ulendo

Looked back through about 10 pages, and search only found really old stuff. I've got a Mercedes G300TD engine w/ tranny in good running shape, and since my 4.0 is getting a bit weak (at 340,000km), I'm eyeballing the swap into my XJ. G300TD is the Benz 5 cylinder, mechanically injected turbo diesel. piston pump, no egr, Garret AirResearch T3...basic bulletproof Benz.

the good - not my first swap, and not my first benz diesel swap. motor is 100% complete as is trans, 120,000km, military take out from a truck that got its rear end crushed by a tank. size, power, and rpm are all compatible. 2 options for install: a cut-n-weld bellhousing to mate the Benz to the Jeep AW4 ( I'm one of the folks who LIKE the AW), or I can go completely frankenstein, and use the Benz motor & tranny w/ a custom divorced Toyota case. ( which I also have...I'd have to cough up mounts, and a shifter assembly for the Jeep floor pan) I work at a diesel shop, can weld cast aluminum, and have all the lifts, gear and test equipment that either option would need, up to, and including access to our in-house dyno to tune the beast 8^D I use my XJ as a daily driver, and a weekend safari-trek truck to haul my kids camping, fishing, etc. my goals are reliability, range, and trail grunt..prior conversions with Benz's have averaged mid 40 mpg gallon numbers, with the record holder being a turbo 240D into a compact SUV that got 54MPG on the highway ( imperial gallons, btw - I'm in canada) so yes, given that I HAVE the stuff, its cost effective. No inspections to worry about here, and the motor is legit & correct vintage anyway.

the bad - right now, I'm into completely unknown territory, and aside from teh gear I've already made myself, no one makes any adapters / conversion stuff for this swap. the SD has a tach output, but I dont know if it reads as a 4 5 or 6 cylinder signal - anyone got any experience with this sort of swap? No one I know has welded the specific alloy in the Jeep bellhousing...how porous were the jeep castings, and are they a hard, or soft alloy? As part of the final setup, I'd like to run a snorkle..the Benz has its manifolds on the RHS, and it'll be tight on top..anyone know of a snorkle that will fit the RHS of the XJ body? ( specifically, I'm wondering if the snorkle for a Toyota Iron Pig/FJ45 will work) oh, and does any one have a line on where to get the OE Jeep data center plate with the glow plug symbol ?

suggestions welcome for divorced LH drop transfer cases, good radiator setups that will fit the XJ body, and anything that might make the swap easier. Its my personal truck, but if I go ahead with it, it'll also be something of a showpiece for our shop in that we work on any & all diesels, so I have a definite interest in making it a very, very slick conversion.

thanks in advance for any constructive feedback

Ulendo

wicked_xj

theres a guy in west Milford nj that has yj with a Mercedes diesel

wicked_xj

btw wrong forum

ulendo

yah - the BBS didnt work quite the way I though - submitted under XJchat, but it dropped it here... been trying to delete it & repost in cherokee, but where the heck is the delet function on this setup??

jpdocdave

i think its a cool swap. there's a guy on wrangler forum that does some diesel swaps into yj wranglers. mainly 4bt diesel i think. he's done some mercedes diesel stuff to.

the xj radiator is very unique, you're pretty much limited to what is made for xj as far as i know.

let us know how it goes, sounds like a really cool build.

ulendo

wth(eck) applies to the grands as well, I guess - If a mod happens to read, and can repost to XJ's, I'd appreciate it.

Trying to anticipate some of the Q's, etc, I posted photos to photobucket, then came back to check that it loaded properly. didnt load where I wanted, but here's a link to the photos of the setup ( including the Benz tranny, and the divorced toyota case) for anyone who's interested

http://s419.photobucket.com/albums/pp276/ulendo/

looks long, but from the front of the motor to the rear output flange is actually 2.5 " shorter than the stock setup.

wicked_xj

welcome btw way

NHJeeper

that's a build I'd like to follow along with.

ulendo

no worries - I'm a photo junkie, and have had more than one page up for prior swaps.
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so, to break it down to my one burning question right now: whats folks opinion here on AW4, vs Benz / Toy setup??

