You must be looking for work Mangoman, you are talking yourself into a major rebuild of that D4.

My humble advice is weld that brake band in situ, then take a photo of both steering clutches and post the photo's on here, typically you can guestimate how much life is left in the clutches by looking at the adjusters on both sides if the tranny top is on, but you can get a rough idea of wear by looking at how thick the clutch packs are, ie how much they protrude out of their brake drum housings.

Dismantling the D4 gearbox is a big job, I've done it, it takes a long time on your own and gets expensive in a hurry with all the bearings and seals, just doing the brakes on mine was over $500, definitely easier if you have all the nice pullers and pushers, I didn't, so I spent a long time problem solving, and still had to take the cross shaft to a Engineering shop to press the clutches back on, it took me months and months to track down the parts I needed and I still hit big hurdles.

The difference with me and you is my D4 was busted badly, bellhousing was cracked from front to back, transmission housing had a big hole busted in it under the main clutch, reverse gear had chewed through it's shaft support, plus the crown wheel was missing 4 teeth, from what I can see of your tractor, you have a little rust etching on some teeth, and 2 gorgeous young kids who need quality time spent with them, and food put on the table.........

Be careful, you keep saying how money is tight, and your Cat will never do thousands of hours of heavy work again, then repair the obvious issues like the brake band, and if the photo's of the clutch packs look OK to the folks on here, then bolt her back together and get going with your life, and trust that tractor to get the job done, go and have some fun helping your buddy next door, if it breaks, then fix it.

I have several old Cats sitting in my yard waiting for parts because I stoopidly kept going the extra yard fixing things on those tractors that really didn't need fixing, trying to return the old girls to original spec, spending tens of thousands of $$$$$$$$$ on tractors that are lucky to do 5 or 10 hours work a year.

I guarantee you, it takes a lot longer than you think it will, and costs a lot more than you think it should, to return a old D4 to original spec.
Mike

Here is a photo from 2011 of my D4 7J tranny, you can see the difference in the thickness between the left steering clutch pack and right steering clutch pack, when you use the brake drums as a reference point. The older gentleman is one of the best self taught Cat Mechanics in Australia, he lives 2,000 miles north of me in the land of mango's, and kindly visited and helped me put the D4 tranny back together, I wouldn't have gotten it done without his expert guidance.

Both clutches were dismantled, cleaned and re-assembled with new bearings and seals, plus we fitted a replacement crown wheel, and gear shaft with pinion, plus all new gearbox bearings, and final drive pinion bearings, plus new brakes, replaced the bellhousing, a few years later, around 2016, fully rebuilt the pilot motor with the expert help of "Edb", then pulled the diesel motor liners and reconditioned the head fitting new valves and rings, finally got the tractor back together and driving just over a month ago.

So there you go Mangoman, bought the busted D4 in 2009, got her running around 2012 but only briefly, wasn't till 2020, and after spending at least $7,000 or $8,000 on top of the buying price, that I got to really give her a good workout, try and avoid following in my footsteps.
Mike

I agree with everything Mike said however, there's a big difference between cat certified rebuild and operational. My 5t has undercarriage so wore out it's almost embarrassing, but its operational. I've done lots of good work with it at my property, and helped others out also. Sometimes you have to pick your battles and bite your tongue knowing something is wrong but can be nursed through.
Definitely be careful to not take something apart unless you know you're going to make it right because once its apart you have to deal with it.
Dont get discouraged since its your first machine, most of the advice you will get is from guys who have done multiple machines and really know there way around a Cat. You need to find the balance between your tight budget and operational

The lift links should be 8 1/2" center to center.

"Mike wrote:

Here is a photo from 2011 of my D4 7J tranny, you can see the difference in the thickness between the left steering clutch pack and right steering clutch pack, when you use the brake drums as a reference point. The older gentleman is one of the best self taught Cat Mechanics in Australia, he lives 2,000 miles north of me in the land of mango's, and kindly visited and helped me put the D4 tranny back together, I wouldn't have gotten it done without his expert guidance.

Both clutches were dismantled, cleaned and re-assembled with new bearings and seals, plus we fitted a replacement crown wheel, and gear shaft with pinion, plus all new gearbox bearings, and final drive pinion bearings, plus new brakes, replaced the bellhousing, a few years later, around 2016, fully rebuilt the pilot motor with the expert help of "Edb", then pulled the diesel motor liners and reconditioned the head fitting new valves and rings, finally got the tractor back together and driving just over a month ago.

