transfer case

F

FG Jeep

NAXJA Forum User
Location
chicago
This is my first post on here however i've been reading up on stuff for a while here. Basicly this is the deal. I have a 94 xj sport. the truck is being built into a crawler that will see some time in the mud. this is a project my brother and i have embarked on and things are going well. However we can't make up our minds on transfer cases.

Here is the powertrain for the build. The truck is running a lq4 6.0 gm gen 3 v8. It has l92 heads and l76 intake. the cam is a 224/224 .581/.581 lift lsx style cam. the trans is this week anyways a built 4l60e, however we are toying with the idea of a th400 instead. This motor combo will be good for at least 400hp at the wheels figuring very modestly. In all reality it will probably be closer to 430-440hp.

So we come to the point of transfer case. the np205 imedately came to mind. however it appears from a few threads i've seen on here a lot of floor cutting is needed and the seat mounts are relocated. we had hoped to use stock xj seats.

we also talked alot about a using a np208. however after doing some research it appears there is no slip yoke eliminator kit avaliable for it and that there isn't much to do beef it up any further then what it is. but it is a fairly stout unit as is.

so then we started to wonder if a np231 was up to the task. I'm not very familar with this cases weakness and what can be done to improve it. This is our first jeep but were coming from a land of k5 blazers.

so we are welcoming any opinions of the 3 listed and any other options you guys think would be worth looking into.

we are really trying to put together a well rounded rig here that is a bit smaller then the full sizes we are used to.
 
I have a 205 in my XJ and it did require a bunch of cutting and I don't think you could run the factory seats and use the 205.

I've no expierience with the 208 so I can not speak twords that.

I don't think I'd run the 231 with the sort of HP numbers you are talking about. There are other larger chain driven cases you might look at though. I don't pay much attention to them so I can't really help you there.

If you are looking for a compact case that can handle some HP I'd look at a D300.

Realistically for what you want though you should look at an Atlas.
 
Try a model 20 from a bronco. Driver side diff. plenty stout and no chain. You did not mention axles so I assume you are using the stock ones for now.
 
cdhowell said:
Try a model 20 from a bronco. Driver side diff. plenty stout and no chain. You did not mention axles so I assume you are using the stock ones for now.
Click to expand...

What the heck do you know?
I want everyone here to know......this guy owned.....


(pause for dramatic effect)






A WRANGLER!!!
 
cdhowell said:
Try a model 20 from a bronco. Driver side diff. plenty stout and no chain. You did not mention axles so I assume you are using the stock ones for now.
Click to expand...
axles haven't been hammered out yet. for right not it is on stock axles. were not scared to fab stuff into the truck so a dana 60 or ford 9 inch aren't out of the question. I would prefer a stout more compact case if possible. As i said i would like to use stock seats. If that wasn't an issue the 205 would be what is going in the rig. at this point we are trying to get everything floor related worked out because we are sending the jeep out at the end of august to have the whole inside and underside of the floor done with spray on bed liner along with some other pannels on the truck. So that is why transfer case is kind of important right now. I'm going to look into a few that were suggusted here and see what i can dig up.

thanks for the input so far and keep it coming.

edit:
the dana 300 i see is a pass side drop for the prop shaft however is sounds as if by omitting one bolt you can mount the other way.

jmop thanks for suggusting atlas. i just dropped them an email about the jeep project. i have a feeling we will probably go with that even though its going to be expensive. I want to build this rig right the first time around. we shall see though. so am i out of my mind to get a transfer case that costs more then the truck did?
 
Last edited:
I'm going to second a d300, if you arent dropping the coin for an atlas. Lower low range than a 205, gear drive, you can twin stick it, fairly compact for the strenght it has.
 
xj6.0 said:
edit:
the dana 300 i see is a pass side drop for the prop shaft however is sounds as if by omitting one bolt you can mount the other way.

jmop thanks for suggusting atlas. i just dropped them an email about the jeep project. i have a feeling we will probably go with that even though its going to be expensive. I want to build this rig right the first time around. we shall see though. so am i out of my mind to get a transfer case that costs more then the truck did?
Click to expand...

You can flip the 300 relitivly easily but by the time you do that and do 32 spline outputs to beef it up and gears if you want lower gears you are into it as much as an Atlas.

I really like my 203/205 setup but it did require a lot of work around the tranny tunnel and I don't think there is any way to keep the original seats withough sacrificing a bit of ground clearence.

Personally I doubt that a 4160LE or a T400 will fit all that good in the tranny tunnel in an XJ. The AW4 is a long but relitivly small auto. Those others are a fair ammount larger.

I wouldn't get stuck on the XJ seats. If you are going to wheel it you should probably invest in a cage. It is a simple thing to put some good suspension seats in at that point.
 
i kind of had a feeling that d300 when all is said and done would be in the same ball park as an atlas. That being said i rather have an atlas. I'm shooting atlas an email this week to get an idea on what we will be looking at with it.

Don't worry the cage is already in the works. the cage is one of the first things we started on. Also plan to strengthen the unibody some as well. I'm not up for crawling rocks without a cage. so that was a no compromise when the build started.

the 4l isn't huge it is a bit wider then a stock xj tranny but it isn't going to require the kind of mods that a 205 would to make it fit. Yes we could do a suspension type seat but we have the xj seats already with the addition of some 5 point harness we had hoped to be in good shape.

it seems more and more that the truck is finalizing itself over the past week. Looks as if we will be running a d44 out of a rubicon wrangler for the front axle with a locker. the orginal plan was to run 38's on it but it might be 37's now more to come on that. Now we just need to narrow down the rear axle setup. been comptemplating a d60, ford 8.8 or maybe a a worked overy 44 in the rear. still up in the air at this exact moment.

while my brother and i aren't scared to fab on this truck and put some good parts into we are trying to keep to a budget. The engine setup isn't to bad because i'm a ls1 guy and have parts around so the motor esspecially since is a gen 3 iron block truck motor isn't super costly. we have some suspension stuff in the works, we building our bumper and other metal working stuff like a custom roof rack stuff like that. Things are starting to come together real quickly here which is good for the build.
 
