D37e-2 bevel gear shaft

[Jkauffman]

Ok so I’ve got a komatsu d37e-2 dozer that I’ve been redoing the steering clutches and brake bands on,and finally have all the parts and the time to reassemble.The first thing I noticed when starting to put it together is that the plate in the bevel gear shaft has a lot of slop in it. :(in other words the bevel gear shaft bearings are bad).Has anyone changed these?I have a manual but it has old black and white picks and is kinda a pain.I still have clutches out so I might as well fix it now.I don’t know much about dozers Lol as this is my first one maybe I should just get someone to fix it.Thanks for any advice

I should say I have a fair amount of mechanical experience and ain’t scared to tear into something(not enough anyways)and think I could fix it but just don’t know much about setting the bearing preload and gear wear patterns

[mike_belben]

id like to help but i dont have the experience with them.  Try youtube?

[Jkauffman]

I know this is a vain hope but if the clutches where in it couldn't move near so much but I'm sure it ain't normal.
Some how I have to make a puller that can pull up to 12 ton to pull the plate off the end because they're pressed on.Don't know why they have to make it that hard 

[Gary_C]

Got any pictures or parts diagrams?

[Jkauffman]

 

 The one picture is of the clutch housing you can see the plate on the left that will need to come off,than the other picture is of course the bevel gear itself and the other clutch is just outside to the left.Don't really have any parts diagrams 

[mike_belben]

I dont think we got all the pics you intended for

[Gary_C]

Here is the other picture in OP's gallery. Doesn't help me much. 

[Jkauffman]

Same dozer different question :.I finally took it for a drive for the first time today.As I was turning on gravel,it sounded like the sprocket slipped in the right track and i was just wondering on how to set track tension as my manual doesn't tell me.The sprockets I haven't measured but they are far from worn out.Also I know absolutely nothing about running a dozer so is it normal for it to bog slightly as you apply brake for turning?I have them set to exactly komatsu specs but as I push full pedal it will bog slightly as it's turning.Sorry for the ramble but any advice is appreciated 

[Jkauffman]

And I shoulda said I know the clutches are at least releasing some because if I just push the pedal in a little bit it will turn but to when I push it farther in to engage the brake it will bog down

[mike_belben]

the drive power to the track you are braking is not fully uncoupled.  The komatsus i am familiar with (D31P-18 in my case.. 1990ish wet clutch) apply pressure to clamp the drive clutches and transmit power all the time unless you push the pedal and bleed the pressure back to tank.  The friction coupling (clutch) will then slip.  

If on the very back top rear of the machine under the batteries has a valve block with two spools facing forward and cam follower linkages and rollers to push the spools then yours is the same.  They get flat spots on the roller and the pins thru the roller wear in half so you can never have correct adjustment.  Basically your brake should not begin to come on until your clutch is all the way bled down in pressure.  If the brake comes on while still coupled the engine sees a load and chugs down to pull it.  It is driving thru the brakes.  

Stomp your steer pedal to the floor a few times.. I mean stab the heck out of it, mash as hard and fast as you can.. See if it will feel right even just once.  I had to redrill all my little linkages under the seat and put SAE bolts to replsce the shot pins.  With a half worn pin one side is normal and the other is worn flat.  The pin revolves in the yoke and sometimes youre too loose, sometimes too tight but you can never have it work right with that shot pin collection.  


Physically remove every pin from foot pedal to hydraulic spool and look because you cant feel a bad one most of the time.  Grease it up good for reassembly since there are no zerks.

Dont run it like that or your brakes will get ate up

[Jkauffman]

I actually have gone over my linkages already,they where terrible.Some pins were wore half the way thru.Both clutches are rebuilt and both brake bands relined 

[mike_belben]

Okay good then just back off your brake adjustments so you can fully clutch before the brake starts engaging. The brakes are coming in too soon and need slack is what it sounds like to me.  You can back them way off until theyre gone to verify that the lugging clears up. You can drive it with the adjustment covers off. 

[Jkauffman]

Thanks I'll try that.It's amazing how bad the linkages where when I got it.The brake shaft that went through the top of the clutch housing had a bad bearing and lots of play with deep grooves worn in the shaft.I had that welded and turned with new bearings on both sides and new pins and bolts everywhere,and I also drilled out and installed bushings in some of the shifter linkages.This should be a good machine now :-\it has a rebuilt motor,rebuilt steering clutches,relined brake bands,new bearings on the bevel gear shaft and new fluids all the way through.I'm also putting a winch on it

[mike_belben]

I think highly of my d31 and dont think i will part with it.  Ive not had an easier starting diesel. It can sit 6 months and fire like its still warm. 


I take that back.  My 350 small cam can sit for 6 years and fire on the first revolution. Another one thats as basic as me. 

[barbender]

BAB- Basic as Belben👍🏻😁

[Jkauffman]

Has anyone ever heard of oil levels in the transmission and steering clutch cases fluctuating?I can easy see it happening in the bevel gear case but steering clutch case??It maybe could come in the steering booster cylinders but how would it get out?Beats me I'm sick of this dozer and wanna push it over the hill now .I know all machines break but man I wish it'd give me a break

[Jkauffman]

Hey I actually think I found my problem!(suprisesuprise)I found on another forum of a fellow with a bigger komatsu that was doing the same thing.It turned out to be the input shaft seal on the transmission pump.And mine is most definitely bad it's leakin oil everywhere.Maybe there is hope 8)
I'm still just a kid workin on very limited finances so every new problem is discouraging but if this is the problem it won't be to bad

[mike_belben]

Keep it up and youll be a wise old man eventually. 