So there you go Mangoman, bought the busted D4 in 2009, got her running around 2012 but only briefly, wasn't till 2020, and after spending at least $7,000 or $8,000 on top of the buying price, that I got to really give her a good workout, try and avoid following in my footsteps.
Mike

Thank you Mike for the advice. I value what you guys have to say, especially when it is someone who has been in deep- deeper than I.

I didn't know it was possible to guess at clutch wear from eyeballing in comparison to the brake bands. I will take some pics. The brake linings dont look too bad- I'm sure there was more than 1/8". There is a crack or two in them but perhaps that is ok.

I would like to get it to a point where I feel decently comfortable that I'm not going to take out a crank because the rod bearings are into the copper etc. If I am in this far and I see something is on death's door and I may very well harm the machine more by throwing it back together and running it, then will just have to wait until there is a penny or two in the til and do the fix. The track frames/ undercarriage are pretty roughed up so I will likely have to do significant work there. I dont want the whole front idler falling off (might be possible at this stage of the game).

Thank you for your perspectives. I have open ears and I believe you that it always takes more time and money. My wife and I had this happen with a house reno. Double the time and money! I stripped and rebuilt my old Toyota Landcrusier years ago and I believe you guys about how projects go.

The D4 7J tranny is very similar to the D4 7U, they share many parts, and ten years ago when I was working on mine, prices for Cat bearings were not too bad, expensive compared to common bearings, but not out of the ball park, but it seems the past 5 years prices have doubled, in some cases tripled for the same part, even simple items like nuts, bolts and spring washers have gone up big time.

Cat make the best parts, including their basic nuts, bolts and washers, and they used to be cheap for what you got, but not anymore, and even used parts like gears can cost a lot of money to not just buy, but to freight too, and finding someone willing to sell the parts can take a long time, a lot of dead Cats have gone to China as scrap the past 10 years, so it's harder to find one getting dismantled.

If you have rebuilt a Landcruiser and done a home reno then you are handy with tools, just don't make work for yourself is all I'm saying, and when you put the tranny top back on that tractor, make sure you put a good lube on all the bolts and nuts, so if you need to open her up again you will get it done in a third the time it took the first go.

Just out of curiosity, have you driven this old girl much yet, were there any obvious issues?
Mike

"Rome wrote:

The lift links should be 8 1/2" center to center.

Thanks Rome!

"Mangoman" wrote:

Thanks Rome!

Your welcome!

"Mike wrote:

The D4 7J tranny is very similar to the D4 7U, they share many parts, and ten years ago when I was working on mine, prices for Cat bearings were not too bad, expensive compared to common bearings, but not out of the ball park, but it seems the past 5 years prices have doubled, in some cases tripled for the same part, even simple items like nuts, bolts and spring washers have gone up big time.

Cat make the best parts, including their basic nuts, bolts and washers, and they used to be cheap for what you got, but not anymore, and even used parts like gears can cost a lot of money to not just buy, but to freight too, and finding someone willing to sell the parts can take a long time, a lot of dead Cats have gone to China as scrap the past 10 years, so it's harder to find one getting dismantled.

If you have rebuilt a Landcruiser and done a home reno then you are handy with tools, just don't make work for yourself is all I'm saying, and when you put the tranny top back on that tractor, make sure you put a good lube on all the bolts and nuts, so if you need to open her up again you will get it done in a third the time it took the first go.

Just out of curiosity, have you driven this old girl much yet, were there any obvious issues?
Mike

Thank you for the pointers Mike. Parts price and availability are an important thing to consider for sure. I was starting to run into that probelm with my old 60 series Landcruiser a couple years ago when I still had it.

I have only put on about 10 hours on it over last winter. Here are the things I am most concerned about:

Had water in all components. I think the clutch compartment trapped water. I drained a good amount maybe 6L or more out of it. Main eng had significant water too. Maybe 3 or 4L? I think it may have migrated from the clutch compartment. Trans, bevel gear, winch were all full of very watery oil. I would like to pop a few caps off and look in the bottom of the main.

Front idler bearings are falling apart.

