Ok small komatsu D20 the pinion gear on final drive and the flange that attaches to it on the inside of case so far I have destroyed 4 sets in the last few months I can’t get the flange on tight enough tried using a 12 ton pancake thru hole jack where it would pull the shaft thru the flange but it only moved it 1mm I need to pull it least 2mm more tried dry ice couldn’t even get it to go in to much ice would form others have said a 4 ft cheater pipe did that last time it only lasted 5hrs before it stripped the splines
Need that nut to be flush with end of shaft
What size is the shaft? Heat on the gear/flange may work better than trying to shrink the shaft. Dry ice and even better liquid nitrogen can shrink things but I'm not sure how much a solid shaft that small would shrink. What torque does the nut call for? It's likely to be more than 12 tons force. Also have you checked for a lip or any kind of irregularity on the shaft or gear that might be preventing it going all the way on.
When you say four sets do you mean four plates or both the plates and the pinions ? Looks to me its a choice to remove the pinion and replace it along with the plate if the pinion is ruined . Or consider grinding out a small area enough to get a good weld . You have little to lose as plate and pinion have failed . The risk is to the seal in from the plate on the pinion shaft .
i have installed 4 flanges and 4 pinion gear shafts and they dont last long. all the suddne i will lose power to the track and i take it apart and the splines on the flange and on the shaft are all stripped out. I did try having it welded and it just broke as well. the book says 7 to 10 tons to press the flange on but all i been able to due is put at 4ft cheater pipe on 2ft 3/4 in ratchet and i can only pull it so far. as in the photos the nut needs to be about flush with the end of the shaft, and thats only as far as i can get it.
I think i might just have to give up on this dozer and get another one, but seems like none are availble any more in the USA looks like importing one from Japan is going to be my only option. i have called shop after shop and I tell them issue and they dont have a solution either. Komatsu i have called just about everyone in Texas and Oklahoma none want to mess with it they dont even have a shop manual in their system to refer to , and its a 1991 model
How was it welded when you tried that? A weld is only as good as the person doing it and the choice of filler metal. I'm sure a qualified welder could get it to stay together. Could the shaft or flange be ground slightly to allow it to push on further? I'd try grinding the surfaces a bit and heating the flange and tightening or pressing while it's hot.
i had a certified welder due it on the 3rd time yeah it lasted for about 3 weeks but it still stripped out the splines, as far as heating it well it takes about a good 15 minutes from going from say heating it up getting it down in the hole then going to the other side and line up flange and get it started then using 2 17mm wrenches i put then in on both sides of the flange run a bolt thru the box end of the wrench to the other one and then turn it where the open end is facing down against the bottome of the case then i would take the socket and then attach the rachet then 4ft cheater bar i would think after all that the flange would have cooled off before i could attempt to tighten the nut to try to pull the flange thur
that would work but the cost of it alone i could buy a really nice slightly used dozer but then i need the pumping unit as well so i could get 3 dozers for that price
Why couldn't you apply heat while installing it? Hyd. torque wrenches can be rented and I think torque guns can be as well. Maybe not where you are though. I'd need to know more about the welding procedures used and filler metal to comment on if it could have been done better. A D20 is a relatively small machine to be tearing itself apart.
You need something like a Cat press and proper press cylinder to make over 50 or more tons. Could always make one. Give dimensions to Vetech63. They are tapered splines?
try to lube well the shaft with grase or aitiseize and then a swing wrench , i don't know the excat name but the ones you hit with a sledge hammer, them usually do the trick especially if you preheat the flange, thighten and then when cool tighten again
A striking wrench. Offset Pattern Box End Striking Wrenches { "1": "Offset Pattern Box End Striking Wrenches" } www.williams-industrial.com
I have done loads of work on Komatsu kit but the smallest types have been D30/31 shovels, the press fit on the Komatsu equipment is a lot lower than on the CAT equipment, if you have pressed the flange on using a 12 ton cylinder that would easily reach your target tonnage I cannot understand your problem? if after pressing it on you think you will still be able to press it a further 2 mm you are only going to do this by splitting the flange, once something is pressed home even at 5 tons force to put a force of 10 tons on it will hardly move it 1/2 mm if that, your requirements to force this flange on to near flush with the end of the pinion would be totally incorrect, there is always around a 2 to 4 mm gap between the the flange end face and the pinion taper end, your problem with this build up is not the flange to pinion fit but some other part causing the damage, might I suggest you check all your Final Drive bearings also the cross shaft bearings and pre load, as I have already said I have never worked on a D20 and have never seen 1 but have done Hundreds of F/Drives on about every make Tractor built, I think you are looking at the Effect not the Cause, wishing you all the Best of Luck Chap.
