Bottom end? For me, regearing to 4.88 (manual transmission with stock wheels and tires) made 1st gear pretty much useless. If I go over 2mph I need 2nd gear. I have no problem pulling out, even on hills, in 2nd gear. Larger tires may give me back 1st gear. Regearing gave me an abundance of bottom end torque.

 

HOTOIL is the transmission fluid -

 

I took a three hour trip yesterday. Most of the trip consists of hills at highway speeds. At 60mph my Jeep runs right at 1800rpms. As soon as I encounter a hill and the rpms drop below ~1500, it kicks out of o/d. It did this before I put my 33's on; however, now it just drops in rpms much quicker than it used to. It makes the Jeep feel like I'm constantly towing my 14' boat behind me. On a flat, it's great, but as soon as you encounter a head wind or slight incline the rpms drop and it downshifts, just like the original poster stated.

I think I read somewhere a while back that there's a different flash for JK's that came with the factory tow package. I remember the flash having "trailer sway control", but was there any changes in performance?

 

5.13 gears with 33's and an AT is a beautiful thing. The flash won't help you at all.

 

Try the 91 octane tune, I found it to be better

 

Holy crap! I think I just fixed my down shifting ( lack of power) problem. Just installed a k&n cold air intake and it feels like a whole different jeep. What an improvement.

 

I agree something is wrong. I have 33's on mine, and although it's painfully slow, it will maintain 70mph+ on hills.

 

The dealer "flashed" the computer today while it was in the shop for the fender liner recall. It seems to be better. I've been rushing around, not driving like I normally do so it's hard to tell.

 

My girlfriend and I took a 4 hour road trip to NH this weekend. The drive was a mix of city driving, mountains, and interstate highways. My Jeep was decent in the city traffic and mountains, but it sucked ont the interstate. On the interstate I had the cruise control set on 70mph, and the RPMs at 2000. As soon as I hit the slightest incline it would shift out of o/d and the RPMs would jump up to 3000. On some inclines it would shift in and out of o/d a few times before reaching the top. I manually locked out the o/d when I noticed it happening.

With the o/d locked out my Jeep will hold 70mph easy and run at 3000rpms. Am I asking for trouble if I leave the o/d locked out?

This Jeep reminds me of my old '66 Bronco. It was gutless as all hell at 55mph.

 

That's what my gut was telling me when I was driving on the interstate. The downshifts seemed pretty harsh for my liking.

Thanks Planman.