Do I need to re-gear with 33's?

I am in the process of lifting my 93' with a 3in PA body lift and F150 coils spacers in front and Warrior #153 shackles in the rear.

I have decided on 32x11.5 tires becasue I have been discouraged from going to 33's. I was told that if I go as large as 33's that I would likely need to re-gear from stock to support tires this large.

Is this true? What would happen with 33's and stock gearing?

 

[Robb]

Depends on what "stock" gearing is.

 

[410Fortune]

4.10's are great with 33's
4.56 are great too
it depends on what you use the truck for and what tranmission you have

Your stock 3.73 will work but your powerband and MPG will suffer..

 

[tomblin1]

After a search found this:
Axle Codes
The following lists the gear ratios on axles.
l 41 — 3.27 non-limited slip
l 45 — 3.55 non-limited slip
l 46 — 3.73 non-limited slip
l 42 — 4.10 non-limited slip
l D1 — 3.27 limited slip
l D5 — 3.55 limited slip
l D4 — 3.73 limited slip
l D2 — 4.10 limited slip

I looked at the factory label on the drivers door, says D1. So looks like I've got 3.27 limited slip. I guess I'll stay with 32's.

 

[Robb]

WOW! That is the worst! Even 32"s aren't gonna like that gearing. It will definately be doable, but it won't be great.

Sorry about that.....................

 

[SteveVB]

With 327s I would regear no matter what size you go up to-
min 4.10s - 4.56s would be better all around with 32s or 33s.

Like Robb said doable, but not great.
Good Luck.

 

[tomblin1]

Can you be a little more specific regarding "doable but not great."

I've got an auto transmission if it makes a big difference. This is my daily driver and it will spend the majority of its life on the highways and city streets of San Diego. Occasional camping, fire roads, minor offroad. Nothing too spectacular.

Will I simply not have enough power?
Will the RPM's climb sky high?
Will I be able to hit decent highway speeds but lose out on the low end?
Will this tear up my tranny?
Will gas mileage bottom out?

I dont have the $$ to regear right now so looking for some advice. Thanks guys

 

[dejello]

Will I simply not have enough power?
- Acceleration and passing power will drop

Will the RPM's climb sky high?
- No, they'll drop

Will I be able to hit decent highway speeds but lose out on the low end?
- You'll still hit highway speeds

Will this tear up my tranny?
- From what I've heard, our tranny (A4LD) is crap anyway

Will gas mileage bottom out?
- Gas milage will drop

 

[Ken Cooke]

Personal driver comments and photos...

Here's my experience w/various tires of various sizes:
LT235's - Great ride, great accelleration, great braking action...No complaints!
31's - Better clearance and road traction (on snowy Michigan streets). Better Offroad traction/flotation, etc.

32's - Much better offroad traction (mind you, I ran 32" TSL-SX's). The truck had a much more difficult time driving uphill. I had to downshift more frequently to accomodate those meaty 32" tires with my stock 3.73:1 gearing and 5 speed transmission w/4.0l engine.

33's - What the Heck happened to all of my Horsepower? I can't get into 1st gear at the stoplight! Where's all of my passing power? 4th gear on the freeway? Wow! I can travel 90 m.p.h. on the freeway, and my speedometer only reads 75 m.p.h. and I'm only running at 2,800 r.p.m. (downhill in 5th gear). Those uphill stopsigns are starting to give me anxiety... My truck can't turn these meats from a dead stop, and with cars behind me, I might stall again and again!! I can't stand this mess! I gotta regear!!!
------------------------------------------------------------------------
33's w/4:56:1 - Wow, I can get into 1st gear again. Those uphill stopsigns don't bother me too much now... I still can't stop my truck on a dime - maybe I should invest in rear discs... - Great clearance offroad, but, I still ride the brake on certain steep downhill trails Entering the freeway isn't a chore like it used to be, but, my top end at 3,000 r.p.m. is now 76 miles per hour (verified w/a G.P.S.)...

You'll love the performance w/4.56 gears. My only complaint is that my 1st gear isn't low enough on the trail making it necessary for me to ride my brakes on real steep downhill sections. An Atlas II would cure that problem for sure...

Now for the pictures!
------------------------------------------------------------------------
My truck w/32's

My truck w/33's - full-stuff w/rear swaybars attached...

 

[ld50]

from what I hear you should never run your tranny in O/D with that gearing and 32 inch tires, it will kill it. 33 would be horrible (IMO)

 

[Alec]

I had stock 3.27s. Even with my supercharger 31s sucked. 33s sucked with 3.73s even with the s/c also. Your engine and tranny will not like you at all with larger tires and 3.27s.

I'd go 4.10 if you're gonna stick with 32s or maybe 33s. If you're thinking about going bigger in the future, go with 4.56 and 33s now. Take the opportunity to get a locker or good LS in the rear too.

 

[JThelen]

i am runnin 33 xterrains on stock gears and axel yet i have had no problems on the road or trail except for a lil power lost in acceleration due to the large tires

 

[Sexploder]

Thoughts?

