I'm real close to instaling 3.08 ring & pinions in my differentials. Anyone else doing, done, or thinking on this?

 

Why not just stay out of the throttle a little? I didn't buy the truck because of the mileage, that is why I have a little civic for my commuter car. My truck was bought for the sheer brute power.
In my opinion I think the negatives would outweight the positives in this scenerio. I don't think a couple of mpg would make up for the drop in low end. When I take the truck out on the road for extended trips I just lower my cruising speed a little and voila 20mpg.
Could it be I am full of bull pucky? Maybe.
Mike

 

I'm not doing this for mileage more than i'm doing it for RPM's....Crusing even at 60mph, i'm up there in the 2100 range, which seems awfull high to me? Over reving the engine on a motor with 155,000 miles is probalby not a good thing.?

 

Need info about your truck. year, model, tranny, etc.
I cruise about 70mph and my rpms are approx 2000. Something doesn't sound right, but I am semi new to the diesel scene and don't really know all that much, yet. Isn't that why were are at FTE in the first place?
Good luck
Mike

 

I am running a 97 psd, factory 4.10's and 35" tires, I typically cruise at about 2100 at 70mph. An easier way might be to adjust your tire size, go larger.

 

if you wanted better mileage, go with slightly larger tires. mike is right, we need info about truck to really say if its worth it. A jump from 4.10 to 3.08 is crazy however a jump from 3.55 to 3.08 is more resonable. I think i turn a bit over 2100 in top gear and 65 mph.

 

I have 373 with stock tires and like they said at 70 I run a flat 2000rpm and get 17mpg thats with a semi heavy foot hope this helps

 

Thanks ALL!!, I have put on Bigger tires, it did actually help! Ride smooter etc....285, 75 R 16's, BIG O. But the jump from 4.10's to 3.08's is why im on here, is it crazy??....it is a 1995 f-250 x-cab, 7.3, 5 sp, stock as far as I know, I bought it used last year,. It has good rancho shocks, and overload spings, heavy duty clutch, which is starting to wear, and a heavy rear bumper. but that's it. Maybe i want to look at 3.55's?? I'm also new to the diesel scene as is mike.

 

A jump from 4.10 to 3.73 or 3.55 is more reasonable, I don't think you would be very happy with 3.08. Can't say I have ever even heard of an SD with gearing that high.

 

Sounds like i'll be heading in that direction! (3.73 or 55's) Thanks for your input James

 

Going with higher gears, could be bad on the clutch, or I guess you could start in granny every where you go.Just a thought.

 

Call me weird, but I rather enjoy shifting!! I'll take that into consideration though!! Looking like all this input is doing the job I needed. I'll go ahead with the swap, just not so drastic. I'll keep you all informed once done!!! Wish me luck!!!!:-)