Komatsu D31 Problems

[JMJ_D31]

Today my dozer started making a winding nose coming from the transmission area under the seat. Shortly after the nose I lost the ability to turn the dozer and the dozer would not track forward or backward. I turned the engine off and let the dozer sit for about ten minutes and started it up again and every thing worked fine for about two minutes and then I lost the ability to turn the dozer and shortly after it would not even track forward or backward. I continued to turn the dozer off and then back on again until I got the dozer home. Do any of you guys know what might be causing this problem? Please help. :Banghead

 

[DK88]

D31??? What dash? What series?

 

[JMJ_D31]

The dozer is a 1985 Komatsu D31p-17.

Thanks

 

[_Rod]

What about the flulds? Have you checked the fluid levels to make sure they are not low?

 

[JMJ_D31]

Because the dozer is an older model I never run it longer than 4 hours without stopping and checking my oil levels. I checked all fluids Friday morning before starting work and when I stopped for lunch I let the dozer sit for 20 minutes and checked my fluids again and found my middle dip stick to be very low, it was barley showing any oil on the bottom of the dip stick. Under the sit I have three dip sticks the left one is for the left drive the middle one is for the transmission and the right one is for the right drive. I'm not sure what the technical name is I know it’s not called left drive right drive but that is the best I can do. I'm thinking this is a transmission pump problem because the dozer runs good for two minutes and then losses power. I'm thinking the pump primes up good when you first crank up the dozer and then just losses its prime. This is my guess but I don’t have the experience that most of you guys have and would like to hear what yall think.

 

[JimInOz]

Is your machine a 4 or 6 cylinder engine.?In the loaders,They changed engines & general design at the 17 or 18 series.
There should be a Bevel Case dipstick,& Transmission dipstick under the seat.
If your bevel case is losing oil into the steering area,your steering might be suffering oil damage.
Have you cleaned the transmission strainer?

There are often Parts & Operator Manuals on eBay. I saw some for the 17 searies last week.

 

[John C.]

As I recall the transmission and bevel gear oil was the same. The steering clutch compartments were separated to keep the brake residue out of the transmission. Also as I recall, the transmission is checked in the mourning before startup because the oil fills all the various compartments when the engine starts. Those machines don't have a torque converter so if you pull the floor plate and look down you should be able to see the drive line. It will spin when the transmission is in neutral but will stop when put into gear. So your first test is to see if that line stops. If it does, then the problem is farther back in the gear train. That could be something to do with the transmission output and bevel gear. If it doesn't then you should be thinking fluid, pump and valve issues. Time to pull filters and check pump pressures.

Good Luck!

 

[JMJ_D31]

My dozer is a 4 cylinder engine and John C. is right I have three dip sticks under the seat one for right steering clutch, one for left steering clutch, and one for the transmission. I have been studying my work shop manual the last three days and my first plan of attack is to check my pressures and clean my strainer. I didn’t know my dozer even had a strainer in the transmission before this week. John C. I will pull the floor pan out and watch the universal joint to see if it stops spinning. I believe it will keep spinning because the dozer operates just fine for the first three minutes. I'm hoping my strainer is clogged and it turns out to be a simple fix.
Thanks for the trouble shooting tips and I will let you guys know how this turns out.

 

[JimInOz]

With regard to the dipsticks,your steering should be "dry" type with no oil.
My 16 series has a Hydroshift 3F/3R Transmission & a 4 cyl engine developing around 63 FWHP.
There is a Damper,Transmission & Bevel Gear to get the machine moving.
I have heard that Bevel gears might be an issue & mine has certainly had a bevel changed in recent times.
Dry type steering discs will also wear out at a faster rate than oil-immersed types.
Dry steering is the cause of many problems on older crawlers.

Your Swamp machine may have worked hard in heavy,muddy conditions. I would renew the Final Drive oil & inspect steering cases for signs of oil or water.Should be a drain plug under each steering case.

I've had no personal experience with 17 series machines,so I'm assuming your machine is similar to mine.The later 18s had a six cyl,70 HP engine.

Good luck...

Jim

 

[JMJ_D31]

I pulled the filter that is located inside the transmission and it didn’t look as bad as I was hoping. I ordered a new filter and O-rings and I will be putting it back together this Friday. I hope this fixes the problem but I’m thinking this is going to be a pump problem not a filter clogging issue.

 

[JMJ_D31]

I put the new transmission filter and O-rings back on Friday and to my surprise it fixed the problem. My dozer is back up and running strong. Thanks to the guys who replayed to my post with helpful tips.

 

[RDG]

JimInOz, pretty sure the 31-17 went to a wet backend the 16 had dry steering from memory. Cheers RDG.

 

[Marmed]

I put the new transmission filter and O-rings back on Friday and to my surprise it fixed the problem. My dozer is back up and running strong. Thanks to the guys who replayed to my post with helpful tips.

JMJ - I have a similar issue, do you have a part number for the transmission filter and o-ring? I'm thinking I need to break down and find a service manual for this thing.

 

[mike_belben]

where is the strainer located on these? mine is a d31p-18. thanks

 

[mike_belben]

Anyone? Im looking for any filter screens on my d31p-18.

Ive found a 1/2" drive ratchet plug up on top where the fwd/rev control plungers are and a small flat rectangular plate on very back between the brake adjusters that both look like theyre for easy access.

My brakes have been adjusted by prior owner but not the clutches. Im at a point where the brake will engage before the clutch, so the machine is driving through the brakes. Any pointers? Im hoping i can pull the rear covers without pulling the tanks.

 

[Redchute7]

I have a D31P18. Has three dipsticks. If sitting on seat the one to left is for the wet clutches. The far right is for bevel gear oil located between the left and rt clutch oil sumps. The left and rt side clutch sumps are connected by a tube and have seperate drain plugs but common oil fill. The middle fill is for the hydro trans in which the level is checked while engine running.