John Deere 755 Newbie

[beenthere]

Also use the google search in TBN (upper window) and type in JD 70 FEL.. past threads will come up as hits.. such as

https://www.tractorbynet.com/forums...erating/36340-removal-70-loader-jd-955-a.html

Post a pic of what you have in front of you and it will also help with suggestions and hints how to proceed.

 

[JD755]

70 Loader instructions attached. Note that you need to use the loader to raise the front tires off the ground when latching/unlatching the loader.

 

[buickanddeere]

obtain and read the JD service manuals from Sharps or from 1-800-522-7448. Bubba’s opinion is not always the design engineers intention.

TractorData.com John Deere 755 tractor information

 

[hotrod1016]

 

[Moukie]

Huge help Team - thank you. I think i have all the fittings to manually check oil pressure; just need daylight and time away from work. Hope to check tonight. Once i get that, i will make decision whether or not to remove FEL and begin tearing stuff apart, or plan B.

Thank you very much. I will be back.

David in SC

 

[Moukie]

Update to where i am. Got the FEL off with no issues. Thank you so much for the video hotrod1016! One less oil leak, setting until i get time and parts to fix; should be easy enough........Now for the oil pressure. I finally got a manual gauge and ran tractor a little today. Sure enough, psi is about 18-20 at start, and drops to right at 10 psi on a warm engine at mid-throttle; hence the idiot light coming on. It is doing what it should. My pressure fluctuates with RPM; from about 11-12 at WOT to about 5 at idle. Is it safe to assume from this that oil pump screen can be ruled out? Sounds more to me like worn rod and main bearings? Please help me with some options/advice:

1) Run as is. Maybe it fails; maybe it doesn't. I only expect to put about 30 easy hours per year on it. What would be the failure if it fails?
2) Go from current 15/40 to maybe a 20/50 wt oil. Should i first remove valve cover to make sure oil is reaching rockers?
3) Replace rods and mains only? Is there potential harm in changing only worn rod and main bearings? Can mains be changed in the machine? Do i have to buy from a JD dealer?
4) What about oil pump? Can it be worn, blocked, causing low psi? I am not sure how to test/verify. Can it be changed from the bottom?
5) Bottom end overhaul, to include pistons, sleeves, rod and main bearings, etc.
6) Full OH, including head rebuild.

I have not done compression test to see if head rebuild is needed. Is there potential harm in overhauling bottom without re-working head?

Do all parts have to come from a JD dealer? i contacted Hoye about an engine kit for a 3TNA72UJ Yanmar. As soon as they asked what tractor it was for, the conversation immediately shifted to me having to get parts from a JD dealer.

All suggestions are welcomed. I don't have too much in this tractor yet, and really don't want to put too much in it. It may be best for me to cut my losses before they get too big?

Thank you,
David in SC

 

[pmsmechanic]

I would pull off the oil pan and the bearing caps furthest away from the oil pump. Those will be the bearings with the most wear. If there are no scratches in the bearing journals that you can hook with your finger nail then I would just roll in new rod and main bearings and replace the oil pump and see what happens when you run it. I would also look for an internal oil leak. That might be the cause of your low oil pressure.

I'm just throwing out ideas. Someone with more experience with these engines might have better ideas. I've never worked on a 755.

 

[pipsqueek]

Do all parts have to come from a JD dealer? i contacted Hoye about an engine kit for a 3TNA72UJ Yanmar. As soon as they asked what tractor it was for, the conversation immediately shifted to me having to get parts from a JD dealer.

Hoye has industrial engine part division, lists the engine parts for the 955 (3TN84UJ) with JD part numbers but not 3TNA72UJ, have listing for 3TNA72. JD parts for 755 engine cross to parts for 455 engine, pistons, rings etc.

Yanmar Industrial Engine Parts: Water Cooled Engines

https://www.mytractorforum.com/53-john-deere/767994-need-engine-rebuild-kit-jd-755-a.html

https://www.mytractorforum.com/53-john-deere/600386-new-me-855-a.html

755 engine block where used according to jd parts:

020DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
3009DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
3015DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
3012DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
3011 - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
3014DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
4019DF - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
4020 - ENGINE, OEM (SERIES 200 DIESEL)
3009, 3011, 3012, 3014, 3015, 4019 and 4020 OEM Engines and Accessories (Waterloo) - PC2370
425 - TRACTOR, LAWN AND GARDEN
425, 445 & 455 Lawn and Garden Tractors - PC2351
445 - TRACTOR, LAWN AND GARDEN
425, 445 & 455 Lawn and Garden Tractors - PC2351
455 - TRACTOR, LAWN AND GARDEN
425, 445 & 455 Lawn and Garden Tractors - PC2351
655 - TRACTOR, COMPACT UTILITY
655, 755, 756, 855 and 856 Compact Utility Tractors - PC2054
756 - TRACTOR, COMPACT UTILITY
655, 755, 756, 855 and 856 Compact Utility Tractors - PC2054
755 - TRACTOR, COMPACT UTILITY
655, 755, 756, 855 and 856 Compact Utility Tractors - PC2054
855 - TRACTOR, COMPACT UTILITY
655, 755, 756, 855 and 856 Compact Utility Tractors - PC2054
856 - TRACTOR, COMPACT UTILITY
655, 755, 756, 855 and 856 Compact Utility Tractors - PC2054
670 - TRACTOR, COMPACT UTILITY
670 and 770 Compact Utility Tractor - PC2227
770 - TRACTOR, COMPACT UTILITY
670 and 770 Compact Utility Tractor - PC2227
F925 - MOWER, FRONT
F925 Front Mower - PC10378
3TNA72C - MOWER, FRONT
F925 Front Mower - PC10378
F935 - MOWER, FRONT

Note 425/445 is just because 455 lumped in with that family of tractor. Same with 655/755/855, have to drill down to part section.

 

[Moukie]

I have a very knowledgeable person recommending to me that I swap 15/40 to straight 30 Rotella and I will get better psi. I have a lot of trust in this person's abilities. Does not seem to make sense to me. He also states that 10 psi should be plenty, and not to worry about it.
Any thoughts on this, from you all that have a lot of experience with these engines? I really want to use this machine, but shudder at the thought of using something that is not quite right. I also fear that if I end up pulling the engine to swap rod and main bearings that I will then end up with a total rebuild including head work. That is money I will likely not ever get back during a sale.

Can rod and main bearings (and rear main seal) be changed without pulling the engine?

Also - where is best place to purchase tilt cylinder and power steering cylinder rebuild kits? I need to do all 3 to stop the "bleeding". Can I do this without special tools?

Thanks for the help.
David in SC

 

[Mechanos]

You can get the seals for the loader cylinders from JD. They are an "off" size so source them elsewhere is more difficult but I wouldn't say impossible. As for the power steering cylinder, the gland is welded on, so in order to rebuild it, you'd need to cut the gland off, size and source the seals and then weld it back together. Or source a completely different cylinder altogether.