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Discussion Starter #1
I'm getting ready to start on my 4bt into a 88 Wrangler YJ Build. I bought a pretty much rust free YJ with a new 4" spring lift (still under) and 33" tires. It has 3.08 gears, which seems to put me right in the sweet spot for cruising rpms.


I also have purchased a running driving step van with a 4bt and a 4 speed. I dont have it home yet, but have to assume its a T-18. Yeah, I bought it sight unseen but from reputable people, so I'm not scared. The price was right too.


I guess my first questions are as follows:


I'm looking at Farmstrong motor mounts. Thumbs up or thumbs down on that choice?


Can anyone recommend a drivers side drop transfer case that is easy to mate to a Ford T-18 4 speed?


With a 4" spring under lift, will I still likely need a body lift?
 

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Welcome to the forum. First off, I'm not a Jeep person but might be able to help you some. First, a Ford application would not be a T18. Ford vans typically had the T19 and there were a few rare ones with the NP435. Very few GM vans had manual transmissions on a 4bt. They were mostly automatics but there were a few manuals. This being said, none of these were the 4wd transmissions and none had an OD gear. Most of what we see used here on the forum is the NV4500 that came out of the Dodge Cummins trucks or a Ford ZF S5-42. If your engine had the Ford adapter plate then the ZF is a bolt on. Transfer case on the Ford could be a NP205 which will bolt to that transmission but need just a bit of clearance work for the shift rails. See photo below. The Ford would be driver's side drop. Another Ford transmission that can be used is the Mazda M5R2-OD which is not as heavy duty as the ZF. Its durability depends on how you treat it. In normal driving situations it is fine. Get rough with it and it will eventually die. As far as engine mounts go, those can go all over the board. The FarmStrong mounts you mention look nice but can have some drawbacks. They use a standard engine mount which will transfer a lot of vibration to your vehicle. The 4bt is well known for its vibration. The best vibration control comes from the LORD brand isolators. You'd have to design your own mounts for those. We have a lot of Jeep guys here on the forum and they can probably help you better on that. Once you get the engine, you need to determine what all needs to be done to it before putting it into your Jeep. Most all of them need some TLC in various areas. Never assume you can take it right out of the van and install it in another vehicle without some work. Need to do the KDP repair and new gaskets and seals as a minimum. Probably will want a better turbo unless this is a P pump engine. Injectors need to be tested. I always tell guys to allow yourself about $1000 for the basics not counting the turbo. If you find other issues that number can climb quickly.
 

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Because you have the Ford adapter, consider using the 5 speed overdrive Ford/Mazda M5R2-OD that was used in F-150s behind the 5.0L V8 or 4.2L V6 engine. The M5R2-OD gear ratios are more diesel friendly than the gasoline ZF gears. They can be purchased used for $200 - $300. Ford used the Borg Warner 1356 transfer case behind the M5R2-OD transmission. The BW1356 can be purchased used for $100-$150 It's a stout transfer case with a 2.69:1 low ratio, but it is a bit wide. I suggest taking measurements from the centerline of the YJ transmission output shaft to the driver's side frame rail and compare them to a BW1356 to ensure it will fit before purchasing one.
 

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Because you have the Ford adapter, consider using the 5 speed overdrive Ford/Mazda M5R2-OD that was used in F-150s behind the 5.0L V8 or 4.2L V6 engine. The M5R2-OD gear ratios are more diesel friendly than the gasoline ZF gears...
My F150 (see link below) has the M5R2. The hydraulic clutch slave cylinder is concentric with the transmission input shaft (Translation: The transmission has to be removed to replace the slave cylinder). There is a known problem with the hydraulic slave cylinder, they start leaking after two years. For more details, click on the thread below, go to page 18, and start reading at post #345.
 

