OM617 swap

[Medicwithamanche]

So I’m finally getting around to writing up my project. Had my 88 MJ since august of 18 and put a lot of work in it making it my own. Added a RC 4.5 lift and their steering stabilized, and added new 15” method wheels and new 31” MT tires. JCR bumpers front and rear with their headache rack. Had it bedlined grey from the army green it was by a local body shop buddy.  Various other mechanical fixes from the PO  including new injectors and plugs, starter, rotor, brakes, and fluid changes. Added light bars to everything and couldn’t leave out rock lights. I own and operate a small pool cleaning business so I made it the badass pool truck! 

 

Ive wanted a diesel Jeep for quite some time now and told myself that I would make it happen when my 4.0 finally gave up. Well long story short is think my thermostat had a catastrophic failure on me and I kinda ran it hot. Blew the head gasket at least cause it idled like crap and was blowing oil all other the engine bay getting it home. I pulled it and set it aside to play with and rebuild a stroker for something else one day maybe. 

 

The plan for a diesel heap was to put in a Cummins 4bt in it because I love the way a Cummins sound. But after hours of reading through forum boards and facebook groups I had decided it was not going to work for me. I’d have to plate and reinforce my frame and get a new axle and suspension up front to do it right for my taste. Plus the cost wasn’t feasible or economic for me right now at the moment. I’ll save the 4bt for a J-series build one day! 

 

I ended up deciding on the Mercedes om617. It’s a smaller power plant yea but it still can get some respectable gains if done right. I sourced my motor from a guy that was only a couple hours away here in Texas. He had the MD4x4 AX15 adaptor plate with him and some universal mounts that I went ahead and made a deal with him on. Brought it all home and have been working on cleaning it and preparing it for the Jeep. I had heard things about the MD4x4 kits and have not heard good things from this particular plate. I ordered new mounts from them but I believe I’m going to go with Joe’s kit from DD when his AW4 kit is available in the next couple of weeks.

 

 

I’d like to keep my aw4 that I had with my 4.0 because I already have it, keeps me form having to buy a new transmission setup, and the 88 models had a stand alone tcu. The aw4 needed a tps, brake, and speed sense in my readings to remain autonomous. I purchased the TCI remote tps to give a throttle voltage and the brake sensor can be wired to the brake lights on my pedal. The speed sensor I believe can be read from the cruise control sensor on my cable so that’s covered. I wanted to have an automatic build without a switch controller so you didn’t have to have a tutorial to drive it. 

 

The Mercedes, I currently have the motor dressed down. Cleaning out the intake manifold and doing the DD EGR delete and ALDA delete. I ordered Joe’s remote oil filter kit too and have plans to build an oil cooler and remote oil filter system. It had 77k on it when the PO pulled it and he guarantees it will start. So I’d like to get it to run before I drop it in the Jeep. I still have grind away the block where the started goes but the stock started from the 4.0 will work once I get the flywheel out of the 4.0. Ill use the MD4x4 plate to do all that and get it running. 

 

There is a bit more I had planned to do but plans didn’t come together. I would have liked to have done the 97 swap while i had it all apart. I went through a cleaned up the 4.0 harness and left all the sending wires for monitoring with the stock dash. Ill still have to run a few more wires through like boost and oil temp and EG temp but ill add those to a pillar cluster. This is a short write up about the build. I have an idea about doing a YouTube series on it but have not decided yet. I have the footage and pictures but have not done any editing. I dream to have the editing powers of bleeping Jeep and dirt lifestyle and guys of the sort but I don’t as of now. 

I want to have this done before the spring comes around so it’s nice to drive around. I’m not in a rush but I want to do it right. I want this to be my overland/camping rig so me and the GF can be gone on the weekends and just relax. I hope to have some feedback on other ideas and plans i could do. Cheers guys and gals. 

Edited January 18, 2020 by Medicwithamanche
Added more details to the Jeep.

[Medicwithamanche]

I also have the plans to do a three link for the front. Was thinking about going with iron rock Offroad but I’m not dead set to use them yet. 

[krustyballer16]

Nice build.
I love my 3.3L Cummins. I didnt wanna do the 4bt cuz it was so big and everyone has done it.

