bigger tires lower gears?

[ForOffRoadDriving]

i took my truck on the freeway for the first time yesterday and realized that 5th gear, even on flat ground seems to be utterly useless! ive got a fresh 3.0l with 650 miles on it, m5od 5 speed trans, 7.5" traclock rear axle with 3.73 gears and 30x9.50x15 tires. when im taking off it seems to have plenty of go power, but when im at the end of 4th and going into the bottom of 5th (never made it to the top) its like someone cut off the power and it just wont go any faster. im wondering if anyone else is running this combination and what theyve experienced (same symptoms or not). im thinking about upgrading to an 8.8 with discs from an explorer (did they ever come with 4:10s stock?) to solve my power problem, but i figured id get some more insight on this before taking things apart again!

 

[TRX501RYAN]

I have a 3,0 running 33's and 4.10's with an auto, it seem okay, but if i hit more then a very slight grade, such as an verpass it will kick out of overdrive,


4.10 will definately help your problem, but your 5th, is basicly like overdrive on manual,

What were your stock sized tires on that unit?

 

[Jay FX4]

im thinking about upgrading to an 8.8 with discs from an explorer (did they ever come with 4:10s stock?)

Yes.

 

[wahlstrom1]

Your best bet for a disc braked 4.10 8.8" would probably be a 95+ explorer sport. The majority of the ones in wreckers I've seen had 4.10s.......or 3.27s. So check them all as they may be in something oddballish.

 

[ForOffRoadDriving]

thanks for the input guys. something im still trying to get used to is the rpm range in which the 3.0 makes its power. ive got a flowmaster 50 series delta flow on it so it sounds like its screaming at me to shift when im at 3,000 but ive read a few posts with guys saying theyre getting 22 mpg while holding it at 3,200? i really like the idea of having the 8.8 with discs to help stop these tires easier, but money is still short from the build and it seems like i just got things the way i like it! something ive been wondering about but have yet to search is how people are relocating the spring pads on the explorer axles to get them absolutely perfect (or is there no such thing in this case?). heres a pic of the rig in question since all of you guys were so eager to help me

 

[Downey]

swapping an explorer 8.8 is easy. i reused the spring pads i cut them off and swapped them on top. to find your pinion angle you need the angle off the back of the tranny. mine was neg 7 degrees so i set my pinion angle at positive 7 degrees. i then cut the shock tabs of the the ranger 8.8 and made them work with the explorer 8.8. go to the tech section and read about the 8.8 install. you can also pm me with any questions its a pretty simple swap. seeing in your build thread you will be able to do that in a night or 2

 

[Hahnsb2]

4.10s would be good with 30s.

FWIW I measured my pinion angle a bit differently. I pulled the 7.5 out and put it on jack stands and placed a level on a perch until it was level then used an angle finder to measure the angle on the pinion flange and copied the measurements to the 8.8

 

[Downey]

^^^^ thats not as accurate. i was told by a mechanic to find the pinion angle that way

 

[ForOffRoadDriving]

so to find the pinion angle im going to have to find an angle meter? where can i get one of these? do you think sears has one?