I need to make a decision on gears. I presently have 3.55LS and I don't think the tires are stock ( 265x75x16 bridgestones) I live in the high country (6000ft) and the truck is gutless. I don't want to spend $$$ on 4.10s and wish I would have choosen 4.56s

Has anyone done this gear change? What is your rpms at 75mph? Is there a big difference in torque? What did it cost installed, and are you 4X4 like me?

Thanks in advance
Darren

------------------
97' F150 Lariat S/C long bed 4x4 3:55LS 4.6L auto...SuperChip, Air Raid, 40 series Flowmaster cat back.
Colorado Springs, CO




[This message has been edited by Darren Dude (edited 01-23-2000).]

 

DD,
There is hope! click or type in the addy below, this will help you out.
I have the same tire size and (had) the 3.55 gears. I upgraded to the 4.10's. and lost about 3 MPH on my top end. The 4.56 geas will surely give your truck a swift kick in the pants when you punch it. Mine sure does, but I have the 4.2, auto w/ the superchip.

Your looking at about $1000 for both axles.

F&B's
http://www.4lo.com/geartable.html

------------------
98 F-150 XLT, SC, SWB, 2WD, 4.2L auto, 4.10 gears w/ LS, Tow Pkg. BFG AT 265/75/16, K&N air filter, Dynomax muffler, Superchip, Edlelbrock shocks, Hellwig sway bar, 3" body lift, signal mirrors...tons of cosmetic products


[This message has been edited by franks&beans (edited 01-25-2000).]

 

Daren Dude,

I went to www.richmondgear.com and did a little figuring. The idea is to get back to stock rpm's. So... Most Fords came with the 235x70x16size tires. These are approx. 29" in diameter. With the 3.55 gears, your rpms in OD at 75 mph should be around 2159rpm. Now your tires are 265x75x16. These measure out to approx 31" in diameter. With the 3.55 gears, your rpm at 75mph should be 2020rpm. To correct the rpms back to where they were stock then you need a 3.80 gear ratio. That ratio does not exist. So, you can either choose the 3.73 and be close or the 4.10 and have a little extra. I think the 4.10's would give you the power you want.

 

F&B is right on the price. The places around here all wanted about $1100 for the gears + install. An aftermarket LS is another $400.

My '97 Expedition should be out of the shop ( www.samsoffroad.com ) this week with 4.10s and an Auburn LS.

If your not in a hurry, I should have some results next week.

Neal

------------------
1997 4x4 Expedition- 4.6L, true dual exhaust w/glass-packs, K&N air filter, SuperChip, airbox mods, Edelbrock shocks, 285/75R16 BFG ATs, Optima "T-Bone" wheels, and Clarion In-dash CD player. Just added Smitty Bilt push bars and nerf bars!!

2000 4x2 F150 XLT Reg. Cab LWB- 5.4L, Tow Pkg, 3.55LS, CD player,Remote Keyless Entry, Sliding back glass, Special Appearance Pkg.

http://members.visualcities.com/NoMo

 

Ill testify to F&B's comment about gears putting a "kick in the pants when you punch it". Although he has the V6, the 4.10's make his truck move swiftly! Gears are probably the easiest and cheapest way to increase acceleration and that seat-O-tha-pants feeling..and boy DO you FEEL it!

F&B's...yer tires are only 265/75's?? I thought they were 285's. Looked mighty-meaty to me.

Take care
DS

------------------
2000 F150 XLT 4x2, supercab, shortbed, 5.4L auto, 3.55 LS, Class III tow/cooling, 4 wheel disk/ABS, Med Toreador solid, Med Graphite int, 60/40 bench, sliding r.window, pwr everything except seat, 16" chrome alloys
*** In the Works - FabTech 3.5",Bullseye spindles,3" bodylift,Eagle 589's w/35x12.50 BFG AT ko's,alarm/keyless entry,Changer/Fosgate amp/JL subs (when i figure how im gonna make the box fit!) ***

 

The 265/75R/16's are 31.65" tall
the 235/70R/16's are 28.95" tall

F&B's

------------------
98 F-150 XLT, SC, SWB, 2WD, 4.2L auto, 4.10 gears w/ LS, Tow Pkg. BFG AT 265/75/16, K&N air filter, Dynomax muffler, Superchip, Edlelbrock shocks, Hellwig sway bar, 3" body lift, signal mirrors...tons of cosmetic products

