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I'm considering a 4bt with T18 Trans and Dana 300 Xfer. This will be going into a CJ7 with stock diffs.

Will this work? If not, what's the preferred setup?

I definitely don't want to play the "weakest link" game.

Thanks as always.

OS
 

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I haven’t ran a 4BT in a CJ yet, but I have been around jeeps for many years.

I have broken U-joints on the Dana 30 front (in good shape) with 33's running a 258 I-6.

Doubt the Dana 30 up front would live long with off-road use. The AMC 20 in the back might be OK with trussing and flanged axle shaft swap.

Better yet is to find a front and rear Dana 44's from a Wagoneer and swap them in. (matching ratios and only a couple inches wider)

Some claim you need, Dana 60's but I doubt everyone needs them off-road.

T-18 and Dana 300 should be just fine...

4BT in a CJ-5 that would be fun...
 

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from what i've read the 4bta has about 290lbs of torque....
the stock cj is about 245lbs of torque?...
i would think the amc 20 would be fine with the one piecs axles...
i was told though that the d30 should not be used in excess...
i think the torque #s are right?
but i'm not looking for a rock crawler either...
 

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watch your axle gears for highway speeds. With a wide ratio T18 and 2.6 low in the d300, you can afford to gear higher (numerically lower)..... like a 3.07
 

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You didn't mention tire & rim size - which could play a big role (in durability & rpms). Stock jeep tires are like 235/75/15's which are roughly 28" or so in height. I personally wouldn't run anything larger than 31's with a stock D30. The 2 piece rear axles would have to go to - they were prone to failure on stock setups. The AMC20 will hold up, but might need bracing if you plan to offroad (weak tubes).
 

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Discussion Starter #6
Thanks for all the info.....I plan to run 33's, SOA. It sounds like Dana 44's front and rear might be the way to go.
 

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1989 Jeep Wagoneer, 360v8, 727, stock for now,
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I'm considering a 4bt with T18 Trans and Dana 300 Xfer. This will be going into a CJ7 with stock diffs. Will this work? If not, what's the preferred setup? I definitely don't want to play the "weakest link" game.
Thanks as always.
OS
I've had my Scout 4BT on the road for 5 years, heres what I've broken.
1. The first breakage was the rear diff, gernaded the the spider gears, open diff pulling up oleander stumps with a real short chain. First gear low range , just let it idle. (repaired and added power-locs at both ends)
2. Front drive shaft at the weld, wheeling. (Stock factory shaft)
3. Rear drive shaft u-joint at the diff, powering over some bumps in 2 hi.
4. Front passenger side u-joint, took out stub axle and inner axle.$$
My thoughts, if your useing it mostly for the street, you can get by with D44s. All of the breakage except #2 were with the engine at or near idle.
I won't say I'm easy on the drive train. I started off driving the Scout using the same style I'd used on my 92 Dodge CTD, use the brakes to pre load the Powr-Loc's to get traction to all wheels. This worked great on the Dodge, never broke anything in 10 years of wheeling the beast. There are some minor differences, The Dodge had only 45:1 low the Scout has 90:1, but I do use 2nd low more at 55:1. The Dodge has vacuume boost brakes, Scout hydroboost. Maybe these differences has someing to do with the breakage other than the the size of the parts. probably some, but I'm putting my money on D60's.
Steve
 
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