Cat 931b engine removal

[msllc]

Hey guys!! My name is RYAN.

Quick introduction: I am new to this site, but not to wrenching. I have removed transmissions from CAT D-6 HI-STAT dozers, replaced worn out steer clutches on a non-HY-STAT D-5 dozers, removed / installed fuel injection pumps, replaced tracks, rollers & sprocket segments on several dozers / tractors. I am a professional automotive, diesel, equipment & heavy equipment mechanic with 18 years of viable experience. I like to repair old machinery for the very obvious upfront cost savings. I also like the completion of a huge project, too. I have a bunch of other machinery (bobcats & forklifts) that I can use to almost everything. I am not a guy that is afraid to spend money on repairing things correctly.

Scenario at hand: I bought a CAT 931B (with 4,000 hours) for $3,000 this past June (2015) from a guy that let it sit for way too long with an open vertical exhaust pipe. To say the very least, the engine was seized up due to rust that formed between piston number 3 & the cylinder liner. Cylinder number 4 was also rusted in place, but not nearly as badly. I went ahead & moved the very heavy DEAD loader to a shop & tore the engine down to the block to be able to inspect the bores for repair. Now that I have done all of that, I need to remove the engine block for cutting of the old / damaged liners from the block. BTW, I have already bought the engine rebuild kit (pistons, liners, bearings, gaskets, etc.) for the re-assembly of this engine once ready. So, that is where I feel 'stuck' because the bell-housing bolts are close to impossible to reach, even with the floor plates removed. So, I am stuck thinking that the transmission & the engine may have to be removed as one unit. Am I right?? I have a few other small doubts, but that is my huge hang up right now. Can anyone help me get this beast back to life?? Can you help me locate a repair service manual for this loader online somewhere??

Thank you (in advance) for the help, advice & guidance.

 

[Cmark]

Can't say for sure without a serial number but it looks as though you have to remove the engine and tranny as a unit and then separate them on the floor.

 

[msllc]

Sorry, I forgot to include that. I am thinking you are right about removing the engine & trans. together. I have several other questions about what type of fluid goes inside of the bell housing? Does that fluid fill itself as the engine runs, or do I add fluid to it, just like filling the beveled gear fluid?? That's the small stuff that has me 'stuck' / hesitant to continue on. The serial number is 29Y02217 & I am pretty sure the year is 1987. Do you know of any on-line service manuals that can help illustrate the job a little bit?? I will try to post a few pictures of it together (when I first got it), then it loaded up on a trailer, then of it inside the shop & then with the engine torn apart. This is a huge undertaking for me. I don't have the 40 hours a week to work on it, like I had at other jobs. I also have to float the bill all by myself, versus an employer taking care of that, too.

 

[msllc]

 

[msllc]

These are the pictures that I have of my little darling!! I've yet to be able to take good pictures of the inside of the cylinders # 3 & 4, but there is some significant pitting of the steel liners. I cleaned up all four holes with a bottle brush / flex hone. The first two holes cleaned up great, but trouble is the other two.

 

[msllc]

Also, not to overwhelm anyone, but is there anything I can do with / to the transmission while is out? Is there anything I should be looking for condition wise? What would you guys do? I bought this loader as an inoperative, so I have no clue what is good or bad!

 

[old-iron-habit]

Admittedly I have not seen everything but I have never seen loader safety supports installed like you did.It seems to be that the leverage required to hold from that low of a point might push the cylinder barrel out of round or split your block. I would cut a couple of pieces of angle iron and wire over the rod section of the cylinders effectivly holding the cylinders from retracting. Then you would have a positive lock with no stress where it is not intended to be.

EDIT: OOPS, I went back and looked again and in the first picture I seen chains from the canopy holding the loader up. Now I feel better.

 

[Nige]

If you have the 3F/1R powershift transmission on your machine the engine & transmission come out as a unit and are split once out of the machine. If you want a copy of the procedure then drop me a PM with your email address.

 

[sealark37]

I have had good luck finding the older service manuals on Ebay. Good Luck, and Regards, Clark

 

[msllc]

Hey Old-Iron-Habit,
I assure you that we have (3) three 1/2" chains (that are 16 feet long & they are wrapped around the canopy & lifting arms several times) on the lifting arms & another 3" strap holding the bucket from curling / dumping forward. The chains are brand new & so are the chain binders are, too. The bucket has been up in the air (that way) since this past July.

Hey Nige,
Thanks for the offer of the removal procedure. It would be a great help to have it. I did PM you with my email address. Thanks, again.

