GCSS

Will a housing currently with 4:10 gears accept 3:54s?
I just don't do any HD pulling and really don't NEED 4:10s.
I am considering 3:54s or maybe even a little lower 3:23s etc etc.. if there is anything available.
I am currently getting 22-25 MPG with the 1 Ton dually with 410s, and I bet I can get closer to 30 with a good gear.
The heaviest I pull is my 2800# gooseneck trailer with my 3400# 65 Satellite Drag car. That's it.
I am open to suggestions.
THX!!
Green County Speed Shop

schaef_12

Yes.................

GCSS

OK.. now I have to try to find some gears.
Which ratios are available???
How low should I go???

Tate

3.31, 3.55 and 3.73 is about all the options you have below 4.10. FYI, 3.31's are double the price of the other two.

GCSS

OK.thanks.
I wonder if the 331s would be a good ratio or will I be killing the truck?
Does anyone use these ratios??
How much are they??

macattack_ga

Just FYI: I've been reading that SOME folks w/ the 4.10 gears are getting better MPG that those of us w/ 3.54 (loaded/unloaded)... I know it doesn't sound right, but maybe the lower gearing keep the motor in the "sweet" spot (RPM range) more that the taller gears.

If you're driving MOSTLY interstate (straight and level) then the taller gears might work out for ya.

Just a thought.

DL1221

Yeah, I want to do the same thing on my 01. It has 4.10 gears and I hate them, the max speed I can comfortably (for my tastes) drive at with that truck is about 65 mph.

My 96 has 3.54 gears and I love them, I can cruise all day long at 75-80 mph. I would go with the 3.54 gears if I were you, good compromise for your type of towing.

Yeah you can get good fuel economy with 4.10 gears, you just have to go slower that's all. 3.54 gears will drop your RPMs about 500 for any given speed.

I was quoted about $1300 from a local shop to change the gears on my 01. But mine is a 2wd, probably twice as much for a 4x4.

dieselfuelonly

When I first bought my 3500 I was kinda dissapointed that it had 3.54s. I thought it would feel like a complete sloth compared to the 2500 with 4.10s.

But with a much better transmission than the 2500 the 3500 will take off faster and pull harder and is much more pleasant to drive than the 2500, especially at highway speeds.

I get about 16 MPG with the 2500 on bio and 18MPG with the 3500 on #2.

However I'd say stay with your current gearing unless you can find someone who wants to swap axles with you because its not exactly cheap.

Box5

i don't think u can just swap gears, I think u need to swap the carrier and all that to. Thats why the best option is like he said^, and find someone who wants to swap axles.

Bluetick

Find a gear caculator, work with the tire diameter. Going to a "taller" tire will
lower the rpm. It could be cheaper to change the tire size the next time you buy your truck new "shoes".

Find the torq curve chart for your cpl. Keep the rpm in the lower range of the sweet spot.

GCSS

well now that is precisely why I am asking around regarding this swap.
The expense to me is just the cost of the ring and pinion.
Gear swapping in these are easy as changing spark plugs in a diesel. (ha ha)
No really....... pull the axles,4 bolts,the carrier is out, drop the driveshaft,pinion is out.
simply swap out the gears and put it back in.
It really is not hard to do.
If there is someone out there who wants to swap out entire assemblys... I might still consider it. MAYBE.
I had an 01 with a 6speed best I could get with it dropping it out of an airplane was 17. I hated the mileage and the fear of the injector pump failure...this is why I sold it and now have my 98 QC 12V 5spd.
Best of both worlds but better mileage.
Well I am located in the middle of Kentucky if anyone wants to swap out axle assys.... holler at me.
GCSS

Tate

Carrier split is at the 4.10 ratio, so you will need the lower ratio carrier for 3.54. They do make thin 3.73's, so you can install them on the 4.10 carrier. 3.73 would be a good compromise, but I think thats quite a bit of money for not a lot of change. 2300 rpm, 2100 rpm, 2000 rpm for 4.10, 3.73 and 3.54 respectively, to do 110 km/h (69 mph). Thats with 31" tall tires, and a 5-speed.

joshua smith

I would like to do this same swap with my 97. I tow a lot in town, 8-10 k, some towing on the interstate, but a lot of empty highway driving. With my gear vendors on, at 75 i am turning 1750 rpms with 285/75 tires which gets me 23 mpg with my setup empty, 17 mpg pulling. With the gear vendors off, i am turning 2300 rpm at 75 whick gets me 17 mpg. I have been thinking of this swap for a while , but have not done it yet. I figured I would drop 300 rpms by doing the swap, which should get me 2-3 mpg more. The only bad thing is that i have limited slip and I dont want to lose that.


1997 CTD 2500 4X4 ex-cab long box 235,000 miles, gear vendors 8 speed, stage 5 TST fuel plate, 4" exhaust, 370 injectors, full DTT trans, turbo silencer MIA, 4:10 gears w/ limited slip, new style tow mirrors, stock turbo and pump

2004.5 CTD 2500 4X4 4 door long box, stock for now

GCSS

what is a "Gear Vendors"?????

joshua smith

Gear Vendors is the name of the company. They make what is called an "under/overdrive" unit. I use it for the overdrive that it gives you. What you do is you take your tail shaft off the trans and replace it with this unit. It will "split" the gears in your trans that you already have, plus give you another gear which is called a "double" overdrive,. The double overdrive will drop your rpms by 500 when engaged. Factory overdrive engages at 45, you press the the button and the double engages at 55 mph. With my truck, at 75 mph with the overdrive off, I turn 2300 rpms, with it on I turn 1750 rpms. You can drive with it on or off. If you use the unit to split your gears, it basically gives you eight gears, great for towing. The website is www.gearvendors.com, take a look, it will explain it better. It took about 4 hours to put it in, plus having the driveline shortened. Cost me about $3200 it was all said and done. Best product for those looking for fuel mileage since sliced bread.

1997 CTD 2500 4X4 ex-cab long long box 235,000, Gear Vendors 8 speed, stage 5 TST fuel plaate, 4" exhaust, 370 injectors, full DTT trans, turbo silencer MIA,X-monitor guages, 4:10 gears w/limited slip, new style tow mirrors, stock turbo and pump

2004.5 CTD 2500 4X4 4 door long box , stock for now