So heres the thing. my F150 is a supercab long bed...weighs about 5300 lbs. 302 engine and 3.55 gears. Im gunna be puttin on some 36x14.5 tires soon and im wondering if i will need to immediatly regear or not. I know that i should regear. Im not afraid of regearing my truck myself (and im sure as hell not payin someone to do it for me!), its just a matter of not having time until the summer (when im going to go to 4.88's or 5.13's depending on if i go bigger on tires or go SAS).

So i ask yall with 33-37" tires how does your truck drive with stock gears vs. steeper gears? For daily driving?, for wheeling?, and for hauling?

You also need to take engine load into account... You're going to be putting an awful lot of stress on your engine if you're trying to turn those tires with a high gear... Keep that in mind.

I run a 33 now on my 150 and am switching up to a 35 or 37 and will need to regear then but with the power increase I gained in the rebuild I will be able to postpone it for awhile. Your touque and hp will go down but you should be fine until summer.

I assumed that the power would go down im just hoping its still drivable!(enough to have fun while going to work and to go wheeling)

I swear...if i had unlimimted free time id have the baddest assed truck...thats what ya get for doing all the work yourself i guess haha

godblessmud said:

So heres the thing. my F150 is a supercab long bed...weighs about 5300 lbs. 302 engine and 3.55 gears. Im gunna be puttin on some 36x14.5 tires soon and im wondering if i will need to immediatly regear or not. I know that i should regear. Im not afraid of regearing my truck myself (and im sure as hell not payin someone to do it for me!), its just a matter of not having time until the summer (when im going to go to 4.88's or 5.13's depending on if i go bigger on tires or go SAS).

So i ask yall with 33-37" tires how does your truck drive with stock gears vs. steeper gears? For daily driving?, for wheeling?, and for hauling?

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Oh gawd..... you're not gonna want to hear this. With that motor and gearing (had that, BTW) 33's are the absolute outer limit- and you won't like how it runs out, or the mileage it'll get. 31's are really ideal for that setup.

The other thing to consider is this: that summertime project should coincide with $4-$5/gallon fuel. Wouldn't be much fun to do the mods and then not be able to afford to drive the dang thing. Just thinking out loud here...

Balls...my mileage cant get much worse, its sittin at right around 10 even for in town and country roads (35-50mph)

Regearing to 4.10s as is would net me more mpg on the current 31" tires (actually measure about 27 ) and with big tires and some 4.56-4.88 gears should get me to right around stock and hopfully back up to 12 mpg

godblessmud said:

Balls...my mileage cant get much worse, its sittin at right around 10 even for in town and country roads (35-50mph)

Regearing to 4.10s as is would net me more mpg on the current 31" tires (actually measure about 27 ) and with big tires and some 4.56-4.88 gears should get me to right around stock and hopfully back up to 12 mpg

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Dude if you're getting 10mpg with 27-31" tires, you've got other problems to worry about besides gearing. I was getting ~13mpg with 3.55s and 33" tires... And thats with a 351 in a heavier truck too.

Keep in mind that this is a lil 302 pushing a 5300lb supercab/longbed...it just has to work to damn hard and my mileage goes down the crapper...it would be more efficient to have a 351!


You know me, im always up on maintenence and i havnt found anything seriously wrong.
I know the plug wires are arcing like crazy and ive got new 8mm wires and a fresh dizzy cap waiting to go in when i have time...
im waiting on a free time to do a compression test, that will be the real test.

But at its best on stock tires 10 years ago this truck barely got 13-15 mpg highway...factor in that the engine now has 131000 miles w/out a rebuild!

The white truck in my sig was a 5.0, EOD, 3.55 LS 4X4. Had 232,000 miles on it when we sold it- original engine and tranny (no rebuilds either). Always got 13-15 in town, 18ish on the highway @ about 75. (ran 30's and 31's on it). No way could a 351 touch that kind of mileage. Check the fuel pressure regulator- when they suck that much fuel, that's usually the reason.

godblessmud said:

Keep in mind that this is a lil 302 pushing a 5300lb supercab/longbed...it just has to work to damn hard and my mileage goes down the crapper...it would be more efficient to have a 351!


You know me, im always up on maintenence and i havnt found anything seriously wrong.
I know the plug wires are arcing like crazy and ive got new 8mm wires and a fresh dizzy cap waiting to go in when i have time...
im waiting on a free time to do a compression test, that will be the real test.

But at its best on stock tires 10 years ago this truck barely got 13-15 mpg highway...factor in that the engine now has 131000 miles w/out a rebuild!

