Repairing older style dozer final drives D6D

Had a friend that ran those older cats he told me if your doing the final drives go with cat easy stuff to get at use after market he would do his finals every 3 thousand hrs. he always replaced the bearings gears he would sometimes just switch sides.

Is this the way to do it? The first ten minutes of the video are a total waste of time so fast forward to the last thirty seconds to see the action.

Well I have seen some Midland Bankers in my days, but these boys take the Gold Cup I feel, lucky that no injury resulted I know they managed to pull the rim but they must have damaged something doing this , the tooling they used was totally the wrong kit, pressing the rim back on might be an interesting thing to view, the correct adapter used to dismount and install the rim would have limited the travel of the rim when pulled to 10 mm, there is always the comment that we used what we had, or that's all we had to do it with, well all they were doing was damaging the equipment, they need to learn their Trade or keep clear of this sort of work, even them little Toffee Hammers they tapped on the rim with made my chin drop, when I give a rim a whack it's with a good bit of force, well worth watching thank you .RC. for posting this Comedy.

Well plans are on hold for the time being. The pump for the sprocket puller need repairs so am waiting on that. In the meantime with all the turmoil going on around the world I decided to order the bearings and seals I knew I would need. According to the Cat website they were all available in this state at various locations. So two weeks ago I put in the order. Went to pick it up yesterday and some bearings were not in the package. I inquired where are they. Oh they are still in the warehouse 600km away. I am not greatly impressed that Cat can not deliver parts in the same state that should be overnight or two days at the latest, instead it is blowing out to many weeks. I have bought stuff from the US that has arrived quicker then that.

In the meantime I have found out if the hub is stuffed I have found a "repair" shop.

tctractors is going to be out of a job soon with all these DIY final drive repair videos from Pakistan

.RC. said:

tctractors is going to be out of a job soon with all these DIY final drive repair videos from Pakistan

Click to expand...

I tend to think my patch up jobs are a bit on the edge to these lads, the top pinion needed the Arc Welder treatment and why did they not lift out the intermediate gears to give them more room? the press fit back together with the Sledge Hammer to the Bull Gear is something I have yet to try, but a very interesting film of doing what you can with what you have, we have to be thankful for the tools and equipment that we have, I do love the Team Effort you often see in these type of films they do have skills. tctractors

I especially liked one of their videos on welding a large hole in the side of a 4 cyl Diesel engine block or the one where they welded a broken crankshaft, straightened and reground it. It would be interesting to know the long-term reliability of some of their repairs

TC got it right in his comment above - "a very interesting film of doing what you can with what you have". If that's all they have available to them and they don't have the option of new or used replacement parts, the answer's what you see in the video. The continuous failures must keep them in work though.

Well I am one step closer.

Well I did not know Cat made repair videos.

R.C. it looks like you have the Bush Repair Kit on rim tooling ? the press sleeve looks like a cylinder liner with a pin window cut in, the ram looks to be a 74 ton job handy enough but for D6 up you really need that extra capacity of the 105 cylinder, the dead shaft adapter for the D6 is 1 3/4" x 12 tpi,if you look at the pictures I have posted you will see how I tackle them, on good ground with an excavator or something I can use I will strip out both frames and final drives on a D6 C/D on my tod easy in a day, if the top pinion/s are damaged that is the Cream on the job for me, you need to sort some lining pins to help remove / install the outer cover they are 1/2" UNC the longer the better, then you need 2 D shackles that you hook into the cover to lift it, its all easy really you just need to think things through also some thick grease to pack the roller bearings in the cover to aid fitting as they keep dropping down and you will damage things. tctractors

Thanks, I have the right tooling, I just did not have a picture of it. There is the bit you screw onto the dead axle, then the slotted spacer you fit against that so all the force is on the hub itself. I have got the sprocket off now. The gauge on the pump is faulty (under reads) which I will have to rectify before pressing the sprocket back on, but it took a bit of tonnage and went off with a bang and the gauge was around 50 ton when it went. I have a video of it here popping. Sadly I obviously did it wrong as the few videos on youtube often show the tooling flying to hell when it pops. This one just popped against the nut.

Splines look fine and I measured the sprocket to hub spline before pulling and it was within spec. However I found the nut that holds the sprocket tight was loose, it had been locked.

First picture is pulling off the outer support housing off the taper. It was pretty tight and I would have been surprised if an ordinary three leg puller like the manual shows would have done it.

Third photo shows the outer bearing damage. Looks to me like it has been repaired before. It was tight when I pulled it off with the nut, But probably not as tight as it should have been. I might have to do something about that. I do not think the chinese knurl trick will work too well.
I have found the pulling apart bit at least is not as hard a job as I expected. I am getting help for the reassembly.

Some more pics.

Dead axle is bent 2mm.
Intermediate gear is a one piece and pinion on it is stuffed. Bull gear stuffed. Bearings stuffed. Top pinion has the start of minor pitting. However it has considerable end float. You can pull it in and out what seems like a 1/4" or so.

So I have rung around the suppliers and ordered three new gears. CGR brand. I did not get the cheapest nor the most expensive, but was surprised at the variation in price.

I am up in the air on the dead axle. Bend tolerance is 1.6mm. remeasuring mine, it seems bent around 2.2mm.

I have cleaned the top pinion. It seems to have suffered more from metal flakes in the oil. Does it look alright?

Sprocket pulling video.

.RC. said:

View attachment 262360 View attachment 262361 Dead axle is bent 2mm.
Intermediate gear is a one piece and pinion on it is stuffed. Bull gear stuffed. Bearings stuffed. Top pinion has the start of minor pitting. However it has considerable end float. You can pull it in and out what seems like a 1/4" or so.

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You cannot judge the end float of the top pinon with the outer bearing not in location so forget this point. the top pinion can rattle on for a good bit I feel, when you reassemble do not use anything with silicone stick to the Red jollop or something like Stag jointing compound, it stinks some but works well, the intermediate gear set has been a 2 piece setup for years now, pressing things back together is the easy bit but getting the outer hub on has its tricks, on the D/ shaft issue I would firstly re-check your detail and if you are right I usually swap shafts side to side, but you are doing a blinding job chap, last thought the hub bearing area needs to be a crack on fit not loose so possibly a metal spray repair??? tctractors

Thanks, I checked the measurement twice at different times and it is around that 2mm minimum. Might be as much as 2.3mm, but no more. It is a bugger to measure, but I have an 18" machinists square I used.

I think the question is how much is too much and when I am putting £2800 of new parts in it should I spend the extra 600 for a dead axle.

I have no idea how much bend is too much other then what the book says which is 1.6mm.

I have found that checking the Dead Shaft is best done with 2 people and a surface clean up on all points of the compass, I use a fine looking square that is a beast of a thing,so i know how hard it is to get the dip correct on this task, the Dead Shaft can be a fair pig to remove and be warned you need to only undo the inner C nut a max 2 turns when you pull it, they will shoot out without the nut in place, if you resort to the Pepper Pot heating of the case to ease removal be warned that as they pop a flame thrower is coming at you, so stand well off when doing it, when the shaft has pulled off the taper you undo the inboard nut totally then you will have to pull it out a good way with the Service press before it gives up the struggle, getting a new shaft in is more fun but you might just leave well alone and go with what you have, again its very hard to measure to the centre of the shaft by yourself and the shaft shape is odd and only the engineered end thread is fit to dip off. tctractors