Tandem drive axles - questions

[Jkessen2]

Hey everyone,

Looking around this place gives me a lot of ideas, which lead to my questions. Right now my questions are axle related, specifically for tandem drive axles.

-What is the 'best' axle to modify to be tandem drive, and what are their lengths? I'm looking for something around 6" long. I've heard TLT's are good, but they seem hard to come by, or downright expensive [the RC4WD ones are $130/axle, but they're aluminum...]

-How do you overcome the fact that the driveshaft will be spinning the opposite direction when it comes out the other side of the axle? (or am I confusing something here...sorry I can only envision it in my mind)

-How do you best accomplish both front axles steering...would you use one or two servos, and if you used one, would you link all of the tie rods together [front axle to axle just behind it]?

..and what is the width of the 1.9" rock crushers? I know their O.D. is 4.25".

...last but not least, how long are leaf springs?

I really wish dimensions were labeled on websites for products.

Thanks in advance!

[spookyseven]

Sorry I cant answer all your questions, but the ones I can answer are, the rock crushers are 1 5/8 at the widest point of the thread, and I have a pair of high lift leafs that meaure about 4 1/2 eye to eye and have about 1 1/8 between a flat surface and the arc.

[hairba11]

Originally Posted by Jkessen2

-What is the 'best' axle to modify to be tandem drive, and what are their lengths? I'm looking for something around 6" long. I've heard TLT's are good, but they seem hard to come by, or downright expensive [the RC4WD ones are $130/axle, but they're aluminum...]

you can find tlt's on here, usually around $100/pair depending on what all goes with them.
I have used wheely King axles before, and seen Axials used also, use two pinion sides and shave the extra lip which is used to align the case halves off so everything mounts up flush. TXT axles would require case modification and a longer input shaft, although I have thought about trying it.

Originally Posted by Jkessen2

-How do you overcome the fact that the driveshaft will be spinning the opposite direction when it comes out the other side of the axle? (or am I confusing something here...sorry I can only envision it in my mind)

you envisioned it correctly, it is spinning opposite. you have to turn the final axle "upside down" so that the ring gear is on the same side as the front axle's ring gear.

Originally Posted by Jkessen2

-How do you best accomplish both front axles steering...would you use one or two servos, and if you used one, would you link all of the tie rods together [front axle to axle just behind it]?

most setups I have seen on an 8x8 use two servos, one for each axle, in theory you could use a BTA setup on the first, and a standard setup on the second with two drag links going to one servo, but steering four wheels would be a decent task for most servos.

Originally Posted by Jkessen2

..and what is the width of the 1.9" rock crushers? I know their O.D. is 4.25".

spooky got that one

Originally Posted by Jkessen2

...last but not least, how long are leaf springs?

I have some repro bruiser springs at about 4.875. and some jugg springs about the same length.

Originally Posted by Jkessen2

I really wish dimensions were labeled on websites for products.

me too. i've been hosed before misjudging sizes and compatibility.

Originally Posted by Jkessen2

Thanks in advance!

You're welcome

H

[Jkessen2]

Thank you for the replies! Last night while laying in bed I figured out how to correct for the driveshaft's backward spinning...it just hit me and I was like "well duh, you just flip it."

[Jkessen2]

Another question about tandem drive axles: Is there a thread on here explaining how to make them, step-by-step? If not that's okay, I understand how to do it pretty well I think. I've looked but haven't found anything [I've searched "tandem drive axle", "8x8", and "6x6"].

And does anyone have the length of either a TLT axle, wheely king axle, or axial axle?

[sloppy]

you know tamiya semi axles are very easy to convert and are readily available on ebay from some good vendors.

all you really have to do to convert them is either at straight axle adapters or aftermarket chubs. both are good upgrades anyway. you also have to switch out the outer drive axles but that is not a big deal