Diesel CJ5 Project, need Trans and Transfer case advice

Diesel CJ5 Project, need Trans and Transfer case advice

DieselJeep

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Mansfield, OH
Vehicle(s)
1974 CJ5, Isuzu 1.8L 4FB1 Diesel
Hi everyone!

My project is a first for me, as It's my first 4x4, and first diesel(even though I tried[and was horrible at it] to sell Jeeps in late 90's, and service/repair semi's at work)!

So, I need some sage Jeep advice on a good choice for a 5 spd and transfer case for my Mid-70's CJ5 project with a 1.8L 4FB1 Isuzu diesel.

Goals of the project are:
1) Mechanical injection exclusively
2) Cheap Fuel
3) Improved Power
4) Reliability
5) Simplicity
6) Cost
7) Fuel economy

All of these are a balance, and variable to a point.

Forced induction is in the works, goal is @ 150-200 Foot lbs. torque.
No, I am not trying to build a voraciously thirsty monster motor. I'm done with that stuff. This will be a daily driver, that is fairly capable off road. Suspension and axles will be stock. I'd like @ 25 MPG+ on highway, but don't want a slug that Grandma gets mad at on the street.

PO says the factory stock axles are @ 3.78(or 3.86) I believe. Somewhere @ that.
It came factory with an I6, and 3 spd., but those were left behind.

With so many parts choices, I'm having a hard time sorting what would be best. Some say T5 is weak, AX15 is good, transfer case output wrong side, Ect...

Thanks in advance for sharing the love and wisdom!!:chug:
 
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You have aroused my curiosity. I too have considered a diesel conversion, or even building a diesel specific CJ. The problem I have encountered is availability of affordable engines. If I can not do it on a budget, It is not a viable build.
 
Glad I could get the gears turning!
I have been thinking about this concept for a few years now.
There is NO WAY I'm paying $5 a gallon for fuel.
Once this is drivable, ALL of my gas vehicles go bye-bye.

I found this motor on Craigslist, fairly cheap. They are out there.

The benefits of this motor were:
Weight: Fully dressed, 368 lbs. UBER light for a diesel. No 700 lb motor for me, TY
Cost: you can find them for < $500
Design: They have cooling piston squirters, beefy webs, forged rods and crank.
They will handle 15+ lbs boost no problem in stock configuration.
Economy: In an Isuzu P'up or Chevette, 45MPG is common

And for whoever would start knocking Isuzu diesels,
they are the 2nd oldest Diesel manufacturer in the world, after Mercedes Benz.
I considered using a MB I5 motor, but those are 700 lbs as well.

Seems for some reason almost all manufacturers think a small diesel has to weigh 700 lbs.

The biggest drawback seem to be
Transmissions: Isuzus are kinda rare here in OH. In the early-mid 80's trans 5th gear is weak.
Late model Isuzu trans are much better, but still rare @ here.
And I wanted to keep the harder to find parts to the motor.
BUT everything for the 4FB1 CAN be found, if you know where to look.

FYI: I will have less than $2 G's in this whole project when done.
 
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I have an Isuzu 6.6TD in my pickup same as everyone else with a Chevrolete Duramax, the engine was a $4800 option in 2003 and at 120,000 mi. the injectors failed for a $4000 repair estimate that I was able to do myself for about $1500 with remanufactured injectors and 2 solid days under the hood then the fuel pressure regulator went out shortly after for another day under the hood and parts $. Ya I've heard of Isuzu.;) Other than that it's been solid.
 
What about a Kobota M108 engine. Its a 100hp Turbo. Not sure of the weight but the Kobota are the smoothest and most silent diesels I run.
 
LOVE what im hearing...im currently working on getting my jeep going and plan to play with it till i can find a good little diesel to go in it. sounds like you have a great start. Id say that you would almost have to consider all all new running gear, unless you can find a adapter plate to like a T-150. A small 4cyl diesel is a great option( close to the same weight as a 6cyl, close to the same hp and torque #s, minor changes needed). I just passed up a 4bt cummins today went for 1200 at a auction.
 
For my conversion, I would want a mechanical pump light weight 6 cylinder. I think non turbo just to keep the cost down. I really like Mitsubishi diesels, but availability and cost would be the determining factor.
 
:chug:
Glad others dig it.

Here's the kicker: The Gentleman I bought the motor from also threw in a Intercooler (from a Peugeot or Saab, plastic tanks, gunna test to @15psi, will work for now), an nice M90 from a T-bird, most of the cast aluminum intake ducting, and two cleaner housings. So for $500 outlay, I guess $350 in my running motor. I forgot. Has 60,000 original miles. ;)

Working on a spare, running, > 100,000 miles, @ $200.

