• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Bobcat S750

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
Hello,

I purchased a 2013 Bobcat S750 from an auction. Auction description said engine was locked. After getting it home, I confirmed that engine would not turn over. Removed drive belt for hydraulic pumps and belts for AC compressor and alternator. Engine would still not turn over, removed starter to confirm it is operating correctly off of machine, which it was. Tried moving engine with prybar on fly wheel, would not budge in either direct.

Next steps will be to pull the injectors to get a look in cylinders. Just have to get it off trailer first and into the shop.

It has a Kubota V3800-CRTE4CB Interim Tier 4 turbo diesel engine.

The questions I have at the moment are, anyone have any tips on what I should look into next? Anyone have any experience rebuilding these engines or know common issues with them?

Thanks for the help,
20240416_191134.jpg
 

Arny L

Senior Member
Joined
Sep 23, 2020
Messages
303
Location
canada
You could cut open oil filter and see what's in the pleats. There are some videos on utube on how to do this correctly. This may give you some insight as to what's happened.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
Just to post an update on current progress with engine. I now have it out of the bobcat and on an engine stand. I have pulled the oil pan, timing cover and lower crank case. I can see that the one main crank journal missing is half missing and chewed up. The metal from the bearing getting chewed up has caused two other main crank bearings to spin. I believe one of the rod bearings are seized due to heat discoloration on crank. Next steps will be to pull the head and pistons to assess if they were damaged.
Anyone know if it is possible get the block machined for the crank bearing holders or if I'm going to be looking for a new block?

Thanks
 

ozarkag

Senior Member
Joined
Apr 25, 2018
Messages
350
Location
ozarks
If a main bearing is spun you will likely be needing a new block. There is no easy way to repair that. A used block should be readily available, in large part because seems Kubota did not melt down warranty engine cores.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
If a main bearing is spun you will likely be needing a new block. There is no easy way to repair that. A used block should be readily available, in large part because seems Kubota did not melt down warranty engine cores.
From talking to a machine shop today that is what I am thinking, I'm going to have to do. I am seeing lots of v3800 blocks around just trying to figure out which one it is that I need now. Are all v3800 blocks the same??? Would anyone happen to know how to identify the Kubota part # for the block? I have the bobcat part# but having trouble linking it.
 

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
13,225
Location
Canada
Block might be repairable depending on the damage. Cast cylinder heads can often be repaired so can't see why a block couldn't be possible to repair.
 

ozarkag

Senior Member
Joined
Apr 25, 2018
Messages
350
Location
ozarks
The bobcat number I have is 7024361 Sorry, that one doesn't cross as easy. There are only several differences that I am aware of in the V3800 blocks. Fuel pump mount and front cover design for one. Would be safest to source a used block from a Bobcat, but with a bit of care no reason another one couldn't work as well.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
I did some digging for some service manuals on this model and was able to come up with a couple of options as listed below. You will need to drain your coolant and disconnect your coolant lines to the radiator as well as any of the panels and guards around your fan assembly, make sure you take a picture of everything before disconnecting and removing any items. I would highly recommend obtaining a copy of the service book if you are looking for step-by-step procedures. Click on the links I have provided below for some options. I hope you find this information helpful.

Yes I have the service manual from bobcat. I already have the engine out and partially taken apart.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
The bobcat number I have is 7024361 Sorry, that one doesn't cross as easy. There are only several differences that I am aware of in the V3800 blocks. Fuel pump mount and front cover design for one. Would be safest to source a used block from a Bobcat, but with a bit of care no reason another one couldn't work as well.
Thanks for looking. Yeah I have found a few different used blocks online and they all look very similar with only a few differences. Think I have it narrowed down to one or two. Ordered a crank shaft today, just need to find a block now. My local bobcat dealer has been less then helpful, really pushing me to buy a remanufactured engine for it which they quote $31k for just the engine assembly. When I first reached out to them about finding parts they said they haven't had anyone rebuild a motor in over 15 years. I might try reaching out to another bobcat dealer to see if they can help me track down a used block.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
Just to give an update on current progress. I have the old engine all torn apart now. Have received the replacement crank shaft and now just waiting on the block I purchased to come in. Everything looks good on the other parts I removed apart from some scratching on the one piston skirt, probably still usable but going to replace it since I already have it out and will re-ring the other three pistons while I have them out. Camshaft looks good apart from some very light scratching on the center journal point, will just give it a light buffing.
 

Isaac mastin

Member
Joined
Apr 28, 2020
Messages
11
Location
Ontario
Hello, all picked up the brand new block from bobcat yesterday. Was a bit surprised how it was shipped from the warehouse. It was wrapped in a tarp in a box with no oil or anything on the surfaces just fresh metal. Was going over it today and not very impressed considering how much I paid for it. Found a few scratches on the deck and rust in the main gallery going from oil pump to filter. I have attached pictures. Do you all think the scratches will be an issue? They do catch my fingernail and go to the cylinder.
 

Attachments

  • 20240611_150357.jpg
    20240611_150357.jpg
    1.5 MB · Views: 8
  • IMG_20240611_154325.jpg
    IMG_20240611_154325.jpg
    2.5 MB · Views: 8
  • 20240611_150405.jpg
    20240611_150405.jpg
    1.6 MB · Views: 8

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
13,225
Location
Canada
I'd see if the warehouse has another one and have it packaged properly and sent pronto! No way I'd accept that unless it was the last one on the planet at no longer made and they gave a 20% or more discount. I'm sure there would be some customers that would want to throw it back over the counter into the garbage bin. I'm guessing it was several hundred dollars. I ordered an aftermarket drive motor and it came well packaged with form fitting Styrofoam and there were signs it had oil in it. Only thing missing was an o-ring on one of the port caps. Not a big deal because I used one from the old motor. Wouldn't have been a big deal to get an o-ring though. You shouldn't have to polish or get new hyd. components re- surfaced to ensure they don't leak. How is it stored that it gets rust around the dowel pin?? Looking at it again the machining in the 1st. pic. doesn't even look consistent. It's got the scratched look and the bigger scratch but to the left doesn't look machined at all. Where's the quality control?
 
Last edited:

Welder Dave

Senior Member
Joined
Oct 11, 2014
Messages
13,225
Location
Canada
I didn't look back and realize this is an engine block. Maybe it gets machined to final flatness after measurements are made with the head, pistons and head gasket etc.? I'm surprised no one else has commented.
 
Top