best overall 8.8 gear

[odogf150]

ey im about ready to swap out my stock gears 3.55 to maybe 4.10 to confisate for my big lift and 35 inch tires. is 4.10 guna be good enough for that? also i heard just doing the gears isnt enough, the tranny also needs work too?

 

[LEB Ben]

Right now, your effective ratio is right around 3.14. So with 35's, to get the same characteristics as the stock tires and 3.55's, you need roughly a 4.00 gear ratio...and the closest to that would in fact be a 4.10. If it were me, I'd want to put a little more power to the ground and would probably bump up to 4.56's. That would be the gear to go with if your axle came with 4.10's stock, to get stock characteristics back.


As for the tranny, I've never heard anyone say the tranny needed anything done to it for a gear swap.

 

[Truckin4life]

Depends on the truck and on the year, if the speedo gear is in the trans then it will need a new gear so your speedo is accurate, if you have a vss in the rear axle, you will be fine.

 

[odogf150]

yea i was think about maybe going to 4.56's but didnt know what the affects would be cause i know 4.10's would do it nice. but yeah my speed sensor is on top of the rear axle housing. but anyway with the 4.56's, i know i will get more power, but will it guzzle gas crazy? i wanna at least burn rubber more easily from time to time but also want mpg in the long run across town or across state.

 

[LEB Ben]

yea i was think about maybe going to 4.56's but didnt know what the affects would be cause i know 4.10's would do it nice. but yeah my speed sensor is on top of the rear axle housing. but anyway with the 4.56's, i know i will get more power, but will it guzzle gas crazy? i wanna at least burn rubber more easily from time to time but also want mpg in the long run across town or across state.

4.10's would probably be a happy medium them...and like I said, would give you the same characteristics as your stock tire and 3.55 set up. Lower rpm=better mpg's. With 4.10's you'd be around 2550rpm at 65...4.56's would put you around 2850r's.


Edit...these numbers aren't accounting for a manual tranny or OD.

 

[Alvin in AZ]

Guys over on FSB recommend going at least one step past "stock" when
going to big tires and lifts because of wind and rolling resistance.

Overdrive?
Mostly city and trails?

Alvin in AZ

 

[odogf150]

yeah i got overdrive and mostly city some trails now that its summer

 

[odogf150]

oh yea and would it be best to have stronger axles in mind with 4.10's, big lift, big tires?

 

[LEB Ben]

oh yea and would it be best to have stronger axles in mind with 4.10's, big lift, big tires?

I'd say you'd be about to your limit. If it's just street driving some mild trails and a little mud, I'd go no bigger than 37's.

 

[Truckin4life]

4.56 gets my vote

 

[odogf150]

and what about just showing off with some 40 inch tires on the streets. ? i ran 40's with 3.55's just cruising it did alrite and i aint thinkin of doing any hardcore mudding maybe some hills and trails just throwing this out there

 

[LEB Ben]

and what about just showing off with some 40 inch tires on the streets. ? i ran 40's with 3.55's just cruising it did alrite and i aint thinkin of doing any hardcore mudding maybe some hills and trails just throwing this out there

I spose you could...but your 0-60 time will be measured by a sun dial.

 

[DNFXDLI]

Not to mention the stress on the driveline.

 

[conanski]

yea i was think about maybe going to 4.56's but didnt know what the affects would be. but anyway with the 4.56's, i know i will get more power, but will it guzzle gas crazy?

You need 4.56's just to get back to the stock final drive ratio and even more gear if you want to amplify engine power. This gear change will actually improve milage and drastically lengthen the life of your transmission.. which you are currently killing every time you drive the truck.

 

[LEB Ben]

You need 4.56's just to get back to the stock final drive ratio and even more gear if you want to amplify engine power. This gear change will actually improve milage and drastically lengthen the life of your transmission.. which you are currently killing every time you drive the truck.

I never understood why there was an issue for the tranny. Is it because it takes more to get it moving which causes more stress and then when cruising it will be hunting for gears?

 

[Lost]

Also if 92 or newer will have to recalibrate speedo

 

[Fellro]

I never understood why there was an issue for the tranny. Is it because it takes more to get it moving which causes more stress and then when cruising it will be hunting for gears?

That would be about right. It takes more to get going, which makes more heat in the converter. On a manual, it is harder on the clutch.

 

[Alvin in AZ]

It takes more to get going, which makes more heat in the converter.
On a manual, it is harder on the clutch.

"just pick a number and plug it in " -Mr Stewart my 8th grade math teacher

So... how does...
2nd gear at 600rpm sound to ya?

-----------------

'75 F150-
T18 + 31.5" tire +3.50 axle = 5.2 mph <--real nice, not too slow, about right
T18 + 31.5" tire +3.25 axle = 5.6 mph <--old setup, felt on the edge of too fast for its weight :/

F250 parts truck-
ZF + 31.5" tire + 4.10 axle = 4.7 mph <--stock, too slow when empty but good when loaded or towing?

Bronco-
ZF + 29" tire + 3.55 axle = 5.0 mph <--seems too slow, starts rolling easy but have to shift-up too soon
ZF + 31.5" tire + 3.55 axle = 5.4 mph <--might be real good with its relatively "low" weight?

The last one is what I've got planned for the Bronco but I just happen to have
six-new 29" tires (from parts trucks) to wear down a little bit first.

ZF 2nd = 2.94
T18 2nd = 3.09
Mazda 1st = 3.91
Mazda 2nd = 2.24

Mazda 5 speed close ratio-
Mazda + 1st + 29" + 3.55 = 3.7 mph
Mazda + 1st + 30.5 + 3.55 = 3.9 mph <--way too slow
Mazda + 2nd + 29" + 3.55 = 6.5 mph <---way too fast
Mazda + 2nd + 30.5 + 3.55 = 6.9 mph

------------------

Alvin in AZ
ps- If things go good today, the Bronco will be back down on its tires
again today for the second time since I got it over a year ago! LOL

 

[conanski]

An auto trans is nothing more than a series of clutch packs so it accumulates wear the same as a manual clutch. Larger tires are heavier and require more force to accelerate and at the same time they reduce the final drive ratio(35's are equavelent to using 2.89 ratio with stock tires, 40's would be like having 2.50's), so you're transferring all that extra load to the only other device between the engine and axle.. which is the transmission.

 

[odogf150]

i aint too worried about the speedo i got that covered already, but i just looked up tire-gear ratio chart in a bronco graveyard mag. and 4.56's w/35's would be an "overall" and 4.11 w/35's both will be "highway" driving. this lil thing gots me slumpd, highway or overall? sounds the same to me? anyone else has or had this kind of dilema too?