ACMOC
Login | Register
ACMOC
D6 9U New to me

D6 9U New to me

Showing 1 to 10 of 54 results
1
doc_dozer
Topic Author
Offline
My neighbor stopped by yesterday because he noticed I was clearing land. He asked if I would be interested in his D6. Serendipitous as I have been watching Craigslist for a couple of months. I took a look at it and it's a 1957 D6 9U with an electric start pony motor and hydraulic blade. Everything works correctly but the sprockets are done. Bushings are at 50% and the idlers need bearings. Track adjusters are at the limits. Pads are excellent.

Is CAT my best/ only options for the sprockets? ( and other parts). I've been getting filters at NAPA for my Mitsu excavator but everything else through cat ( for the excavator and getting ready to put my D2 back in service). I'll do some of the work myself but will probably have to hire some of it out due to time and weight.
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
Old Magnet
Offline
There are options to Cat sources. Undercarriage parts are still plentiful as aftermarket items. Key is to track down part numbers and inquire as to where the items can be obtained. Current track and sprocket solution is to go the 6.91 inch pitch to replace the old 6.75 inch version.
Please log in or create an account to join the conversation.
doc_dozer
Topic Author
Offline
Reply to Old Magnet:
There are options to Cat sources. Undercarriage parts are still plentiful as aftermarket items. Key is to track down part numbers and inquire as to where the items can be obtained. Current track and sprocket solution is to go the 6.91 inch pitch to replace the old 6.75 inch version.


Replace the whole thing then. can the pads be saved and used on new rails? I was hoping to get by with rebuilding the idler and replacing the sprocket 😊
The CAT service guy lives about a mile from here, once the machine is in my driveway I may flag him down to talk about it....

I ordered parts and service manuals a few minutes ago.
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
Old Magnet
Offline
Reply to doc_dozer:


Replace the whole thing then. can the pads be saved and used on new rails? I was hoping to get by with rebuilding the idler and replacing the sprocket 😊
The CAT service guy lives about a mile from here, once the machine is in my driveway I may flag him down to talk about it....

I ordered parts and service manuals a few minutes ago.
If your rails still have life you can install a new sprocket rim, 6.75" pitch, part number 3H2643.
6.91" pitch rails use a different part number grouser/pad.
A 6.91" pitch 5S0834 ring utilizes sprocket segments.
Please log in or create an account to join the conversation.
ccjersey
Offline
Before you make a decision price new track rollers and sprockets to match your rails (get part numbers off them and or measure stretched lengthof 4 links center to center of 5 pins)

If it still has 6.75" rails but they are worn to 100%+ (and it sounds like they are since the adjustment is all the way out), you might be able to swap to the 6.91 bolt on sprocket segment type weld-on ring. If a new 6.75" pitch ring doesn't result in enough improvement to the track tensioners travel, you can consider having the pins and bushings turned or if that is not justified, or you have a 6.91 ring installed, a link can be cut out of each track and return the adjusters to the fully retracted position.

One thing to watch out for if you need to back the adjuster in all the way, the threads which have been exposed for years while the tracks were too long will be rusted away and may soon strip if the tractor is operated when the bad threads are screwed back into the nut. Better to replace the adjuster bar before this happens than to ruin the "nut" too. Last one I bought was from Florin and was quite reasonably priced, maybe $100-ish.

If your final drives are leaking oil down the inside of the sprockets you may want to have the sprocket rims replaced after pulling them to fix the seals. If the seals are good, the rims can be replaced with the sprockets still mounted on the tractor. If only the outer seals are leaking, those can be replaced when the track frame outer support is disassembled to install the ring.

Lots of options depending on what you find.

Oh........we like pictures!
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time😄
Please log in or create an account to join the conversation.
doc_dozer
Topic Author
Offline
Reply to ccjersey:
Before you make a decision price new track rollers and sprockets to match your rails (get part numbers off them and or measure stretched lengthof 4 links center to center of 5 pins)

If it still has 6.75" rails but they are worn to 100%+ (and it sounds like they are since the adjustment is all the way out), you might be able to swap to the 6.91 bolt on sprocket segment type weld-on ring. If a new 6.75" pitch ring doesn't result in enough improvement to the track tensioners travel, you can consider having the pins and bushings turned or if that is not justified, or you have a 6.91 ring installed, a link can be cut out of each track and return the adjusters to the fully retracted position.

One thing to watch out for if you need to back the adjuster in all the way, the threads which have been exposed for years while the tracks were too long will be rusted away and may soon strip if the tractor is operated when the bad threads are screwed back into the nut. Better to replace the adjuster bar before this happens than to ruin the "nut" too. Last one I bought was from Florin and was quite reasonably priced, maybe $100-ish.

If your final drives are leaking oil down the inside of the sprockets you may want to have the sprocket rims replaced after pulling them to fix the seals. If the seals are good, the rims can be replaced with the sprockets still mounted on the tractor. If only the outer seals are leaking, those can be replaced when the track frame outer support is disassembled to install the ring.

Lots of options depending on what you find.

