Good evening guys. I'd like to start off by saying I've been lurking for years here on HEF and there is always good information lended from the members. Definitely a good community of people willing to share information and I appreciate it ! I'm happy to say I finally joined up, I maybe not be a wealth of information but if I ever can positively contribute I will! Onto my problem, I have got a 83 caterpillar d3b. Had her for three years. I think this problem was pre existing as I talked to a mobile mechanic who worked on it 6 years ago. The call was "no forward or reverse drive" it was very low on transmission fluid is what he found. ( found his # on slips that were provided with dozer. ) I used the machine to level maybe 200 yards of fill the first year and the last two years she's just been sitting around. Debating selling it but I just can't sell it in good faith with the issues it is having. I'd like to identify and fix the issues prior to posting it rather than take a big loss being truthful or hiding it. Once in a while the transmission will froth over from the fill tube. I had the side panels off of the engine bay it's got what appears to be the same as the once in a while transmission overflow leaking out from between the adapter plate and engine it seems. Is there a passage between the two?! My thought is the transmission fluids milky due to a bad radiator, but what gives with the adapter plate/ block joint leak?? To top it off I believe I have a wrist pin knock... listening to 50 YouTube videos half of the 3204's sound like sewing machines the other half sound like mine... you might wonder why I'd bother with a machine in this poor of condition but the undercarriage is all new from the previous owner. full chains and pads and sprockets. and I've repacked 4 of the 5 cylinders so far. Definitely good bones on her
There should be a breather on the transmission. Could it be plugged? What transmission do you have, 3F/1R or 3F/3R? Are you sure the leak at the back of the engine is trans. oil? I had the main hyd. hose coming off the pump and curving up behind the engine spring a leak on my 931B loader version of your D3B. It was odd because it was a 4 wire hose.
3F3R my bad I should have included that! It really appears that it is coming from between the adapter plate and block. I will inspect with a mirror today. Engine oil is clean and stays up though. I appreciate the response Welder Dave.
I was thinking it could possibly be hydraulic oil not engine oil. If it it's trans. oil I'm not sure if a plugged breather would cause that much oil to leak, maybe?
My D3B has a mechanical oil gauge, meaning no wires just a line from motor to gauge. Think it might be the oil gauge tubing?
Having trouble with the "extension "not being accepted with the video. Will post soon. It is definitely coming from the block to trans joint though. Would the radiator heat exchanger put water in the trans ??
Sorry guys youtube link seemed to be the easiest way to post the video. It did not come out for about a minute , I put it in forward and reverse a couple times and it just started to seep out as seen in the video. also, thoughts on the hammering sound? I am thinking wrist pin bushings as it reads good oil pressure.
Block to Trans has a sealed with CAT Green sealant, or at least that's what I used HeavyEquipmentForums
Not sure if that noise is bad, mine is pretty loud and it's been rebuilt
Just thought of something The oil leak is up high, and that should not happen if it's coming between block and bell housing. The oil should never be that high. If it is getting that high then the trans scavenger pump is not able to remove all the oil going into the housing. Check the screen in the trans
Ohhh like the whole bellhousing area is getting flooded ? Is that supposed to be dry? I have heard of a Wet bellhousing but I don't fully understand it's function
Great thread and job you did. Is that machine still in service? And does that rebuilt engine sound as loud as mine ?
The housing should only have a small amount of oil in it when running. It should never be full Yes, still have it and it's noisy, a diesel thing
I Have a 6bt in my bronco I am used to a rattle sounding diesem but Jesus the 3204 in my dozer just sounds terrible to me ! Terrified of it coming apart.
I'll put it this way. I have a Ram diesel, International diesel, 955 diesel, 416 diesel and the D3 is the loudest of all of them. Just talking idle, and have no idea why but it's like a hammer knocking on a steel block You tube is ok, but if it was not this loud before then look into it, otherwise it's probably fine
In operation a small amount of oil is permamently leaking past the rotating seals in the torque converter and finds its way into the converter housing, bell housing, whatever you want to call it. This is normal, unless that is if the converter seals fail in which case the quantity of oil going into the housing is significantly larger. The oil either drains by gravity back to the transmission housing from whence it came, or in some cases has a scavenge pump constantly sucking to keep the converter housing somewhat dry. Many machines have a mesh screen in the bottom of the converter housing (usually built into a pipe fitting on the outlet for the drain) to prevent any larger particles migrating back to the transmission case. Your tractor may or may not have one.
Been awhile but I don't think it has a scavenge pump torque convertor and transmission are the same housing and it gravity feeds back to transmission. The only fix I can see is pull engine and put a new gasket on the flywheel housing. The engine don't sound bad to me they have a loud fuel knock due to being direct injected. You could check the pump timing
Another post i found a member claimed there is a strainer on the bottom under a 4 bolt square cover . I am anxious to pull it up on some blocking and drop that skid pan, see whats going on under there. like all dodge mentioned, That cavity should never be that full (its leaking from maybe 1:00 position looking forward) so somthing is amiss.
