The Cat 3406B Engine. Know Your Engine. Caterpillar 3406 Information And History. 

Do you still work on the B models?

Can u tell me why when I turn on my cat 3406b make like a noise that he want to turn off and u have to accelerate???

@@janiersuarez9485 mine does the same when I, too, turn mine on. I place a weight on the accelerator pedal (mallet) to rev it to 700-1000 rpm. After a few minutes if you take ig off it stays at 700. I just thought it was a mechanical(b) thing

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What year was the last B made? And what are the best options to turn up a C? I bought a 3406 and told it was a B but now I think that it’s actually a C

I'm 27 years old and I know exactly what you mean. I grew up around tractors of this era. I can still remember the scene in my head of my old man rowing through the 18 speed late at night and counting down the days until I could take my CDL test. Those were the days.

@@joepellish5380 trucks are far quieter now but a Volvo D13, DD15, ISX15 and MX13 all sound very different

Arguably the best sounding diesel engine ever made is a two stroke Detroit, probably the 12v92 specifically

@@bruni5289 And they are heavy leaky gutless wonders, The best place for a 2 stroke Detroit is sitting at the bottom of the ocean still attached to the boat hull that it once powered.

@@longliner205a4 a 12v92TTA puts out ~700 horse and ~2,000 lb-ft of torque with a dry weight of ~4,000 pounds. A 3406 weighs 6,000 pounds. Two stroke Detroits are much better than mechanical CATs

+Edward Baker Pulling 600hp you probably never have to shift, just roll out in 4th from a light then upshift to 8th and good to go lol.

Edward Baker just buy the 3406b model And I got injection Palm bleak I planning to do re build can you give me a number or where where you did your pump. plz. My number is 7632736456

The one I ran was lo3, lo5, hi3 and hI5. Did NOT know what a load was. SCARY pulling, like the old Mack Hi-torque rise. Just wouldn't quit.

Edward Baker lol my dad has one in his 92 freightliner with stock pump ,injectors and turbo doing 630hp no fuel adjusted on the pump either all he did is time and set valves to his spec and put a custom exhaust manifold on it and he has a 70hp propane kit was dino tested at 700hp

What size nozzles you using ?

What about ones with PEEC?

@@SOU6900 People don't understand PEEC and they have a problem.

I'll second that!!

It's the first engine I got certified on, I loved em except for that stupid oil pan gasket.

So dont buy one unless this work is completed on them

@@natemofield281 easy.... Get a couple tubes of Permatex's 'The Right Stuff' & NEVER worry about another oil leak!!! 😂 BUUUUUT you BETTER have a box of razor blades, thin wedges & a good 1lb 🔨 if you wanna disassemble it again!!! 🤣🤣🤣

In Australia, the 7FB was prior to the 4MG and the 8TC was the beginning of the PEEC engine. Specialised in these motors for 10 years and still have yellow blood going through me, soo much so, my son is now a cat mechanic

Which 3406 has the best reliability and fuel mileage? I'm thinking of getting the B, but have heard good things about the E.

Do you still work on these motors

How much are those 88 going for ?

joe blow more common than a Cummins up here man

They are some bad motors I got one in my truck shit that joker got over million miles on it and still run like a top and will pull her ass off yes sir

I live in Michigan as well, with Michigan being one of the last heavy haul states I think these engines will be around for a long time. 3406 engines hold up better than most.

Do you happen to know of a reputable B model mechanic?? I live in MI also.

@@derichsimmons3798 The governor on the 3406B I drove went out a few (5?) years ago. We took it to citywide truck and crane in wixom MI. They charge for their work but they are the best around. They had(have still?) a guy that cut his teeth on them in the early 90's. Very knowledgeable guy, very personable. The 3406B governor is supposed to be dynoed to be properly set-up. It also requires some special tools. This guy did it with experience and seat of the pants. Truck ran the best it ever did afterwards. We asked MI CAT about repairing it before going to citywide and we think we heard crickets on the other end of the phone...

Mechanical engines smoke end of story

@@dennisaldrich536 : What rot. Smoke means incompletely burnt fuel, which means excessive fuel consumption. Since, in the applications these engines are designed for, and the operational life they typically attain, the cost of fuel is by far the major cost of an engine over its life. Hence, most users will not accept smoking.

+Jim Zivny I'm very comfortable with the electronic engines, and I'm trying to get into the mechanical pumps, but don't have a seasoned guy in the shop to show me the works. Gonna have to learn on my own.

Put your hand on every pump manual you come across.....lots of critical numbers and running changes and what worked....also don't use any "new old stock" fuel system parts....remember how many times they took sulfur out of diesel in the last 25 years! They won't last a month

They are called scroll fuel systems. Like rolling a paper scroll open. The helix on the pump determines how much fuel is metered into the cylinder. You have a fill port and a spill port. Just think of rack and pinion. As the rack moves all the pumps move the same. As the rack opens up, it increases the angle of the helix (more). As the fuel cam lift's each pump, with the increased angle, takes longer to reach the spill port. So going up a hill engine speed slows down due to load. Flyweights in the gov. slows down. Spring force becomes stronger allowing rack to move into the full on position. Which increases angle of helix, taking a longer stroke on each injection pump to reach spill port, thus more fuel on the piston. Going over the hill, flyweight speed increases. Now flyweights are stronger than spring force. Pulling rack back, reducing angle of helix. Now on each injection cycle less stroke is now available to spill port, thus reducing amount of fuel metered onto the piston. Sleeve metering is about the same except you have a sleeve riding up and down on each pump. As the sleeve is moved up or down determines a longer or shorter stroke to reach the spill port.

