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Rig Options...

2K views 41 replies 19 participants last post by  Charly 
#1 · (Edited)
I'm building my '88 YJ and I want to make sure this is how I want everything to be. Please feel free to give me any suggestions...thatd be great.

I will be running 38.5" SXs, 5.38 gears in the diffs, and have a relatively low center of gravity. Goign to have the hood and fenders combined and making a new rear tub that angles in so I will be at about 104-106" of wheelbase.

Now for the DriveTrain:

Chevy 350 or 383 Stroker to a NV4500 (6.34 first gear), to a 2:1 Klune V, to a 4.3:1 Atlas II.

Suspenion: TJ Coils or Coilovers. WIshbone 3 Link rear, Possibly 3 link front (RE style Radius arms and Track Bar OR trianguated 3)

Axles: High Pinion Ford 9"s or High Pinion Dana 60s, not sure yet. Front steer only, hydro assist.

Now my crawl rations will consist of:

293:1

147:1

68:1

I was curious as to what you might do differently or what else you might contemplate. I am going for streetable but will probably trailor it most of the time. So flame away! :D
 
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#2 ·
I don't think (unless someone's making them now) you can get 5.43 for a HP nine. Last I remember for the HP9s was something like 4.88s, maybe 5.13s.

If you are set on the Ford 9 (I am running them with 36s and 5.43s, standard pinion) I would go with the 35 splines rears and the biggest you can get up front (I think 31 spline). I would also highly recommend the warn alloys and CTMs.
 
#3 ·
Hmm? First I believe the KluneV choices are 4:1, 2.72:1, and the new 5.4:1 (for the married NP205. So, you will have to refigure your #'s
Secondly, that is a lot of torque multiplication (using your numbers and the 4:1 Klune that would be a crawl ratio of 587:1 or 398:1 for the 2.72 Klune......WOW axle snapping torque) not considering the reduction in gearing from the tire diameters. You might want to consider a FF 14 bolt in the rear, IMO that would be way stronger than the 9". Prbably more beef up front too, I know it depends are how heavy your right foot is. Hell, why not Rockwells front and rear.......or at least WMS front and rear 14 bolts?
 
#4 · (Edited)
Yea I thought there was a limit for the gear ration on the HP 9"s. I was on klunes site and I read that the Goliath Klune Vs were 2:1 and 2.7:1 in 2 different spots so I wasnt sure.

I wanted the HP 9"s for less weight and more ground clearance. I'm not really heavy on the skinny pedal so I think it would hold up just fine.

By the way for Lockers I'd have ARBs front and rear.
 
#5 ·
On the Klune website, which is not updated because they do have a new "Goliath" 5.4:1 Klune for the NP205, they have listed a "Goliath" box which offers 2.7:1 low range. I did not see any mention of a 2:1, that does not mean it doesn't exist. I still think that may be a lot of torque going through a semi float axle that supports as well as takes the twisting action of all that torque multiplication. Wouldn't a FF 14 bolt after being attacked with a grinder be a better choice for the rear. Remember while climbing there is weight transfer to the rear, you may have almost the entire weight of the vehicle along with the torque being applied to the rear axle shafts. As far as less weight, I hate it when people say that! It is a Jeep, fairly light weight, PLUS where is "all that weight"? Nice and low where you want it, I would opt for stronger heavier front and rears. Which will also aid in articulation and stability of the vehicle. I am not knocking yours or anyones choices, I am just adding some ideas. When I was puttuing together a rear Detroit locked D60 for my CJ8 (also running a 383 stroker, SM465, D300, 38 SX's, and future plans for a Klune "David" 4:1.....may need to upgrade to a 14 bolt as I am running a 30sp D60) I had some buddies talking about "Oh, they are so heavy", Yes they are but next to the tires, that is the lowest place to have some beneficial extra weight. John
 
#6 ·
Well heres the thing...I hear of plenty of people runnin the 9"s..thats kind of why I want to go with them.

Now Jeeps are not as light as you think...mine will be weighing in at about 2 Tons...so its not exactly "light".

14 Bolt seems like it might be unecessary as I won't be running anythign bigger that 38's.

Who knows maybe I will go the 60 route. Still unsure.

:::jaSon:::
 
#7 ·
First why waste the money on a 5 speed on a trail rig/occasional street vehicle. If your worried about on road RPM get higher gears in the axle, they will be stronger any ways.

With a 350 or 383 you will have lots of torque on tape, and be able to idle down to 500rpm so I don't see why you would need super low gears.

personally I would run a sm465 which has something like 6.3 or 6.6 first (drawing a blank right now for some reason) then an atlas and 4.10 gears for strength. This would be lighter/cheaper/stronger then your proposed setup. if you really want the klune run the 2.0 klune and a 3.0 atlas (I think they call it the highlander) this would give you plenty of options and a good low range.

Just my thoughts, the ultimate drivetrain will always be debated and comes down to personal preferance, personally I prefer fewer shifter to mess with and like to use the advantage of the low first gear in a truck tranny to allow you to run higher transfer case gears and axle gears so you don't have to shift out of low range every time you hit an easy part of the trail (I've spent time on the trail doing that it sucks stopping after every rough spot to shift into high range because of your 4:1 transfer case gears)
 
#9 ·
I may be off base here, but...

I'm currently running an NV4500/Atlas II, and lemme tell you that bitch is LOOONNNGGGG. running behind a 258, I've got a rear shaft that's only 16.5" running length.

