Steering and track bar are the most common culprits.
—
There must have been a time
when we could have said no.
—
There must have been a time
when we could have said no.
32RH, 4.56 gears, & 33” tires... long interstate trip?
- Thread starter Xposure
- Start date
OP
He said all the steering components and bushings were all replaced when he swapped the front diff and got an alignment as well. That was about a year ago but only a few thousand miles. Says he’s never has death wobble. So far so good.
You'll be fine. 3000 seems to be the top rpm for most people although they probably have no idea why. It is just a number someone picked somewhere along the way.
Sure it'll do it... but be way more comfortable with 3.73s or 4.10s.
3K rpm is where the 4.0L starts to make real power. But on long flat straights, closer to 2K delivers better economy. Long cruises. I like 2200. And drop a gear or two for hills and wind or passing.
But your question, yeah it'll be just fine. Wear ear plugs.
OP
I had a old highly modified 1973 Mazda rx3 set up for road course racing that felt like it was going to break in half going over pavement seams and was so loud I got a noise ticket in it. Also no radio and no ac so had to drive it with the windows down. I took it on a 300 mile interstate trip to North Carolina....I figure if I can live in that sucker for 300 miles running 75 at 4200rpms and screaming loud with racing seats and harness seatbelts then I can take a road trip in just about anything. Hahaha.....as long as the vehicle is up too it then I’m up too it.
OP
Just wanted to give a little update....I drove this Jeep today and at 70 it was right around 3300 or 3400 rpms. That’s with the 4.56 gears, 3speed auto, 33” tires.
Did you have a bridge ported 12A engine. I had a highly modified Turbocharged 13B in a RX7. Awesome engines!
OP
No, it had a large street ported 13b carb engine swapped in that made about 220rwhp but only weighed like 1600lbs. I also had a 95 rx7 with a street port and hybrid twins that made about 420rwhp....that all feels like a lifetime ago....I didn’t have time or money for all that when kids came along and sold everything....Now I only have remnants of some parts and such laying around lol. Now I’m buying cars for my kids lol
Last edited:
Word on the street is YES, the 4.0 can handle it.
Me personally ? I could not.
I'd consider 65mph on the interstate to reduce noise and engine cycles.
Xposure, I had a similar rpm situation with my previous TJ. It had the same 32RH transmission you have and it had similar highway rpms with its 4.88 gears and 35" tires. I regularly took long (250--500 mile) trips in it and while the rpms were higher than I would have liked, the engine is fine with them. I just slowed down a bit to 60-65 mph at the fastest in the interest of possibly slightly better mpg and didn't worry about it.
OP
Yea it sounded pretty high strung at 70mph....with no cats and a flow master exhaust and the top flapping like crazy my wife wasn’t really feeling wanting to take a interstate day trip in it. I was thinking if I was to put a cat back on it that will quiet it down some then drive 65....of course I could also get 35’s....but it has a brand new 5 tire set of Duratec 33’s so can justify that unless someone wanted to trade
You know speaking of the top...it flapped way more than others. Even at 20mph it was flapping. The soft tops of the other Jeeps I’ve driven didn’t flap at all at ‘city’ speeds under about 55mph
OP
Yeah 70 mph would be faster than I'd like with 4.56 and 33" tires with the 32RH. Can't you just slow down a tad? I just got used to driving in the slow or next to the slow lane when taking my TJ on long trips. How I came to be running that combination was I had regeared to 4.88 when my TJ had its OE 5-speed manual transmission and 35's. Then I decided to upgrade the transmission to the 32RH which left me with the 4.88's I had installed several years earlier.
Aftermarket soft tops tend to flap more because their fabric is generally thinner. Bestop's Sailcloth tops are what the factory installed and they are significantly quieter. You can also try "inflating" the top to quiet it on the highway. With all the windows zipped completely closed, turn the vent or A/C on and turn the fan on to at least the #2 fan speed. That will make the top tighter and less noisy. If the A/C is on, make sure it's not in the Recirculate setting which sucks the top inward instead inflating it out outward as all the other settings do.
OP
I can slow down a tad but around Birmingham, AL the interstate flows at about 80 so going ‘slow’ in the outside lane people will just about run you over and cut you off trying to get over to their exit.
That’s good to know about the recirculate, we did have the air on high but I’m not sure if it was on recirculate or not. My guess is it’s like you said, the top was replaced and it’s a cheaper thinner top so flaps like it’s a flag lol. I know that on the back for a few inches to the left and right of the swing door the the clip part of the top had broken. The plastic piece that runs up under the lip had cracked and broke off. The rest of the top looked nice and not too tight which makes me think it wasn’t all THAT old....it was just a cheaply made top.
OP
Become one with the big trucks carrying heavy loads in the slow lane grasshopper.
Shoot, we don’t have a slow lane here lol....I found out that in my daughters Prius if you drive 65 vs 72 it gets nearly 5mpg more so I started doing that and the 18 wheelers come right up on your butt then work at going around you. But hey...it was worth irritating everyone to get the extra 5mpg Haha
NovaTJ
Member
OP
19 mpg at 3200 rpm doesn't sound likely at all. My bet is either the speedometer hasn't been recalibrated so it is accurate or the gas gauge indicator's position was used in the calculation.
Last edited: