We have a leaking final drive seal on our one of our D4D dozers that we are fixing up, so split the RH track to begin the process of taking things apart at the back end......then took the track adjuster cover off & this is what we found. Does not look good so far, as the slide mechanism about ready to let go. We already had the track split to gain access to the sprocket assembly area when we discovered this. Is the safest bet to put the track back together again & then compress the spring with the bar wedged between the sprocket & the chain to compress it, then try to run the rod nut up to hold the spring, or can we deal with it after safely another way? Also, likely the nut may well be seized to the rod & will likely not turn.....what to do then?
Ugly. If I was doing that job I think I would bend a piece of 1/4" plate or 1/4" x 3 or 4" flat bar in a curve to fit over the hump in the spring and then wrap a heavy chain around it under the track frame if you can get between the rollers. Let the grease out of it, then start torching coils at about the third coil from the rear one at a time. It shouldn't pop out of there, but I wouldn't want those to be my last words either....
If the spring is not snapped or damaged and the through bolt is OK its safe enough to handle, the humped back is the cause of compacted muck from under it forcing it to this shape, people might say it's caused by this worn and that knackered but compacted muck causes all that stuff, the rear push mount can often be bent again the same muck thing applies, the recoil can be stripped and the same spring installed 180, there will be a bit of welding to the guide areas and lugs, the back mount might need a cut and shut job but as you are going to pop the frame its a simple job to sort. tctractors p.s. the double spring thing helped some on stopping this hump job.
Do you think the track needs to be joined up again to & wedge a bar between the sprocket & the chain in order to compress the spring a bit & tighten the nut more easily?
Something around the spring to contain it sounds like a good idea! I would like to salvage the spring if possible, but not at the expense of loosing my head though!
I would ignore my advice and follow TC's words, if we were to take a vote here, I think HEF would crown him the king of CAT repair at least, and I would be one voting for him. He's repaired more of these than I've ever seen even though I think we're about the same vintage.
Yair . . . I would second lantraxco's comments in his #6 post however note the words in tctractors #3 post . . . I have seen a couple of springs in larger tractors that looked like that and had broken through bolts in which case sacrificing the spring as per lantraxco's #2 post (in my opinion) would be the safest (only?) way to proceed. Cheers.
The through bolt is easy to test, just put a socket on the end nut (it might have a Jamb Nut or a bolt and washer fitted as a lock) if you can undo this nut the rod is good, then oil up the treads some putting a washer in front of the nut that will fit through the hole on the frame and tighten it up until the recoil spring is just loose in the frame mounts, then whip off the 2 clamps at the front and the 4 bolts on the adjuster cylinder, push back the cylinder some and lift the recoil from the frame, things happen fast with these recoils so don't stand in front or behind the things, I could print many tales of doom and damage caused by them but I don't want to make you "Rev Up" tctractors
We got the track frame off ok on our D4D 83J2543 Dozer without the recoil spring causing a major catastrophe & now we are not sure how to get things apart on the outside of the sprocket. To get the nut off on the outer sprocket area, can we use a drift pin and hammer to turn it off, or do we need a special wrench? Seems the cogs on the nut are soft & hitting on them marks them up pretty bad. Can anyone sort of describe the sequence of events necessary to get things apart here, as we will have to get the to the final drive seals as they are leaking.
You have impeccable taste in tractor's Metalman. I have a D4D LGP whose recoil spring is buckled in the exact same way as your tractor's, and I note from the top photo that you are also running an old Massey Ferguson MF165, identical to a couple of my old Massey's from the '70's and '80's era. I will be watching closely how you handle the delicate task of completing that recoil spring replacement. It is a procedure fraught with risk, for sure, and I have heard some horror stories about recoil springs going ballistic when incorrectly depressurized.
If you look in on the Shop Talk section you will see what needs to be done on your rim job, the recoils are safe enough to handle and work on as long as you know what you are doing and what to expect. Today I am going to pop off a Cylinder Head from a D4D LGP 7R series tractor with the 3304 engine, this is the start point for the customer on a full engine rebuild that he will be getting I feel, on the recoil thing the spring is under around the 10-12 ton loading, it is compressed down from free to spec' lenght by about 6" to 7" (Inches) if this helps, the humped back springs need more caution to undo although the Hump bit looks a lot less when its out of frame. tctractors
Ok, so this is what I did to my D4 which had recoils which were a bit like a camel, i just got a bottle jack on a bit of wood and jacked it down off the track to where i wanted it looking straight and the built the retaining metal work up with weld.........Tony will tell us now thats a typical farmers bodge up
Thanks for the replies on the recoil spring "disarming technique's", however I plan to leave the spring problem as a secondary issue & delve into the leaking RH final drive seal issue first to see what we find. This was the machine that we found on the scrap pile last fall & I bought the machine for scrap price of metal, so really have no idea what all is wrong, except we did start it & moved it around some after getting it home & things seem to work, so there is hope for her yet. Re the final drive disassembly, there is some sort of external nut (with all the outer cogs on it) here, held in place with a locking tab that & think may be used to set the preload on the outer bearing? Having said that, I wanted to ask how we get that outer hub that the track frame pivots on apart & then this nut off to finally get at the sprocket to pull it off. Does turning the nut with the outer cogs on it somehow drive the outer hub on the outside off, or is it pullers for the outer hub? The "Shop Talk" link that TC sent was helpful, but I didn't see in the pics how the nut & outer hub comes off, but maybe I was missing something?
