Gear ratios and bad advice
- Thread starter Brantley
- Start date
374gatorgirl
Member
Thank you for your insight! For now I’ll have to continue dealing with poor gas mileage. What other potential problems arise because of a bad combination of tire size to gearsize
Thank you for your insight! For now I’ll have to continue dealing with poor gas mileage. What other potential problems arise because of a bad combination of tire size to gear size
You might want to check that the previous owner(s) hasn't already regeared it. Does the speedometer read low or high? What highway speed are you traveling that gets 5 mph off?
If the speedometer reads 50 when you're really doing 55 for example you probably have stock gears. If it's reading 60 then it may be regeared already
374gatorgirl
Member
Got to chime in. I drove 33s & 3.07s for 10 years. But not thru the automatic.
First with what you have how does it perform in 4LO on a gravel road. For me this was why I never regeared. It ran like a Mustang in 4LO and would hit 60mph.
Second in 2HI on the highway how is it? I assume you will often shift to second gear to pass, climb a grade, run into a headwind. If you can handle that, great.
Third, and this is the deciding factor to regear, from a stop, how does it perform. I'm thinking it has trouble getting enough lift from a stop. With mine and the 5 speed, I noticed the difference but with the automatic, if it struggles it is hard on the torque converter too.
Where to regear too....... I disagree with most advice you will see here. If your TJ is for the extremes of the sport yes you want 4.10s or deeper gears. But if this is a Wrangler to enjoy places only Wranglers go.... ie beaches, forestry roads, back country trails, even 4.10s are too deep.
I have a Rubicon with 4.10s AND an overdrive 6th gear. You do not have overdrive, 3rd is direct like my 5th gear. And I wish I had the 3.73 ratio with my 33s. 3.73s with your 3 speed automatic is similar to 4.10s thru an overdrive standard. I will get shot to hell for being honest but unless you want to climb that waterfall..... go 3.73s or taller.
First with what you have how does it perform in 4LO on a gravel road. For me this was why I never regeared. It ran like a Mustang in 4LO and would hit 60mph.
Second in 2HI on the highway how is it? I assume you will often shift to second gear to pass, climb a grade, run into a headwind. If you can handle that, great.
Third, and this is the deciding factor to regear, from a stop, how does it perform. I'm thinking it has trouble getting enough lift from a stop. With mine and the 5 speed, I noticed the difference but with the automatic, if it struggles it is hard on the torque converter too.
Where to regear too....... I disagree with most advice you will see here. If your TJ is for the extremes of the sport yes you want 4.10s or deeper gears. But if this is a Wrangler to enjoy places only Wranglers go.... ie beaches, forestry roads, back country trails, even 4.10s are too deep.
I have a Rubicon with 4.10s AND an overdrive 6th gear. You do not have overdrive, 3rd is direct like my 5th gear. And I wish I had the 3.73 ratio with my 33s. 3.73s with your 3 speed automatic is similar to 4.10s thru an overdrive standard. I will get shot to hell for being honest but unless you want to climb that waterfall..... go 3.73s or taller.
There should be a tag on the diff cover/s that will have the ratio imprinted. Something like, 3.07, 3.73, etc is what you'll be looking for. The 3spd auto with 33's and 3.73 should actually be very usable. If it is performing poorly it is very likely you have 3.07.
obviously we have different goals. Me I like speed. I grew up with go karts... the 100mph kind, and rally cars. I have zero interest in crawling up a waterfall. When the the highway sign says, slow to 60kph for a curve,,,,, even in my TJR I take that corner at 60mph.... even with a trailer. Different goals, different needs, different results.
Fotmula One, NASCAR, INDY, LeMans and the Baja 1000 are the motor sports I love.
Why is that so hard to understand?
You guys are so frickin' close minded. You treat different opinions as personal attacks.
That isn't what is happening. What is happening is that your gear recommendations don't make sense. They never have. And they never will.
Great looking Jeep! Looks super clean. Congrats! Time now just to love Jeep life. With summer around, top down and doors off, nothing like it.
Good gas mileage will never be a TJ’s strong suit. It is what it is. Learn to punch penny’s and save for the next sheep mod, or gas!
To measure your true lift, look behind one of your front tires and find the big coil spring. You want to measure that spring. If there is a plastic spacer sitting on top of the spring, include that in the measurement. Don’t include the rubber coil spring isolator at the very top. Stock length is 12”, so anything above that is the amount of lift you have (e.g. 15” would mean you have 3” up front). Do the same in the rear, but stock is 8” and so anything over that is your lift in the rear.
Then report back. This will help determine what is the best tire size for your lift.
Then we can think about re-gearing for that tire size.
But for now just enjoy your new Jeep. There’s nothing else like it!
None really, the on and off-road experience is simply lackluster. Honestly, the $1000 I spent to have mine regeared is the best money I’ve spent on my Jeep (I already had the right carriers). I have power, not saying it’s fast or something, but it gets up and goes and I have reserve power at 60-75mph so I can pass. Zipping around town is a ball.
Well. You can be the spokesman for those who want to hit the highway in 4 low. I'll admit that I just don't get it. Maybe I'm missing something. Do the Baja guys shift into low range when they are looking for that kind of speed?
The big one, if you are way too high, ie 3.07s, 33s, automatic or clutch, you might not have enough lift from a stop and damage the torque converter or shorten the clutch life. I had no problems with a clutch, not so sure about an automatic tho.
Honestly, lift from a stop is the only physical reason to regear.
I conceded that I don't get it. Because I don't. Then I asked a question about a context I am less familiar with. If I really wanted to be snarky, I would have asked about transfer cases in NASCAR, not Baja.
Gearing can be a double edged sword. Gearing to low can create a whole new set of issues. I'm not saying that you should not re-gear, but pay attention to your driving expectations and what you want end goal.
Thanks for qualifying that.
The fast trucks at Baja are all 2WD Trophy Trucks. They are engineered for a specific purpose of winning similar to the King of Hammers 4x4s. Not a lot of need for 4WD when you have 100mph of momentum.
But I discovered the plusses of 33s and 3.07s by accident. And I gave it a chance. Ended up finding a lot of reasons to like it. 4LO and 60mph being the big one. I understand the need for deep gears rock crawling. But as you said, I'm not sure you will ever get it. I never give my opinion when a guy states he is building a rock crawler or gearing for 35s/37s. I leave you guys to it. Actually, not true, I will back up most opinions when gearing for 35s/37s, or gearing 33s in an SE. The room for compromise or choice disappears with bigger tires or smaller engines. But when the question is less focused on crawling, more focused on pure all around wheeling, 33s with the 4.0L, I state my opinion. And then get slagged by those with closed minds. I'm not surprised you missed that.
It would be real easy for you to discover the world of wheeling beyond crawling if you wanted to. Real easy to find out why cars with 8 speed transmissions hit top speed in 5th gear and lose speed in 6th, 7th, 8th gear. Real easy to find out why manual transmissions are all but history today. Real easy to find out why, in the 1970s overdrive transmissions became a standard.