I have Dirtbound Offroad's 3 link and love it!

Sent from my SM-G973U using Tapatalk

[Pete M]

awesome!   

 

need more pics and specs and such for the rest of the truck too! 

[Medicwithamanche]

So last night I got the starter area cleaned up and finished with a flap disc. Just used the MD plate to measure it. The stock 4.0 starter fits nicely now.

I think today’s plan will be to separate my aw4 from the 4.0 and work on my wiring for it. Pulled out the tranny harness last night but now I need to figure out what wire goes where and at least get the transmission plan together. 
 

I think I can finish putting the interior back together today too. Pulled it out thinking I would do something inside but never did. 

[Medicwithamanche]

Well I got is in the engine bay last night. I used the MD AX15 plate to keep it all together and left out my flex plate for the moment. 

 

I separated the AW4 from the 4.0 sunday

and cleaned it up and let it dry. I got it the wiring harness labeled and sorta know where everything needs to go. Need to tie in my reverse lights figure out where to run my brake and VSS wires and get my remote TPS tied in. I think I'm gonna get one of those kits that has the waterproof male and female plugs and redo everything that way. Just in case I need to pull everything out in the future. I bolted in my starter and had to shave away an 1/8" of the MD pate to get the starter fully seated against the bell housing. 

 

My MD4x4 motor mounts showed up yesterday and I got the frame pieces on. I had to tap the front mounting hole because it wasn't already tapped but looked like it had a tappable plug in it. Props to jeep engineers btw, the MD kit places the frame mounts further back than stock so good job on using those holes. But the MD perches had to be welded to the frame mounts. Was hoping it was all bolt and play but it made that way to accommodate angled pitch for higher lifts I suppose. Ill have to wait and get that welded this weekend when i can get some more help at the house. 

 

After I got everything in i started to check for clearances. the motor is still supported by the engine hoist but it close enough to the oil pan where it'll connect whenever it flexes a little. My fear is ill have to end up with a complete custom suspension. I was going to wait on the long arm kit because of financial reasons but i might have to bite the bullet and go ahead and get he long arm kit with taller springs and a drop pitman arm for now. Ill have to get a new trackbar at some point too because it sits close t the oil pan. I really don't want to notch the pan because thats a lot of welding but i might end up having to. 

 

the Aw4 i need to figure out cooling. I was just going to use the stock cooler lines but I'd like to do soft lines and tie them back into the radiator so does anybody know what thread the transmission lines are by chance? 

 

I still need to get cooling on the 617 figured too. I have been debating on using the brass push locks or the an fittings. I want a clean but cost effective build, as ironic as that sounds. 

 

Still a long way to go with finishing up. I still need to work on pluming, wiring, new radiator fans, starting system, glow plug relay

[Medicwithamanche]

Another update. I got my stuff from Joe in the other day. Stuff looks great and it’s awesome. The EGR delete I got done with a buddy and got it all cleaned up.

 

 The oil relocated plate is on and I just used the stock turbo feed line and carefully bent it around to where it needed to be.

 

 

I still need to plumb in my remote oil filter and cooler but waiting on those to arrive in the mail. I got his ADA delete too and it was the easiest thing ever to put on. I don’t need cruise control anyway. 

[Medicwithamanche]

So my Doomsday AW4 kit arrived Friday from Joe and I pulled the motor back out to fit it. Still waiting on the flexplate and crank adaptor but that should be here this week after it gets machined. The flexplate had to have 6 new holes in it to match the Mercedes crank adaptor. Joe is sending all the new hardware too when he does. So far top notch products I’ve got him so far. 

  

 

 Still have all my wiring to do but I got the transmission harness to tie into the rear of the engine harness and sending units but that unfortunately may be the last thing I do. I have connectors that are at the house that I’m gonna use to tie the harnesses together. Gonna use the Jeep sending units for cost reasons at the moment. Not like the 4.0 is gonna need it. Lol 

 

I need to figure out my ignition wiring to make my fuel pump run. I believe ill be able to use my same fuel tank as long as I’ve had all the gas cleaned out. I drained the tank the day after I pulled the motor and the cap has been off since so I’d bet its dry. Would need to change out the fuel filter and prime the line prior to filling but it’ll work I’d hope. 