well i have photos of the orginal shaft and the nut was pretty much flush when tightened, now with the nut on as tight as i can get it theres only like 3 threads at best holding on the shaft, and i have only gotten the flange this close and it always fails it loosens up and then just spins in the flange, the main bearing on the shaft is brand new, the end bearing that sits in the case is brand new, if i leave the way it is now it will just loosen up ,, i cant take the nut off and just tap on the end of the shaft and it will pop out no problem when i orginally had to get that flange off i had a gear puller on there several steel wegdes behind the flange and had to hit several times with a 10lb sledge before it shot off the shaft,,, heating it up i can due but it takes so long to get it set and braced so i can put a ratchet on it and 4ft cheater pipe maybe 10 to 15 minutes i have to put a wrench on one side of the flange then another on the other side then a bolt thur the wrenchs and it jam up on the bottom of the case to tighten the nut i think by then any heat benifits will be have lost in the time
i have a shop manual and i got to get at least 1mm from the face of the flange and im not there some little tap on the end of the shaft and it pops out i basicly been down sense Novemeber and now dozer been sitting on floor by my shop sense April, im to the point i might have to go start washing dishes to bring some $$$ in every mechanic i have shown pictures to or called says they dont have a real sure fire way, Enerpac dosnt make one small enough any more that will fit in the space, there are used ones on the intenet but I had a buy ship one to me and I thought it did the job but it only moved it about 1mm i got a message that CAT makes a 50ton unit that will fit in that space but so far no dealer has gotten back to me on that it exist
im not sure the nut that goes on the shaft would be able to hold up to a striking wrench its only about 12mm wide and has fine threads, i have stripped the nuts before trying to use a sledge on the ratchet
Your replacement part may not be a match.
well, i thought of that got the last 2 from a different vendor but Komatsu pretty good on getting OEM parts from I would think, I just keep getting told it not getting pressed in far enough when the other shafts you can see the marks where it was spinning im at least 2mm or 3mm away from where it should be
Try taking the worst pair and place the plate over a solid bench with a hole big enough to take the shaft and with a heavy hammer wack the shaft into the plate . See if that drives it in enough . Seems to me the splines are not matched . When the welding failed why was that ? I can see reasons why it might , 1 the plate was loose on the inside that had it wobble and break the weld . 2 not enough weld there , that may come about because the welder was replacing the nut rather than joining the plate to the shaft. 3 the plate not square to the pinion when welded . Can you post the Dozer serial number and the part numbers of the plates and pinions , I may be able to check if the parts match your tractor .
at this point i woud have it looked at by a machinist that would calculate tolerances, new parts even oem don't always fit unfortunatly
control also contact taper with some chalk marker or the waxy contact tracer if you have it
The D31 needs 4-12 ton of press force to fit pinion,but the book recommends using 50T push-puller. Use molybdenum disulphide grease on splines.The D31 manual is very specific about the steps required.....is your manual showing these steps?
The space I have found with Komatsu equipment that they give you is very restrictive, I use an odd style cylinder to press up the tight space flanges on D41's etc, might I describe it to you as it works a treat, it has SKF stamped on it and measures at it's widest point 150mm, it has an internal thread cut in it that is 85mm x 2, with a thickness of around 45mm (it might be thinner?) this I can place onto the flange with my adapter that fits onto the pinion thread and press it in place, so the cylinder is 150mm with a centre hole of 85mm and a thickness of 45ish mm the ton force I would put as around 20 ton and it works a treat, it does have as I said SKF stamped on it but nothing else other than 85 x 2, as I know the press fit targets are a lot lower than CAT I have never be worried about its use, I hope this helps as i realize you are at your limit with this task, again might I wish you the Best of Luck to overcome your problem.
Take it apart and put Prussian Blue on the splines , reassemble, tighten and then disassemble to check the mating surfaces to see if they match. If there is not contact over the full length of the splines in the hub, then it is likely it was machined wrong. Or machinists dye would likely work also