cat D343 questions

Talonewo · May 21, 2016

Long story short I bought my boat from an estate and had had no handoff from the previous owner, what you see is what you get type deal.

I have several questions about the engine, a CAT D343AT. I found a nice Cat mechanic (non marine guy) on line who offered to help so I made the attached video and put on YouTube, he was not able to help much as most of my questions are marine specific. Check out the video.

https://youtu.be/lt5nTgrCGw0

Three main questions, glow plugs(can't find wires or switches), the two electrical boxes on the forward port side of the engine and PTO take off for a hydraulic pump.

I'll take any help I can get.

Thanks

Joel

sunchaser · May 21, 2016

Joel

Assuming the 343 parts you are looking for are cat originals they should still be available. If marinized by an out of business non Cat shop it can indeed get difficult. With engine serial number in hand contact Dave on boatdiesel. Have you gone to your local Cat off road equipment dealer in TX?

Ski in NC · May 21, 2016

343 glow plugs are inside the rocker box screwed into the combustion chamber between the valves. Can't remember how the wires come out of the box. Look around rocker box for wires coming out. Or take rocker box cover off and take a looksie. One of those relays in the vid is probably for gp's, the other for starter. Just guessing there.

Somewhere I remember that 343 went to direct injection later in production run, but memory is super foggy there. Maybe that was when they went to the 3406????

BIG CAT · May 24, 2016

The 2 boxs are a time delay relay box for energized to stop fuel systems. The other box ( big one) is the over speed box. There is a 75% verify button on it for testing the over speed. That box also handles crank termination and oil speed step if it was a generator app. You will want to get a book to keep on hand. Any cat dealer can order it for you but be prepared to wait. Even as a tech for a dealer it take for ever to get them. I can look at my files and see if i have it in pdf. As for the glow plugs. Iirc they screw into the top of the precombustion chamber. If you pull a valve cover follow the injection line to the head. It will screw into what looks like a round piece of solid metal. The glow plug would threaded in the adapter. Wiring shouldbe coming out of the spacer between the valve. Cover and head.

BIG CAT · May 25, 2016

BIG CAT said:
The 2 boxs are a time delay relay box for energized to stop fuel systems. The other box ( big one) is the over speed box. There is a 75% verify button on it for testing the over speed. That box also handles crank termination and oil speed step if it was a generator app. You will want to get a book to keep on hand. Any cat dealer can order it for you but be prepared to wait. Even as a tech for a dealer it take for ever to get them. I can look at my files and see if i have it in pdf. As for the glow plugs. Iirc they screw into the top of the precombustion chamber. If you pull a valve cover follow the injection line to the head. It will screw into what looks like a round piece of solid metal. The glow plug would threaded in the adapter. Wiring shouldbe coming out of the spacer between the valve. Cover and head.

Ok i do have to manuals in pdf if you want them. I just need your email.

kulas44 · May 25, 2016

BIG CAT, you da man. It warms my heart to see acts of kindness like this. Great forum.

Talonewo · May 26, 2016

Thanks Much Big CAT, I really appreciate the help. I sent you a PM with my email if you could send the pdf that would be great.

I look forward to reading about those two boxes, I don't like not knowing what stuff is... what I'm most concerned with is routine maintenance, I don't want to have costly repairs due to my ignorance of not performing routine maintenance. I understand the basics; make sure I have clean fuel, clean oil and plenty of coolant... other than that not sure what I need to do to keep this engine running for ever.

As for the glow plugs, what is a typical setup on a marine D343? would there be a separate switch for the glowplugs or would it be something like my ford F-250 with the old 7.3 diesel, you turn on the ignition switch and then wait for the light to go out before you start... on the boat would turn the key on wait for some time before you attempt to start? Being in the south it rarely gets cold enough to need them... the one time I needed to start it when it was cold I used starting fluid, a small spray in the air cleaner and it fired right up, is that bad for the engine?

Will the pdf you are sending have any info about the power take off points for this engine? Like I said I would like to install a PTO hydraulic pump. I have to assume in its other uses in bulldozers and graders this engine had the option for a PTO hydraulic pump.

BIG CAT · May 27, 2016

Talonewo said:
Thanks Much Big CAT, I really appreciate the help. I sent you a PM with my email if you could send the pdf that would be great.

I look forward to reading about those two boxes, I don't like not knowing what stuff is... what I'm most concerned with is routine maintenance, I don't want to have costly repairs due to my ignorance of not performing routine maintenance. I understand the basics; make sure I have clean fuel, clean oil and plenty of coolant... other than that not sure what I need to do to keep this engine running for ever.

As for the glow plugs, what is a typical setup on a marine D343? would there be a separate switch for the glowplugs or would it be something like my ford F-250 with the old 7.3 diesel, you turn on the ignition switch and then wait for the light to go out before you start... on the boat would turn the key on wait for some time before you attempt to start? Being in the south it rarely gets cold enough to need them... the one time I needed to start it when it was cold I used starting fluid, a small spray in the air cleaner and it fired right up, is that bad for the engine?

