Getting more speed from my NP435.

[Andrew]

I puchesed my 92 YJ about 8 months ago setup as such:

4.0l
NP435 (Novak)
231
Ford 8.8 rear, Dana 30 front both locked

It is lifted on 33"s

The Jeep has 96k on the motor, and 6k on all other drivetrain.

I like the Jeep, and its low range with the granny trans, but the best hwy speed I have hit yet is 65mph.

It is geared 4.11s right now.

Does an overdrive unit exist, similar to a Warn unit? I would imagine it would make the rear driveshaft too short?

 

[ScrewLoose]

Look up the Advanced Adapter Ranger Torque Splitter.

My opinion though is to do a trans swap if you wanna DD this thing.

 

[Thatg9659]

Upgrade to 37's

ax15+241crawlbox+D300 will near match the granny low you have now.

 

[Andrew]

I didnt figure there was a best of both worlds answer.

the prior owner (he bought it from his neighbor, who built it)did look into swapping an AX15 back in, it was in some notes from his mechanic.


Most roads around me are 55, so it works, but freeways get a bit annoying.

 

[Andrew]

I looked it up, and it does seem like a viable option, although pricey, and I would probably have to make my Jeep LJ length.

Ill have to shoot them a email about my transmission. They put a new mainshaft in it to match the 4.0l according to the build notes.

 

[The Freeak]

As others have said, the overdrive from Advance is perfect for your situation. I'm running one in a nearly exact same application.

EDIT- If you are worried about overall length, just sell the 231 and swap a flipped D300 onto the back of the 435. It will be an upgrade and close to same length as/ or shorter than your current arrangement.

 

[The Freeak]

I looked it up, and it does seem like a viable option, although pricey, and I would probably have to make my Jeep LJ length.

Ill have to shoot them a email about my transmission. They put a new mainshaft in it to match the 4.0l according to the build notes.

I just re-read your post and realized something- The main shaft is likely the output shaft. The input shaft should not have been changed. The stock output is 31 spline (assuming a 4wd trans was used), and much longer. Most kits include a new output shaft and tailshaft housing (To accommodate the 6 bolt 231/ D300).

 

[TRINDU]

I puchesed my 92 YJ about 8 months ago setup as such:



It is lifted on 33"s

The Jeep has 96k on the motor, and 6k on all other drivetrain.

I like the Jeep, and its low range with the granny trans, but the best hwy speed I have hit yet is 65mph.

It is geared 4.11s right now.

2700-2800 RPM isnt your limiting factor for 65mph. That's real similar to 4.88s and an ax15, which is would you'd want anyways.

 

[total newb]

Did you stop at 65 because of rpm or no more power to push?
Cause o/d isnt going to help the power issue

 

[Andrew]

Theres not a power issue, but seems like its turning pretty good RPMs at that point.

 

[total newb]

3k is a perfectly acceptable rpm for freeway speed. People have been running that for litteraly decades

 

[Andrew]

I have never had to wind one up that high before, but this is the first non AX15/nv3500 trans I have owned in one.

The Ranger case still sounds tempting though......

 

[gmcxt]

I have been back and forth on the ranger OD for a while. its 1200$ to drop about 700RPM at 60MPH. IT would be nice but its just one more cost and one more thing to fail. Also splitting 2nd and 3rd gear would be nice at times. Im not sure what flavor of NP435 you have but heres a Ford 435E. 1000-5000RPM WOT