Not sure how much the klune adds, or what you can recoop from the wheel-base length, but it seems like you're going to need a shoe-horn or something man...
 
#10 ·
NE-RokToy said:
First why waste the money on a 5 speed on a trail rig/occasional street vehicle. If your worried about on road RPM get higher gears in the axle, they will be stronger any ways.

With a 350 or 383 you will have lots of torque on tape, and be able to idle down to 500rpm so I don't see why you would need super low gears.

personally I would run a sm465 which has something like 6.3 or 6.6 first (drawing a blank right now for some reason) then an atlas and 4.10 gears for strength. This would be lighter/cheaper/stronger then your proposed setup. if you really want the klune run the 2.0 klune and a 3.0 atlas (I think they call it the highlander) this would give you plenty of options and a good low range.

Just my thoughts, the ultimate drivetrain will always be debated and comes down to personal preferance, personally I prefer fewer shifter to mess with and like to use the advantage of the low first gear in a truck tranny to allow you to run higher transfer case gears and axle gears so you don't have to shift out of low range every time you hit an easy part of the trail (I've spent time on the trail doing that it sucks stopping after every rough spot to shift into high range because of your 4:1 transfer case gears)
Very good point, and I like the idea of the 4.10s in the diff. ONly problem that with the Klune V 2.7 and Highlander my ratios would be roughly the same with the klune engaged and atlas disgenaged and vice versa. Im just looking at options so I can be high geared so I can do some sand wheeling etc.

I want to stick with the NV4500 because I like having the extra gears. I dont think driveshaft length will be a problem..ill have a roughly 104-105" wheelbase.

Any errors in my assumptions? (had the calculator out haha)

:::jaSon:::
 
#11 ·
You do not want a HP9" rear, I run a 35 spline HP9 now and its a good axle but not nearly up to what you have planned. A HP9"/60/70 hybrid front on the other hand would work well and give you great clearance and be light in weight. For the rear a 14-bolt would work or a standard 60.

Also are you stuck on a manual? Just seems easier IMHO to throw in a 700r4 and an Atlas 3.8 and be done with it.
 
#13 · (Edited)
"I prefer fewer shifter to mess with and like to use the advantage of the low first gear in a truck tranny to allow you to run higher transfer case gears and axle gears so you don't have to shift out of low range every time you hit an easy part of the trail"

I agree totally with this. Although, with a manual tranny you can always choose 2nd, 3rd, or even 4th gear if you are in low range and have enough gearing. Yes/No? it really depends on what an individual does with his vehicle, there will never be just the right combo......we can try and come close though!

Your Jeep is FAT...6000lbs.? John
 
#14 ·
cj8scrambld said:

I agree totally with this. Although, with a manual tranny you can always choose 2nd, 3rd, or even 4th gear if you are in low range and have enough gearing. Yes/No? it really depends on what an individual does with his vehicle, there will never be just the right combo......we can try and come close though!

Your Jeep is FAT...6000lbs.? John
most transfer cases make an annoying howl in 4th/5th gear expecially when set up with low gears. i drive fast on the trail, i love the challange of rough rocks but I'm still young and ahve a short attention span.
 
#16 ·
get the 60's 35 spline high pinion 60's.

also i agree with just get an auto and an atlas. shorter, cheaper, and in my opinion it wheels better. i ran a manual for many years and now that i have an auto i'll never go back. for a trail rig an auto it is for me. i run a th400 and a 3.8 atlas.
 
#19 ·
High5 said:

also i agree with just get an auto and an atlas. shorter, cheaper, and in my opinion it wheels better. i ran a manual for many years and now that i have an auto i'll never go back. for a trail rig an auto it is for me. i run a th400 and a 3.8 atlas.
Couldn't have said it better. Autos are the only way to go. I run an SM420 and it really hurt me a couple of weeks ago in a local rock crawling comp because of difficulty in controling the Jeep. I'm changing to an auto after wheeling 30 years with a stick.
 
#21 ·
You must have a crazy budget to allow for all this. Your rig will be EXPENSIVE. Personnally, I like things simple, cheap and strong. Your drive train is going to be very long. With the high pinion rear you can probably get away with it, but I think you're making things more complex and expensive than they need to be. Crawl ratios of over 150:1 are just silly (w/ a v8 anyway). I'd go for a TH400, Klune 2.7:1, NP205 for simplicity, cost, and strength. You don't like autos (try wheeling one before you decide) so find a SM420 or SM465. Even w/ 4.10 gears your crawl ratio would be around 150:1 With 38s on the road, I'd go with 4.56s. With a non-overdrive tranny you'd be around 2600 rpm @ 65mph.
 
#22 ·
Yea me and my dad were going to build it, and my dad wanted to go all out. But I think I've changed my mind, and my dad bought a CJ that I think sucks (spring under, 33s) and he somehow thinks its the greatest thing in the world. So he doesn't want to build one any more....but we might still, not sure yet.
 
#26 · (Edited)
Well actually...

Now im thinking of going w/ an automatic, even though I like 3 pedals better for a few reasons.

Probably a 350 backed by a TH350, Klune V (2.7:1 or 4.3:1 not sure)...and 5.13s.

I'll probably work out alot of things as I go, and its my first jeep so I'm going to have to take my time. Whole thing is going to be a learning experiece but hopefully I'll have some people who know what they're doing help. :D

EDIT: First jeep I've completely built, I've wheeled my dads CJ and my TJ for a lil while now. :D
 
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