Don't get confused between the transmission pump suction strainer/magnetic screen that is located on the side of the transmission case under the aforementioned 4-bolt cover [1] and a small screen literally in a pipe fitting on the torcque convert housing drain line. [1] - the magnets and the suction screen should be removed and inspected/cleaned every time the transmission oil is changed. See the illustration below for the location of the screen and also the two breather, one on the bevel gear housing and the other on the transmission case. If your machine has the 3F/3R transmission it must be either a 27Y or 28Y prefix. I looked at both and cannot see a screen listed in the torque converter drain line anywhere. Final thought - if you do not yet have an Operation & Maintenance Manual yet you should really should get one. They are only about $50 to download a pdf copy and can prove invaluable if you are doing all your own maintenance.
For manuals you could also check out this company who produce the manuals for Cat. In their eBay shop they list all three manuals; O&M, Parts, and Service/Repair. See this LINK and search for "D3B". If you look for a Parts Manual it will depend on the Serial Number. for a 27Y-prefix machine it is SEBP1252, for a 28Y machine it is SEBP1253.
Apologies for getting ya'll side tracked. I looked into my manual and could not find a scavenger pump or drain back. Must be think of one of my other machines With it leaking that high up and engine oil is fine, the only place in my pea brain would be the housing is full and it's coming from the trans
Holy crap you are helpful Nige!! thank you . I am getting the factory CAT book tonight from " northeast equipment manuals in Wakefield NH. Seems he's got a warehouse of antique machinery manuals! it is indeed a 27Y serial. Will add to signature at next opportunity. if i have not got a torque converter drain screen that rules out that being clogged and filling that void.. Maybe my TQ converter seal is bad filling up the cavity. It does pause for a moment before moving the first time you operate it as if the converter is draining. that strainer hidden in the drain line, what you are saying is it appears i DO NOT have one , Just a suction strainer to service correct?
i agree. Something is up because the transmission fluid has erupted from the fill tube before and its all aerated looking.
According to "The Book" you do not have a screen/strainer in the converter housing drain line but if I was you I think I would be pulling apart the fittings that screw into the housing just to take a look. That will probably involve having to remove one or more sections of the belly guard (CAREFUL - they WILL be heavy) and while you're doing that I would suggest to also drain the transmission oil and service the suction screen & magnetic filter, but maybe that's just me being anal. If you do service the suction screen post up sonme photos of the material you find on the magnets and in the mesh of the screen itself. TIP: If you have anything such as old railroad ties handy then get the tractor up on some to give you a little more space to work underneath.
Nige 100% on everything you said !! I'm a "while I'm in here "type also.
Belly pan is 1 piece. 2 bolts underneath at the back and 3 bolts on each side. Take the 2 underneath out first. A small floor jack helps because the pan has to be pulled backwards off the lip of the track frames I beam cross member.
If oil is being aerated, it's getting air in it, it's that simple. Air gets in when oil levels are low and the pump sucks air, or if there's a suction leak in the line to the pump. The D3B's with the 3F/3R transmission utilise a transmission pump that's mounted up on the top left front of the transmission housing. It sucks oil from the bottom of the transmission housing, which is the oil reservoir. There is normally oil in the flywheel housing around the torque converter, this is all one compartment with the transmission housing. There's a magnetic screen in the line to the transmission pump, and oil goes from the pump to the filter at the right top rear of the transmission via oil lines, before the oil is then distributed to the transmission control valve, steering clutch hydraulics and the torque converter. There is an important "ratio valve" in the transmission valve body that controls the amount and pressure of oil going to the torque converter. This ratio valve is designed to limit the level of oil pressure going to the torque converter on startup with cold oil, to prevent TC damage. Once oil pressure reaches the maximum set level at the ratio valve, the oil is dumped back to the transmission reservoir. If the oil cooler in the bottom of the radiator is leaking, it will not aerate the oil, it will simply put coolant into the transmission oil, and you will see milky oil in the transmission. Here is the transmission schematic for the D3B 3F/3R transmission. EDIT - Just went back through the thread and examined the photos and video very closely - and to me, that oil looks like milky oil contaminated with coolant - not aerated oil. I suspect your oil cooler in the bottom of the radiator is shot.
Oz dozer thank you so much for this all. the explanation and diggin up those schematics for me. i truly appreciate your time spent on me. So, My oil is milky water contaminated. I have definitely added coolant more than once. This does seem straight forward. i have a great radiator shop local, they did my case 680 radiator two years ago, new core all hand soldered in bill was 1,050 USD. aftermarked would have been 700 and he said they are of poor quality so i went with the hand made. I will likely do the same this time around . Trans oil has frothed over like a volcano when adding trans oil. This is due to...? low oil, sucking air from the pickup possibly due to the leak at the TOP of my transmission / engine adapter to block joint? (whats seen in the video) so this leaves that to question still, why is the torque converter void seeming to get so full that it leaks from the TOP of that joint? using the machine the first time you go to move it might not grab. shift to N or the opposite direction and back again and it'll act normal unless its sits till cold again. a friend has RR ties. I plan to get this week so maybe over the weekend i can drive it up on them and dump that belly pan off and have a look at the suction strainer under the 4 bolt cover. . I did also get the big CAT manual for the 27Y machines last weekend. Will definately post pictures of findings!