Hitachi 35-2 track issue

[MrFritsch]

I recently bought an older hitachi ex35-2. I’ve been making some repairs to get it functional. My inquiry is the tracks move very fast like they’re in high speed and do not have much torque for turning. The rollers need to be serviced as they are hard to turn. I check the 2 speed button on the floor and it wasn’t hooked up. I reconnected with no change in power. Both tracks move freely in both directions with plenty of power, just wont go in opposite directions to turn. Any suggestions?

 

[Diesel Dave]

Welcome to HEF MrFritsch .
I suspect the rotary manifold needs to be re-sealed.
Put one track in the air and try turning the track that is on the ground.
If the track in the air turns then the rotary manifold is bypassing internally.
The same internal bypass could also send high pressure oil to the propel motors high speed shift spools.

 

[MrFritsch]

Awesome, thank you for the reply! I’ll check in the morning. Is the rotary manifold considered the “swivel joint”?

 

[MrFritsch]

The tracks don’t move in opposite directions either.

 

[Diesel Dave]

Awesome, thank you for the reply! I’ll check in the morning. Is the rotary manifold considered the “swivel joint”?

Yes, Swivel joint..aka center joint , rotary manifold.

 

[MrFritsch]

When lifting the one track off the ground and running the track that’s on the ground it drives like it should and had decent power. I’m thinking it has to do with the 2 speed or the swivel joint seals aren’t bad enough for your test

 

[Diesel Dave]

Is the fast speed travel indicator light on in the control console ?
Whats the machine serial # ?

 

[MrFritsch]

The light turns on when I run the glow plugs but not when the machine is running. I lifted both track in the air and rhe both operate separately in any direction. When the machine is sitting on the ground the tracks will only go one direction and I can stop one track after they are both going but can’t just run one track at a time without starting both

 

[Diesel Dave]

Try the travel with the high speed control solenoid coil unplugged to eliminate a possible wiring harness issue.
If still operating in high speed , disassemble the high speed solenoid valve and check for blown orings or a sticking spool.
.
Solenoid valve block for machines sn # 02001 to 03404

.
Solenoid valve block for machines sn# 03405 and up is shown below, could not find a parts breakdown for this one.

 

[MrFritsch]

Follow up, this thing is a complete basket case but I have about everything fixed. The motor cylinders were about .030 tapered so I got that resleaved and rebuilt it myself. Then repacked some cylinders. Pulled the swivel joint to reseal it like you all suggested and found the swing motor bolts were missing and some broke so got that repaired and swivel joint rebuilt. Then I got to the wiring. All the wiring for the pilot safety and high speed was cut and all switches were bad. Got that stuff repaired, found both solenoid coils were bad so replaced them. The spools were froze so I got those freed up and reassembled but the pilot controls were still locked on and it was stuck in 2 speed. Tore it apart again and found that the pins insides the solenoid spool was replaced with a longer screw so it was manually set to be engaged full time. Made some replacement pins and it was finally good to go. I’m still glad I rebuilt the swivel joint as the seals were pretty worn out. Whoever owned this before my sure did a number on it! But it’s great now, I gave it a paint job right away. I’ll attach a few photos. I did all the work excluding machine shop sleeves. Thank you for all the help, learned lots on this project.

 

[Diesel Dave]

Good job.
Looks great ,thumbs up !