Cat 931C SN 2BJ00191

You might want to see how far back you can get the track adjuster. If the tracks are pretty slack it might be easier to take them off and put back on than pounding the master pin in and out.

Welder Dave said: You might want to see how far back you can get the track adjuster. If the tracks are pretty slack it might be easier to take them off and put back on than pounding the master pin in and out. Click to expand... We are going to try that first this weekend and then switch to the master pin if that doesn't work.

OK, I've spent some time going over this machine, and it seems pretty decent. I'm going to replace the top roller on both sides when I break the track to work on the track adjuster seals. Other than that, the undercarriage is pretty solid. The transmission and brakes\clutches seem to be fine. It has wet brakes, thankfully. The biggest issue it has is blow by (pic below shows some smoke coming from tube). There is a fair amount of smoke coming from the vent tube and out of the oil fill tube, when the cap is removed. It's not the worst I have ever seen, but it's annoying enough that I wouldn't want to run it too long and inhale those fumes, and I don't really want to bother with rerouting the tube as I have seen others do. So, I would like to do some minimal level of in-frame in the coming months. I need input from smart people who have experience with this scenario. Ideally, I would like to replace pistons and rings with a 3-ring option, but I don't want to bore for oversize. I would love to get away with just sticking with OEM bore size and honing cylinder walls in-frame. This machine is on a farm and will have very little use, so I am not looking to spend a lot of money. Assuming the cylinder walls are not badly gouged or out of spec, does my plan pass muster? If so, are there good options, such as IPD, for 3-ring pistons and rings that are OEM spec? Or, should I just go with actual OEM parts for this scenario? Thanks in advance for any feedback or advice!

I think I would clean the breather and give it a good run and see how it is

pittsburgh cat man said: I think I would clean the breather and give it a good run and see how it is Click to expand... Yes sir, that's one of the first things I did. Also, new air filters and new precleaner (old bowl disintegrated). It made little to no difference.

does it have a working hour meter just wondering how many hours on it

pittsburgh cat man said: does it have a working hour meter just wondering how many hours on it Click to expand... Funny you should ask. It has a digital one that wasn't working. I got it working today and the hours were zero'd out. I guess because it didn't have power for a long time. I am guessing it's on the second pair or chains, because the pads look original to me and are in decent condition. The set of chains on it now have plenty of life, I would guess 75%. I would guestimate somewhere north of 6000 hours. What do you think?

I would think you are in the ball park

pittsburgh cat man said: I would think you are in the ball park Click to expand... If it's around 6000 hours, do you think I can get away with doing an in frame and going with new oem spec pistons, rings, and honing, assuming there is no damage to cylinder walls or out of spec?

The 3204 came with 2 ring pistons and are known for blow-by. Some have said it's not even worth doing a blow-by test. It might be wasted money to replace the pistons until you know how much oil it's using and the overall condition of the engine. There's nothing wrong with boring the cylinders if it's done right. Even if the cylinders are good, I think an in-frame rebuild would be next to impossible. You can't remove the oil pan for one thing. If you're doing the pistons you might as well check everything else while it's apart. If it 's not using much oil/smoking and has power I'd just run it. Excessive idling is bad for a 3204! Run it hard and see how it performs.

Welder Dave said: The 3204 came with 2 ring pistons and are known for blow-by. Some have said it's not even worth doing a blow-by test. It might be wasted money to replace the pistons until you know how much oil it's using and the overall condition of the engine. There's nothing wrong with boring the cylinders if it's done right. Even if the cylinders are good, I think an in-frame rebuild would be next to impossible. You can't remove the oil pan for one thing. If you're doing the pistons you might as well check everything else while it's apart. If it 's not using much oil/smoking and has power I'd just run it. Click to expand... Thanks for the feedback. I was under the impression that the oil pan could be dropped while in frame. If not, this project might just have to wait a little longer.

The track cross member is in the way. Engine and trans. have to come out together too. Weigh about 1700lbs.

Unless you need to do work to the trans theres no reason to pull it for engine work. On a loader its a bit tighter but still on a 5 or so hour job to pull it out

Tyler d4c said: Unless you need to do work to the trans theres no reason to pull it for engine work. On a loader its a bit tighter but still on a 5 or so hour job to pull it out View attachment 357563 Click to expand... That machine is looking nice!

Others have mentioned unbolting the crossbar (pic attached) that runs right under the oil pan, and then jacking up the machine to have enough clearance to remove the oil pan and do an in-frame overhaul. Can anyone confirm if they have successfully done this? I took a look today, and it seems feasible.

I think you would be much farther ahead pulling the engine block it up oil pan down pull the head then stand it up on flywheel housing to remove pan and do your pistons and cylinders it will be a lot less aggravation a lot easier on you body and probably quicker and you can probably do a better job of cleaning

Tyler d4c said: Unless you need to do work to the trans theres no reason to pull it for engine work. On a loader its a bit tighter but still on a 5 or so hour job to pull it out View attachment 357563 Click to expand... The loader frame makes it real a PIA. Not that much more work to pull engine and trans. together. Following the Cat procedure helps immensely!

Welder Dave said: The loader frame makes it real a PIA. Not that much more work to pull engine and trans. together. Following the Cat procedure helps immensely! Click to expand... Ive done it eithet way one loaders and dozers dont really make a difference to me

Welder Dave said: You might want to see how far back you can get the track adjuster. If the tracks are pretty slack it might be easier to take them off and put back on than pounding the master pin in and out. Click to expand... FYI, the master pin didn't seem to want to budge, so we were able to push the idler all the way in, and with enough slack in the track, we were able to pull it off to the side far enough that we could then move the idler forward far enough to replace the track adjuster seals.

ksliger said: FYI, the master pin didn't seem to want to budge, so we were able to push the idler all the way in, and with enough slack in the track, we were able to pull it off to the side far enough that we could then move the idler forward far enough to replace the track adjuster seals. Click to expand... See my Post #14 on Page 1.