Gear Ratio

[BRSTQUEST]

I Am Getting Ready To Buy A 05 Chevy With A Duramx/allison Combo And Want To Know What The Proper Gear Ratio Will Be With 35" Tires....i Know With My V10 With 35's It Was A 4:56 Gear Set To Bring It Back To Stock, But Is It Different With The Diesel(less Rpm's And The Such)....thanks For Any Info....

[rvrpig]

A gear ratio should be the same weather it is gas or diesel..I would think.

[RidinRed]

Your varience will be the same regardless of engine or fuel. The differance will be where you want it to run best. you should see about 15% change in callibration on the speedo, and as I recall about 500 rpm lower at highway speed?

[djunkie]

I say drive it with those tires first before you decide. With 35's the 3.73's it comes with may not be too bad. That motor makes a shitload of torque. How much do you tow with it? And what weight do you tow?

[BRSTQUEST]

Well The Truck Is Going To Be A Weekender And Toy Mover Only, So It Won't Be Driven Everyday To And From Work....i Usually Two Twice A Month On The Average.......the Boat Is Probably 4500#'s And The Winter Toys Trailer Is 9000#'s Or So......i Just Want To Make Sure The Tranny Is Not Overwork Unnecessarily(sp)......when I Regeared The V10 From 3:73's To 4:56's It Made A Huge Difference On Towing And Drivability, Wish I Would Have Done It The Same Day I Lifted The Truck....thanks For The Info

[sigepmock]

3.73's and 35's are fine with the DMax. Get a programmer like the Granetalli Predator run it on 65hp tune around town or towing under 8000lbs and the 40HP tune for towing heavy. It will also allow you to recalibrate for the larger tires so the tranny shifts correctly. I did a lot of research before doing my truck and this is the concensous I got for a safe and reliable set-up on 35's. Also with the Hand held programmer you can return it to stock in 5 min before going to the dealer for warranty work. I think the Edge programmer is the best, it just takes a little longer to un-install.
Also get a EGT and Boost guage so you can keep an eye on things, just in case. Here's a pic of my guages:
http://www.hotboatpics.com/pics/data/500/5495guages-med.jpg

[cdog]

I Am Getting Ready To Buy A 05 Chevy With A Duramx/allison Combo And Want To Know What The Proper Gear Ratio Will Be With 35" Tires....i Know With My V10 With 35's It Was A 4:56 Gear Set To Bring It Back To Stock, But Is It Different With The Diesel(less Rpm's And The Such)....thanks For Any Info....
You can order the truck with 4:10's. That will be the way to go. The gas engines are more affected by the rear gear ratios than the deisels. I had a 02 HD with 4:10's and the 8.1 on 38's and it would bog a little in O/D with a tow load. I needed 4;56's to put it back to stock. 4:10's with 35's would be the perfect match. But try to buy it with the 4:10's because the GM gears are way better than the aftermarket ones.

[CornWater]

A gear ratio should be the same weather it is gas or diesel..I would think.
This is absolutely not true... 4.56 would be overkill with 35's and a diesel...

[sigepmock]

3.73 is the only way the Dmax comes because of the gear ratio's in the Alison and the Dmax working RPM range. At least that's what GM told me. I know of 7 dmax's with 3.73 and 35's that tow like champs. I just got 35's on my truck yesterday....dmax, 3.73's, 35's I to be honest I couldn't feel the difference and I don't even have the programmer on yet.
Chris

[cc322]

Call these guys UNITRACK 714 630-4327 ask for Devon, they will walk through the whole chart for you. They are the best and come highly recomended. BTW just talked to them and advised 4:10 to get mine back to stock 03 F-250v-10. good luck.

[BRSTQUEST]

Thanks All For The Input On The Right Ratio.....i Just Bought The Truck Today From Photoglou And It Gets Delivered Tommorow At Work!!!!!!! I Can't Wait To Start Messin With It, I Love New Trucks...just When I Got The Ford Finished I Go And Buy A New One To Start Spending Money On......i Think I Need Help Or A Sugarmomma

[rvrpig]

Sorry I Meant That A 3.73 Will Be About The Same Weather It Be Diesel Or Gas.

[PHOTOGLOU]

Congrats brstquest.... 3.73 are the only way GM makes the diesels but just ask Duffster (who bought my DMax) 37" tires 3.73 gears power programmer and 15k trailering weight was NO PROBLEM.... Jay

[duffster]

Jay is correct 3.73 gears work just fine plus diesels like low RPM’s. I think if you go any lower you might see some issues.