Oh........we like pictures!
Good information. Thank you both! I will be measuring the rails this week once it gets moved here.
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
Paso Bob
Offline
Reply to doc_dozer:
Good information. Thank you both! I will be measuring the rails this week once it gets moved here.
I would also give consideration to looking for a parts tractor with a bad engine and good or average undercarriage.
D-4 7U-43159 with 4S dozer and Cat 40 scraper, D-7 3T-1179 with Cat 7S hydraulic dozer, D-7 17A 13,944, D-8 14A-1160 with Cat 8S cable dozer, Cat 12-99E-4433 Grader. All runners and users.
Please log in or create an account to join the conversation.
doc_dozer
Topic Author
Offline
Reply to Paso Bob:
I would also give consideration to looking for a parts tractor with a bad engine and good or average undercarriage.
So I finally got it home last night. The undercarriage is toast. The rails are 100% worn. The bushings weren't which tells me that someone replaced them at some point when the tracks were getting pretty worn but they didn't address the rest of the machine. One upper roller has a broken flange. There are no grease buttons on the lower rollers and the previous owner had said they were sealed. I paid $4k for it, so compared to what I have seen in the Northeast I don't feel so bad. Granted I would rather not need to replace the undercarriage but it is what it is. Both pony and diesel run well.

I can look for donor machine but I think I will start down the route of replacement.

I suspect it makes sense to follow Old Magnets suggestion to go to the 6.91 pitch.
Searching through the forum and trying to put it all together it looks like replacement looks like:

New sealed upper rollers ( i'm willing to bet that the rest are worn out but i'll check more carefully)
New sprockets and rails - from which model? D5 or D6 and does year matter? I have spoked rims, do they get cut and welded or will do new ones get pressed on?
Possibly new bottom rollers - again, off what machine. I can't really tell how work they are. I need to do more research...
Will my track pads bolt right on to new rails?

Thanks in advance!
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
doc_dozer
Topic Author
Offline
Reply to doc_dozer:
So I finally got it home last night. The undercarriage is toast. The rails are 100% worn. The bushings weren't which tells me that someone replaced them at some point when the tracks were getting pretty worn but they didn't address the rest of the machine. One upper roller has a broken flange. There are no grease buttons on the lower rollers and the previous owner had said they were sealed. I paid $4k for it, so compared to what I have seen in the Northeast I don't feel so bad. Granted I would rather not need to replace the undercarriage but it is what it is. Both pony and diesel run well.

I can look for donor machine but I think I will start down the route of replacement.

I suspect it makes sense to follow Old Magnets suggestion to go to the 6.91 pitch.
Searching through the forum and trying to put it all together it looks like replacement looks like:

New sealed upper rollers ( i'm willing to bet that the rest are worn out but i'll check more carefully)
New sprockets and rails - from which model? D5 or D6 and does year matter? I have spoked rims, do they get cut and welded or will do new ones get pressed on?
Possibly new bottom rollers - again, off what machine. I can't really tell how work they are. I need to do more research...
Will my track pads bolt right on to new rails?

Thanks in advance!
[attachment=44658]IMG_1362.jpg[/attachment][attachment=44659]IMG_1363.jpg[/attachment][attachment=44660]IMG_1364.jpg[/attachment][attachment=44661]IMG_1375.jpg[/attachment]
Attachment
Attachment
Attachment
Attachment
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
neil
Offline
Admin
Reply to doc_dozer:
[attachment=44658]IMG_1362.jpg[/attachment][attachment=44659]IMG_1363.jpg[/attachment][attachment=44660]IMG_1364.jpg[/attachment][attachment=44661]IMG_1375.jpg[/attachment]
Attachment
Attachment
Attachment
Attachment
With new undercarriage, it will be an enviable machine. Folks on here have good examples of the Cat canopy if you need measurements to re-establish it.
Please log in or create an account to join the conversation.
doc_dozer
Topic Author
Offline
Reply to neil:
With new undercarriage, it will be an enviable machine. Folks on here have good examples of the Cat canopy if you need measurements to re-establish it.
Thanks! I would like to fix it at some point. I hate working without a canopy of shade!

One thing I forgot above is parts sources.
I know about Cat of course, and Berco, but are there other parts sources to consider?
I also have source a junk yard lower diagonal brace for the right side of the blade....
Charley
'44 D2 5J 6987SP
'57 D6 9U 25158
and bunch of Farmalls😉
Please log in or create an account to join the conversation.
Showing 1 to 10 of 54 results
1
YouTube Video Placeholder

Follow Us on Social Media

Our channel highlights machines from the earliest Holt and Best track-type tractors, equipment from the start of Caterpillar in 1925, up to units built in the mid-1960s.

Upcoming Events

KORUMBURRA WORKING HORSE & TRACTOR & 100 YEARS OF CAT RALLY

Chapter Nineteen

| 5875 STH GIPPSLAND HWY, NYORA

Booleroo 2025

Chapter Thirty

| Booleroo Centre, 54 Arthur St, Booleroo Centre SA 5482, Australia

CAFES 2025 TULARE, CALIFORNIA

Chapter Fifteen

| Tulare, California

Wheatlands Warracknabeal Easter Rally

Chapter Nineteen

| 34 Henty Hwy, Warracknabeal
View Calendar
ACMOC

Antique Caterpillar
Machinery Owners Club

1115 Madison St NE # 1117
Salem, OR 97301

cat@acmoc.org

Terms & Privacy
Website developed by AdCo

Testimonials

"I became a member recently because the wealth of knowledge here is priceless." 
-Chris R

Join Today!