I hear ya on gettin discouraged.  I bite off more than i can chew all the time and something seems to break daily. Havent had $ in years. 

[stavebuyer]

Has anyone ever heard of oil levels in the transmission and steering clutch cases fluctuating?I can easy see it happening in the bevel gear case but steering clutch case??It maybe could come in the steering booster cylinders but how would it get out?Beats me I'm sick of this dozer and wanna push it over the hill now .I know all machines break but man I wish it'd give me a break

I have no explanation as to why, but it seems to affect dozers more than any other type of machine. They do so much when they are working that they entrap you. I will chalk up my first episode to inexperience. The second to bad luck. The third to being hard-headed and the fourth I can't excuse but hopefully was enough to break me of the habit.  :D

[mike_belben]

It is so valuable to me i try not to use it.. Or at least minimize its tasks to those only the dozer can do.  

I mentioned trading it for another machine the other day and even my wife, who hated it for the longest time, said dont you dare. 

You know its a good machine when the spouse says it stays. 

[Jkauffman]

Just a update.I replaced the transmission pump seal and it fixed the fluctuating fluids.But the turning problem persists,it will turn completely fine some times then just suddenly quit and not even try to turn(the clutch isn't releasing because it bogs).If I push in the inching pedal and release,it will turn completely fine every time and will work for a while than quit. : The times when it is working it turns like a champ with no engine load so I don't think it's the brakes like I thought earlier.I ran it quite a bit longer this time to try and figure it out

Also if you push in both brakes at once it will not release at all.Could this be a weak transmission charge pump?

[mike_belben]

This still sounds like bad pins or oblong holes or maybe bad rockshaft pivots in the little roller wheels that push the release spools in the steer valve.  On my d31 its right under your butt ontop the bevel gear case.  


Sounds like youre experiencing an intermittent dumping of fluid pressure in the clutch clamping fluid circuit.  The spool is just a steel bar in a steel block with some land grooves cut in it, and probably a centering spring.  Look there to be sure the centering spring that returns the spool to position is doing its job. And that the rollers that depress the spool (and all those associated linkages and every pin) are repeating the exact same travel with every single stroke.  


If 5 pins and bores in a string of linkages each have a little tolerance as the pins roll to their worn side..  Then if all 5 pins align at their worn side simultaneously you will get a tolerance stackup that is pretty significant from each of the 5 contributing to the whole string.  The result is your foot moves the entire pedal stroke but sometimes the roller that pushes the spool doesnt move enough.  

[mike_belben]

Im thinking through this.  when it wont steer at all but bogs the brakes have come in but the clutch is still pressurized because the steer spool has failed to relieve pressure.  When you inch the throttle back, pump flow drops so pressure in the clutch coupling drops and allows the clutch to break coupling with the final.  Hmm. 




 Either your rollers arent always moving the spool because of slack stackup in the camming mechanism like i described, or perhaps and issue in the steer valve is causing the steer spool to have a lot more friction some times vs others.  Like maybe theyre worn on one side or maybe there is warpage in the valvebody causing a crossleak that backpressures the spool and makes it harder to stroke.  Maybe its bent like a banana and the spool bore has worn in one orientation that it tries to rotate out of then binds, or maybe there is a return spring inside thats broken or binding.  Those are the things id look for.  I think youre close. 



Have you got any good info on your winch addition?  I cant find any good info on komatsu winches other than allied will set you up if youve got a fat wallet.  I cant even find what thread pitch the winch mount bolts are and ive looked hard.  I know theyre M20 and have tons of part numbers and asian vendors but cant find the pitch.  


Does the winch use an additional pump inside the bevel case on the pto shaft or does the PTO direct drive the winch gear?  The PTO shaft in mine looks dangerously small for 80hp and i dont wanna break anything. 

What did you have to pull to change the transmission seal?  Ive got a milky final on passenger side and milky clutch housing on driver side.  Any idea how many gallons they hold?  30wt motor oil i think?

[Jkauffman]

Well I can't help a whole lot on the winch because I didn't use the pto.I went poor mans way n just put a hydraulic winch on.If I recall correctly there was a place in Canada that had a winch that woulda fit mine(crawler sales limited)?it was rebuilt with installation kit for 12,000.I will try to get you the pitch in the bolts

As far as the pump seal,it wasn't bad.Remove belly pan and u-joint and a couple hoses and the pump will unbolt from the face of tranny.You actually wouldn't need to remove the pump but I did because I originally was gonna replace it

Oil quantity for steering case is 30 liter for my dozer(d37e-2)mine share oil from side to side via a tube but the tube is at the top of the tank so only when oil is filled all the way up to the top of the filling range will it transfer to the other side.

Oil quantity for final drive is 15 liters for d31p,pl,pll-18 and for all others is 12 liters 

Yes manual calls for 30weight engine oil,I put pure guard 30 weight in mine and that stuff is incredibly thick and sticky when it's cold but after you run it awhile it thins out.I really wonder if you couldn't find a hydraulic oil that'd work but idk

[mike_belben]

Thanks man.  Lets see your hydraulic winch, is it mounted yet?