Komatsu Dozer Steering Issue

[Tommy]

My D37P-5A won't turn to the left. When I pull the stick to the left, I can hear it put a load on the engine, but it doesn't turn. The linkage is moving all the way into wherever it disappears into the machine housing. Looks to be the same amount of movement as the right turn makes.

Also, the angle button on the blade control has quit working.

Any help or advise is greatly appreciated.

 

[JeremiahSr]

either the left clutch wont release or the right clutch is not pulling. put it against a pile a dirt and be sure both tracks spin. that will rule out if the right clutch is pulling or not. then, while still locked up to tha pile of dirt, try to steer it both directions. compare the difference watching how the right track goes into neutral. if when trying to steer left the left track is in a bind or doesnt seem to be neutralizing, the clutch isnt being released. thats done with a hydraulic piston on side of clutch cover. could be a bunch of things causing it not to release. but this will at least narrow it down further for you.

 

[Tommy]

Jeremiah,

I'll try what you suggested and let you know. When the left steering "broke" I was going along the side of a trench I was cutting with the blade and the dozer was tilted to the right at a pretty decent angle. Unknown to me, the track adjuster was going out on the left side and the chain went slack. When I realized the chain was slack, I leaned on the stick pretty hard to the left and tapped the brakes to try to get the machine to exit the trench by turning left . I'm not sure why, but it wouldn't turn out of the ditch to the left. Up to that point, the left steering had worked fine. Maybe it was because the left chain had become so slack. I put it in reverse and turned right, then back forward to exit the trench. I've since replaced the seals in the left track adjuster and at the same time replaced the seal on the final drive at the left sprocket.

Up to the time the track adjuster broke, I'd had the machine a couple of years and hadn't really done anything other than routine maintenance. The steering was perhaps a little weak but basically everything worked fine.

Thanks for the advise.
Tommy

Attached a couple of photos of what I've used it for.

 

[Tommy]

Both tracks spin against the dirt. Try to turn right and the right track stops spinning. Try to turn left and both tracks keep spinning.

 

[RDG]

Sounds like LH clutch is not releasing if both tracks keep driving. RDG.

 

[Tommy]

Sounds like LH clutch is not releasing if both tracks keep driving. RDG.

So how do you figure out the cause and fix it? I know the linkage is working at least down to where it disappears inside the housing. I can see it moving just like the right side under the seat. You can also hear it lug the engine down a little when trying to turn left. I "fixed" my 82 Jeep CJ's clutch by putting the bumper against a tree, pushing in the clutch and hitting the starter with it in 1st gear. It had been sitting up for about a year when the clutch got "stuck".. Not so on the dozer. I was using it when the steering worked and then all of a sudden didn't anymore. LIke I said earlier, when it happened, I leaned on the stick to turn left pretty hard (not sure why that would make a difference) and tapped the brakes tryiing to get it to turn left when the chain had gone slack. I don't know if that would affect it either. I can't really see how it would.

 

[StanRAUUS]

Look to see if there is a inspection cover, release bearing has issues from your’ descriptions and testing.

 

[RDG]

Have seen a D31-17 snap the end of the clutch throw out fork down inside the steering clutch housing, just went all of sudden. Cheers RDG.

 

[Tommy]

Have seen a D31-17 snap the end of the clutch throw out fork down inside the steering clutch housing, just went all of sudden. Cheers RDG.

Seems like I might have heard it if that happened, but with the loose chain, it may have been trying to jump the sprocket at the time, so I probably would not have noticed. Thanks and I'll check it out and look for an inspection cover.

 

[TOM V]

Have seen a D31-17 snap the end of the clutch throw out fork down inside the steering clutch housing, just went all of sudden. Cheers RDG.

In the last 10 years I have had to replace 2 release yokes on 2 different D31A-17 dozers, I don't think it's uncommon for those to crack.

 

[Tommy]

Can't see an inspection cover. It's difficult to see anything but the linkage going in. Guess I'll have to remove the seat. The piston referred to by JeremiahSr above I assume is the piston that activates the linkage on the outside of the clutch. I can see the piston cylinder moving when I steer to the left. I'm guessing it's not supposed to move other than the rod coming out of it and going to the linkage. Maybe it's loose and not allowing the clutch linkage to move far enough to release it. Don't know if you can access it from the back of the machine or by removing the seat.

 

[cclark746]

I have a D31p-18 will not track right. Just all of a sudden quit, I can here the brake trying to engage when you intitially try to steer right it locks up for a sec then releases and continues to track straight. it will track left with no problems. Any suggestions will help, could this be a brake adjustment issues.

 

[cclark746]

I will push a pile tomorrow and see if both tracks spin and how it responds during pushing and trying to turn.

 

[cclark746]

I pushed a pile and both tracks spin fine and it will steer both directions while under a load!

 

[Stonemobile]

This is my first post so if I've done something please overlook. Anyway I was wondering if you found problem? I have a d31p-20 that started doing the exact same thing. Thanks for any advice.

 

[GAK30]

We have a D31p-18 that will not turn left. Turns right fine. Both tracks pull fine and will spin when pushing a pile so I assume the steer clutches are not slipping. When I pull the left control, both tracks stop. I checked the pressure to both steer booster cylinders and get 310-320psi(about 22kg/cm^2) which is correct. I only have pressure on the side being activated (no pressure to the right with the left lever pulled, etc) so I don't see how the right cylinder can be disengaging the clutch. The transmission main pressure is 310-320psi, also ok. This started suddenly when dad was pushing some brush. Anyone have any ideas?

 

[GAK30]

After thinking about the problem a little more, I had the idea that possibly the bearings supporting the ring gear may be worn or destroyed to the point to allow the ring gear to move side to side. I removed the inspection cover and it does have movement. The ring gear moves left when the left lever is pulled and back to the right when the right lever is pulled. I haven't had the chance to get it torn down but what appears to happen is the left steer cylinder disengages the left clutch but also pulls the ring gear enough to the left to disengage the right clutch also.

 

[sgil1220]

i have a similar problem. my D31P20 the tracks wont turn right or left. but it does move foward and back

 

[mike_belben]

D31P-18 and maybe other models have an inching valve on the top very back of the rear end housing in center. Its under the battery tray and has two small hydraulic spools that disengage each respective drive. They are pushed by cam follower type rollers, and with time the cumulative slop in control pins, linkages and bushings makes it so that the cam follower wont push the spool far enough. Or sometimes it will and sometimes it wont depending on the slop stackup. If you tighten the brake bands youll just drive through them so dont. You need to replace these worn metric pins with new stuff or atleast weld up and regring the grooves worn into them. I drilled most of it oversized to the first SAE dimension it came to which was only like .030 to .040" of material removal then install a bolt or american pin. Use soft stuff so it takes all the wear.


Dont be afraid to pull the inching valve right out, its all contained and you wont lose any fine parts but beware there are 4 small metal hydraulic feed tubes that have O rings at each end. Change em out, a universal O ring kit is fine.


Today i lost reverse only on my machine. I have forward in all 3 speeds and i have all 3 reverse detents on the stick. The rods are all there and moving the parts they should so its definitely internal. It used to take a while for the machine to engage reverse when cold.. Never forward, that was always fine and still is normal. But i have no engagement in reverse at all at any throttle. Im guessing an O ring in the control guts failed. Still pushes great going forward.

Any ideas?