D31S Final Drive Repairs.

[nick lamb]

Hi Jim, Don't forget to do the top pinion as it will be near to failure judging by all that metal swarfe in the casing.This requires the tank off and the steering clutch out.More flange pullers required I'm afraid.If you've gone this far check the crown wheel pinion too.
A large wallet is desirable for final drives

[JimInOz]

Nicky,
Thanks for the pictures.
I was lucky enough to find the pinion,bullgear & housing at a good price,so they are on the way.
Both pinion & bull were suffering tooth damage & housing had damage in bearing retainer area.
OEM wanted $25K to fix.My price might be $3K, plus time.
This shows what a ripoff you can avoid ,by doing the hard yards yourself.
My pictures show a cleaned up inner housing coz I degreased it....but I wonder if my unit ran out of oil or bearing just failed.??
Recent work included steering & bevel replacement.

I have the steering out ,& just need to get a nut undone & separate the flange/pinion .Still trying to find a local source for pusher & puller.

Jim

[tctractors]

Jim those dinky final drives can be pressed up in a simple workshop press, you dont need all the fancy crap to squeeze them up, study things up and you will understand my verbs, throw it all under a press, then fit it onto the main case in a chunk.

[FOWLER MAN]

Jim those dinky final drives can be pressed up in a simple workshop press, you dont need all the fancy crap to squeeze them up, study things up and you will understand my verbs, throw it all under a press, then fit it onto the main case in a chunk.

Good advice there Jim, even managed to do an old 60S that way.
Fred

[tctractors]

Fred, the sad thing is if jim was in the U.K. I would sort it for him as I have all the fancy crap to do it. sometimes people over read service manuals with the follow it to the letter process, jim if you look at all your parts carefully you will soon have it done, the duo-cone seals are simple to fit, clean the area the rubber bit fits in, dont oil this area with anything, then fit the half steel bit with the rubber O ring on it into its location, I often use a 1/4" drive extention on a ratchet to poke the O ring in , its easy to do then just check its looking even and level, the only fancy service tool you need is between your ears.

[FOWLER MAN]

All good advice again Jim, but don't slice your fingers on those duocone seals.
Fred,

[JimInOz]

Hey guys,
I appreciate the advice. I started cleaning up everything a while ago,but a few other things averted my interest(been working on a nice 434 tractor,plus a BD2F Dozer).I recently bought the bearings locally for a good price...mostly NSK & Rollway brand.
I'm just about to get back into it...& today have been wondering about the best order to fit things.
I was gonna fit Bullgear,shaft,sprocket etc into it's outer housing & fit that...then maybe fit pinion last.I'm wondering about how it all meshes if I have the pinion in there first & try to fit the housing into it.I know it can be done,but I want to make it as easy on myself as I can...I'm working alone.
Alternately,If I can fit pinion first & press the pinion to flange from the final drive side,I'll do that...maybe using a 20T jack .
I'll eventually nut it out,just need to sit & look at it.

The old girl had $$ spent on Bevel & steering before I bought her. The steering is excellent...light pressure only to get her around.She has a nice 4 in 1 & I've welded an old IH "DROTT" logo plate on it...plus she has a good ripper.

Tony,I saw an old post of yours . I believe you owned & operated many Komatsu DS units in your time.I enjoyed reading your posts on fixing heavy gear on HEF...very interesting topics.
I operated D55S,D57S & D41S in the 80s. I liked them all & always thought the Komatsus had good push . I now enjoy the little stuff like Mitsubishi BD2 & MF 200s.

Jim

[tctractors]

Jim before you get all spannered up on the top pinion thing, sometimes its posible with the outer case and gears removed to get the pinion complete with flange and housing out in 1 lump, if so its a simple job to press it to bits and back together again under a shop press, always leave the nut on the pinion loose to stop things flying, I often strip out D8H/K's this way.

[JimInOz]

Thanks Tony,
I'm just about to press the Inner Races on the new Pinion.
I think I'll need to press the steering flange on last ,after the pinion is seated in it's (bearing) retainer.
I have cleaned up the replacement Bullgear & shaft,ready to reassemble soon.
Will need to do likewise with outer housing.

Finally making progress.It's a good job for me over the holiday break,as I get a few spare hours.

What's the best thing to do ,regarding giving new bearings some lube ?
Do I add a few drops during assembly,or do I just drive machine around slowly after I finish the repairs,& let the oil find it's way in???


Jim

[tctractors]

Jim can you fit the built up top pinion with flange into the case in 1 chunk,on a few CAT's its possible only with the final drive stripped, that is bull gear removed, if so you dont need any fancys tools on this task.
On the oil thing, I use some grease on most locations, the top pinion bearing in the outer cover might need stiff grease to keep the rollers into the outer race, use lining pins in the main case to slide it all back together