Thoes axles wont hold the power you are talking about. The front axle will be a weak link in that its a low pinion gear set as well as the u joints will not hold up to that tire size and horsepower, even if you get a set of alloys. A Dana 44 or Ford 8.8 for the rear wont hold up eather to 400+ HP and 38s, ring gear and shafts too small to be reliable. You need a Ford 9" or a Dana 60 with 35 spine shafts. A good friend of mine ran a well built 4.6L stroker with a HP Dana 44 and 31 spline Ford 9" rear and every few trail rides something would blow up. After a HP Dana 60 went in up front and a 35 spline 9" in the rear, his truggy was a whole lot more reliable. Now the same axles are in a custom tube chassis buggy with a mild LS1 and on rare occasion (doing something stupid :D ) does something blow up.

AARON
 
was that rig more mud or rock based. what kind of obstacles were causing the failure etc.

The engine as i said is gen 3 chevy v8 its a lq4. which is basicly a cast iron verson of a ls1 in a 6 liter displacement. It is found in hd 2500 silverado's. the l92 heads are the new 6.2 gen 4 chevy v8 truck heads. they were orginally designed for the z06 c6 vette and work with all 4 inch bore gen 3 and 4 blocks. however they were opted for the truck motor when the vettes displacement grew to 7liters. the intake a is a l76. It is a high flow 90 mm unit that has a high floor to work with the l92 heads the l76 is a low profile version that fits under lower hoods like the pontiac g8 and holden commadore where the l92 intake is to tall. this combined with a 224,224, .581/.581 lift 114 lsa cam. a very proven torquey cam that makes good power all the way to 6800 rpms and in heads and cams setups in the smaller displacement ls1 makes 400-425 hp all day long. this is considered a smaller cam for a 6.0l v8 but none the less a proven performer. It doesn't take much to push the 6.0l over 400 hp and these are very proven parts that work on the lsx style motors. So i'm very confident that this motor will make that output.

So even with a set of chromemolly axles and good locker the 44 isn't gonna hold with a 37. the d44 is a pretty stout peice that is why i'm surprised thats all. What if a smaller gear is used and in conjunction with different transfer case gearing. I'm just looking for some input here because i have a line on a 44 and am really considering pulling the trigger.
 
A 44 front won't hold up with the tires you are talking about and the HP. A D44 has the same size u-joints as the late model D30. All you will be getting from that Wrangler 44 is a larger ring and pinion. If I remember right they arn't even a standard ring and pinion set. Even in mud it won't last long in my opinion.

Personally with that sort of power and 38" tires, I wouldn't considure anything smaller then a 60 front and a 14 bolt/D70 or 35 spline 9" in the rear.

It will run with chromo shafts all the way around but by the time you did that you are still weaker then a stock 1 ton axles and you've spent as much money as it would take to get 1 tons.
 
xj6.0 said:
So even with a set of chromemolly axles and good locker the 44 isn't gonna hold with a 37. the d44 is a pretty stout peice that is why i'm surprised thats all. What if a smaller gear is used and in conjunction with different transfer case gearing. I'm just looking for some input here because i have a line on a 44 and am really considering pulling the trigger.
Click to expand...

Just remember that the Rubicon 44 is just a D30 with a low-pinion D44 center section. People have run them with 37's but that doesn't mean that it will last if your hard on it. It would be a shame to put alot of money into a Rubicon 44 just to upgrade again down the road.

Consider going with a HP D44 out of a 70's Ford truck, or start thinking custom housing from Currie or Spidertrax with a 9" center and D60 outers. A few guys have gone full D60 in the front.

Greg
 
i did not know that about a rubicon d44. I thought it was a true 44 not a 30/44 hybrid. well that seals that then back to the drawing board on the axles. we don't want to run smaller then 37 inch tires so i guess we are going to be looking at some different axle choices. thanks for the input on the rubicon axle. I'm finding out that this a little bit different ball game then the k5's i'm used to. still fun just a little bit different.
 
stak has some cool stuff.

the pipe dream of running 44's is long gone. we will be using 60's or 9 inches or something to that degree.
 
Remember that most full float D60 rears are 30 spline (same as a D44). Thats why I recomend a D70, 14 bolt or a 35 spline 9".

The cheapest would be a 14 bolt. The D70U has a smoot underside so it slides over rocks nice. A 9" can be built super strong but arn't as strong as either the others in stock form.
 
I don't necessarily want the weight of a 70. i would like to keep this thing somewhat nimble on the trail. something full sizes aren't which is why my brother and i picked up a xj. So it will be combonation of well thought out weight placement a gob of horsepower and a stout drive train with 37's or 38's.

thanks for the advice about some 60's have lesser spline setups in there. i will keep that in mind.
 
xj6.0 said:
thanks for the advice about some 60's have lesser spline setups in there. i will keep that in mind.
Click to expand...

Actually they "all" do. 35 Spline 60s are very rare, few, and far between. And only the HDs, rare as well, can fit the larger shafts without modification. Your only options are to have the spindles bored out, or have D70 outers put on.
 
I think you need to look at the Ford 208's in the early 80's Bronco for a tcase. They have a fixed yoke on them. I know this for a fact. The 205 or 203/205 is a nice economical beffy unit that will handle any power but takes a lot of mods to get in unless you let it hang. I chose to tuck it up and am now tryiing to figure out my seat becase the factory will not fit.
 
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