Here is the in-depth write-up that I hope can serve as a how-to for OM617-swapping 96-04 Tacomas/4Runners (and T100's).
I picked up this $600 1997 4Runner 5VZ/A340 4x4 (rear e-locker) with roughly 250k miles and it was SHOT! Completely rusted out even though the body doesn't show it. Destroyed interior. Radiator blew up and mixed trans fluid with coolant to make a milkshake in the trans. Now I haven't read a single report of anyone flushing their trans and successfully driving it after that. Even the ones done under warranty at the dealership with the power flush had trans failure shortly after. Keep an eye on your radiator if you've got an automatic! The PO claims he noticed it right away and had it towed home where I picked it up. I flush the trans, added a new radiator, and put another 30k on the 5VZ! I daily drove it to work, used it to tow the mower trailer around, and even drove it 3 hours into Iowa with the trailer to get a band saw. Did a fair amount of wheeling with it, too, enjoying the rear locker. Eventually, it started losing coolant, so the 5VZ got yanked and sold.
The plan for this has always been for R&D. The only money I have into this rig is the new radiator and mounting the free tires someone was throwing away. Sold the 5VZ to cover the purchase. Can't beat that! I'm currently swapping in an OM617. I'll be using the 4Reigner to test trails I'm cutting in our pasture, as well as haul the tree cutting equipment around. Since the frame is already falling apart, I don't expect to keep this around much longer. I had originally planned to do a TDI swap after the 617, but have since decided not to worry about making TDI adapters for the Toyota Automatics, as the torque converter pilot stub would require turning down, and that is probably too much effort for most people. Once the frame folds in half, I'll pull the 617 back out to go into something long-term, and I'll save the rear axle and trans.
Rolled over 291,000 miles tonight. I thought I'd have all the kinks worked out by now and ready to rack up the miles, but unfortunately, I will have to pull 4Reigner into the shop and disassemble the front end entirely. I'm going to just knock it out all at once, so it will likely be down for several days. But first...
Tomorrow, I'm planning to drive to the zinc plater to pick up OM60x swap parts and test my mpg on a nice highway cruise with minimal wind. I hope I make it! I'm trying to avoid 2 major issues:
-My 1R-0750 fuel filter failed twice on me in the past 24 hours. I was just putting along, and all of a sudden, my hood had diesel drifting up it. The o-ring bulged out, and it appears to have swelled. I removed it, reinstalled the o-ring, and reinstalled gutentight! 30 miles later, it did the same damned thing đĄ Each time, I spent an hour power washing/hotsying off all the diesel since it coated every part of the vehicle except the roof. I don't have any spares, and the Napa Wix filters I've had on order since February still aren't here. I had a stock 617 filter, so I threw that on to get it used up. I'm hoping CAT can do an analysis on this failed filter so I know why/how it failed. I have several hundred miles on it, and it's been in use since 2020. The o-ring must have come in contact with an incompatible fluid recently, causing it to swell and pop out. I can't think of anything else.
-Despite my good smacks with the BFH to the oil pan prior to installing the engine, now that the motor mounts have settled, the pan is rubbing on the crossmember. I do feel that with more smacking, the pan would've cleared. But for as big of pain as it's going to be to remove the pan now, I'm just going to cut and weld some clearance slots. I realllllly didn't want to modify the frame in any way, but for future swaps, since the modification would be so simple/minimal, I believe that's the route I'll take. The crossmember actually tilts to the front. So the front has clearance, but the sides rub on the back. I will have to pull the 4 motor mount bolts, drop the trans xmem, and hopefully be able to jack the engine up high enough to remove the pan. For now, I've stuffed some rubber padding in between to prevent any metal-on-metal contact, and God willing, get me back safely tomorrow. The pan modifications are so simple that I don't think anyone should have any problems performing themselves. This is not something I plan to offer in my store, unless these swaps really takes off.
-The ebay e-vac kit is complete garbage. I'm returning it and I've got the Holley one from Summit Racing ready to install. The ebay unit only sits at 25°. It needs to be at 45° to work. Once I get some actual vacuum flowing, I'll work on installing the catch can. I'm not going to risk installing the catch can without vacuum and blowing oil out my beautiful cerakoted expensive turbo. I honestly don't even notice oil drops from the 5/8" heater hose right now. My rear main leaks take all of my attention âšī¸
-I will install a new trans mount when I do the oil pan mod. The old one still worked fine, but I stripped the threads out of 1 hole the other day when messing with the pan, and now I have a terrible vibration since the mount can move just slightly.
-I got my 2018 4Runner wheels for $200 with lugnuts, and the wheels are 95% immaculate. Got some brand new 265/65R17 Atturo AT's for $420 that someone ordered and didn't want. $100 to mount & balance, and the tire shop newb didn't even wipe the brake dust off before sticking the weights on. The wheels are back at the tire shop hopefully getting weights that actually stick this time đ The 17's were necessary to clear the 231mm Tundra brake upgrade. Powerstop has a $35 rebate right now, and Summit had a sale, so I got new KC2324 rotors, pads, and red calipers for a flat $350. These are 1 step down from the highest end they sell, which would've been $365, but are for heavy towing, which I don't plan to do with this. I'm sure the brakes will take me several days because that's just my luck with this rust bucket. Right now, when I touch the brake pedal, the whole front end shakes violently.
-I need to brace my aftercooler a bit more. It vibrates like hell. I'll get this figured out when I have to pull the downpipe. So far, I don't see the mandatory need for a hood scoop as my EGT's stay in check. But EGT's are considerably higher than with the cooler sticking out in the wind without the hood on. I may even consider louvers and an electric fan. The though of rain coming in a hood scoop scares me.
-Once the oil pan is kosher, I have a custom skit plate ready to be bolted on to protect the pan and radiator.
-I'm comfortable with how everything is working wiring-wise. So, I'll be completely removing the wiring harness and breaking it back down to strip out the rest of the unneeded wires. Then, I'll close the loom back up nice and tight so it looks factory, and secure it nice and tight with clamps and zip ties, with the intention to not touch it again.
-Lastly, the reason for stripping the front end down is to replace all of the failed parts. My chyna a/c clutch gave out after 3 minutes of use. I had brilliantly cold air for those 3 minutes đ colder than I ever had when the 5vz was in. But now I'll be installing a new drier, flushing the system, and installing a new USA-made compressor just for the peace of mind. The Dorman p/s pulleys have all been crooked. The first 2 were noticeable in my hand. I thought the 3rd would pass, but now the pump bearing is chirping. So, I'm installing a Trail Gear 4.5" billet pulley, and hoping the pump isn't ruined. If it is, I have warranty till December, and I should be able to just remove the battery to get the pump off. I'll be installing some new prototype parts while I'm in there, too, so it'll be much easier to just remove the radiator and have easy access to it all.
Once we're back up and running reliably, I'll be finding a permanent air cleaner housing, installing a painted valve cover, and this thing really needs a real front bumper with some KC's. I don't have any other plans except maaaaaybe a custom torque converter.