Builds Another OM617 in an FJ40 thread (3 Viewers)

[daner]

Morning all-I had started a thread on this build in the general tech thread, but now that I'm getting a better idea of the challenges, most of them involve the OM617. I should mention that I have no experience with this motor, and inherited the 1/2 finished project as a pile of unlabeled, disorganized boxes. This is going to be tough as I am not a great mechanic, have minimal tools and limited budget... and am clearly in over my head!

If any of the moderators want to merge the threads here, I'd appreciate it!

1966 FJ40 Project Pinchfist aka Atoyot, a backwards diesel build.

On the upside, the guy I bought the motor, 5-speed Toyota etc. did a good job sourcing parts. He rebuilt the turbo, installed a new water pump, all new gaskets on the motor etc.

But, as others who have done this swap have reported, one of the most difficult challenges is getting enough clearance between the front differential and the ginormous Mercedes Benz oilpan. After lowering the motor into the approximate location, it was clear that this was a bigger issue than I had hoped for:

My hope was to keep the 1966 (mid 65 build date) stock in appearance, including ride
height. It should be noted that there is no weight on the front springs, so they will compress when loaded.

Thinking about "plan B".....

 

[daner]

Rainy. Cold and nasty out. So I dragged the motor inside and started (trying) to attach the Toyota 5-speed transmission. After watching a few Youtube videos, I think I have the new clutch assembly figured out. But it is also clear that I am missing a lot of parts.

 

[duncanrm]

Wow.. that sump is a real problem.. even with a little bit of clearance there'll be no room for the diff housing to flex upwards on that side.. how have other people solved this?

 

[daner]

The other OM617/Land Cruiser build threads I have followed have used a combination of a lift+oilpan modification. There is a company online that will modify the cast aluminum Mercedes oilpan, but it is not cheap, and I have read more than a few online build threads where modified oilpans have leaked.

Before I go that route, I may have another option: The motor/transmission setup I purchased included a matching set of 1985 Toyota truck axles (with front disc brakes). These have a much smaller differential, but same width and bolt pattern. If I do a spring over swap using the Toyota truck axles, I may have enough clearance without modifying the oilpan.

As I mentioned, a lift is not my first choice.

 

[Rock40]

Well, the mini-truck axles do have the same wheel bolt pattern but they are NOT the same width as the axles on your 66'. They are in fact, quite a bit longer, roughly 5" I think. You would benefit from the slightly smaller differential housing and the fact the differential may be slightly more outboard but if you want to retain a "stock" looking truck the mini-truck axles will completely ruin it.

You could keep the truck looking "most" stock by using an Old Man Emu 2.5" lift, I know, not the route you really want to go here. You'll likely have to modify the pan as you have mentioned and really dial in the passenger side bumpstop but you'd probably have enough clearance to make things work afterwards.

 

[dirtyboots]

Is there something unique about the pan that makes it difficult to weld / modify? With all of the fab talent I've seen on Mud it seems like an easy job for some of these amazing fabricators. This pic is from a Jeep WJ swap someone fab'd a pan from scratch after a quick google

 

[daner]

Dirtyboots-I may look into a custom oilpan as a last resort. It may not get as much clearance as needed as the oilpump is in the middle of the lowest part of the pan..btw the oilpan is a cast aluminum unit that can be modified and TIG welded, which is also an option, but not something I have the tools or skills to do. I can barely get two pieces of angle iron to stick together with my welding skills...

Well, the mini-truck axles do have the same wheel bolt pattern but they are NOT the same width as the axles on your 66'. They are in fact, quite a bit longer, roughly 5" I think. You would benefit from the slightly smaller differential housing and the fact the differential may be slightly more outboard but if you want to retain a "stock" looking truck the mini-truck axles will completely ruin it.

You could keep the truck looking "most" stock by using an Old Man Emu 2.5" lift, I know, not the route you really want to go here. You'll likely have to modify the pan as you have mentioned and really dial in the passenger side bumpstop but you'd probably have enough clearance to make things work afterwards.

Thanks-there are some affordable options for lifts (unlike my Willys truck, which has no aftermarket support). From all the sources online, the Toyota mini truck pre 1986 solid front axles are 55 1/2"
The 1985 axle I have measures over 56." The stock FJ40 front should be 56" or 57, depending which internet source is more accurate. Pretty much the same.

 

[AirheadNut]

You can get a steel oil pan that would be much easier to modify. BTW, you'll love the OM617. I have one in my 5100 lb Mercedes G and it can really get up and go. I have been really impressed.

 

[daner]

Thanks-Do you have a source for a steel oil pan? I didn't see one when I searched.

