to high of gear ratio

[dscowell]

Today I was wondering what effect it would have on your 4x4 if you had your axles geared to high. Just kind of a random question sense I know what it's like to have the too low what would happen if they were too high?

[Patrolman]

Poor MPG and always having to shift into a lower gear. My 66 CJ had 3.54 gears I think, rolling on 35's with an old 3-speed manual tranny and a weak V6. There were several paved mountain passes I drove in 1st gear. What a PITA. It also made the MPG suffer.

[Rick]

My 66 CJ had 3.54 gears I think, rolling on 35's:eek:

[Patrolman]

Yeah, shocking, but I didn't build it. Never got around to changing gears before I sold it.

[Coonburger]

Engine has to work alot harder to maintain speed and get up to speed. Auto tranny's need to be watched very closely cause heat build up is very likely. Shifting back and forth that kindof thing. Now if you have the motor to make up for it not a big deal at all.

[Robert B]

for a good while I ran 3.42 and 35s and a 4 speed granny so only 3 useable gears... it put great wear on the clutch as I had to slip it a lot to get the truck rolling from a stop...... had very little power and very short time when I did have it ........pulled many hills in 3rd gear and a few times had to go to 2nd which is like 20 mph at max rpm ....... I will say once I finally got to speed on the highway it was great for mpg but any hill and I would have to down shift and use many rpm to keep it near speed ....... if you did little city driving and much highway it would be better but in town it just causes tons of extra wear and tear, at least on my near 6000 pound monster

[xaza]

With 4.88 gears and 31s, auto tranny I can chirp the tires going into second on dry pavement :D, but gas mileage goes to nothing above 65 and I am often in OD on residential streets. :confused::lmao:

[Coonburger]

damn........ iam lucky i got the 3.42's with 35's but the 454 makes up for the loss big time. It can still roll the tires easy but imagine with some gear muahahahahaha

[Hypoid]

the 454 makes up for the loss big time.Yup, that is what gearing is all about! :)

[Fordguy77]

Assuming that by too high of gearing you mean numerically lower;

As been said, less acceleration from a stop, cant pull hills as easy, makes towing more difficult, Engine works harder...
However it does boast higher top end speed, lower rpm at cruising speeds and less work on a motor at high speed.

Just in case anyone is wondering what Higher and Lower is:
(ratios apply mostly to trucks and bigger SUVs, Cars and Smaller SUVs have a significantly different range)
High Gearing- Is typically anything numerically less than 3.53's
Low Gearing- Is typically anything numerically higher than 3.73's

Note ratios are for example only and don't pertain to anything other than said example.

[trailfiend]

I've got stock 3.55's and 31's in my XJ with the 4.0 and auto, from what I understand the gearing thing makes a bit of a shift with manual trannys. But I believe my RPMs at any given speed are about 3-400~ below stock, which frankly is just fine around town, I imagine with lower gearing (4.10ish) I would probably net better milage around town and highway. My biggest complaint with 3.55 gears and the 31's comes into play on the highway, I get by alright on the climbs, but it's a little gutless. I'd like to regear to get my RPMs up a couple hundred to hit the sweet spot for power so I don't have to downshift as frequently on small hills.

Of course, I have the feeling I'll end up waiting to regear until I'm ready to go to 33's and jump up to 4.56.

[06HokieTJ]

Of course, I have the feeling I'll end up waiting to regear until I'm ready to go to 33's and jump up to 4.56

Love love love my 4.0 and 4.56's and 33's!

[trailfiend]

Love love love my 4.0 and 4.56's and 33's!

I can't wait to do it, seems like the perfect sweet spot gearing for the amount of highway and mountain driving I do!

[ExplorerTom]

I also have a 4.0, 4.56s and 33s- although an Explorer, not a Jeep. It runs great. I started out with the factory 3.55s on 30s. Then I regeared. At that point, it was a race car around town, but on the highway 70 mph was the upper limit- not because of physical limitations, but because it just seemed to want to stay there. It was kind of a resonance kind of thing.

Then I got the 33s a few months later. My effective ratio is now about the same as a stock tire Explorer with 4.10 gears, which is still pretty good.

[curt86iroc]

running 3.73s on big 32s makes my 4.3 seem like a pig on the highway. gas mileage dropped significantly and i constantly need to drop into 3rd for hills. ill be looking for 4.10s in the near future.

[Popsgarage]

The wife's Blazer'll be running 3.73's with 33's for a while. Might go to 4.10's if that don't work but not until after I swap in a 44 in the rear. We'll see how well it works soon. Probably gear down to 4.56's or 4.88's to run the 37's I'm looking at. But they won't go on until next year. Need to get some of these first. Hutchinson DOT compliant beadlock wheels on the JK pattern. This'll require some fender trimming for sure. http://rockmonsterwheels.com/products.php?product=jeepjk

http://rockmonsterwheels.com/images/jeepjkwheel.png

[The StRanger]

Im running two different set of tires on the Ranger and running the stock 3.73 gears
The factory tires where 245/70R16s
Now for Street & towing I run the 265/75s and for Trails I run the 33 by 10.50s
The 265s are good & torquey. The 33s make it a little weak runnin I 70
But Im fine with it now.

[Tom]

My '12 JK has 3.73 gears. Stock tires were 32.1. I now have 33.3s. I've noticed a loss of power going uphill on the hwy. With a 6 speed manual I have to go into 5th more oftten. Still get 21 mpg highway though.

[carpenle]

I use this chart http://www.4lo.com/calc/geartable.php when ever I have a question on gearing.

[JFjeld]

Its not just about gear ratios; the trans, engine, and tire size have a lot to do with it. I run 4.88 gears in my TJ, but I have 35s, a 4-cylinder, and 3-speed auto (30rh). Excellent offroad, fine around town, but just plain sucks climbing the mountains in 2WD. Fairly often, I'll have to drop into 2nd to get up some of the mountain climbs. For that reason, if I'm heading West on I-70, I usually take Hwy 6 through Clear Creek Canyon and come out at Idaho Springs.