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Reverser forward pressure test

R

Richie0

Active Member
Joined
Aug 30, 2021
Messages
26
Location
Pennsylvania
Hello, I bought a 1993 john deere 310d and drove it home quite some distance with the brake hanging up, I didn't think much of it. Now when cold the machine goes forward and backward just fine although when you let the trans warm up it slips very bad in forward to the point where it will barely move on flat. I believe I have burnt out the forward clutches and think the final step before tearing the reverser out would be to pressure test it. Can any one guide me through how I would accomplish this test?

Thanks.
 
F

Finca SDR

Well-Known Member
Joined
Dec 5, 2017
Messages
246
Location
Costa Rica
Sooo, when I got my 310d my reverser stopped working also. Maybe that's when people decide to sell their machines but it was pushing hard when I bought it so I choose to think it was just bad luck.

Anyways the first time we disassembled it found a broken Bellville spring I think it's called and a bronze disc washer and the clutch disks etc. Put it back together and it worked well for a couple days, forward blown again. Rear worked the whole time through this saga. Drove the fugger backwards 3 kms one time to the shop it sucked.

Eventually we found that a duct in the housing, that is right inside at the collar of the housing where the driveshaft exits into the torque converter, had gotten a little piece of metal in it and ground a perfect ring around the inside of that collar where the shaft comes out. The housing and the shaft were worked pretty hard. It sucked.

Had to take the housing and shaft to a very capable machine shop where they bored it out and pressed in a new bushing in the housing and filled and turned the shaft. Impressive work.

In this story there is a sub drama about an evil or incompetent mechanic who would repeatedly do everything wrong or intentionally leave time bombs, and another good and noble mechanic that figured out the problem right away. All the other operators in the neighborhood told me I had to drop the zero mechanic and get with the hero mechanic if I wanted my business to work out.

I'm not saying you'll have mechanic drama the only reason I bring it up is that the good mechanic checked the workings of the transmission with an air hose, just seeing if pressure would actuate everything properly. When air started hissing out the collar where the shaft exits the housing the problem was found.

My guess is the broken spring and everything was sorta there when I bought it but a little piece of junk got free in the system and caused all my headaches. But the things been working problem free for the last four years and in that time I've learned a lot more about backhoe mechanics and maintenance.

Good luck

PS - sorry I dunno anything about the pressure tests except that the good mechanic had the meters and said "yup you definitely have a problem!"
 
mg2361

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,331
Location
Pennsylvania
Occupation
Equipment Mechanic
There should be a plug on top next to the steel tube just in front of the output yoke. That would be for system pressure. On the left side just in front of the output yoke should be another plug. That should be for forward pressure. At 1500 rpm you should see 135 +/- 15 psi system pressure and 135+/-15psi in the forward port in forward. Forward pressure can be as much as 15 psi below system and that would be within spec but I don't usually see that. It is usually pretty close (+/- 10 psi).
 
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