I couldn't help but notice your beautiful truck. I just had a quick question and your opinion/answere would be a great help since you have experience with a lifted I-6 truck. I want to lift mine in the future with a 6in lift and I would like to put on 35's. I've got a 3:31 rear..I notice you have 3:56..would you recomend that with the 35's to me or I was even thinking 4:10. I know I could get away with 33's and still keep my 3:31 but I'd like to go with bigger tires but not totaly kill my engine.

 

Actualy i have 4.56 gears. I drove for a while with the stock 3.09 gears and the engine had no problem moving the truck along although it was really tough on the tranny. 4.10's would be fine with 35's, i decided to sacrifice gas milage for acceleration when i went with the 4.56's. I think i calculated that i would need 4.21 gears to keep the stock final drive ratio. Since 4.21's dont exist i had to choose highway milage (4.10) or pulling power (4.56).


Hope this helps
-Jon

 

Hey thanks for the reply, it will help me out a lot....your truck is a beauty, I hope to get mine like yours soon.

 

So does getting lower gears (numerically higher) ease the strain on the tranny? I have 4.10's stock with 35's and an AOD. Will swapping 4.56's or 4.88's help keep my tranny in better shape? Thanks.

 

It does ease the stress on the tranny. With the lower gear ratio your tranny doesn't think it's pulling a boat around town trying to turn those big tires. You should be in good shape with 4.10's though. I don't know if the cost would justify switching to 4.56. You definetly don't want 4.88 unless you are planning on going with some larger tires. With 4.88 and 35" tires you would probably be running 4,000 RPM at highway speed.

I think one of the most important things on the electronically controlled trannies like the E40D (i'm not sure if this applies to the AOD) is to make sure you reprogram the computer so that your speedo is accurate. This way the computer will adjust the tranny shift points to where they should be. And that will definitly help the tranny out.

Another good idea with auto trannies is a tranny fluid cooler. I've heard they will extend the life of a tranny 50%. I'll be installing one when i put my new tranny in. THe way it is now i could fry and egg on the tranny after a few miles of driving.

-Jon

 

I was going to look into a tranny cooler for my 5spd...I don't think mazda intended that tranny to being doing half of what I do with it.

 

I think you're right about the gears. If and when my AOD tranny goes out, I'll probably swap in a C6. Since that tranny doesn't have OD, lower gears would wear out my engine pretty quickly! As for the AOD, it is mechanically controlled like the C6, so I cannot recalibrate my speedo by conventional methods. They do sell aftermarket calibraters for around $200. So I'll wait until I find the tire size I'm gonna stick with before I invest in one of those.

I'm pretty sure I have a stock tranny cooler. My truck came with the tow package (4.10's, class III receiver, tranny cooler) so I don't know how the stocker compares with the aftermarket coolers.

But you're right, gear swaps are very expensive, and it would be hard to justify spending $1500 on a gear swap when I already have 4.10's and I don't plan on going bigger than 35's with my half-ton. Maybe if I strike it rich someday Thanks for the replies!