6.2 injector tips fit perfectly, turbo Cummins 4bt timing components fit in the in "Altitude Compensator"...

Did you know a Perkins Diesel was a CJ5 option? :D

And when I am pushing 150 ft lbs, from a motor that weighs 360lbs, in a vehicle that weighs one ton...:rolleyes:

Already have 6 gal of "alternative fuel"...
 
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An Outstanding Individual from AZ found the Holy Grail of this build in a Pick-your-part.
A 1993 Isuzu Rodeo 2.6L I4 2WD Manual trans Bell housing.
These came with a WC T5 stock.

RARE item.

BUT will bolt right to the 1982 1.8L 4FB1 Isuzu diesel(from a Chevette), and a T5 5 spd...

It's on it's way.

Carl, you kick serious Bootay.
 
What about a Kobota M108 engine. Its a 100hp Turbo. Not sure of the weight but the Kobota are the smoothest and most silent diesels I run.


I looked into these once and they are in the 700lb. category at best. I think they'd make a sweet engine, especially since you say they'd be rather quiet but you'd have to start looking into suspension and steering upgrades. That might kill a low budget project... then again, pretty much any diesel does.

Kubota Engine America - Compact Diesel Engines
 
I looked into these once and they are in the 700lb. category at best. I think they'd make a sweet engine, especially since you say they'd be rather quiet but you'd have to start looking into suspension and steering upgrades. That might kill a low budget project... then again, pretty much any diesel does.

I would respectfully disagree.
I'll have @ $500 bucks in TWO NICE RUNNING LIGHTWEIGHT diesel motors... And no suspension mods required. Yes, they aren't putting out 400 lbs of torque. But I'm not looking for power bragging rights. But if I get 25-30+ MPG(which is possible), a winch will get me through the rough spots. I won't care how long it takes me. I'll still get there.

I like to say, the "romantic" and/or impatient get ripped off during a purchase. So if you MUST have "THIS" or "THAT", NOW, then you generally pay too much.

I went to look at a CJ2a when I bought my CJ5. The only thing I knew as fact was I wanted a smaller/lighter Jeep or Willys, and I wasn't gunna pay more than $1,000 for it. I wasn't "romantic" about having a CJ2(I actually wanted a CJ5 anyways). And for the motor, all I really knew was I wanted a small, lightweight, mechanically injected diesel. I saw the CL ad, and did quick research for a few days, then called him. Ended up I spent $150 LESS than his ad was asking for, and got a BUNCH of freebies. And didn't have to worry about selling an unwanted(by me) diesel Chevette automatic trans.

It's all about being honest with yourself concerning your goals, and sticking to 'em, religiously.

And I REFUSE to pay $5 a gal for fuel. Which in a few months will be the reality.

Food for thought:
If America's Infra-structure falls(and it's obvious that most of the politicians have that in mind, Rep AND Dem), gasoline will be un-burnable in gas motors within a year. And only the very rich will be able to afford it if it's still available. However, I will be able to walk up to any abandoned vehicle, drain all the oil based fluids, and use them for fuel after filtering and being cut with #2.

AND be impervious to an EMP. Some might call me crazy.:rolleyes:

So if you have been considering a diesel project, I personally wouldn't wait too much longer...


PS: That's a neat link to the Kubota diesels!
 
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I know that the newer Jeeps run pretty good 5 speeds, I think they are the NVG 3550. I used to get JP Magazine and they swapped one into a CJ6, and it worked pretty well. the only issues with this trans of course would be your final drive shaft length (not too bad if you leave your suspension stock) and adapting it to your engine. I know kits are available to bolt it up to your xfer case.
 
Whoa.:eek:
Going on a tangent again.:rolleyes:

Any Trans and Transfer case advice?:D
I would think these guys could help:

Cummins 4BT & Diesel Conversions Forums

If you read my profile, you'll see I've got the beloved 700 lb. diesel engine of which you speak. I'd be interested in hearing about you alternative fuel plans...two tank system? Pollack switch? I blend diesel and wvo in a 1.6 vw and my 7.3 Ford (International), I haven't needed any pre-heating. I haven't done much of the work myself, so it's been expensive.

The one big flaw is the 4 speed tranny. It's got a very low granny first gear, therefore I spin 2500 rpm at 60 mph..not very economical. When I had the differentials regeared, in exchange for gold bricks at the local 4 x 4 shop, I got 3.92s, 'cause that's what the kid I got the Jeep from had in the rear, with the factory 3.73 in the front!