Will the pdf you are sending have any info about the power take off points for this engine? Like I said I would like to install a PTO hydraulic pump. I have to assume in its other uses in bulldozers and graders this engine had the option for a PTO hydraulic pump.

Can you send it again. i didn't get it.

i will answer your questions tonight. (heading out the door to a hosp. job.)

Talonewo · May 27, 2016

Here is my email;

joel@mc130.com

Thanks again.

Joel

BIG CAT · May 28, 2016

Talonewo said:
Thanks Much Big CAT, I really appreciate the help. I sent you a PM with my email if you could send the pdf that would be great.

I look forward to reading about those two boxes, I don't like not knowing what stuff is... what I'm most concerned with is routine maintenance, I don't want to have costly repairs due to my ignorance of not performing routine maintenance. I understand the basics; make sure I have clean fuel, clean oil and plenty of coolant... other than that not sure what I need to do to keep this engine running for ever.

As for the glow plugs, what is a typical setup on a marine D343? would there be a separate switch for the glowplugs or would it be something like my ford F-250 with the old 7.3 diesel, you turn on the ignition switch and then wait for the light to go out before you start... on the boat would turn the key on wait for some time before you attempt to start? Being in the south it rarely gets cold enough to need them... the one time I needed to start it when it was cold I used starting fluid, a small spray in the air cleaner and it fired right up, is that bad for the engine?

Will the pdf you are sending have any info about the power take off points for this engine? Like I said I would like to install a PTO hydraulic pump. I have to assume in its other uses in bulldozers and graders this engine had the option for a PTO hydraulic pump.

ok. i sent you a couple emails with pdf's that should answer most of your questions. the only thing i need to look into further is the pto. i looked at the parts break down and it shows a driver asy that looks like it bolts to the front of the engine. there was also mention of a aux drive. so before giving you some bad info i want to check with some old timers for clarification.

Talonewo · May 28, 2016

Thanks much Big Cat, I received the emails and the 5 pdf documents, exactly what I was looking for. I'm sure once I read through them I will have more questions, hope you don't mind. I'm looking forward to what the old timers will have to say, while looking around on line I saw a picture of a marine D343 with a pulley(forward) and sprocket(aft) mounted in that spot I pointed to in the video just below the oil breather, put that together with the auxiliary drive document you sent and I think I understand. Thanks again.

Talonewo · May 28, 2016

here is the pic, you can see the pulley and sprocket

BIG CAT · May 28, 2016

Talonewo said:
here is the pic, you can see the pulley and sprocket

Hmm. The one part i was looking at bolts to the front bell housing and the other looks different. But seeing the drive pulley in the pic. I would think that you would be able to drive a pump off it within reason.

BIG CAT · May 31, 2016

ok finally got a little time to do some digging. the engine in the pic with the belt drive is an industrial engine. the parts would fit if you could find them. i checked availability and most of the major components have been discontinued. so the only way you can get that aux drive would be to find a used one and hope its got a good and housing. as best i can tell all the seals,bearings and gaskets are still serviced so you could rebuild it if you can find one. the other thing you might want to check into is the marine gear. some of the ones i have seen have pto provisions.

zermenojl · Jul 18, 2018

PDF documents

BIG CAT said:
Ok i do have to manuals in pdf if you want them. I just need your email.

Is possible for you to share those pdf files with me ?
J_wicho@yahoo.com

Thanks

BIG CAT · Jul 18, 2018

zermenojl said:
Is possible for you to share those pdf files with me ?
J_wicho@yahoo.com

Thanks

Sure can. I'll try to get them out tomorrow when I get to the shop.

ab_gear · Feb 4, 2020

Service manual

Can anyone help me with the service manuals for Caterpillar D343 in electronic format ?

pkirkll · Aug 8, 2021

would it be something like my ford F-250 with the old 7.3 diesel, you turn on the ignition switch and then wait for the light to go out before you start..

I have a two position thumb switch on my D343--- on the strbd side about 3/4 way back it has to be depressed and then turned to the left for 30-45 seconds--- then back opposite to engage the starter.... idle on mine usually is rev up a tiny bit to get her purring--

Mine has two hydraulics pumps forward of the bell housing that operate the hoist, 3' bow thruster, and other hydraulics like pot puller, etc.

Cape Mark - 1943 Seiner 80'-BC

pkirkll · Aug 8, 2021

manuals

ab_gear said:
Can anyone help me with the service manuals for Caterpillar D343 in electronic format ?

https://www.jensales.com/products/caterpillar-engine-service-manual-ct-s-eng-d343.html

pkirkll · Aug 8, 2021

I just realized this post is older than me.....!!!

cat D343 questions

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