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NP231 quasi-rebuild

Posted: Sun May 22, 2011 3:35 pm
by Baseshakers
I need to open up my tcase to re-rtv it since it Is leaking at the seam. When I have it open I am planning on at least replacing the seals. Any other recommended maintenance/improvements? New bearings? Any low $ strength improvements? FYI I don't have a slip-yoke eliminator since my rear DS is pretty long and I get minimal vibrations.

Re: NP231 quasi-rebuild

Posted: Sun May 22, 2011 8:44 pm
by Kurt
Only a couple of "upgrades" come to mind but not sure they are worth the cost if you are looking to go Atlas or NVG241OR in the future.
- HD wide chain upgrade
- 2 LO

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 1:36 pm
by nostaw
An SYE gets you a 32-spline HD output shaft on the rear output... Only other option besides the one Kurt suggested is one of the 4:1 kits, but that is 1/2 a new case and is probably more easily accomplished with a NVG241OR swap.

JW

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 5:07 pm
by Frank
Id glue that one together and save the coin for a 4x1 later. FjR68

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 5:25 pm
by ChrisD
I thought someone mentioned that the 4:1 TC was not worth installing for the wheeling in this area.

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 6:39 pm
by DOUG
Chris wrote:I thought someone mentioned that the 4:1 TC was not worth installing for the wheeling in this area.
After wheeling the Rubicon for the last 7 years, I'm doing a 4:1 in the Scrambler next winter.


BTW...liking the new smilies!!! :happy-jumpeveryone:

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 6:58 pm
by ChrisD
So what makes the 4:1 so great? I know that I am loving the 4.56's and 32" tires setup, but not sure if 4:1 would be to low.

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 7:26 pm
by johnsxj
Chris wrote:I thought someone mentioned that the 4:1 TC was not worth installing for the wheeling in this area.
The theory is that in this area you tend to need more wheel speed in many places (going through mud, climbing rocks with muddy tires, etc...)

Places like Moab and even lots of Rausch Creek where there's lots of traction on the rocks a 4:1 t-case can give you greater control by cutting down your speed.

On the down side, it also multiplies the torque going down the drive shafts to the axles. So if you're a throttle driver :angry-cussingblack: :angry-cussingblack:

Re: NP231 quasi-rebuild

Posted: Mon May 23, 2011 11:15 pm
by Kurt
Chris wrote:So what makes the 4:1 so great? I know that I am loving the 4.56's and 32" tires setup, but not sure if 4:1 would be to low.
If 4:1 is too low for a given situation just upshift a gear or two.

Now that I run 4:1 I'd never go back to a stock ratio. :)

Re: NP231 quasi-rebuild

Posted: Tue May 24, 2011 7:56 am
by ZAEDOCK
The NP231HD I picked up from JB Conversions about 10 years ago, includes every available option for the 231 (except 4to1). I figured in all the upgrades to my original case and found this option to be much cheaper and obviously, less time consuming (for me, more important with kids and 10 projects going on).

The wide chain, 6 pinion planetary, and 32 spline output really add piece of mind too.



The NP231HD is built with every possible strength upgrade including all that is available through the aftermarket and original equipment manufacturer (NVG). We begin with a bare, empty case and fill it with new components consisting of the following:
Wide chain (genuine Borg-Warner Morse)
Wide-tooth main sprocket and front output shaft
Heavy Duty SYE kit with 32 spline output shaft
6 pinion planetary gear set
Choice of input gear spline (21, 23, 27, 29 or 32 spline)
New bearings, seals, small parts, filter pickup, thrust washers, etc.
New replacement front output yoke is optional



http://www.jbconversions.com/products/n ... stdsye.php




As far as 4 to 1 vs 2.72 to 1 goes, I've found that I do about 50/50 in compound low. If I can't crawl it, I'll use 2nd gear for a squirrel powered attack. Keep in mind that my 2nd gear (3.57 to 1), is almost as low as most rigs 1st gear, but it helps to move 600 lbs of wheel/tire with the rodents. I think if I had a 4.0L or V8 powered rig, I would go 4 to 1. With a V8 and auto, I think I would do an Atlas 3.0.

Re: NP231 quasi-rebuild

Posted: Tue May 24, 2011 1:07 pm
by Frank
My Dana 300 had a 2.50 or something close to that , stock. I had 32" swampers. Did most , if not all wheeling in first and the technical stuff Id slip the clutch a bit. Paragon consumed my clutch in three days. Still got to see most of it and was really new to the sport. Repaired it and went with a LOMAX 4x1 and still had the 3.73s in the axles. Most of the technical wheeling still was in first but had the 2nd option every once in a while. Next was a switch to 35s and 4.56s . Wow , can do most things in second and save the first gear for the crazy stuff. I know now , I should have gone with 4.88s. You guys have 5 speeds mine is a 4 speed. As a daily driver, going to 4.56s was a 300 rpm gain on the street in high range. 4.88s would have been about 800 so I cheated myself a little. But having the gear to walk down something with out locking the brakes , or spinning them to clean them out and then the throttle control to walk up some thing is just plain worth it. Id say go with the most gear you can and upshift ! Love mine. FjR68

Re: NP231 quasi-rebuild

Posted: Thu May 26, 2011 12:13 pm
by Baseshakers
thanks for the input guys! how about a master rebuild kit? http://www.novak-adapt.com/catalog/231_ ... _parts.htm my bearings are probably shot after running the case low and with a lot of stop leak, so this may be a good addition... thoughts?

Re: NP231 quasi-rebuild

Posted: Thu May 26, 2011 4:15 pm
by Kurt
Or go for a...

Image

...from JB Conversions instead of putting money into a 231

Re: NP231 quasi-rebuild

Posted: Thu May 26, 2011 4:30 pm
by Baseshakers
What's the $ for that? $200 for a rebuild kit...

Re: NP231 quasi-rebuild

Posted: Thu May 26, 2011 5:05 pm
by DOUG
Who cares how much for that...it;s got green studs!!