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95Z28A4, the BW1356 transfer case is a decent unit, but will probably be too wide to fit in a Jeep. It's what's in my F250 and it just about goes frame rail to frame rail there. That's why I mentioned the NP205. Even it may be close in the Jeep. Russ, on the issue of the clutch slave will be on both the M5R2 and the ZF S5-42. Both the main OD transmissions in the small block bolt pattern are designed that way. With the high 3.08 gear ratio he may get by using just a 4 speed. Would just need one from a 4wd application instead of 2wd.
 

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My F150 (see link below) has the M5R2. The hydraulic clutch slave cylinder is concentric with the transmission input shaft (Translation: The transmission has to be removed to replace the slave cylinder). There is a known problem with the hydraulic slave cylinder, they start leaking after two years. For more details, click on the thread below, go to page 18, and start reading at post #345.
That seems odd. Do you think your combination of parts could be causing the slave cylinder to over-extend?
 

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That seems odd. Do you think your combination of parts could be causing the slave cylinder to over-extend?
I really do not know. I have heard from multiple sources that this is a common problem in stock Ford trucks. The stock master cylinders and slave cylinders are plastic. Most of the aftermarket replacements are also plastic. This time, I was able to buy aluminum parts for a small premium. My fingers are crossed...
 

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Discussion Starter #9
Thanks for the responses. I should have the Van home this week so I can start pulling the motor and transmission. I am "planning" on pulling them as a unit. I am also "assuming" i can pull the motor with tranny attached through the door of the van with my cherry picker. Can anyone chime in on success with that method-or do I have to go out the front? I'm hoping to sell the van intact for someone to repower or use as storage, so I didnt want to cut it up. Of course, I may just cash it in for the aluminum scrap value too...

I will look up the LORD motor mounts and see what they are. I can wrench, fabricate, and have the tools. Just like to ask those who have been there and done that what to expect before I get started.

A divorced drivers side drop NP205 may be an option too; depends on how long my rear driveshaft would end up being..
 

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... I am also "assuming" i can pull the motor with tranny attached through the door of the van with my cherry picker. Can anyone chime in on success with that method-or do I have to go out the front? I'm hoping to sell the van intact for someone to repower or use as storage, so I didnt want to cut it up. Of course, I may just cash it in for the aluminum scrap value too...
A picture is worth 1,000 words.
Removing motor - Low res.JPG
A younger me (about 2011). The ground was sloped, the plywood and come-alongs worked much better than trying to drag the cherry picker in the dirt.

Unbolt the doghouse and the floor section over the transmission (I think I remember a floor cross brace that unbolts also). Lift straight up, rotate and ease it out the door.

We drove our Grumman van for a year+ to get familiar with the 4bt. Got the governor spring replaced and installed a crude intercooler. Eventually, the tires wore out and 4 new 19.5 sized tires was a budget buster.

2018 03 23 - Floor - Low res.jpg

The van became a heavy duty storage shed. The van was backed into position, against the ramp leading into the shop overhead door (the land is 3 dimensional here). The step bumper is against the dirt ramp, just a few steps from the shop. I put the van on blocks (tires are slightly off the ground) and carefully leveled it. Heavy duty (flatpack) shelving from Lowes fit under the roll-up doors.
 

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You may find a divorced transfer case will make the drive train too long on a Jeep. Will have to see how long that transmission is. Probably has a brake unit on it that you can remove which should help in length. The LORD mounts tend to be a bit hard to find in the aftermarket. Also, a tad expensive compared to other mounts. There are a few aftermarket units that are similar but not necessarily identical.
 

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Discussion Starter #12
Thank you all for the input. I'm at work but I see the van was delivered (driven) to my home at 1:28 pm, so I cant wait to get home and check it out. Yeah, security cameras are awesome. I have a 4 day weekend and I'd like to think i can make a little headway on getting the motor out, although I also have 80 acres to brush hog.

Motor / tranny / transfer is all out of the jeep and it is sitting in my air conditioned shop. Just need to get the motor and tranny unit out of the van on the cherrypicker and get it rolled in and the weather can do what it wants. It's going to anyway! I'm going to attempt to pull the grille off the jeep and stab it in as a unit and then block it up til I get some motor mounts.
 