It occurs to me that with the T19 and Dana 300... you could get any hwy speed you wanted, with the proper diff gears.
 
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I would think these guys could help:

Cummins 4BT & Diesel Conversions Forums

If you read my profile, you'll see I've got the beloved 700 lb. diesel engine of which you speak. I'd be interested in hearing about you alternative fuel plans...two tank system? Pollack switch? I blend diesel and wvo in a 1.6 vw and my 7.3 Ford (International), I haven't needed any pre-heating. I haven't done much of the work myself, so it's been expensive.

The one big flaw is the 4 speed tranny. It's got a very low granny first gear, therefore I spin 2500 rpm at 60 mph..not very economical. When I had the differentials regeared, in exchange for gold bricks at the local 4 x 4 shop, I got 3.92s, 'cause that's what the kid I got the Jeep from had in the rear, with the factory 3.73 in the front!

It occurs to me that with the T19 and Dana 300... you could get any hwy speed you wanted, with the proper diff gears.

Thanks for the input, Gents.
I will definitely check out that forum as well. TY!
That's kewl, if you are running a 4BT. I certainly ain't trying to knock that powerplant.
It was just too heavy, thirsty, and a bit pricey for my plans.
Mad Respect you are burning Alternative fuel.:notworthy:

I was actually considering a 4 cyl T5 5spd. I guess the very max Torque I'll be pushing will be 200 Ft. Lbs., so I guess if I use the PROPER fluid(specific grade ATF), I should be fine. Plus I would guess the gearing would be close. Seems the biggest problem with the T5 is guys putting the wrong oil in them which causes 95% of the problems with them. There is actually a jeep 4cyl T5 on the local CL. Unfortunately I have other commitments to pay for this week. What's REALLY crazy is there the 90-97 RODEO 2.6L I4 manual trans bell housing bolts perfectly up to the Chevette diesel, and almost any T5. the starter is even in the right place. So if I go with a T5, I have almost no fabbing, save the hyd line/clutch pedal. What are the odds of that?

I actually bought the CJ5 without motor, trans., and transfer case.
The Dana 300 seems like the transfer case I want. Didn't know they had different ratios. MAN! There is so much yet to learn and sort out.
 
Another alternative (if you can find them) is the 81 - 87 Isuzu turbo diesel 4D55 (available in the pickups). They are great running and pretty bullet proof - well the one I drove never died... :D
 
I am waiting to get my bell housing(should be here NLT Weds.) to measure the trans side mounting surface and bolt pattern. As a newb to Jeeps trannys, I have to ask. Judging only by the pics here: http://www.jeep-cj.com/forums/f2/transmission-transfer-case-variants-types-cjs-53-86-a-134/
is the bolt pattern of the Jeep T5 identical to most of the other Jeep manual trans.?
This Holy Grail(as a rare separate bell housing that bolts to my motor) I found will bolt my motor to the T5 in an Isuzu Rodeo(don't know yet if different to JP trans pattern. But I know T5 pattern in S10 is different).

I have read a lot of T5 bashing. Now considering I am only gunna have maybe 150- 200 ft. lbs (after boosting), would a T5 be OK and reliable? I HAVE heard folks using a T5 behind 360's, and being just fine.(I'm guessing mostly street driven by responsible adult). I know off roading can be very hard on parts. BUT, I am NOT trying to do crazy stuff, with a V8 pushing 400+ FT lbs TQ. I'll do that stuff SLOWLY with a winch(and be fine with that). I also WILL be using this as a daily driver(a REAL daily driver), and would like some economy. BUT I don't want to blow a trans in the middle of nowhere when I DO go off road.

ALSO. Whatever 5 or 4 spd I use, what would be a good Transfer case to use? I am looking to bolt everything up directly, no adapters, ect., and having a hard time sorting everything out. I like the single stick simplicity(and cost), but what is the advantage of a twin-stick 300? Would this be overkill for my project? Thinking it might be, and don't know if it will bolt directly to a T5.

Please remember also: extra rotational mass in heavy duty trans and/or transfer cases will significantly hurt my street acceleration, and my economy. And with a low HP/TQ output, I don't want to overkill on my duty ratings unnecessarily, but you guys got me terrified of a few of the stock trans...and the words "Light Duty".

1974 CJ5, pass side front pig, @ 3.73 gears (I believe, whatever ratio is near that, factory.). Narrow track...

PLEASE chime in. Getting close to the point where I have to start looking for my Trans and transfer case.
 
