Start to rebuild my 1980s cat d3 engine today. I had zero Diesel engine rebuild experience so far. Create this thread to record what I did. Spend about 3 hrs today to get engine head pull up. Everyhing went smoothly. Dont have any problems so far. Tomorrow I will start drop oil pan and hopefully to get piston rod out. Since I did not buy rebuild kit yet. I saw some oversize piston ring online. How do I measure what size piston ring do I need？ Is that possible to just change piston rings ？ i am using my machine to clear my 15 arces land. So far have half of the work done.
Do yourself a favour, cover those fuel pumps you don,t want dirt anywhere near them.
Sure do.lol. Thats a good tip. Thanks
The oil pump rides in the front cover and the block does not have removable liners. If the engine is original it likely has two ring pistons , three ring pistons are available and are way to go IMO.
Figure out have to pull engine out from dozer. But not feel comfortable at all to pull engine out by myself. What I ganna do（cry）
Why are you rebuilding it?
Lots of blowby.
If you have a good hoist its not that hard. I pulled mine by myself, only needed the wife to steady it has it went back in Edit: just noticed your using a 4x4 to lift
Using a 4*6 to lift the head. Start to unbolt the console. Have on side 7 bolt out easily with my impact air gun. The last one can not put impact in in very tight space. Try to use wrench, wow. Bolt is damn tight. Only one tube left for console which go under transmission somewhere, guess need to take it off under machine.
It would have been a real good idea to do some research on rebuilding the engine in your D3B and/or asked on here before you started. 3204 does not use liners but can be bored for oversize pistons. If the bores are real bad then they can be over-bored with liners installed. IPD has 3 ring pistons. Cat will have a procedure for pulling the engine and you can probably rent an engine crane to pull the engine out. Have you rebuilt other engines before? The 1st thing I think most people would do is clean the engine as best you can before you start.
Rebuild my honda Trx500 4 wheeler is the only experience... Pressure wash the engine before I started. But found way more dirt in some spot... I can feel the engine block have to be bore oversize. Get couple local phone number from Facebook will call to see how much will they charge to bore oversize, what is the price range usually?
I didn't need to support the tranny when removing the motor, it had its own mounts supporting it along with drive line in rear. Drain the tranny before separating the motor or pulling the starter, the bellhousing is floating in oil from the tranny CAT uses mechanical gauges for tranny and engne temmp, they look like small metal lines.
befor i pulled motor if crank is good you might find some one to bore in frame, they do a lot of cummins in dodge trucks, one machine shop in birngham and one by me i know has a porble boring bar.
Engine has to be pulled. If you're going to do the engine, do the complete engine not a Band-aide repair. Huge difference between a single cylinder quad engine and a 4 cylinder diesel. To have a shop rebuild the engine could be $7000+. Everything needs to be measured and checked and a new oil pump should be installed. I wouldn't think a 3204 would be a first time diesel rebuild.
You can measure the cylinders for inside diameter and out of round just below the carbon area to see how bad they actually are. Use that to make a decision on how far you want to go with the motor. In the photos it doesn't look like you have removed the head gasket. Do that and take some photos of the top of the block and post them here. Those two areas are your indicators of the amount of wear on the block. You should also take some photos of the head before and after you clean it up. The areas by the injector holes and the places where the gaskets seal are the critical areas. Do you have a service manual for the machine and does it have a section on rebuilding the engine?
The "red" head gasket (or is it just loads of red gasket sealer?) shown in the photos doesn't look like a genuine Cat head gasket to me. That would seem to indicate the the engine has been apart before. I wonder why someone but a head back on with so much sealer on the gasket..?
6n8649 is the piston number. Remember the previous owner told me engine was rebuild before. I am trying as fas as I can to get move forward. Looking for mechanic at the same time.
Red is a gasket paper from what I can tell.
More block top pics.
Thanks. I have collected all your info you replied as my service manual
Make sure you have the rods rebuilt 3204s are known for wrist pin bushings wearing out
Thanks. Making progress today. Tomorrow will be able to pull engine out. Guess Will need to get whole front radiator/bumper stuff off first.
Don’t even bother to look what condition the oil pump is in - replace it.
Yes. Is the the oil pump？ I will check the part number get a new one. What I understand the process of next is pull engine out and then get rod/piston out of engine block. Bring block to shop to bore it oversize，buy rebuild kit depend on the how much shop bore it，and move to next step， am I right？
My personal preference would be to have it bored and sleeved back to standard.
IPD has 3 ring pistons up to .040" over. My block only needed to be bored .010" and no problems related to the pistons or bore. Higher compression and starts instantly.
I prefer the sleeves also. Standard sizes always seem to work better for longer.
I wouldn't consider trying to rebuild an engine without a service manual, that is penny wise and pound foolish! Particularly if I had never rebuilt one before!
You got to start somewhere. At least he is learning on his own dollar.
That is the hydraulic pump. The oil pump is under the front cover. It has a wear sleeve that is pressed into the front cover. IMO if this sleeve is not damaged leave it be, often when you remove it the replacement sleeve has a tendency to spin in it's bore.
^^^Agree Your pic in post 24 is the hydraulic pump. Just leave it to the side, your able to remove the motor without disconnecting lines.
Making progress but not lot. Starter almost pull out. Front off. On my second picture don’t know if the bolt and chain will pull the engine out?
I'd remove the dipstick tube before moving, it might get flattened if it bumps into something
Yippee!!....I’ve been waiting for a thread like this for sooooooo long.
Lol. I am struggling in the process to get the 300 dollar manual
Thanks. Will do. Since the starter in its way，is that tube screw in？ All transmission bolts r off. Two engine mount bolts off. 3 little birds r waiting food from mom.
I think its just pushed in there if memory serves The one bolt on the starter next to the frame is Be-ouch to get out. I used a boxed end wrench from under the motor and was able to move one point and a time. Just barely enough room.
A stubby wrench might work on the one starter bolt as well but the starter should be able to stay in if you lift straight up. I don't remember having to pull the starter on my 931B loader which is worse than the dozer. Engine and trans. have to come out together on a loader. On reassembly leave the oil filter off or it will get dented. You pulled the head off, otherwise there should be lifting hooks on the engine.