Another FJ62 OM606 swap thread

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Joined
Nov 11, 2024
Threads
5
Messages
105
Location
Austin TX
I thought id start a thread on here in case my limited knowledge helps someone down the road. Ill start with a little background on my rig and lead into the swap info:

I purchased this truck in September of 2024. I found it locally in Austin TX from a coworker's husband who owned it for the last 22 years (only driven 40k miles in 22 years but had 171k on the odometer). The previous owner had a binder of receipts for all the service it in its life and was truly a rust free truck. Even the C-Channels look brand new which was crazy. I had looked at several different 60 series over the years but they were all too rough for the asking price. The truck came with an OME lift, ARB front bumper, and custom rear swingout.

One of the first things I did was scrape the roof rain channel clean down to bare metal and re-sealed it with 3m seam sealer and had the roof repainted. The old seam sealer was old and cracking but luckily had been garage kept so no rust issues were noted. I also baselined all the fluids, found a radiator leak, replaced that along with all the rad hoses. Desmogged it, changed plugs, wires, cap, and rotor. The plan was to drive it as is for a few years to determine next steps. I always intended on motor swapping it, just had hoped to get more miles out of the stock 3fe. But so far so good, no major issues and had been pretty reliable driving around town. I decided this would be my new daily driver as it put a smile on my face everywhere I drove it.

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Early spring of 25 it started having some shifting issues, turns out the kickdown cable was a mess and needed to be replaced. Thanks to AJ’s Yotas for the fix on that one.

After the kickdown cable I did an Axle rebuild, new brakes all around, and started taking her on adventures. First it was hunting trips out to the hill country, then out to Big Bend and New Mexico for spring break family adventures, Then Summer of 2025 I drove her out to Maine with my son to drop him off at Summer Camp.
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I started running into “overheating” issues out in Maine. The water pump took a s***, so I replaced that along with a new thermostat. Still running hot. Tried a new fan clutch, actually ran worse. Change the fan clutch fluid to 12000cst, no change…

Then the fuel pump died, so I changed it out with a new… The fuel pump died again, though I had a bad fuel pump so I swapped another one in…Which also died. Then I realized with the help of the hive mind that my fuel pressure regulator wasn't draining back to the tank, over pressurizing the fuel pump and burning them up. Spent half my summer in the dirt under the truck removing the gas tank and trying to get the damn thing running well enough to drive home.
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I ended up having to tow the 62 back to Texas as I was out of time to repair things and had to get back for work. Uhaul absolutely saw me coming on this one, it was 2400 for a one way trip from Portland Maine to Austin TX, ouch! Plus with all the issues it was having I didn't really trust it to get me back home anyways. I hauled ass and made it back in two and half days!

I ordered a new FPR, and replaced it when I got home. Now it would start up and run and stay running without frying the fuel pump.

Once home, summer in Texas really made the 62 run hot. Never in the red, but confirmed with an IR gun would run 220-230.

I went through everything again, drained and flushed the block hoping for an answer, but no improvement. Anytime it was over 85 degrees outside the truck ran hot. This is basically march to November in Texas and just wouldnt work. I didnt want to spend any more money or time on this 3fe, its too slow, gas mileage is awful, and the auto transmission is zero fun!

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That led me to engine swap ideas. LS was the easiest answer. Great motor, tons of power, lots of info and lots of people doing them in the cruiser world. So I bought an OM606 instead.

I picked up a 78k mile motor from a 1999 E300 turbo diesel. These motors can be run with a mechanical pump minimizing any computer control BS and love boost! The guy I bought the motor from was planning on putting it into a Jeep CJ and had already swapped to a rear sump oil pan, replaced the glow plugs, and had a pile of new parts to throw on it. It was a good place to start.

Current plan is a Borg Warner s200 turbo with a small 0.48 housing (S252) which should be good for about 350hp and 450 ft lbs of torque. 7.5mm dieselmeken pump, H55 transmission and split case.

It should be a nice upgrade from the 3fe, doubling the horsepower and torque, and doubling the MPG’s. Low end power is not exactly a strong point of the 606 but I cant imagine its any worse than the 3fe paired with the auto transmission
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Current status is the 3fe is out of the truck, i've test fit the 606 and currently having motor mounts made. Hoping to have the engine and transmission mounted in the truck by March and running and driving by April.
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A few more pics of current progress and little more info on the swap.
I am using Diesel Pump UK’s H55 adapter which requires a 2h bellhousing. I found the bell housing in Australia. And paid a load of money in Tariffs not only for the bell housing but also for the adapter plate from DPUK. Everything appears high quality and bolted up without issue. I haven't had a chance to hook up hydraulics to make sure the clutch engages and disengages as it's supposed to, hoping I don't have to drop the transmission later on to solve any problems with this but that's a possibility.

