regearing for 33's

[95offroadx]

i have 33's on my explorer.. right now it has 3.73 gear should i go to 4.10s or 4.56 gears

what does regearing do to your truck like in performance? .............i heard you should only go like 60mph on a highway is this ture?

since my explorer is 4x4 should i only regear the rear or rear/front?

 

[dman726749]

you HAVE to regear the fron and back if you want to use the 4x4 option. i would go with 4:56 gears becasue the jump from 3:73 to 4:10 does not seem worth the money if you ask me.....and as for going 60 miles an hour i have never heard that.

 

[glfredrick]

I'm currently running a set of 33's on my 92 Ex with 3.73's. What happens is that you end up loosing the use of overdrive until you are over 65 MPH. Below that, engine RPM is too low (it lugs at 1700 RPM).

4.10's will work to restore some performance - 4.56's will really pep things up a bit - rather like a performance increase (quicker acceleration). My kid is running 4.56's with his Jeep XJ and 33's and it does great.

I'm going to run 4.10's just becasue I already have them at hand. I would opt for the 4.56's if I had to purchase them new.

As for the 60 thing - I don't have a clue what that is about. I run mine down the road over 60 (over 90!) all the time... In fact in the past three weeks I have been to Florida, West Virginia, and Dayton (from Louisville) and had no problems whatsoever.

 

[Overkil]

i have 33's on my explorer.. right now it has 3.73 gear should i go to 4.10s or 4.56 gears

I've been wondering the same thing. I'm leaning towards 4.56 gears. With 33's and 4.56s, what would we be looking at as far as RPM at, say, 75mph?

Sorry 95offroadx, didn't mean to hijack the thread but maybe that info would be helpful for you, too.

 

[svande8952]

I've seen a truck try to drive in 4 wheel drive with different gear ratios in the front and back-it's hilarious-as long as no one is injured.

 

[svande8952]

go to www.randysringandpinion.com they have calculators for RPM with different gear ratios.

 

[glfredrick]

Go here: http://home.comcast.net/~cboug/Tire_Gear_Calculator.htm

For a nice speed and gear calculator.

 

[FordLover]

I had 3.27's and went to 3.73's when I went to 33's, and it drives fine, but would have better performance and towing ability with 4.10 or 4.56's. Note that mine is also not a daily driver, but it will get up on the freeway and do 80 MPH. Mine is also a 5 speed, and I have a feeling an automatic would suck up more power from the motor, and require 4.10's at least.

Yes, regear front and rear. I drove with 3.73 in the rear and 3.27 in the front for almost a month. you CAN use 4x4, but you need to be in some really soft stuff, otherwise you'll most certainly break something.

Not sure about the 60 thing, but that's probably only with extreame gear changes, and it's offset with tire size change. Say like a mustang going from 2.73's to 4.30 gear ratio, but keeping the same tire size. That will make the cruising RPM in top gear go from like 3,100 RPM to something like 5,300 RPM.

 

[Pahelo]

I went from 3.55 to 4.56. WOW what a differnece with a 5.5 lift and 33s.

 

[Mcane6]

i have 3.27 and im going to probably 31" maybe 32"
what should i go to??
would the 3.27 be ok with the 31"

 

[dmasini]

i have 3.27 and im going to probably 31" maybe 32"
what should i go to??
would the 3.27 be ok with the 31"

I have 3.27 with 31's and I don't see any difference in power than before I put them on.

 

[unclemeat]

I had stock 3.73 axle ratio with 33s and a 5 speed and the X was a dog. I regeared to 4.56 ratio and I could not be more happy. Execelent throtle responce, much more fun to drive. Fuel mileage picked up about 3 to 4-mpg. With the 4.56 ratio and 33s the engine RPMs are approximately 5 % higher than the stock 3.73 ratio and 30.5s. You need the extra power to turn the bigger tires.

 

[Buckshot]

I have 3.73 and used to have incredible acceleration and power for an OHV on stock tires. I noticed a pretty significant drop in performance (in part due to weird tranny shift times now?) just moving to 31's. Next step will be 4.56 in prep for 33 or 35's (also 'cause I agree that the .37 increase going to 4.10 seems like a lot of time and money with too little ROI.) Besides, 4.56 should make 31's scream in the meantime too....of course, I'll have gotten used to the power in the 4.56 and 31's so I'll *have* to go to 4.88 when I move to 35's to feel the same!

Is this like when you always have either too much cereal or too much milk left over after each bowl - no matter how many damn bowls you eat while trying to get the ratio perfect?

 

[95offroadx]

i thought about it more and more and came up with some new questions..will my gas mileage drop any? will it help my 0-60mph by more that 1.5 sec? how much does it cost(both front and rear) is there any gear ratio between 4.10 and 4.56? right now i cant not do a nice burnout will it help me be able to do one?

 

[glfredrick]

Putting in 4.56's will give you back about what you had with stock sized tires (actually a tad more - but it isn't worth mentioning).

Mileage may drop but that is from rolling larger rubber - and it may actually get better if you get the RPM's where they belong and stop lugging the motor.

I can't say what it will do 0-60 times - but it will increase - that's for sure...

Gear cost is somewhere in the neighborhood of $150 per axle (slightly less in back - more in front) the shim and bearing kits run around $70 an end - and installation varies depending on the shop - figure on doubling the cost of the parts and you will be close.

Most trucks will smoke the tires with 4.56's... But you have to remember, you are turning a LOT of rubber - and that lot of rubber weighs a lot more than stock - so the performance is bound to be somewhat different. Plus, your contact patch is way different from stock tires... Some say that should make the large tires spin easier (according to physics, there is less # per square inch of rubber - hence less friction), but it has been my observation that exactly the opposite is true...

I even once demonstrated this to a college physics prof with my 70 Chevelle... I slapped on a set of stock tires -and lit them on fire - then went back to my BFG's (slightly aired down) and picked up the front end while they barely chirped... (I was launching at 7800 RPM - and sidestepping the clutch) There were more factors at work than he thought - and I sort of stacked the deck, running a known combination - but the class was impressed and I got to drag race my car in the school parking lot...

 

[Buckshot]

Your physics would be correct if you readjusted for the increased coefficient of friction in a larger contact patch due to larger tires (especially when aired down) and better traction on BFG's than stockers.

You forgot the caveat "all other things equal" less #/sq.inch=less friction.

But, hey, I like the idea of smoking the tires for education.

 

[95offroadx]

so it will be around $800 for the parts and installation?

 

[Buckshot]

If you can get it for $800 - go for it! I've seen quotes from $1000 - $1500 from 4x4 shops to regear both...

 

[dreamr]

I was quoted 1500 form Randy's ring and pinion to regear the front and rear for 4.56's. This of course includes parts, labor, and the master install/rebuild kit for the diffs so I don't have to worry about them in the future.

They said they would throw in an Auburn Ected selectable locker for 600 more. No labor

 

[Arnie897]

Go with the 4.56's and you won't be sorry. I paid 1350 for front and rear. This price included all the fluid, labor, bearings, seals, etc... I don't mean to dog the explorer engine but 160hp out of an OHV is not much. The lowest gearing you can go with is the best choice for you. I don't need to go 95 down the expressway so I settled for 75 at 2.9RPM's.