Getting more gears....

[vdb11]

Hello all I wasn't sure whether or not this belong here or in the trannies section, but I put it here since it is mostly a drivetrain question. I tried searching this, please let me know if I missed a thread somewhere with this in it.

My question is, is there an alternative to a really expensive overdrive when it comes to splitting gears? I have an NV4500 and I would love to have a couple more gears in between. Anyways, does anyone make a transfer case with multiple speeds/splitter? I saw there are some small splitters for the SM465 4 speed and even those are expensive. What about a 2 speed rear? Is there such thing as one that was set up to run a single rear wheel? Or even better yet an 8 lug? I am assuming this is doubtful, but I could use some reassurance that my idea is not possible without a full overdrive unit, or I will keep thinking about it. I can only see four options anyway, a 2 speed rear, an overdrive kit, some kind of splitter/ multiple speed transfer case, or a different tranny. Anyone else ever pondered this question or have done it? Thank you!

 

[LtEng5]

if you want to have some fun you could put two trans together like the old 5+4 in the big trucks used to run.....5 speed in front of a 4 speed; 2 sticks and a hand full of a 36" steering wheel....

 

[Heartbeat Hauler]

I think you are gonna be outta luck. I don't believe there are any 2-speed rearends out there that would fit under a pickup. I think some of the older trucks, like pre-60's 1.5 ton trucks had them, but were geared to pull serious weight and I think they were underdrives instead of overdrives.

If you wanna split gears you will most likely be using a Gear Vendor Unit or the US Gear Unit. These two are auxillary transmissions that attach where the tailshaft attaches.

 

[ak diesel driver]

I don't know if they still make them but there used to be a unit fit between the clutch and the the tranny

 

[BigBlueChevy]

What is it your pulling with a 2500 SRW that you need more gears for if you don't mind me asking?

You can use a rear out of something like a Chevy/GMC C60 or one of the MD internationals. Problem is that your going to have to run the wheels off of that rig in the rear unless you plan on using the front I beam as well... Plus, the negative there is that the 2 speed rears are, like above stated, usually geared VERY tall. Where talking like a 6.38 / 8.38 ratio. Your 2500 probably runs 3.73's? Your going to have the engine screaming at over 3100 rpms just doing 55mph in OD(and yes that's in 6.38 low)

Perhaps you should look into another transmission? A GM ZF-6 behind a DMAX will bolt up behind your 6.5... Not 100% sure about clutch compatibility though. May need one custom made. Could also use an NV5600(6 speed as well), but again, a custom clutch will more than likely be needed. Of course, a 10 speed would solve just about everything there for you
http://www.youtube.com/watch?v=2CG0Yx3cmsc

The simplest, and most cost effective route to go right off the line is to go with a gear splitter like the Gear Vendors under-drive units. No messing with swapping transmissions, or custom clutches, no moving the transmission in general.

 

[BigBlueChevy]

This is mostly going off of info in your sig but here is what I came up with on the Gear Vendors website. Essentially about $3000 for there entire kit.

http://www.gearvendors.com/cgi-bin/...-ELECSPEEDO&submit.x=14&submit.y=16&submit=GO

 

[vdb11]

Ha well its not like I am towing anything too ridiculous. I might tow a max of 13-14k. Even just driving unloaded I hate how much I have to wind out 2nd before I shift to third and towing is worse (keep in mind my gears go L-1-2-3-OD, so what I call 2nd to third is like 3rd to 4th technically) I don't like screaming it (anything over 2500 rpm is screaming to me, I know it isn't really) but I definitely don't like bogging it since it is no good for the transmission, let alone the weak bottom end of the 6.5. If I could keep it between 1700 and 2300 all the time I would be ecstatic. The bigger trucks have so many gears they can keep it in the peak torque range all the time, which I guess would explain why they can tow much more with the same or less hp and torque than today's modern pickup diesels.

I didn't realize they were geared that tall. I have 4.10s in my truck but that would definitely kill my cruising speed. I was also afraid of that I would have to use the rear wheels from the rig with the axle as I guess they are not the same bolt pattern, which would be a huge PITA, not to mention look dumb. I was hoping maybe there was a light duty 2-speed 8-lug rear axle that I did not know about. But I guess if there was, everyone would have one

I have looked at the Gear Vendors units, and I would LOVE to have one of those, I just can't justify the price for the little I tow. It's kind of one of those things I would love to have, like a dump bed (which I will make at some point!), but for the little I would actually need it its not worth the price. A different tranny is an option too. I have seen that video BigBlue, that is awesome, I would love to have a 10 speed. That might almost be too many gears ha. Something like that ten speed would be nice too because you could probably skip gears when just driving around with no weight, but then they would be there when you need em. Thank you for all the thoughts guys! I really appreciate it!

 

[Ed HD]

We have a 2 speed rear in our 65 C60 and we start in 2nd High unless in really soft ground with a big load. Those gears are super low, and will be going the entirely wrong direction for you.