Marsh Mutt, the Massey that I have is an early 70's 135 & still in good shape, although I don't use it that much any more, just some occasional brush hog work & rototilling. Great starter, even in the cold weather with the Perkins diesel in it.
The bearing pre load is set by this "Outer Cog" that is adjusted using a C-Spanner, on page 1 of my junk in shop talk the 6th snap onwards is handy for you, anyhow this Cog thing is clipped with a lock bar but the slide section is also clamped with a pinch bolt that needs undoing loose, then after you have re-fitted the nut flush with the end onto the dead shaft you tighten the cog thing that is standard R/H thread so looking at it you turn it Anti -Clock, the chances of this popping off is usualy slim but the loose nut on the dead shaft will catch it, at this point I stick the rim pull kit on and pop it free, it can take 1 ton or 30 ton pressure to pop free, when this chunk is off things get harder, re-check my pictures? tctractors
If you turn the nut with the lugs on it counter clock wise as you face it, it will force the inner cage holding the outer hub bearing cup inwards towards it's cone and increase the preload. I would put the nut and disc back on the dead shaft with 1/8" clearance, tighten up the preload then hit down on the outer holder with a sledge, it should come off the taper then. Later Bob
Metalman, I have always used a tug through the sprocket to remove these hubs as nothing gets damaged, if you read the service book it shows simple thread pullers tugging at the hub, all I will say is some near fall off the taper, others hang on in some form needing some load to set free, the hub is not pressed on its just forced onto the taper via the D/Shaft Nut, you don't need to re-fit the disc back in place, just screw on the nut flush with the end of the shaft, when the hub pops free an amount of oil will leak out so prepare for this with a tray under the sprocket. tctractors
How does tugging on the sprocket work to remove outer hub when the big adjuster nut is in the way??
This is a simple thing to explain O.M. firstly you remove the outer hub cap then undo/remove the dead shaft nut,disk, dirt cover and bracket off the hub, then re-fit the nut just loose flush with the end of the dead shaft, unbolt and dig out the lock, slacken off the pinch bolt on the lower side of the hub, then tighten up the hub pre-load adjuster nut firmly, then stick on the pulling kit (I fit the adapter 1"3/8 onto the dead shaft in place of the nut as I have the kit) and put some load on it until it pops the hub free, the bull gear can move about an 1" 1/2 inside the gear cover so there is no chance of any damage. tctractors p.s. I do All Cats like this D4 through.
OK, got it, thanks tc.
So, we were able to get a Spanner wrench & used the technique that Bob suggested & after turning the cog nut counter clockwise tight & hitting the outer hub with some sharp blows, it came right off. Now we are going to call upon the Cat dealer to press the sprocket off the tapered spline in order to get at the inner seals. The outer seals looked pretty good, rubber O-rings were still good & the mating surfaces of the seals looked good, but will get all new seals. The outer bearing looked real good too. Maybe it will just seals to replace..........
Did the outer bearing come off the hub easy? or did you have to force it off with the sprocket nut, when the sprocket has been pressed off you will need to remove the outer case to check the bearings and gears. tctractors
We had to press the bearing off with the sprocket nut TC. So you would go the step further & split the case as this point to check things out if it was yours, not just change out the seals? The outer bearing looked great to me.
So here are the outer Ducone seals all cleaned up & they look good, the rubber O-Rings pliable & very soft yet. The metal surfaces are smooth & when paired up look great. There was some junk built up behind them which perhaps allowed some uneven pressure & prevented a good seal, allowing leakage? Is it a given that they be replaced without question, or upon close examination if all looks good, is it a good idea to consider re-using them?
I'll send you some info on inspecting Duo-Cone seals to determine if they can be re-used or should be replaced. The Toric Rings should be replaced automatically; they are relatively cheap and available as a separate Part Number without having to buy the whole thing. As a matter of interest did the tractor have EP gear oil in the final drives when you drained it..? If yes then I have an idea why the Toric Rings are so soft and which could also explain your leak.
Definetly pull the case and look at the gears. Hopefully your pinion gear is ok; if not your in for a whole new experience Outer bearing is rarely a problem; but the inner one is. Any doubt renew it. I usually renew the outer bronze bush the track frame pivots on too. D4D is a good little dozer that can still do a lot of work
These are typically ground on a taper from the outside edge in, when new you can see a narrow contact patch at the outer rim. As they wear the contact patch moves inward toward the center and the outer lip will get thinner and thinner until it becomes a ragged edge. These are not expensive even through CAT and aftermarket should be readily available, Off Road Equipment will be able to source the lowest priced ones for you, as they pull from most of the warehouses in the US. I can't tell much about the seal surface from that photo, bit if it was me I would replace them because I hate to have to do things twice if I can help it. Don't worry about aftermarket either, they work just fine. Sudden thought, Check CAT Classic parts at your local dealer, might be the easiest and overall cheapest way to get them.
Ok, thanks to everyone for the replies re the Duo Cone seals & how much further to go with the inspection inside. Will keep you posted as to our progress.
Well, after watching a You Tube video of a red neck sprocket removal procedure by someone else, we decided to try to come up with our own version of a sprocket puller for on our D4D, so we could replace the Duo Cone seals & it worked fine for us too. We took a 1 3/4" thick plate & rough cut the outside & then carefully drilled 3 holes @ 120 º apart, put some threaded rod through with nuts & backing plates behind the sprocket & used a 30 ton pancake jack (hand pump) to press it off. We had our machining guy make an adaptor from a chunk of 4" solid round to butt up against the splined spindle. See attachment for the home made adaptor. It came right off for us. Is there a red neck way to put the sprocket back on I am wondering that anyone had used?