+Steve Mitchell Thanks for watching.

Autocar trucks are a beast anyway, they make 9400i naviturds crap their pants

Are the 3406B is a good engine I would like to know I’m looking to purchase one

@@dankdouglas2306 just look at all the comments from drivers & mechanics that love them to this day. I've driven plenty & they were all great runners. And you can build them up to push big power very reliably. Emissions might be a problem in some states..... at least California.

I'm running a 3406c serial# 5KJ08745 mechanical pump its in an 85 w900b. Not the original engine though. Tag says its only 400 horse. Its a little sluggish. Ive turned the fuel up but it needs timing advanced and bigger turbo. No aftercooler on the 85 kw either

@@jeremydavis6133 Serial number is a 400 HP @ 2100 RPM's. FRC has a lot to do being sluggish. If your not in a emissions area. You can take the line off and put a cap on it. Remove the FRC and install a plate. VTU is know to slip and this engine has no fix. You can buy a reman carrier and over time it will start slipping again. I have seen people weld a spot between the snap ring onto both parts. When you do this the carrier will not be a good core. SIS shows this to be a JWAC aftercooler. The fuel pumps are known to bypass fuel, not giving a full injection. Sometimes they will stumble on acceleration. You can lap the pumps, install new bushings and bonnets. With that old of a engine the pumps are more than likely worn out anyway. I have never seen a 5KJ 3406C model. Cat offered a 350 HP, 1800 or 2100, 400 HP 1800 or 2100, 425 HP 1800 or 2100, also these in CARB (emissions BS) and the big one a 515 HP. Only three of these was built and you have to have a high torque transmission and clutch. Do not know if you get all the parts for the 515.

@@johngoldsmith6629 im not an expert i dont know what the VTU or JWAC stuff is. I just know I love the 3406 but this one doesn't pull anything like the last b model I drove that had a big turbo and pump advanced. The 85 kw has no air to air cooler. This truck had a b model and when it died they bought this c model as a new complete crate from what I understand and just set the whole thing in. Shortly after the guy died and it set in a barn for a decade or more before my boss bought it cause I told him I wanted it. The motor and everything is pretty fresh I think he even has paperwork on it. Ive put a little over 100,000 miles on it. I think it may have a water cooled intake. Its got a pipe from the oil cooler area that comes around and goes into front of intake but I dont recall ever seeing that on any other 3406 so idk what it is. It has the 12 point head bolts

@@jeremydavis6133 A JWAC is a jacket water aftercooler. The pipe off the turbo goes over the valve cover to the intake. Inside is a core that is cooled by water. Bad thing is the air temp can only cool down to coolant temp. While a ATAAC, air to air aftercooler, uses ram ambient air gets the air temp even lower. Thus more air you can pack in the cylinder. VTU is variable timing unit. The 3406 92U, now called A model used a slide advance. You could adjust the pin timing, but the advance would start and stop by spring force. No real adjustment. When the 7FB's came out Cat improved the timing system. You now have static timing (pin timing). Start of advance screw and end of advance screw. You have to use the timing indicator group and you can dial in the timing. However had some problems and few recalls. Race wears, bolts came loose, big spring would wear or break, quad seals would blow out. The major one is the carrier is three pieces. Pressed in and held with a snap ring. Over time the inner piece would get loose and as the engine was running. The inner piece was going slower as it was slipping, causing the engine not to have proper advance for the speed. This carried over into the 4MG's and it was a major problem on that series. The 4MG's had numerous recalls on the VTU. Since it was current production at the time. Cat repaired the carrier and made it thread into itself. But the 7FB style never got the fix. Looking at SIS, you VTU is the 7FB style. So it is possible that your carrier can run slower then actual engine speed, so your VTU may not be advanced as it should. And with this style it is harder to know over the 4MG's. The darn thing has a shield over it. Cat put some timing marks on the inside on reman's so you know they have slipped. You have to take it apart to see them. Sometimes you can use a small pick and try and see if the inner carrier will move without removing it.