 

My oil cooling system needs to be done. Still trying to figure if i wanna use barbed push lock fittings or make it nice and use AN fittings. I will have the motor running by the end of the month and hopefully driving as well. Interior is back together and looking to do a new audio system after the motor starts. 

[Medicwithamanche]

So I’ve been working a lot lately with not a lot of time for the Jeep. The motor and tranny have been mated and put back in the Jeep.
 

 

All my wires have been labeled and just need to be connected. Starting relay needs to be wired and I need to rewrite all my aftermarket lights. Got the starter lined up and can now turn the motor over. Not much but enough to bump it over.  Oil cooling plumbing is all in just need to find a good spot for my remote oil filter. I tried to work on my exhaust and I’m running into a problem with clearances and connections. I have to figure out my best option for connecting my downpipe to my turbo. 

 

 

I’m probably going to have to get a bigger lift. Didn’t really want to but I’m having bad clearance problems with my track bar and my oil pan now. I have the RC 4.5 atm but I may go to a bigger long arm kit later once it is running. 

 

Motor mounts are welded and painted just waiting to get holes drilled. It seems like a check a couple boxes and more boxes show up. Wiring and plumbing are my biggest hurdles at this point and will be tackled soon enough. 
 

no real details today just a quick update while I’m stuck at work. 

[Pete M]

more lift will only help until you flex or hit a big bump.   Seems to me like a notched pan and/or a custom trackbar would be the solution. 

[Medicwithamanche]

SO great news!! She runs and starts with the key!! 

I have been working on getting my remote oil system finished and finally have it completed short of two AN fittings for my cooler. I had to get a custom power steering hose built to go from the Jeep steering box to the Mercedes pump. I set up my alternator wiring and it’s working well, charging like it should. My wiring for the auto transmission needs completed and I need to work on making a bracket to put my aw4 cable and TPS sensor wired in. I’m thinking a bracket with a strong spring to allow more travel from my throttle cable than the TPS has. I need to wire in my fuse block wires and somehow figure out a timed delay relay system after I turn off the key to kill power. Little nuts and bolts are all that’s left to finish it. Short of putting my driveshafts back in its drivable. Started working on all my axillary lighting wiring and have my dash put back together. Just an update from my last post in February. Hope to have it finished by the end of the month and move on to my next project. 

[Limeyjeeper]

Very cool project. Wish mine was going as fast.....

[Medicwithamanche]

so i know i haven't posted lately but you know how life gets. She actually been in the sunlight for the first time since December. i got my driveshafts bolted back in and drove it around the house the other day. A little depressed about the power output but i was suspecting that and i didn't give the turbo time to spool of boost. Plenty of time after i get it road worthy to work on power increases but for now it gets from A to B. I cleaned up all my wiring except for my aw4 wires and external ups set ups. Is till need to fabricate a bracket of some sort to accept the TPS sensor and the aw4 cable (I can't think to the purpose of it atm). I need to get an CAI setup, Cooling fans still need to be wired in and a vacuum system to stop the engine when key is turned off still needs to be wired in. thats easy enough to just pull vacuum from the vacuum pump and wire the switch to key negative and a  ground, just need to get the parts ordered. vacuum line into the cab and a syringe do the part right now. exhaust will have to wait till it is road worthy so i can take it to the shop for help. I figure I would update everyone on progress in the build. I'm getting low on motivation but it needs to be finished. 

 

[Pete M]

as long as you keep pluging away at it everything is fine.   gotta keep the momentum even if the motivation falters.    

[JMO413]

Awesome!

[Bucket Boy]

Very cool! Glad to see someone thinking outside the box.

[Medicwithamanche]

I haven’t made the time to post in a while so here’s an update. The motor is all in order, will have to probably have to cut the oil pan to get my track bar from connecting but that’s on the back burner. The truck can run around the house with just 1-2 and 3rd gears. I never got my tps setup to make the aw4 shift correctly but i just use the stock shifter. I had been sourcing RAdesigns rail shifter but never got around to ordering. Exhaust is still unfinished but that’ll come in time.

