Another OM617 Swap: 1998 Tacoma
 

Hi all.

I managed to do this swap for under $2000 CDN including the truck, but it also took 8 months and i'm estimating over 150 hours to complete. For those that are trying to do this from scratch, you will need some serious discipline.

1998 Tacoma 4x4, the day I picked it up. Seller said it overheated and leaked its coolant everywhere, he wanted nothing to do with it and was asking $1000. I had cash in his hand within a few hours of him posting the ad, can't let deals like this get away right?

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EDIT: Nov , 2018 - How it sits now. The frame ended up rusting out, the engine still runs great!
(I'll leave this thread up for reference.)


https://cimg4.ibsrv.net/gimg/www.yot...20bf287dc3.jpg

Towed it less than a km to my house, tried starting it for kicks, and it actually ran. Poor 5vzfe, good motors but this one was done. 4 out of 6 cylinders had poor compression. probably blew its hg between cylinders.

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Pulled it out.

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A friend of mine gave me the om617 out of his 300sd parts car, this saved me the cost of the motor. It was rough. Wasnt sure if it ran at this point but he drove it to his house, so apparently it did at one point.

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Big mercedes yanks the little mercedes engine out of my other truck. It's a 1980's unimog doka(4 door) diesel with a hiab crane, pretty cool work truck!

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And i'm too tired to post any more, so stay tuned

Holy Moses the unimog is freaking incredible!!!!! What a neat looking beast!!!

Yup its sweet,

Front view

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and check out the shifter setup,

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The knobs are for front/rear PTO, gears 1-6, transfer case, high low and super low range, fwd/reverse select, and air locker. gears 1-2 are for crawling, 3-6 are for highway speeds, it tops out at 80kmh(50 mph), and will crawl so slow that you can barely notice its moving. no joke. also has a hand throttle thats out of view. I hope to incorporate something similar into the Tacoma.

So back to the Tacoma..

I welded plugs into the toyota flywheel, and redrilled to the mercedes crank pattern.

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Also turned my pilot bearing bushing on the mini lathe.

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Did you cut the pan,cross member or do a body lift for pan clearance? That mog is so sweet!

I ended up cutting the cross member, i'll have pics up soon

Le adapter plate, the metal shop had this chunk of aluminum in the bin and gave it to me for cheap, the dimensions were perfect! Used a hole saw for the crank hole.

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and here it is mocked up

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Got the engine in for the first time to see how it sits (sans motor mounts), it had to go back quite a bit, the front pulley is sitting where the rad should be.
The v6 is such a short motor compared to this one.

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It could also be a bit lower, the crossmember is sitting right where the oil pan is. The good news is the diff and steering rack are so far back in the tacomas that they don't interfere.

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Great work... Can't wait so this swap in a Tacoma

Thanks man.

So I decided to move the drivetrain back 3".
Moving the drivetrain back meant moving the transmission mount back, as well as lengthening the front and shortening the rear driveshafts. I did not have the capability/cajones/time to do this myself, so I took the driveshafts to a driveline shop ( http://www.patsdriveline.com/ ) which is somewhat local to me, and they did a good job. turned it around in <1 day. Cost was about $350 for both, balanced.

I told them to shorten both by 3", and built the motor and transmission mounts AFTER the rear shaft was installed. The front shaft, being a slip-yoke, would have plenty of spline engagement to take up whatever little bit of difference there was in length (due to sitting at different angles).

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Transmission mount I made up.

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Mount and driveshaft installed!
I should also mention that when they re-tubed the driveshafts, they used thicker wall tubing. Bonus!

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Got tired of doing driveline stuff so worked on a funner project in the meantime..

The om617 no longer needed the electric in-tank fuel pump, so I took that out and replaced it with an inline filter. If you look close you can see a little slash cut I put in the bottom of the filter..obviously you wouldnt want a flat bottomed tube against the bottom of a flat tank.

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The gas cap restrictor had to go too. F that gas nonsense, no turning back now.. ;)

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looking good

^ Thanks mike, your runner looks sweet btw, always liked the 80s graphics on those things.

Back to the adapter plate, I finally got the metric hardware I needed. Flywheel bolts are m10x1 22.5mm long, the adapter to engine bolts are m10x1.5, 25mm length. I used hex head bolts so I could counterbore them flush. Unfortunately I didn't have an end mill to do this, so I made my own bottoming drill. It's crude but it works. Drilled all the holes deep enough with a standard bit so the flat bit would remain centered, then followed with the bottoming drill. If you are going to make this bit, grind the point down flat, then grind a slight relief angle back into it, so it doesn't chatter.

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