 

[Welder Dave]

29Y is a 3 forward/3 reverse transmission but I believe it comes out complete with engine as well. My 931B is a 25Y which is 3F/1R transmission. The 3F/1R has a screen while the 3F/3R has a filter. On my machine they said it was a good sign that the screen was clean. Black flakes indicate the clutches are going. Checking the filter would be a good start. A 3204 doesn't have liners but can be bored out. If really bad can be bored and sleeved. The better set up when rebuilding is to put 3 ring(IPD) pistons in because Cat only offers 2 ring pistons and 3204's are known for lots of blow by.

 

[msllc]

Yes, it does have 3 forward positions & 3 reverse positions, too. (Does that change the transmission model number / name?) Except for the bell-housing bolts, I am very close to having it apart. I need a week to re-focus on that project before I try anything more on it.

I could use a diagram of the timing gear marks behind the front cover. If I had that, I think I could remove the front cover to verify the marks, then tear it completely down & take the block to the machine shop for liner removal, press work & boring to fit the new pistons. I will be posting pictures as I get each of those events done.

Any ideas of how to check out the transmission while it is on the ground? Is there anything that I can do to take care of common / known problems??

 

[msllc]

Welder Dave,

I heard that a whole lot when I ordered the rebuild kit by serial number & model number. I am not 100% sure if it does, or it does not. I keep thinking that I could feel a tiny edge / rise when I dragged a plastic scraper across the deck. If I remember right, there are liners in this block. I am certain that # 3 & 4 cylinders need love. I got four liners. Hopefully a good machine shop can cut out the old or cut the old bores to accept the new liners. I have no real idea how that will work out. After all of the research that I have done, I really fortunate that my block is still re-buildable; so I think!!!! I need this block torn apart & sitting on a machinists table for inspection. I can not wait to get this part of the project behind me. It won't speed me up to the point of being reckless, but I am getting more & more motivated as the weeks tick on by. I am sure that it'll need brake work or steer clutch repair, but just running is a huge feat with in itself.

All,

The other issue with this machine is that some dumbie left the fuel cap off the fuel tank for a very long time, I guess they might have lost it. So the fuel tank needs to be cleaned thoroughly in order to ever use it again. Can anyone talk me through what needs to be done with that tank??

 

[msllc]

looking at selling this loader with all parts that I have removed & a complete engine rebuild kit. Looking for around $5k for the entire machine. Tracks look great.

 

[Welder Dave]

3204's didn't come with liners and were bored out when rebuilding. Liners could be installed if boring needs to go more than .040 over. How come you aren't going to fix it yourself? 5K might be hard if it's all in pieces.

 

[sealark37]

Your trailer will be glad to see the last of that machine. Regards, Clark

 

[Nige]

looking at selling this loader with all parts that I have removed & a complete engine rebuild kit. Looking for around $5k for the entire machine. Tracks look great.

Considering the state it's in right now (engine disassembled) and the previous history you have posted here it's only worth scrap price of about 5.5c/lb IMHO. So that makes the whole machine worth about $850. Consider anything you get above and beyond that as a bonus.

 

[wosama931b]

To bad you don't want to fix the motor, and I know that it's expensive to fix.
I have a 29 Y also and have done a lot of work with the small cat. Sam.

 

[msllc]

I really don't have a need for this machine, so keeping it doesn't make too much sense. However, I bought it to repair. I feel too anxious to repair it, given the condition of the block on cylinder # 3 & # 4 They is a good deal of pitting in those cylinders to the point that I know the piston rings would never last, much less seal the piston to the cylinder walls. I'd like to see it up & running one day, but it seems like I will be into even more work to remove the engine, haul it to a cooperating machine shop, have them recondition what needs to be done, then haul it back, re-install it. I am not sure that I will be able to devote all of the time that it may need.

As far as the asking price of $5,000.....that is about a little less than what I have into the machine, new battery, rebuild kit & so on. I think it is a good number. I think I can sell a lot of parts off of it & make quite a bit of money pretty quickly, but I thought it could help someone if they bought it, even if it is in pieces. I think a more experienced / better funded mechanic would be best in this case. I could finish this project up, but I would rather sell it at this point.

Can anyone tell me what it might cost to bore out two cylinders to accept new liners, then bore / hone them out to accept the new pistons?? I basically have to bore them out as I have already bought the rebuild kit. Maybe that might help me feel less anxious to the point of keeping it.

 

[msllc]

OH MAN!! I sold that trailer last December. It was pretty intense to load that "dead dozer" onto that trailer with just a winch & a BOBCAT 863. The area where it was parked, PLUS the random piles of cured concrete piles interfering with any logical recovery technic made it even more difficult to load onto that trailer. I was quoted $500 an hour to have a towing company even try to help with it. I ended up using that FOUR TIRE 14K pound trailer to move it as a last resort. Just moving this machine was close to a nightmare. I was happy to sell that trailer, even though it was not damaged by being over-loaded during it's very slow 30 mph drive back to the farm with it in tow.