Jeep Grand Cherokee + Cummins (3.9L) ISBe + Allison 1000-Series = :)

[mschoenheider]

Matt,

I think you may have a problem using the output shaft you have in the LCT-1000 with a 231/241. The diameter on the normal input shafts (male) into a 231/241 is about 1. 25" (at least it is for the 21 and 23 spline jeep and dodge input shafts). The outer diameter on the female transfer case input shafts is approximately 1. 935" If you use a 1. 75" male splined shaft in the female input shaft, you will have a very thin wall on the female shaft. I don't have a 29 spline input shaft here to measure, but I don't think they are substantially bigger, if any bigger , than the 23 spline one I measured. Mark

Mark

 

[HoleshotHolset]

Hey, Mark:



I looked through the email you sent me this morning and couldn't find any common t-cases with a 34-spline input so I have started to research what is involved in replacing the output shaft on the LCT-1000 with a smaller one.



I'd hate to loose strength by going with a smaller shaft, but I'm pretty sure I'll find a workable solution that doesn't make too many compromises. If I have to drive around a 2wd Jeep for a while, it's all good. The eventual goal is 4x4, though.



Matt

 

[Bjarni G]

I have heard (cannot confirm this) that the NVG273 in the Ford Superdutys have 34 spline inputs. Not sure if it is the same diameter as you have.



Bjarni G.

edit: here it is: http://www.drivetrain.com/transfercaseappford.html

 

[Brayden]

Hey Matt,



PM me here or email me again. . Sorry for no response. . Super busy... .



PM's are actually easier because I can distinguish between members here and some of the random emails. I get plenty of email interest.

 

[HoleshotHolset]

Bjarni: Thanks for the info/link - that page has a LOT of good stuff on it.

I'm pretty sure I'll have to swap the output shaft to something a little more common. The extension housing will also have to be swapped out.



Brayden: Thanks for the response. PM sent.



Once I have the Jeep on the road, I'll look back on all of this stuff and either laugh or cry.



Matt

 

[Brayden]

I believe the 34 spline shaft you are speaking of is the 2wd output shaft. .



The 4wd shaft is 29 spline, same one found on the NV4500/NV5600.



One less headache there. :beers:

 

[Matt S]

Matt,

What does the emissions sticker say on that engine? Your combo has peaked my interest but the DMV in California is a little strick.



Matt

 

[HoleshotHolset]

What does the emissions sticker say on that engine?

I don't have the exact wording, but it reads just like what you'd see on an ISB out of a Dodge Ram... "This engine is intended as a Medium-Heavy duty engine and is certified to operate on diesel fuel. Don't use this engine in an urban bus, or we'll take your first born child. Blah, blah, blah. "



I can get a picture of the data plate on here if you'd like.



Matt

 

[DKarvwnaris]

Matt,

What does the emissions sticker say on that engine? Your combo has peaked my interest but the DMV in California is a little strick.



Matt

You can always find a 5. 9 front geartrain housing assembly and either pull the data plate off of it or just replace the entire thing on the 4bt with it, they are interchangeable. I know of several guys who have done this to get the light duty truck emissions tier listing. ( I myself would NEVER EVER think of such a thing since that would be a blatant violation to a CARB facility's inspection stations who can barely see the difference between any type of diesel engine, let alone a 4bt verses a 6bt group).

 

[Matt S]

I don't have the exact wording, but it reads just like what you'd see on an ISB out of a Dodge Ram... "This engine is intended as a Medium-Heavy duty engine and is certified to operate on diesel fuel. Don't use this engine in an urban bus, or we'll take your first born child. Blah, blah, blah. "



I can get a picture of the data plate on here if you'd like.



Matt

When you get a chance I wouldn't mind a picture.



Thanks!

 

[Matt S]

You can always find a 5. 9 front geartrain housing assembly and either pull the data plate off of it or just replace the entire thing on the 4bt with it, they are interchangeable. I know of several guys who have done this to get the light duty truck emissions tier listing. ( I myself would NEVER EVER think of such a thing since that would be a blatant violation to a CARB facility's inspection stations who can barely see the difference between any type of diesel engine, let alone a 4bt verses a 6bt group).

I see your point. The rules only state no heavy duty engine. It doesn't mention medium duty engines.

 

[HoleshotHolset]

Here's a (crappy) shot of the engine data plate... I can get a better shot if you need it.



Matt

 

[Matt S]

Thanks for the picture. I don't know if it will pass here or not. It might not and I hate to do all that work for nothing.

 

[tractorman]

check out this jeep converison

http://www.canev.com/Jeep.html





#ad






#ad




#ad




#ad

 

[Matt S]

That's pretty cool alright. I'm looking into a VW TDI to mate to a 4 or 5 speed in a small jeep.

 

[Sled Puller]

Say, there seems to be a few older 4bts around here with 400 turbo Chevy autos behind them. I wonder if a 2. 73 or 3. 07 rear diff ratio would work with that transmission, since they have no overdrive?



Keep up the good work Matt, can't wait to see how the electronics work out.

 

[therabbittree]

sleddy. . the 3. 07s run great but i would still recommend a overdrive ratio. . because i ran 3. 07s with a torqueflite and say 75-80 mph was about tops and screaming. . might be good for offroad or racing use, but i'd stay away from a no overdrive trans in a street vehicle. . that allison should be sick . 62 overdrive and beef. now 3. 07s and the allison sound nice . . mummn can we say top end and mpg... with a transfercase a low hole is possible for creeping...

Thanks

deo

 

[Sled Puller]

You know me, the sweetness of the cheapness caught my eye!! :-laf

 

[DKarvwnaris]

Say, there seems to be a few older 4bts around here with 400 turbo Chevy autos behind them. I wonder if a 2. 73 or 3. 07 rear diff ratio would work with that transmission, since they have no overdrive?



Keep up the good work Matt, can't wait to see how the electronics work out.

Most of the bread trucks I canibalized for the 4bt's have had 3. 42 gearing at the lowest (numerically). Something to keep in mind for these rigs was their primary useage in city traffic and moderate speeds of 55 mph or lower.

I would look for a 3. 07 rear end, but much higher ratio than that and you'll loose too much low end torque, not from the engine, but the transmission's torque rating at low rpm's.

I will never build another conversion without an overdrive, automatic or manual. Its an insignificant cost factor to me in the short term, but especially in the long term.

 

[mazdarotary]

Hey do you guys think a 4 cylinder Cummins could be mounted in a 3rd gen 1/2 ton gasser truck. If so how much do you think it would cost,and would it be powerful enough?



Chris