 

[AirheadNut]

This was what I was thinking of: 123 / 126 Turbo Diesel Engine Oil Pan and Gasket - INCLUDES oil pan plug! | Product | MercedesSource.com
But now that I look at it again I see that your problem is not the steel bottom pan but the cast upper sump. Probably the best option is to get it modified by someone who is good with a TIG welder. The oil pickup can also be modified to move it out of the way of the diff.

Interestingly, on my G-Wagen (which has a swapped 617A and a modified lower pan) the axle is behind the low hanging sump.

 

[daner]

Wow. That's not a bad price and it is good to know that if I do butcher the cast aluminum one, that is available. Thanks!

 

[AirheadNut]

So is the lower sump on your engine cast aluminum? I was under the impression that they were all steel.

 

[DPV7070]

Found this thread today. Check out the link to my OM617 swap. It might help or give some ideas. Let me know if you have any questions.

 

[daner]

So is the lower sump on your engine cast aluminum? I was under the impression that they were all steel.

You are correct and I was incorrect: the bottom part of the oilpan is steel. Hopefully this will make modification a little easier.

DPV7070-I have read and reread your thread many times, it was very helpful and I may need advice from time to time as i really don't know too much about this motor...

Thx, Duane

 

[daner]

In the years since I've had an FJ40, I have forgotten the pleasure of trying to carry an FJ axle across the yard by myself...the old back is paying the price tonight!

On the positive side. I'm feeling pretty optimistic I can get the OM617 in the truck without doing major surgery to the ginormous OM617 front sump oilpan or or spring over lift. Here is a pic of the clearance with the Toyota mini truck axle in place of the stock FJ40 axle. Big difference!

Even without modifying the oilpan, there is 4" of clearance between the oilpan and the differential. There is also a little more than 4" between bumper stop and the axle:

As I was gleefully welding new motor mounts, I smelled something burning. I had googles on and didn't want to stop, but when I did, I found my sweater was on fire! Burned a hole in the sweater and the undershirt. This is why we can't have nice things!

 

[Rock40]

I know I'm the squeaky wheel here but did you double check the overall width on that 85' front axle? I can remember with almost certainty that the inner axles (both sides) are much longer than the inner axles on a 40. The birfields are the same length however and the 85' will have slightly larger birfield bells.

 

[daner]

I'm not really sure what measurement you are referring to: The actual measurement (WMS to WMS) of both the 1985 Toyota mini truck and the 1966 FJ40 front axles are both between 56 and 57".

The spring perches will need to be redone, and the clearance on the passenger side for the inner u-bolt will be a challenge as will the steering, but the axles themselves are with 1/2" of the same width.

 

[Rock40]

I'm not really sure what measurement you are referring to: The actual measurement (WMS to WMS) of both the 1985 Toyota mini truck and the 1966 FJ40 front axles are both between 56 and 57".

The spring perches will need to be redone, and the clearance on the passenger side for the inner u-bolt will be a challenge as will the steering, but the axles themselves are with 1/2" of the same width.

OK, I'll stand corrected then. My memory sometimes isn't what it used to be, I thought they were much wider than a stock 40 axle.

 

[daner]

Moving real slow here before committing....Need to pull off the lower oil pan and see how much I can gain if I cut off a corner.

 

[daner]

Fail/win!

After looking over the mocked OM617/Toyota 5 speed transmission/transfer case for the last week or so, I've decided to make some changes: I had originally planned to do this with an 83 L52 transmission from a 1983 truck as the L52 trannies are 5" shorter than the one I currently have. That extra 5" is big as the OM617/transmission transfer case measures 70", which is really pushing the envelope lengthwise as far as squeezing it into an FJ40 with a 90" wheelbase. With the L52, I was able to maintain a 20" rear driveshaft. Short, but do-able.

But, the L52 transmissions are considered one of the weaker Toyota transmissions, so I decided to stick with the 1986 G52 5-speed, which most consider to be a better transmission. Fail.

This meant I needed to move the motor as far forward and up as possible, and will have to install low profile electric fans as opposed to the clutch fan assembly that sticks out 4" or so. But, after fiddling around with it all weekend I think I have it! The top of the motor is 3/4" below the hood, and only 1" between the motor and radiator. But, on the flipside I was able to squeeze the transfer case in the existing space without having to cut any sheet metal. Win!

I don't think I'll win any awards for getting things done fast... or for pretty welds....it took me two days to fabricate two motor mounts, but I am happy with it and I hope they will last longer than I will.

As an additional "Win" I was able to get the engine hoist out of the driveway...and that makes the wife happy!

Here is one of the new motor mounts-they are hydraulic motor mounts from a Cadillac STS. Beefy. And hopefully smooth.

And a pic of the clearance between the valve cover and hood: