Off Road Vehicles banner

1 - 20 of 20 Posts

·
Registered
Joined
·
1,380 Posts
Discussion Starter #1
anyone out there running stock gears and 35's
significant power loss or horrible mpg's now.
debating onthe 35's but i can't afford the gear swap. Really thinking about sticking with 33's and a 3 inch lift.
 

·
Registered
Joined
·
1,057 Posts
You didn't mention transmissions. I know people with Manuals that get along fine, but want bigger gears.

With 35s, the minimum gear with an AT is 3.92 and that's pushing it. No torque, and definitely harder on the transmission than it should be.

If you have 3.55s and try to run 35s with an Automatic, then if you don't pay for gears, you're likely to end up paying for a transmission rebuild, and another a few years later....

Running that large of a tire, with that small of gears puts a HUGE amount of stress on the tranny. It will get hot, and when it gets hot, it will die.

If you're worried about reliability, stick with the 3" lift and 33s... At least until you can get bigger gears under it.

Now if you have the manual, then go ahead. You won't be able to tow, but you'll do ok in every gear up to 4th. 5th will be for dead-flat roads and downhills....
 

·
Registered
Joined
·
1,852 Posts
so a 3 inch lift and 33's are fine with stock gears and an auto tranny?
 

·
Registered
Joined
·
807 Posts
i have a friend running 35X14.50 inch groundhawgs and he gets 16 mpg on the highway. thats with an exhaust, intake, and throttle body spacer. he had the trans built up and a shift kit installed just before the lift and tires and with about 40k on it since then he hasnt had any problems. thats with an auto too.
 

·
Registered
Joined
·
1,380 Posts
Discussion Starter #6
i have a 318 with manual tranny, k&n filter, and flowmaster duals. will that be enough to keep decent mpg's and run 70 mph without frying anything?
 

·
Registered
Joined
·
1,852 Posts
hey i am getting a 3 inch lift and am going to run 33x12.50's i have the 360 and auto tranny. will i be alright with the stock gears? i would think i would be ok since i mean it came with 265's (31.7) so what does another 2 inches hurt? i am going to be running bfg at's anyway
 

·
Registered
Joined
·
1,057 Posts
roughrider,

With the manual, you'll be fine, just will lose some power, may find yourself downshifting sooner on hills.

Canyonero,

I think you're friend is smoking something, or I need to start running Hawgs... 16?!?! He has a deisel, right? :): I haven't seen that kind of hwy mileage ever. But then, if he only goes 55-60mph... I'm always up around 72-75mph on the highway...
 

·
Registered
Joined
·
969 Posts
When I ran 36's with 3.55's my gas mileage went down to 9mpg and the power was definitely not there. Thats with an auto tranny.
 

·
Registered
Joined
·
1,852 Posts
hey arron, will i be alright i am doing the same thing as roughrider with the 33x12.50 but i have the 360 and auto?
 

·
Registered
Joined
·
1,057 Posts
33s shouldn't be too hard on it, especially if you have the 3.92 gears (towing package includes those, I think). Even with 3.55, it's not horrible. Just bee good at changing your fluid, and remember that you're on the "HD service" and not the light-duty service schedule.

Also, for anyone that's worried about it, if you put in a tranny temp gauge, especially one with an alarm, you can find out if you'll be ok or not. If it's getting too hot, you'll be able to catch it and slow-down or down-shift.

May also want to make sure your bands get adjsuted every so often. Most quick-lube places won't. Don't know if the dealer will or not. Didn't feel like finding out for $100 they wanted for a tranmission service...
 

·
Registered
Joined
·
3,036 Posts
On 2002-02-22 13:03, woody wrote:
roughrider,

With the manual, you'll be fine, just will lose some power, may find yourself downshifting sooner on hills.

Canyonero,

I think you're friend is smoking something, or I need to start running Hawgs... 16?!?! He has a deisel, right? :): I haven't seen that kind of hwy mileage ever. But then, if he only goes 55-60mph... I'm always up around 72-75mph on the highway...

yeah i 16 mpg really hard to believe. with the tall tires and the high gears i was only getting like 6 mpg with 36"s swampers. hell i never even got 16 mpg the whole time i owned the truck.
 

·
Registered
Joined
·
1,852 Posts
arron i think i have the 3.55 because i am only turning about 2500 at 75 maybe a lil less what does it sound like to u?>
 

·
Registered
Joined
·
8,235 Posts
if you look on the bottom side of your hood, it should tell you your factory gear size along with other optional info.
 

·
Registered
Joined
·
3,036 Posts
On 2002-02-23 18:37, HaWiiLuVeR wrote:
if you look on the bottom side of your hood, it should tell you your factory gear size along with other optional info.

besides the window sticker, doesnt it say it inside the glove box?(i dont remember and im to lazy to go out and look!) or is it just what axles are underneath?
 

·
Registered
Joined
·
46 Posts
I have been running 35's with 3.55's for a little over a year now. I have noticed the power loss some and MPG going lower. I know that before I go any higher I need to get new gears though. I really don't have any complaints.
 

·
Registered
Joined
·
1,057 Posts
Sportram,

That math doesn't add up. 2500 rpm in which gear? by my math:

3.55s, 33s, and 75mph:
OD - 1900rpm
3rd - 2700rpm

3.92s, 33s, and 75mph:
OD - 2100rom
3rd - 3000rpm


I got this by:

5280/(33xpi/12)=revs per mile

rpmile*75 = revs per hour
rhp/60 = rpm of tire
rpmt * 3.55 = driveline rpm

3rd gear is 1:1, so driveline-rpm = engine rpm

OD is 0.69:1, so driveline-rpm is faster than engine rpm.
 

·
Registered
Joined
·
807 Posts
with 4:10's and 33's its not uncommon for my truck to get 17-18 mpg on the highway going 55-60. however when the outside temp drops, so does the mpg.
 

·
Registered
Joined
·
1,380 Posts
Discussion Starter #20
i really appreciate everyone's reply's and opinions. will probably add 35's this summer. for now i'm gonna steal my dad's 33inch hawgs off his ford until i can get the lift to clear 35's
 
1 - 20 of 20 Posts
Top