AW4 is already in, has a lockup convertor, and overdrive. I'm already rigged for manual 1-2 control, and manual lockup if (when!!) I need it. even with OD, I'll have to regear the axles to get the motor at 'happy' rpms for 70 mph ( 110kph) cruise. 4:1 low available for the 231...gives ~39.9:1 in bull low with 3.54's, and ~51.43 with 4.56's...if they'll hold the torque and 33's

Mercedes K4C 025 transmission & modified Toyota t-case. I own them, but would have to come up with a new t-case cross member, and a clocked mounting system & shifter for the t-case. Havent looked at U-Joint sizes yet, but thats not usually a big deal. 4.7:1 marlin low available. Tranny is non overdrive, non lockup, but has front and rear pumps, can be bump started or compression braked, and a 4.38:1 1st gear. ( 5.38:1 reverse!!!) It would NOT require a regear in the axles for 33's. ( ideal cruise rpms are 2400-3000rpm on the OM 617, and I have 'the usual' 3.54's in the axles) trans, marlin gear, and existing axles give ~72.87:1 in bull low , without needing low ( weak) axle gears.

So would a frankenstein rig be a no-no here? ( this is my first Jeep...been excommunicated from one other brand (Rover) user group for 'corrupting' the strain.) is 72:1 overkill, or just plain fun? diesels are a bit different in the mileage department, so lockup vs non lockup isnt a major difference in mileage...whereas adapting the AW bellhousing to the Benz will be finicky, and a PITA to weld up.

opinions? thought? other options?

Fish N Kid

I have the same mercedes 5 cylinder and transmission in my possesion. I'm looking to get a CJ or wrangler to dump it in. I have been doing as much research as possible to find out what all is going to be involved. Your write up is exactly what I have been looking for as far as information on the diesel and transmission set up goes. What do you think is going to be the best set up?

Like you said, either go with the mercedes transmission and bolt up a transfer case or build an adaptor plate to mount a different transmission/ transfer case assembly.

I'm not going to do anything exotic with the tire - wheel set up. Mostly use for street use and the occasional step off road. I am thinking I will just put some 31"S on it. Stock rear end should be fine?

Would you mine sending me the pictures with text boxes of the OM617 you put on photobucket? I could really use the information.

I do have a question or two about the final drive ratios. I understand about the 4.10:1 or 3.84:1 rear axel gear ratio..... but how do you arrive at the final number of 78:1 or 54:1 ?

I'm very interested in this build. I have a '95 Cherokee 2 door that is my "daily" driver. Cant start the diesel project until I sell my Mazda RX7. ... Leaves time for research and parts gathering.

Thanks,
Shawn

ulendo

Shawn ( Fish n kid) I 'd gladly send you the high res photos, but there doesnt seem to be any contact info in your profile...there''s a 'see full size' button at the top left on photo bucket. Worst case, click full size, then print it.

t-case options are relatively simple...if you dont like doing machining, there are Divorced NP203, and NP205's from full size fords, the case from an older Nissan 720, Suzuki Samurai Case, and even the ( not available in the US) Niva full time case. If you can handle basic machining work, I've built a custom, divorced toyota transfer case, using a mid 80's mini truck as the donor.

gearing is, obviously, totally dependent on what hard parts you use...no matter what combo I run, I'll be using an aftermarket low range, etc. Jeep would then be 2.82 1st gear in the AW4 * 4:1 low * 4.56's. First gear on the benz autos is usually 3.98:1, although there are some that are even lower than that. My choice of the toyota allows me to fit the marlin 4.7:1 low range. I've been collecting bits for a couple of years, and also have one of the 'other' auto's, with slightly lower gearing. that combined with possibly going to 4.10s, or 4.56's allows for crazy low crawl ratios. ( figure 4.38*4.7*4.56=94:1) the nice part is that the uber-low 1st gear doesnt leave the big gap between low, and high ranges: high 1st is more or less a sequential gear numerically above low 4th. ( 3.98*1 vs 1*4.7 with most of the benz autos, 4.38 vs 4.7 with my setup)

Fish N Kid

On the transmission / transfer case subject.... I am thinking about weight. Isnt adding a divorced transfer case to the Benz transmission going to add quite a bit more weight? Would the transmission/transfer case combo that comes with the jeep be a little lighter? I dont mind machining an adaptor plate to mate the Jeep transmission to the Benz 5 cylinder.

Do you have any pictures of the install? What did you end up doing for the motor mounts?

Have you made a final decision as far as your transmission combo will go?

I'll take pics of my install as I go to share. But like I said earlier, at this point I just have the engine and transmission from the mercedes. What type of business / shop do you work at / own?

I'll update my profile with contact infor now.

Fish N Kid

Kujawasr@gmail.com

okcjeeper

I'll move to the right forum..

93XJLI

sounds like you're in deep and know what you're doing

go to www.novak-adapt.com and give them a call for info on the bellhousing, adapters, and just about anything else you need, theyre very knowledgeable.

I'd keep the AW4.