Left track tensioner bent. Guide studs missing. Adjuster threads look like they have been on the bottom of the ocean.

Main clutch sticky to disengage. Sometimes I have to spike the brake or bury it into a snow pile to pop it loose. Need to figure that out.

Pony has a lot of play on the flywheel end. I think it was something like .060"? Too much I'm sure. Leaks oil like a sieve out of crank seal. I want to check out the pony internals and make sure I'm sure it's not about to knacker itself.

Front cover on main has a 3" crack in it. Leaks like a sieve as well.

And a bunch of minor things like:

All blade linkages sacked.

Trunions sacked.

Probably more than half the pads are flopping loose.

Cracks in track frames.

Hyd creeps very quickly.

Winch inop.

Needs cutting edges and corners.

No generator/ alternator.

Pony block need needs repair. Cracked and leaking coolant.

Lots of other stuff I'm sure. I think the top roller bearings might be knackered, front idlers, probably bottom rollers too. You get the idea.

I should be somewhat handy. I am a HD mechanic but I havent worked on a single crawler other than help do undercarriage on a D8R 15 years ago when I wasnt even an apprentice. I dont even work in what many would regard as a "real shop" 😁I work for the municipality so its different. I do have access to alot of good tools.

I will post up a few pics of the issues later on

Sounds like something I'd drag home, all the good old Cats were bought 20 or 30 years ago by the older collectors, guys who only wanted running tractors with good undercarriage, and paid scrap price for most them, leaving us "newbies" to drag the basket cases like your D4 out of the bushes.

You being a proper Mechanic will have no trouble straightening the old girl out, but you wont do it in a weekend, start putting the word out for the parts you need, like the engine cover, best place to ask obviously is on here, but also put a advert in the ACMOC magazine, that goes to the 3,000 financial members of ACMOC every few months, this bulletin board is only regularly visited by a handful of ACMOC members, fewer than 100 I'd suggest. A advert in the mag might find a 6U or 7U wreck near to home, well nearer than southern California, or Australia!

You shouldn't have too many problems finding most the parts you need, they made a lot of those 6U and 7U D4 tractors, 50,000 or more, plus as I said previously, they share a lot of tranny and undercarriage parts with the earlier D4 tractors including the RD4, D4 7J, and D4 2T and 5T, plus the newer sealed D4D bottom rollers will bolt straight on, aftermarket companies like Berco make them. I suspect your bottom rollers will be shot, seems a Cat with a blade never sees track roller oil very often.

You are no dummy, slow and steady wins the race, if you go fast buying bits you will spend 2-3 times more than you need to, racing out buying parts from the first offer, sounds stupid but you will probably find it cheaper to buy a complete D4 motor, or complete D4 wreck, than buying individual parts like the front cover. You have a ACMOC Director just down the road from you who works for the biggest Cat Dealer in the world, get hold of Nathan and pick his brains, he will know of a few D4 wrecks in BC I'm sure, plus he probably knows a few good folks you can talk to for guidance if needed.

Working on these old girls is not rocket science, the best advice I was ever given was from Eddie Bedwell ("Edb") was "Always return a Cat back to original spec before attempting major repairs", and that is priceless, because you can spend days and thousands of $$$ chasing a issue like your sticky main clutch, only to find a good flush with diesel scrubs those plates clean of the oily crap holding them stuck, or the clutch linkages are just plain flogged out.

In those dry clutch compartments drill a 3/16" hole in those large drain plugs and fit a split pin to let any condensation or water drip out, also, while the tranny top is off, have a real good look at the main clutch linkage, there is a strong single spring that helps pull the clutch disengaged, if it is missing, or someone has fitted a lightweight spring there, you will find your main clutch will hang up, my D4 7J does that. Part number of that spring for your tractor is 4B6378, they are not cheap, about $50 when I checked recently, but a situation where the original spec spring length AND tension is needed, and definitely a part that is easy to fit while the top is off, a real pain in the butt to fit if the top is on.

The pilot motor can be very expensive to rebuild, $1,000 is easy to spend on a badly worn one, though luckily most the parts needed are available, cranks can be a challenge to find, but they are out there. Ask around, a lot of old Cats got converted to electric start and their pilot motors got put in the back of the barn, any pilot motor off a D2 or D4 will fit, just the top manifold changes.
Mike