@@johngoldsmith6629 ok yeah its the JWAC I didnt realize cat ever used that. I just thought it wasn't cooled. But yeah the Pyro runs a little warm I gotta watch it and sometimes back off and drop a gear. It is pretty tall geared though with a 15 over,355 rears and tall 24s. Under 1500rpm it builds too much heat. The VTU you're talking about must the under the cone cover. It was really a slug when I got in it and a shop said they replaced the timing advance thing but I didn't notice any difference. About 2 weeks later it came apart and punched a hole in the cone cover. It still didn't run any different with the hole in it. Boss put a new timing advance thing and cone cover on it and it still didn't run any different. Thats when I backed the fuel screws out one turn at a time and drove it. I ended up with both pump screws 3 turns out from where it was. Its helped alot I'm out of turbo now it won't spin any harder so more fuel is not gonna help. But its still just not snappy like it should be. What is the FRC thing you mentioned? I'm in Sw Missouri we don't do emissions. Also I thought I could have the pump timing advanced by pinning the pump and rolling the motor back a hair to get pump half a hole off. Is that not possible on this motor? Thanks for all your info

Hey guys can someone tell me where to install the oil pressure port for a mechanical gauge on my 3406b

+Jason McKee California really hates every engine pre 2010, which I'm sure the was influenced by the truck manufacturers to push people into new trucks. I get your joke sir lol. Most other states don't seem to mind the older engines though.

Gotlotsodirt unfortunately all new trucks have that eyesore badge “certified california clean idle”, seems like any new truck that isn’t even remotely close to that state or has not even been within a thousand miles from there has to fit that retarded standard

Best of luck in your new home!

@@AdeptApe Yep. The stupidity and tree-hugging bureaucracy is really bad in Cali. The 2010 engine mandate has helped the pollution issue in Cali, but overall they're shoving their own problems up other people's a$$es.

3306 started off as a 1673 basically also had a B and C version, 3306, 3306B, 3306C.

The 3306 and 3304 were absolutely BULLET PROOF none rebuilt so many for CRC engine shop forgot the number. I built one that came in with more than 30,000 -yes 30,000 hours. Number 1 cylinder hadn't fired for some time - a water pump for dust control Las Vegas.

@@johngoldsmith6629 I had a 1673 (C ?) in my 1st truck; 1966 International CO 4000 that I bought in 1976. 245 hp. R96 10 speed . ... . I had 4 1693's . . . Good ol' engines . .. ...

@@paulfisher6142 The 1600 series was mostly refereed as Clatapillars. Sound like a bunch of loose bolts running. Lasted forever, fuel mileage sucked, but fuel was cheap. I have never seen or worked on a 1676 in a truck. The few 1673C's I seen was 76R prefix. Worked on two if I recall, they was almost gone when I started. One 1673 or 1673B came in I think, I asked to work on it, got turned down.

+Steve Ross A 3406 shouldn't be going over 2100 rpm really, most of the 3406E and C15 are governed there it seems. One of the B models in the shop doesn't smoke at all, even revving it, I've never seen that before on one of these. You are right that it is possible, but most of them smoke at least a little.

As Josh mentioned, the 3406B's were manufactured with nozzles, and those components are not the best for atomizing the fuel charge, thus, the black smoke.

Adept Ape totally agree. I had a B model in an 85 KW W900 and the guy who worked on it was an old timer that had pretty good hands when it came to tuning them. If I were to do another one, I would rebuild it with parts from IPD ( they offer an upgraded piston and liner combo plus other fixes ) make sure the bottom end is balanced and blueprinted and put the liner protrusion at the high end of spec.

NOTHING will rev like a V8 Mack

Liner protrusion is a weakness..... counter boring is a must

The difference between an engine and a motor is actually a big controversial subject, but if you say an engine everyone knows what you are talking about.

1958johndeere620 you had me at Autocar...... was it an A64 ( I think that was the street model ) or a vocational model?

I honestly don't remember. It was the regular front axle, not the model where the front was slightly back. I have a 97 one now but that has the volvo engine. Looking at the models I would say it was the acl64. It had the 8ll but an overdrive shift pattern.

Could add a brake saver but probably way to expensive 🤷‍♂️

@@40KRK what's a brake saver?

Which Cummings motor was it?

Yes def didn't like being turned down. I drove 7 axle dump/ pup set ups with them & when turned down... forget about it. Shit fuel mileage & miserable to pull around 98,000+lbs with. Turned up tho.... pleasure!

Magnum Johnson Thank you sir.

Other CAT engines use a puzzle gaskets, such as 3304's which were smaller.

Always use something on the joints of the gaskets will seep if you don't.

Why they never went to larger studs like the 1693 was totally beyond me. I developed many inventive ways to remove broken studs, Cat even had a line up tool to drill them out-had one.

I have an A model in my 359 its not original the previous owner removed the B and put an A in it for whatever reason and im trying to find out all i can about it but im not having much luck online. Ive heard you can do a timing advance and go with a C model turbo and get somewhere around 515hp but but i cant find the info on how to do it.

Matt Pamp it would take a steel hauler to not spell peterbilt right

It was probably the autocorrect on his phone 📱

Sweat equity i can spell it any way i want

@@mattpamp8204 You tell em, Matt

These was a 360 HP used a T18 turbo off a 1693. The major problem was not the spacer plate change. But removing asbestos from the gasket. Did not have a handle on that. The aluminum spacer plate just accelerated the failure. The original engines lubed the rocker arms via the head bolts. A lot of oil in the cooling system failures. Block and cylinder head was redesigned with a oil dowel in block and a hole in the cylinder head. I had one years ago someone put a earlier head (no holes) on a dowel block. Thus the rocker arms failed due to no oil supply.