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Discussion Starter · #22 ·
Well Its been a while and I picked up a 8.8 with 3:73s for the rear and MORE 8.8 brakets, a 1" body lift, a set of 3:08 gears for the 8.8, still tracking down a rubicon d44 for the front. And just put on four 31"x10.50" BFG AT/KOs on and used the RPM calculator on novak told me to get to 70mph with my stock np231(1:1 high) and the th400(1:1 in third) and 3.07/8 gears and 31" tires I would need to got to almost 2200rpm, with a overdrive auto(lets way .75) I would only need to rev it to 1750prm and since other members of my family would need to drive the jeep on occasion I would need a automatic since none of them can drive a stick(kill my dream of a nv4500) so to get to a descent rpm range I need a overdrive auto, there is the 700r4, same bolt pattern as the th400, and it should theoretical withstand the 4bt but I would need a converter plate or order one of those RV converters with the right pattern, And then to adjust the TV cable correctly. I also tow about 2000lbs every once and a while so another thing against the 700r4. Then there is the 4L80E which can surely withstand the 4bt, but its electronic and more expensive, that means a expensive controller or controllers which I've not heard good things about.
So a built 700r4? or a 4l80e and a controller? or is there any other overdrive autos that can mate up to the 4bt? that I missed?
 

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or is there any other overdrive autos that can mate up to the 4bt? that I missed?
47RH Auto OD from 1994 - 1995 Cummins equipped Dodge Ram. You'll need the Dodge Cummins flywheel adapter, flex plate & starter. Pressure switches can be used to activate overdrive and torque converter lock-up. IIRC cost of switches, wiring, etc. is about ~$100.

Mike
 

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Discussion Starter · #24 ·
Do you know what transfer case came with the 47RH? or what ratios it has? Because I called a local yard and they had a 1994 4x2 and a 95 4x4 though he couldn't tell me it they where the diesel or not.
 

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Do you know what transfer case came with the 47RH? or what ratios it has? Because I called a local yard and they had a 1994 4x2 and a 95 4x4 though he couldn't tell me it they where the diesel or not.
Transfercase should be a NV241 with 2.72:1 low. In case you're not familiar, the NV241 is a stronger version of the Jeep/Dodge NV231. It could be a NV241DLD or NV241DHD. I believe the DHD is PTO capable. The NV241 input shafts have different spline counts dependent upon application. Be sure to get one that matches the 47RH output. Some NV241 transfercases came factory equipped with a fixed rear yoke that would be beneficial with the short TJ rear driveshaft. I run a fixed yoke on the NP231 in my XJ with 5" lift.

It may be possible to mate a NV241OR (with 4:1 low) from a Jeep Wrangler Rubicon to a 47RH using the correct input shaft, but I don't know this for sure.

Mike
 

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Discussion Starter · #26 ·
From looking as some diagrams it looks like the 47RH is 31" with out transfercase thats kind of long for a TJ. The diagram was junk so it might be wrong.
 

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you will be fine with 3.07's up front and 3.08's out back or 2.72's and 2.73's with no binding, they are close enuff together to not hurt anything. Ford, IH, Gm and others have bee doing it for years, GM 3/4 trucks with 44's up front and 14 bolts out back are 4.09 front and 4.11's out back, early broncos are the same way, most 3/4 ton IH's are that way 44 front 60 rear, 4.09's and 4.10's. I have presonally ran 4.27's and 4:30's for years with no problems in a 44 front and 9" rear.
 

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Discussion Starter · #29 ·
Well I know that the 47RH comes in a diesel version from behind a 6bt in ram2500 its just finding the legth of the trans/xfer case from the diagrams and photos its a long transmission. Might not even need a rear driveshaft if its too long I could connect the output from the transfer directly to the pinion on the 8.8 :rasta:
 

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re:transmission choices?

What about using the 545RFE that was mated to a 2005-2006 Jeep liberty CRD...I know that they do use electronic controllers...Not sure if you were trying to avoid those? Could one have a adapter made so the bell housing would mate to the 4BT??

Jason
 

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CRD libby's aren't the only ones.... they use the 545RFE in all of the 99-06 grand cherokees, dakotas, etc... 4.0L or 4.7L
 

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re:trans

CRD libby's aren't the only ones.... they use the 545RFE in all of the 99-06 grand cherokees, dakotas, etc... 4.0L or 4.7L

I thought they did..are they different or the same??? It would seem like a good trans to use and suncoast sells a heavy duty TC for it.

My question to you guys is:

Does anybody make a adapter for this combo for the Cummins 4BT?

Jason
 
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