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I have had 4 f150 4x4 302 e4od sc lb truck (With cap and Half bed of tools) all got 13 + even loaded. My 94 gets 15+ every day.And I live in a very hilly?mountain area/

Those tires without regear will cook the trany. Kill power ,and put more stress on motor. (I have run 35's with this combo and 4:11)

Basically you truck will get single digits MPG and take 2 blocks to get up to speed .

But I know how hard it is to wait. Just look at the extra expense you may have buy not waiting for gears. Gas and possible tranny motor problems.

As for general driving I have had about every lift manufacturer lift on trucks . Some ride better. But it come down to tire size, Even with a good lift tire bigger than 33" can be fun at Highway speeds At time and not in a good way.

If you live in flat area . Not going to offroad yet . And no stop and go traffic you will be fine.

But keep us posted will be good info for other guys

well im running a new 4.9L(i personally rebuilt it last year) and an M5OD 5 speed 4x4 and 3.55:1 gearing with 33/12.5/15 tires. i can say im happy with what I've got actually. are you planning on lifting the truck? if not your MAX tire size you can put on would be 33". everything else would rub and scrape the frame and bumper. there would be rubbing with the 33's but very minimal against the frame when at max turning. the mileage your getting isn't good. id lookup on that for sure. when youve got those new gears and 36" tires you will be getting as good mileage as an M1 Abrams Tank.....2 1/2 mpg.... i don't mean to put a bullet in your ballon but im just trying to warn you before something does go wrong

I'll second Ernie on the Fuel Pressure Regulator Recommendation. Sometimes the regulator can go bad, or you can lose vacuum pressure from an o-ring leaking. Those small rubber rings can go bad after that many years... I had a mileage problem and it turned out to be the fix.

Ryan

Which o-rings are you talkin' about Ryan?

Fuel pressure regulator eh? Not an item im very familiar with **reaches across desk and cracks open Haynes manual** Time to start reading

And yes, what O rings are you talking about?

Travis, im lifting it with a 6" skyjacker class II suspension lift.

Im thinkin of buying the 36"s and running them to see how it does and if it brings the suck then i can either pony up and get it regeared or run on 33"s until i have time to do it myself.

That sounds like a good plan, at least you have something to fall back on. I think you're gonna have to regear before running 36"s, though.

There's a pair of rings on the FPR. I can't remember exactly how it's set up, but there are o-rings involved. One one of the inlets, there were two, and one of mine was shot, the other was aging, but not falling apart yet.

Ryan

O'Rattlecan said:

There's a pair of rings on the FPR. I can't remember exactly how it's set up, but there are o-rings involved. One one of the inlets, there were two, and one of mine was shot, the other was aging, but not falling apart yet.

Ryan

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So what exactly were the symptoms and how did you know the o-rings were the culprit?

Im waiting to hear back from a couple local shops about what it would cost to regear to 4.88s. Can anyone tell me what they have payed for regearing at a shop?

I really dont want to go to a shop cause i know i can do this myself but its a matter of time, and if the price is right

O yea and im gunna look into the fuel pressure regulator tomarow hopefully i'l kepp yall posted on that

Regeared mine from 3.55s to 4.10s. Crossing that 3.92 threshold means I had to replace the front carrier (and you will too). One wrench that got thrown into my install was when the tech broke the crosspin bolt on my rear carrier and charged me for a new tracloc Told him I knew he broke it and he discounted the price. Can't complain, my LS carrier was shot anyways, so I got a brand new unit for a decent price. He used ALL factory parts (Ford r&p + tracloc in the rear, Dana Spicer r&p + open carrier in the front). Total ended up being $100 less than what the ticket shows (after the carrier discount):





For a grand total of $1524. Without that rear carrier (assuming your tech doesn't break the crosspin bolt which, from what I've heard, takes some skill NOT to do), the grand total would have been about $1300. It was a little on the expensive side but the shop came highly recommended from a few other people and the guy promised he could turn my truck around the same day (important since it's my only means of transportation).

I run 5.13's with my 40" Ground Hawgs (which really only measure 38"). I wouldn't want any less gear in it. I have a c-6 tranny. No o/d. On the highway, it cranks up around 3200 at 70, but I have all the power I could want.

With you having o/d, I wouldn't be afraid to go to 4.88's. You will not be happy with the 3.55's, even temporarily. The 302 will hate it and your clutch will too.

Holy Crap Chris!!! I'm glad I was able to do my own gears. Since your labor was $700 I saved about $500. I spent $200 to buy a press. Now I feel good.