic symptom, you don't notice it in the lower ranges because it is not taking as much power to move the tractor. Hook it to a tree and I'll bet it slips in 3rd. If the engine dies down and stalls that's another issue. Like I said before, engage the PTO, have someone stand behind it and put it in 4th gear and hold the brakes and slip it, I'm betting the PTO stops while the tractor is not moving. On later power shifts that test is not applicable as the PTO and hydraulic pump no longer drove through TL plate.

 

[Lizer]

(quoted from post at 11:17:47 07/21/21)

(quoted from post at 13:01:07 07/21/21)
I looked for that site glass but I can't find it.

There should be two of them on the drivers side of the tractor.
You kind of have to crawl between the front of the rear wheel and the tractor to see them well.

As far as I know an 870 should have them but I have seen a photo of a 70 series without them.

I did find them. Not what I was thinking of as they were a hex bolt with a glass center. I couldn't make the fluid level from them, it looked like *maybe* the fluid was all the way to the top of the full glass. Shouldn't it just be about halfway?

 

[mEl]

This post was edited by mEl on 07/25/2021 at 01:41 pm.

 

[mEl]

Lizer, If I were you I would get a 5 gal bucket or two and drain the Transmission till the top sight glass is clear and refill till it fills. I suspect that your tranny is way over full, that is to me the only possible way that oil could be burping out the fill hole. The standard oil level is well below that fill hole by quite a few gallons.