D31S Final Drive Repairs.

[JimInOz]

OK fellas,
I've been holding out on my latest project.
A few years ago,I picked up a good Komatsu D31S-16 ,which has a failed final drive on the right side.It's time I got her running.
Before I dismantled her,I gave her a short run in the shed....the steering is wonderful,engine starts & runs OK,& she has the ripper & 4 in 1.
I've never fixed a final drive,so looking for any advice that might make my fix a good one.
The repair manual is OEM,but not very informative...I figure that experienced,hands-on advice is always helpful.
I remember reading Roly's D8 fix & will re-read that.
One concern I have is that I need a 50Ton push-puller to fit the pinion to drum flange.Not easy to hire one here,so I may need to
find another way,or buy one.
Also,the bearings are NTN.Just wondered if I should lean toward any brand to replace them.?

After usually working with 4 ton gear,this 7.5 tonner is a bit of a step up in every department.

Thanks for your input...
Jim

D31S Bullgear # 29001 Upwards.jpg

Final Drive Job Sept 10 (24) (Small).JPG

Final Drive Job Sept 10 (19) (Small).JPG

Final Drive Job Sept 10 (14).JPG

[Jeremy Rowland]

Hi Jim, thanks for posting the only help I can be is that I would think that there would almost certainly be other brands of bearings that would fit your final drive, I would however stick to a popular named brand as you don't really want to have to strip the thing down again in a hurry!
Just take any numbers off your bearings and measure the critical sizes; bore, o/d and width and what type of bearing; taper roller, ball, etc.... give these to your local supplier or source off the net and you should be able to save a pretty penny or two.
There may be a way round the push pull that you need but I cannot help you further with that, perhaps somebody else may have the technical info to help with this?

Jeremy

[modelman093]

OK fellas,
I've been holding out on my latest project.
A few years ago,I picked up a good Komatsu D31S-16 ,which has a failed final drive on the right side.It's time I got her running.
Before I dismantled her,I gave her a short run in the shed....the steering is wonderful,engine starts & runs OK,& she has the ripper & 4 in 1.
I've never fixed a final drive,so looking for any advice that might make my fix a good one.
The repair manual is OEM,but not very informative...I figure that experienced,hands-on advice is always helpful.
I remember reading Roly's D8 fix & will re-read that.
One concern I have is that I need a 50Ton push-puller to fit the pinion to drum flange.Not easy to hire one here,so I may need to
find another way,or buy one.
Also,the bearings are NTN.Just wondered if I should lean toward any brand to replace them.?

After usually working with 4 ton gear,this 7.5 tonner is a bit of a step up in every department.

Thanks for your input...
Jim

D31S Bullgear # 29001 Upwards.jpg

Final Drive Job Sept 10 (24) (Small).JPG

Final Drive Job Sept 10 (19) (Small).JPG

Final Drive Job Sept 10 (14).JPG

NTN are fine as are Timkin, SKF and FAG. Stick to any of these and you'll be OK. There may be other good ones but there's a hell of a lot of cheap C**p out there. Just as important is the way you go about installing them. Don't intend to insult your intelligence but smiting with a lump hammer is out! bearings going into housings can be shrunk in the freezer and onto shafts expanded by warming in oil - I won't go on!
Angus

[JimInOz]

Jeremy & Angus,
That's just the sort of hints I need.I've done a bit of repair on TD6 & 9,plus Mitsubishi dozers,but most of those repairs require basic tools & equipment.
As your machine gets larger & better built,you need better tools & more experienced brains.Also,if you are not doing repair work constantly,you forget the little things that make life easier...
The D31S-16 were a well liked machine in the 70s/80s.I'm told they were well made.

D31S Sept 10 (3).JPG

Hoping to start a business doing hire work. I have a Furukawa FL90 loader & this Drott will fit in nicely.

I'll take any tips you can give, lads.

Jim

[martyn williams]

Nice project Jim.
As Angus has said there are a lot of inferior parts out there.In the UK its pretty easy to obtain bearing by taking numbers off them or just measuring the old bearings.
I think collecting Komatsu tracked loaders will take off in the near future as a few are starting to come up for sale.
How is the TD6 doing ?
Regards
Martyn

[Julian]

..
I think collecting Komatsu tracked loaders will take off in the near future

My dad was involved with the shipping over of these machines. He was probably involved with the very first machines to arrive in the UK.

Julian.

[JimInOz]

Hi Martyn & Julian,
I'm looking forward to getting into this project.I'm waiting on the parts to arrive.
Meanwhile,I'll look at sourcing the bearings (probably from USA) ,big gasket & the push-pull tool.
Over the years,I was lucky enough to operate D41S,D57S,D65P,D75S
& always wanted to get on the smaller D31S.There were a few here,but I never got the chance.I think a few made it to the UK too.
Regarding the bearings,the NTN are good Jap bearings....but I just wondered if fitters tend to like a particular brand when replacing them.

Martyn,how are all your projects going?
Is the TD6 going OK?

I have no IH gear left,but still selling spares for the TD 5/6/9/24 machines.I get a LOT of calls for BTD6/8 parts.Everyone loves them & tries to keep 'em going...

Jim

[martyn williams]

Hello Jim
Hope to get the TD6 home soon,between weather and work have not had much chance.Still been trying to get a starter motor for it with no luck.
Those Komatsu 's are well built machines.
Keep us posted on your progress Martyn

[Julian]

Meanwhile,I'll look at sourcing the bearings (probably from USA) ,m

I'm sure you won't be needing the USA! You must have a bearing factors down under, all cities in the UK have them.

Near me I have this place handy:

http://simplybearings.co.uk/shop/

you can search by dimension &/or part number on this site.

They got me all the bearings for the gearbox in my dumper, and the clutch release bearing from the other side of the country. In the UK the stockists are all coupled together via a trade web-link computer thingy-ma-gig and can instantly check stockholdings around the country.

Part number or dimensions (for cross reference) and grade is all you need I think.

PS, looking at those pictures I can't see why you need a puller. Provided you can get some tube of the correct size to sit on the bearing outer shell then why can't you drift them in? Looks like it's been bone dry of oil for some time in there....

Julian.

[JimInOz]

Hi Julian,
I'll probably source everything from the USA...mainly coz their prices are about half of local prices. Everything here is expensive.
I tend to buy a bit of stuff out of the States...they are spoilt for choice over there...

The Komatsu manual states that a hydraulic 50T push-puller is required in fitting the pinion.It shows a picture of the thing sitting in the steer housing.Says that 4-12 ton force required to do the job.
I think Cats & others have press fit parts too...

Martyn,
I think I saw new TD6 starters on eBay this week.Good price but big postage cost.
I had a guy looking for one too...

Jim