 

I had been using the truck around the farm the other day and was running okay. Parked it that day and noticed a red puddle under the Jeep. Leak was coming around the bellhousing, meaning to me the torque converter or the front pump is leaking. Either way the tranny has to come out. I had really wanted to do a manual transmission for the build but the aw4 was still useful at the time. Ive sourced an external slave ax-15 out of a Dakota behind a 5.2. I still nee to source a 4.0/ax15 bellhousing to use but i got the master and slave cylinders from the seller. Manual pedals is till need to source as well. The most fun part is my tcase is gonna need to be changed. My aw4 is 21 spine output but the ax15 is a 23 spline output. I have two options, either open my case and replace the input shaft or get a new transfer case that has 23 spline. 

 

Long term goals are to have long arms all the way around, 3 link up front and 4 in the rear, and do custom gauges in the dash. I would like to have a few more gauges besides what’s in the dash and like the look of 2 large multi use gauges. A little embarrassed of how much i have put into a 30 year old truck but it’s a labor of love. Just a long winded update tonight while laying in bed. 

[Pete M]

glad to hear it's coming along!    plenty of us have sunk, I mean invested large amounts of cash and time into our trucks.  comes with the addiction.  

 

your update needs more photos though! 

 

[BeatCJ]

Last time I looked, Davey's Jeeps had the external slave bellhousing listed for sale on their site. A little spendy as I remember, but they are a relatively limited supply part.

[Medicwithamanche]

I found one on eBay Beat. it should be here by monday next week. Pedals will be here shortly as well. I believe i have all the parts on hand come next week. I had to reach out to Joe from Doomsday Diesel for his flywheel but I've got everything i believe. Reading another swap I've learned i need a new floor cover though for the transmission shifts to come up through. 

 

As far as my Tcase though ill need to either source a new to me 2000+ np231/23 spline or get the proper 23 spline input shaft for my 88 case and breakout open and swap them. Ive never opened a transfer care but I'm almost eager to try it! 

[Medicwithamanche]

Updating with some phots of my engine bay.

 

Acquired my AX15 and hydraulics and new bell housing and pedals will be here first of next week.

I need to drill for the master clutch cylinder still but I have everything to mate the transmissions to the engine. Still working on the Tcase input shaft. Do i buy an appropriate Tcase or rebuild mine I already own. 

[Medicwithamanche]

So I got the center console pulled for the swap. Did some cleaning while it was up. The original carpet is more blue than I remember though. Lol thought about a custom center console but that comes later. 
 

so I thought I was being productive today too and was gonna get the pressure plate and clutch installed. Torqued my flywheel to 60ft lbs with blue thread locker and went to center the clutch and remembered the pilot bearing. Mildly important is an understatement to say. So I still need to order that. Bearing or bushing y’all think? 
 

Have also been playing the the tcase. Separated the halves and ordered a used input shaft. Ordered the 94+ 23 spline so it doesn’t work. Had to order another from Morris and went ahead and got the seal kit to go ahead and reseal the case while I have it out. It should be here next week sometime. 
 

not much to report today but I like to continue keeping those following about progress. December 16th last year is when I pulled the 4.0 out. So maybe it makes it driving again on the road before the anniversary. 

[Pete M]

I prefer bushings.  especially if you need to have a custom one made.   Do you think you can find one on a shelf somewhere?

[Medicwithamanche]

OD diameter is 45mm, input shaft is 15mm. Not having much luck finding one. There’s a couple brass bushing I’ve found but the OD it too big. I’d have to turn it down anyway so ill looking into a custom turned one at a machine shop. 

[MercManche]

On 12/5/2020 at 6:29 PM, Medicwithamanche said:

OD diameter is 45mm, input shaft is 15mm. Not having much luck finding one. There’s a couple brass bushing I’ve found but the OD it too big. I’d have to turn it down anyway so ill looking into a custom turned one at a machine shop. 

 

Let me know if you still need that bushing made, I have some extra ones lying around, cheaper to by boxes of 5 than a single piece. I bored mine to 3/4" but I could also do it for the 19/32" shaft. 

Doing the same swap in mine, curious to see how you overcome the steering & track bar issue.