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Thank you all for the input. I'm at work but I see the van was delivered (driven) to my home at 1:28 pm, so I cant wait to get home and check it out...
Drive it for a bit, get a feel for the 4bt. With 80 acres, you won't need licence plates.
 

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Discussion Starter #14
Just brush hogging about 80. I live on a bit over 300....

So, it turns out that what I bought (pig in a poke) is a 1994 Oshkosh chassis Grumman Olson body step van. The 4bt and 4 speed are both excellent. I drove it around. Starts at the touch of the key, very responsive, shifts well. It is intercooled, which maybe is to be expected on one that new, but I was surprised. So maybe its a GM model instead of a Ford model? I searched the internet, ran the VIN, etc, but I guess I'll find out when I see the tranny. The odometer shows just over 50,000 miles, which I find hard to believe, but I did read that they often installed a new odometer / speedometer when the chassis was repowered, so maybe I got really lucky.

Heres a question: Has anyone been able to use the factory intercooler and radiator in a YJ? My measurements show it to be very tight to the firewall unless perhaps the belt driven fan is eliminated. The intercooler will barely fit width-wise, but i think with a little trimming it would.

I'm going to offer up the chassis and body for someone to repower or use for storage, but it may bring as much for scrap value I reckon. Planning on bolting a tow bar to the bumper and its about 5 miles to a scrapyard if I go that route.
 

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By 1994, I suspect that the van was built with the 4bt installed. Most likely, the Oshkosh chassis arrived at the Grumman Olsen factory with the complete driveline installed.

I "suspect" that you will have to use some sort of aftermarket intercooler due to space limitations.
 

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It's a pretty good bet it's a Ford adapter plate if the transmission is a T19. The GM manual flywheel is not common and that adapter plate would have the engine in a tilted position. If were a 5 speed it would most likely be an Eaton transmission on an SAE2 adapter plate. Russ, you're certainly correct that van was likely built with the 4bt and not a conversion.
 

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It's nice that the engine still has its ID plate. Can come in handy should you ever want to get parts from Cummins. See you got busy and took the engine out. Now the fun can begin.
 

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Discussion Starter #19
20190707_183117.jpg 20190707_084411.jpg

I wanted to get it out over the holiday weekend cause now I'll just get to work on it evenings and weekends as time allows. I also wanted to get it in the shop, as it is air conditioned!

I power washed the motor twice to get it squeaky clean for the upcoming work. The trans is in fact a Borg Warner unit, assuming the T-19.

So here are my new questions:

Has anyone used front air bags to help with the weight? I have a newly installed 4" lift and dont want to sag much beyond normal ride height.

Can the oil pan be reversed to put the deep end towards the rear? Is there enough pick up to allow that? Seems it would correct a lot of clearance issues.

Is the KDP an issue on a 94 model? I've done one on a 6 in the truck years ago, so I'm familiar.

My PS pump had a remote reservoir. I assume they make one with an attached reservoir. P/N?

Has anyone used the van motor mounts? Both the van and the jeep have inside frame widths of 32", but the mounts sit inside the open C on the van. This would allow me to pare them down to fit inside the jeep frame, and possibly leave a notch to set on top of the frame for better support and dispersion of the stress risers. Thoughts? Height permitting of course. if the oil pan can be rotated that allows lots of room to work.

I'm going to pull that mount assembly out of the truck tonight. It bolts to the frame and has a nice crossmember built into the mounts. I'm also going to take the rear trans mount and the accelerator pedal. I left as much as I could completely attached to the motor when I pulled it. Had it out in 4 hours with a little help from my wife when it was time to wiggle it out of the hole.

I appreciate any and all responses. I'm not wanting to recreate the wheel, just learn from how you all have approached it.
 

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Is the KDP an issue on a 94 model?
Yes, all inter cooled engines from 1991.5 to 2002 can be effected by the KDP. Yes, even the early 24v engines.
 
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