If you change the gears in the rear, do you have to change them up front too?
If not, in 4wheel drive, wouldn't the wheels be going at different speeds.
If so, how do you change the front ratio

 

Yes, change both! At least that's what I've been told.

 

That is far from a stupid question! [scrambles and looks for his physics books]

Makes sense to change both out. But how come no one does that? You always hear about people changing the gearing in the rear.

 

If you are a 4x4 you MUST regear both. You will have a plague of one thousand locusts thrust upon you if you don't do both

You vehicle will be very unpredictable with different gearing front vs rear. Not to mention possible breakage of stuff.

 

You have to change both if you want to use 4wd otherwise you will screw up your tranfer case. I think most will agree.

 

It's just assumed that when somebody says they're going to regear, they mean both diffs. Of course, if your going to bother regearing, then you might as well put a front and rear locker in too...but that's another story...

 

I love learning things from this board. I honestly dont think I would have thought of all this, should the time to change gears have come up.

 

If you don't regear both then the tires will try to turn at different speeds. That wil trash your transfer case and cause a surging as one axle tries to catch up with the forward movement of the other axle. It is a recipe to wreck a lot of stuff.

Some mud specific vehicles that run different size tires front/rear do run different gear ratios but there the theory is that if the front tires spin faster then the truck is less likely to sink.

 

k I have another stupid question. Why would you regear your truck? bigger tires?

 

Plus if they run different size tires the would have to regear to run the same - don't forget that tire size is part of the equation for finding final gearing.

C

 

You could always try and fit 35's in the back and run 30's in front. Might look a little funny, but I don't know. :alien:

 

mud boggers can get away with it because theyre never getting good traction. if you were in mud or ice youd be okay, plenty of slipping, but put it on the pavement and ill bet you start breaking stuff. im not going to let you guys prove this on my truck . sometimes guys can only afford one end at a time and theyll actually take out the front driveshaft just in case the hit 4wd by accident!

 

Yes both diffs have to match. One of my main issues with the Dana44 is the 5.38 & 5.29 gear difference.

If Dana could run a 5.29..................... It would be done.

 

I'm pretty sure if you geared different front-to -rear you'd break down w/ in a mile or two. Maybe a couple more miles on grippy dirt. You wouldn't get far, that's for sure!

 

Earlier fords used to run 4.09:1 in the front and 4:10 in the rear the theory being that the front will pull a little faster in loose stuff(when you really need 4x4, before rock climbing became popular) and it accually worked pretty well, of coarse the disclaimer told you not to operate in 4x4 on hard surfaces

 

yes, or just never engage 4 wheel drive until you do get the front changed to match.

 

you guessed it.

 

k-
I just upgraded to 33" MT/R .. would I need to regear? Or is it only like w/35" and larger?

 

I'm not speaking from experience b/c I'm still on stock rubber, but from what I've heard people go to 33's without regearing all the time. You'll probably notice a power loss, but most just live with it. To fix that, you would want to regear.

 

Ok. now my next question is:
How do you re-gear an IFS suspension.
That is what I have up front. I know about the gears in back.