Today I finished the water pump mod improving cooling to the rear cylinder which is a known issue on these engines. I also put a new water pump and thermostat in as well. The factory water pump has a plastic impeller and the upgraded one is metal, any opportunity to avoid simple failures I will take. I also installed a more functional and better looking fuel filter housing from Diesel Pump UK. This simplifies the fuel system and adds functionality to the fuels system as it has a prefilter fuel pressure port for better monitoring of fueling.


I also installed the mechanical injection pump from Benzforce. Benzforce is local to Austin and uses Dieselmeken elements for his pump rebuilds. Choosing a mechanical pump has been the biggest challenge for me due to lack of information out there. There are many pump builders and all claim everyone else’s pump wont work for your situation. Ultimately, I chose a local company instead of someone overseas or across the country in case I do have issues, I won't have to deal with expensive shipping and long wait times
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Last big mod was to swap out the valve springs for stiffer ones. apparently at higher boost these engines can experience valve float. Im not a mechanic and have never really done anything beyond "bolt on" mods, so this felt like a pretty monumental task. Thankfully youtube exists. I really took my time making sure I followed all the steps and had the correct tools for the job. What is likely a 2-3 hour job for someone who knows what they are doing took me about 8 hours of work. But I was double and triple checking every step of the way and got them all swapped out and everything put back together. seems like all the timing marks and pump timing are correct after doing the job. I guess we will find out when I fire it up for the first time.
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That pretty much brings me up to date. Im hoping to get the motor mounted in the truck this week and then can start working on pedal assembly and little things needed for the H55 swap. I purchased cruiser matts pedal assembly, wiring harness, and block off plate. I have two weeks off for spring break so Im hoping to knock a bunch out then. My goal is to be able to fire it up and possibly drive it by April.
 
Did you mention that the combo looks SWEET all bolted up? Can't wait to see it sitting in place in the engine bay.

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Maybe you can help Galen clean his shop after?! :lol:
 
Did you mention that the combo looks SWEET all bolted up? Can't wait to see it sitting in place in the engine bay.

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I cant freaking wait! Ive got a lot of work this week to get it ready. I think I need to prioritize getting the Tcase back together on the H55 as the engine bolt on stuff wont be quite as difficult once its in the truck
 
Maybe you can help Galen clean his shop after?! :lol:
I take a load of trash with me everytime im out there and have already dumped 15 gallons of oil from his shop. lol. I need a go fund me for some large industrial shelving so we can organize the insane amount of OEM parts he has in that space!
 
@cruisermatt the shop rental fee is garbage and recycling removal!
 
And I forgot to mention, Big thanks to @bottombracket for allowing me to use his shop space, tools, knowledge, and extra hands to accomplish this. I have just enough knowledge to be dangerous, and barely enough money to fix my mistakes I make along the way. Ive never owned or worked on a diesel engine or have completed an engine swap so every step of the way are firsts for me!
 
LS: they are awesome and I wanna drop one into my dad's '69 C10 sitting outside the shop....but that is a much different beast.

Nick, you are more than up to the task and moving 10000% faster than any of my builds. LET'S GOOOO!

We build community via shared knowledge, shared space, wrenching, and occasionally even driving these things. Happy to play a small part in your rad build.
 
You will also get triple my gas mileage 😂
that is definetly a bonus, id be thrilled with 18-22MPG. It would be awesome to install a Long Range America 40 gallon tank as well and have about 800 miles of range. But im rubbing pennies together at this point with how much Ive spent on the swap so far. There are so many other things id like to do while the motor and trans are out but Im going to push that down the road for another day. Mainly, cleaning and undercoating the truck. Its in great shape right now and Id like to see it stay that way for another 35 years! Id also love to re-spray the engine bay at some point. Maybe next year Ill pull it all back out and do a light body restoration and respray. I do have a little experience from a previous truck build on body work and painting that turned out really nice. I restored this 87 4runner a few years back but have since solid axle swapped it and cut the fenders to fit 37's and turned it into a rock crawler. Theres too many "while im in here" ideas to entertain them all... lol
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