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Just a fly by comment... uhh,, the problem with breaking parts and jeeps or 4x4s in general has allot to do with traction or the size of the tires.

I had a T5 in a 86 Fire Chicken, I bought the car new, and I beat the hell out of it. I put 200k on it, and it was still shifting fine, and never had problem one. I also dumped a 350 in that car at around 120k with a cam, heads, headers, aftermarket ignition, probably making around 350hp, and when I say I beat on it, well, I was 18 when I bougth the car, and have a real need for speed.

My point is, I could not hook the car up (could not get traction with small tires), I like to believe thats why it never broke. I also religiously serviced it. So go with the light duty trans/transfer case of your choice (there are still some Id stay away from), just don't firewall it and side step the clutch, and keep the tire size reasonable, you should be fine with a little "finesse". (think of your transmission/transfercase/driveshafts/axles as a fusable link. Dont give a reason for one of the fuses to blow, usually its too much power or too much traction, you can usually get by with one or the other, its a problem if you have both)

One other note, not sure if you plan on wheeling this thing, but have you given any thought to the diesel fumes you will be eating when moving slow (crawling in low gear), and the exhaust that is going to be coming in the back of your jeep as your going down the road ?

Thats the only thing that has kept me from dumping and oil burner in my Cj. Ive got 4 diesels, a 7.3L, a powerstroke, benz 3.5L and a 5.9L cummins, I love all of them, but dont think I can do the smell on the trail. I should also mention that I dont drive my jeeps much, unless Im going wheeling (they are not daily drivers). Although, I heard second hand today from my B/O who works for a large oil/gasoline distributor to expect "gas" to be $6 by June, and $10 by winter. So your oil burner is not a bad idea all things considered, but expect the smell.
 
I appreciate the input, alot, I'm kinda stuck.
Funny you mention those 2 things.
They are what I'm stuck on.

And I certainly, agree. Good maintenance goes a LOONG way. And I shift like I have an egg in my hand. I'm 38 now, and this Project is the polar opposite of anything I've built in the past.

And I guess you are referencing the French boat anchor. Sounds like I'll be just fine with a T5 then. Just have to sort out the clutch components. Maybe I'll get lucky once again there too. So what Transfer case bolts stock to the T5? D300, or Dana 20 maybe?

I DO plan on going off road, as often as possible, but not Heavy Duty Parts breaking style. Be perfectly happy crawling, and winching, if necessary.
And probably after the S/C is mounted.

I am going with a military theme custom, so I want to have a slightly knobbly tread/edge of section, like the BF Goodrich T/A KO's. But I don't have huge HP to rotate 400 Lbs of 35 inch tire/wheel. And with 3.73(?) gears, and 60HP before Boosting, I sure need a smaller tire on the road. I have an offer from the Gent I bought the Cj from to trade the AMC chrome(not good shape) 15"(x8?) wagon wheels, for some 16 inch military rims. I don't know yet the width (6.5 or 7?). If I do, should I go for the smallest 16" size (LT215/70R16), or do you think that still really be to tall? I also hope to get a very "squared shoulder" look to the tire/wheel, with little sidewall bulging and roundness. At least on the street, at 30 or 40 PSI., not at low air for traction.

I have a cobbled 2" body lift from way back when made of square tubing to remove. CJ also has an aftermarket set of springs lifting it I'm guessing 4-5". Wheel wells also cut, so have to fix quarters. Long fenders are being replaced with short nose anyways. My point being, there's way too much space between the body and the tires, and it has fairly large tires now. Hoping I can keep the lifted springs and it not look stupid with possibly smaller dia. tires.

Stupid off the cuff question, is it possible to use shorter shackles with the heavily arched springs?? These look to be @ 4" or 5" center to center.

As far as the smoke puking, I have been worried about smell. I have been trying to decide if I should put a vertical stack on it for that reason. Thing is, sometimes I really don't like what people do with them. Like fingernails on a chalk board. I do already have a FlowMaster @ the right size, and thought about a simple downturn aimed straight at the ground, exiting behind the seats. Would that create problems fording, say if I stalled? Or should I use a stack? Is that what you might be hinting at? Would the odor be less with a stack? Internationals point at the ground...

I have fairly decided on a custom semi-permanent Intake snorkle.


Yes, I am a Newb to off-road. But not forever.

Sorry, no pics yet.
I'm in the process of moving myself, as well as dragging the Cj home.
THIS COMING WEEK! :chug:
 
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