can someone help me understand..... in my bronco i have 3.50 gears. if i put like 3.89's of 4.11's what would that do for me?
thanks

 

TOURQUE!! you will be able to spin 33" tires better than you spin your stokers!! well maybee. but it gives you a lower ratio. your driveshaft will be making more revolutions per revolution of your axel. its great for running bigger tires.

 

think of a higher number gear, as you using a longer handled ratchet wrench when you loosen a bolt. You gain an increased torque, by lessening the distance you move. Hence, your engine will be turning higher RPM's in order to obtain the same speed, but you will have more torque at all speeds as well. If you pull a trailer, or just plain have trouble accelerating as fast as you need/want, this may help you. If you dont do a alot of high speed driving, it wont really hurt you at all. Where it hurts is if you do a lot of high speed highway driving it will force you engine to rev faster/higher and probably use more fuel accordingly.

 

how much higher will the Rpm's be with 3.89's or something in that area?
i run about 2000 Rpm's at 65 on the highway now...i do pull some stuff nothing serious

 

there are some websites that have calculators for this information. 4lo.com has them, as do many of the gear manufacturers. You can input your gear ratio, tire diameter, etc, and get the actual theoretical rpm you should be turning. not sure of the exact overdrive ratio. Any help here?

 

If you are running stock tires and are just looking for a little extra punch, all you need is like 3.79 or 3.89.. That will be plenty of gearing. IF you increase your tire size above 33" then you should get 4.10 gears.

Also don't forget that you have to change the gears in both the front and rear axles or you will break your transfer case.

Hope this helps!!

 

Ok im gonna jump in here and add more confusion, lol. Right now im running stock everything in my 90 bronco eb. The gears im not for sure about, its an auto tranny so im gonna assume just from reading that im running 3:55 gears. Im going to go with a 4" lift and 33" tires. I do quite a bit of highway driving since this is my one and only ride. I also play in the mud at times as well, arkansas mud that gooey stuff that sticks to everything . I dont, and will never, do any rock climbing. So what type of gears would be best for this. I live in the hills so take that into consideration as well. Also would switching over to a 9" rear be better? What would u suggest for the front, stock or what?

 

if u do mostly highway/street driving, and are only putting 33's on, i woudlnt touch it, it should be fine as it is.

 

89 351w AOD w/ 33" tires and 4.56 gears. @ 80 mph I'm running around 2200-2300 RPM's. went from 12.5 mpg to 12.

Bottom line, the torque is awesome.

 

isky, would i get better gas mileage if i went up to say 3.90 or so gearing? If i change the gears in front and back, can i keep the stock 8.8 rear and the stock TTB front?