Overdriving the Front Axle?

[SCX10Dingo]

Does over driving the front axle really help with steering and climbing? Does it make the truck drive poorly on hard surfaces? Any other downsides? Is it really worth doing?

[johnnyh66]

Originally Posted by SCX10Dingo

Does over driving the front axle really help with steering and climbing?

Yes.

Originally Posted by SCX10Dingo

Does it make the truck drive poorly on hard surfaces? Any other downsides?

A little but not anything destructive imo, revers is wonky.

Originally Posted by SCX10Dingo

Is it really worth doing?

Yes.

[SCX10Dingo]

Thanks for the quick reply! What ring and pinion ratio would you recommend for the front?

[Big Tex]

Originally Posted by SCX10Dingo

Thanks for the quick reply! What ring and pinion ratio would you recommend for the front?

theres only one ratio for OD bud its 36T/14T factory gears are 38T/13T and yes they have the through-pin output for the wb8 drivelines in the newer kits as well Axial HEAVY DUTY BEVEL GEAR SET 36T/14T

Originally Posted by SCX10Dingo

Does over driving the front axle really help with steering and climbing? Is it really worth doing?

and yes its WAY better in my opinion, if you have a torquey motor like a 35t with the right gearing on a 3s lipo when making a sharp aproach you can blip the throttle a few times to sorta achieve what a dig does for ya, its actually pretty sweet,

and the main part that you will notice a change in is the uphill climbing, it wont roll as often or in some circumstances at all when climbing up rocks or a steep hill, one of the first mods i make to my axles is OD the front end

[05Fronty4x]

I underdrove the rear axle recently, I haven't noticed any downsides. I have noticed slightly less tire scrub when turning, so it definitely helped there.

[Dostradamas]

On this subject I am curious.
What differences are there in undergearing the rear vs overgearing the front?
I want the front to spin faster than rear I get that but what advantages / disadvantages are involved.

I am thinking undergearing the rear would make it easier on the drivetrain while overgearing the front would cause the drivetrain more stress.
Any difference worth noting?

[SCX10Dingo]

Great info.

[Big Tex]

Originally Posted by Dostradamas

On this subject I am curious.
What differences are there in undergearing the rear vs overgearing the front?
I want the front to spin faster than rear I get that but what advantages / disadvantages are involved.

I am thinking undergearing the rear would make it easier on the drivetrain while overgearing the front would cause the drivetrain more stress.
Any difference worth noting?

ive done both, and ive never noticed any amount of stress increase vs factpry 38T/13T from OD vs UD or both combined,

ive also never had issues with overheating or breakage either, i run factory wild boar shafts no sweat

and whether you OD the front or UD the rear its the same effect with the climbing aspect of your rig, and the most popular is to OD the front.

[ninja turtle]

Originally Posted by Dostradamas

On this subject I am curious.
What differences are there in undergearing the rear vs overgearing the front?
I want the front to spin faster than rear I get that but what advantages / disadvantages are involved.

I am thinking undergearing the rear would make it easier on the drivetrain while overgearing the front would cause the drivetrain more stress.
Any difference worth noting?

If you have a weak drag brake under driving the rear helps more then overdriving the front. I think you might see less torque twist from doing the rear too.

[Big Tex]

Originally Posted by ninja turtle

If you have a weak drag brake under driving the rear helps more then overdriving the front. I think you might see less torque twist from doing the rear too.

ive never had a problem with torque twist, well i run 40wt oil in my shocks for trails and ive never noticed it

[SCX10Dingo]

Would it be recommended to overdrive the front OR under-drive the rear? Any real difference? Would doing both have more of a negative effect on trying to run around on flat concrete and pavement?

[Big Tex]

Originally Posted by SCX10Dingo

Would it be recommended to overdrive the front OR under-drive the rear? Any real difference? Would doing both have more of a negative effect on trying to run around on flat concrete and pavement?

no like a said in my previous reply, ive run both with no issues, the rigs are light enough for the drivetrain to slip when it needs to, unlike a 1:1 that wont even budge with different ratios, i ran OD and UD in my 11lb rig no sweat.

and again like i said, OD the front is just the popular vote, but its all personal preference bud, whatever you wanna try go out there and try it, thats what this hobby is all about, our advice can only go so far, so get out there!

[SCX10Dingo]

Originally Posted by Texas Creeper

no like a said in my previous reply, ive run both with no issues, the rigs are light enough for the drivetrain to slip when it needs to, unlike a 1:1 that wont even budge with different ratios, i ran OD and UD in my 11lb rig no sweat.

and again like i said, OD the front is just the popular vote, but its all personal preference bud, whatever you wanna try go out there and try it, thats what this hobby is all about, our advice can only go so far, so get out there!

Makes sense. I appreciate the help.

[Big Tex]

you cant tell from the camera angle here but this climb is almost straight up, right there my rig weighed about 9lbs 14oz so almost 10lbs,

the overdrive helps with not rolling onto your back as much by the front pulling your rear end up the hill instead of the rear pushing up.

[05Fronty4x]

Lol, come on guys...underdriving rear/overdriving front, it's the exact same thing: an offset gear ratio between the front and rear axles.

Putting the underdrives in the rear has a greater effect, not because it's the rear, not because it's underdriven instead of overdriven, but simply because the offset in gear ratios is greater than if you were to put the available overdrives the front. Though this difference is so small you wouldn't even notice, so do which ever you want, it's the same for all intensive purposes.

Stock (38/13) = 2.92:1
Over (36/14) = 2.57:1 or a .35 offset
Under (43/13) = 3.31:1 or a .39 offset

Imagine our rigs came with 43/13, and you put 38/13 in the front, that would be considered overdriving the front, right? Yet my rig has those same exact gear ratios front and back, but it's considered to have an underdriven rear because we started with 38/13.

My point is that the words are basically meaningless, it's the numbers and more importantly the difference (offset) between front and rear ratios that count.

[johnnyh66]

well, keep in mind the ratios are different.
While doing one axle or the other will essentially do the same thing, using the different gear combos will give you a slightly more or less ud/od effect.

The greatest difference is doing both axles, that's what I run.
And the least difference, I think w/o doing the math, is to just do the front axle.
With just doing the rear axle in the middle of how much a difference in ratios.

[SCX10Dingo]

Nice demonstration!

Since you bring up vehicle weight..... I think my dingo is about 8lbs. I have aluminum wheels (motoworks or something like that), and about 3 1/4 oz in each wheel. Does this sound pretty close, or should I add more weight to the wheels? I wanted to make it a little heavier for better traction, but not so heavy that it would have more heft to pull up steep climbs.

[johnnyh66]

05Fronty4x replied while I was typing but yeah... what he said.

[johnnyh66]

Originally Posted by SCX10Dingo

about 3 1/4 oz in each wheel. .

That sounds fine to me but some will say it's too much.

[05Fronty4x]

Originally Posted by johnnyh66

well, keep in mind the ratios are different.
While doing one axle or the other will essentially do the same thing, using the different gear combos will give you a slightly more or less ud/od effect.

The greatest difference is doing both axles, that's what I run.
And the least difference, I think w/o doing the math, is to just do the front axle.
With just doing the rear axle in the middle of how much a difference in ratios.

That is correct, the difference in offset from stock ratio is so little between the 2 other ratios you'd never notice though.