Sorry for the late posting on this thread, I've been doing a lot of research on getting my ex setup for wheelin. It seems that everyone has different opinions and experiences when it comes to gearing ratios and tire size. I am looking to go to 33s but I am debating on weather or not I should re gear. From what I understand, my stock 3L73 8.8 ford rear differential is a 3.73 ratio with some sort of locker. It's a pretty good overall gearing, but I don't want to risk messing up any other components by putting so much stress by having that combination of gearing and tire size. I want to get your guys input on weather you think I should re gear and if so, to what. I will be using this as a commute car as well so I still want to be capable on roads in addition to off road. Thanks

 

[obie]

Your rear diff is limited slip, not a locker. It works by using clutches to transfer traction, but isn't as good as a locker for offroading. They still work great for the street, and will still perform much better than open diffs for offroading.

Also, unless you have the V8, your truck will see a large power drop with 33s. If you have the V8 and want to keep it good for street and highway, 4.10s are really good.

If you have the V6 SOHC, then 4.10s will still give you a good balance of power and driveability with 33s. That's the gearing I have in my Sport Trac. 4.56s will do better offroad, but won't be so street friendly.

If you have the V6 OHC, 33s on 3.73s are going to suck. You'll need 4.10s minimum.

What kind of commuting do you do, and how long is the drive each way? Also, what kind of offroading do you want to do? Both of these will play a very large role in what gears to run, as well as what type of limited slip/locker you'll want.

 

[Sexploder]

Your rear diff is limited slip, not a locker. It works by using clutches to transfer traction, but isn't as good as a locker for offroading. They still work great for the street, and will still perform much better than open diffs for offroading.

Also, unless you have the V8, your truck will see a large power drop with 33s. If you have the V8 and want to keep it good for street and highway, 4.10s are really good.

If you have the V6 SOHC, then 4.10s will still give you a good balance of power and driveability with 33s. That's the gearing I have in my Sport Trac. 4.56s will do better offroad, but won't be so street friendly.

If you have the V6 OHC, 33s on 3.73s are going to suck. You'll need 4.10s minimum.

What kind of commuting do you do, and how long is the drive each way? Also, what kind of offroading do you want to do? Both of these will play a very large role in what gears to run, as well as what type of limited slip/locker you'll want.

I have the 4.0 "pushrod" V6 (its listed as a 96 even though it was built in 95). I figured that in the time being, I will just go with 31s with my 5" lift. That should give me plenty of flex and clearance more than my stock setup at the moment. I mainly use my car to get to and from school which is about 5ish miles as well as around town once and a while. I wont be tackling anything extreme in terms of off roading, but I hope to give it a shot at some intermediate-advanced terrain later down the line. From what I understand and from what I have heard from other people, my 8.8" D4 rear diff is a hulk in terms of strength and its great that it has the LS too (i don't know how good the LS is though and if it is any good). So far, I plan on sticking with my rear diff setup unless you think I should do something else to get the performance im looking for with 31 inch tires.
Thanks for the input!

 

[Ken Cooke]

Way back in 1999, I ran 31s on my Ranger (5 speed manual) with 3.73 gears.

Your 31" tires will feel like they are at the correct gearing with your stock gearing.

You will feel a little drag with 32" tires. Getting into 1st gear from a dead stop will not be difficult.

With 33" tires and a manual 5-speed transmission, you will feel the larger tire size working against you with 3.73 gearing. Getting up to speed on a freeway on-ramp will be much slower. This is where I regeared to 4.56 - so that getting into 1st gear would not be so difficult. I should have gone straight to 4.88 gearing, instead. The problem was that my first gear just wasn't low enough.

 

[Sexploder]

Way back in 1999, I ran 31s on my Ranger (5 speed manual) with 3.73 gears.

Your 31" tires will feel like they are at the correct gearing with your stock gearing.

You will feel a little drag with 32" tires. Getting into 1st gear from a dead stop will not be difficult.

With 33" tires and a manual 5-speed transmission, you will feel the larger tire size working against you with 3.73 gearing. Getting up to speed on a freeway on-ramp will be much slower. This is where I regeared to 4.56 - so that getting into 1st gear would not be so difficult. I should have gone straight to 4.88 gearing, instead. The problem was that my first gear just wasn't low enough.

and I bet having a manual trany helped a lot in terms of having a better control over when the shifting occurs with bigger tires installed. I wouldn't want to try that with my auto transmission. I think ill just plan on going with the 31s as of right now.

 

[Ken Cooke]

and I bet having a manual trany helped a lot in terms of having a better control over when the shifting occurs with bigger tires installed. I wouldn't want to try that with my auto transmission. I think ill just plan on going with the 31s as of right now.

Regearing your differentials can be expensive. I spent about $1,000 back in 2000 to regear my Ranger.

 

[Maniak]

and I bet having a manual trany helped a lot in terms of having a better control over when the shifting occurs with bigger tires installed. I wouldn't want to try that with my auto transmission. I think ill just plan on going with the 31s as of right now.

The torque multiplication of the auto trans actually helps overcome some of the gearing mismatch. Think of it like slipping a clutch without the smell of burning clutch

However, like you said, once you're moving using the manual trans you have more control over the shifting to try to work around the gearing problem.

~Mark

 

[Sexploder]

Regearing your differentials can be expensive. I spent about $1,000 back in 2000 to regear my Ranger.

Ouch. I have a friend that knows a 4x4 shop that said they could do it for about $400-500. If i ever regear in the future, ill just go there. (Although ive never been there so for all I know, it couldn't be the best quality job). Ill just cross that road when I get there.