 

DS,

Nice to see your smiling face here again. We have to hook up again. To answer your "Q", I do have the 265's. Yea they look nice but I can do better. If and when these wear out I would like to go to the 285's, I would gain another 1.1" in height and my gearing will STILL be better than stock LOL. I can even go as tall as the 295/75's and be right at stock power like when I was running the (235's with the 3.55 gears). But I probably won't do that. I would be looking at taller "side walls" and that will create increased body roll and that "swimming, swaying" feeling when turning a sharp corner. Do you remember those sharp corners on our test ride DS? LOL! I think it's time we "test" ride my beast one more time ;-) You up for another?

F&B's

 

Any of you gear changers out there do the gear swap yourself? How much of a pain is it? Do they make complete swap kits for front and rear diffs? Not a certified mech but do know how to turn wrenches. Just went to 35" BFG tires on 97 4X4 and would like to get the umph back. Comments.......
TIA
JMJ

 

The question is 4.10s or 4.56s or do they make something in the middle(4.30s) I don't want to spend $1000 and be dissapointed.

Thanks
Darren


------------------
97' F150 Lariat S/C long bed 4x4 3:55LS 4.6L auto...SuperChip, Air Raid, 40 series Flowmaster cat back.
Colorado Springs, CO

 

Frank & Beans

I can't figure out that calculator My tires are 31in. and I want to know what my rpm's will be at 75 mph with 4.10s , 4.30s, and 4.56 gears. I have an auto trans.

If anybody can figure this out I would be extremely pleased

Thank You in advance
Darren

------------------
97' F150 Lariat S/C long bed 4x4 3:55LS 4.6L auto...SuperChip, Air Raid, 40 series Flowmaster cat back.
Colorado Springs, CO

 

Darren, I would reccommend 4.10 with 33" or smaller and 4.56 with 35" tires. I did check mine this weekend and it runs about 2300 rpm at 65 mph. $1000 dollars seems a little high. I paid approx. $140 per axle plus $300 for intallation and about $60 in misc parts. Just remember that if you go to the smaller gears, you will get that "kick in the pants" feel but you will also loose some top end.

See Ya


------------------
97 F-150 Black, 4x4 XLT ext.cab,sb,offroad pack.
4" Susp. lift, 3" body
4.56 gears w/LS,
Flowmaster 50 Series w/ duals out rear
35" Wild Country Tires,
16.5x9.75 Weld Scorpio V wheels,
Pre-Runner Bumper w/KC Lights,
Westin nerf bars,
Rancho 9000's and remote,
Lift Lips,
K&N Filter,
Superchip,
TransGo Shift kit,
Bug shield,Tinted windows
Sony ES head unit,Sony ES changer,MTX Thunderform sub,Boston Acoustic Pro-Series up front, Polk in rear,PPI & Coustic Amps,Alpine Alarm

Check it out at:

http://members.aol.com/squanto804/scottwebpage.html

 

Darren Dude,
My calculations show with 31" tires at 75 mph in overdrive you rpms should be:
4:10 = 2330
4:30 = 2450
4:56 = 2600
These numbers are rounded to the closest 10s but they should give ya an idea. You do realize that your speedo is going to be off quite a bit? I doubt that Ford is going to be able to correct it for you.

Mike

------------------
99 Lariat S/C 5.4 4x4
Amazon Green/Harvest Gold
3.55/LS
Superchip
K&N Filter
Mobil 1
B.F. Goodrich All Terrain T/A KO Tires
dom562@icqmail.com

Oshkosh, WI.

 

Squanto804-

You got 'em installed ULTRA cheap. The "good" shops here in Tulsa are quoting 8+ hrs of labor for just the front (because of IFS). Another 4 hrs for the rear.

I agree with you on the 4.10s. Leave the 4.56s to the rock crawlers

 

If anyone is installing 35" tires and wishes to swap for new gears. Don't bother w/ the 4.10's. Do your self a favor and go w/ the 4.56 gears. Last week "Gimpkiller" let (ME) drive his 97 4X4 new 5.4L, reg cab., 4" Rancho susp. lift, 35" tires w/ Weld rims. This is a PERFECT set up, the power off the line was impressive and had eye opening passing speed on the open road. The 4.10's wouldn't even come close to preforming like the 4.56's do.

F&B's

------------------
98 F-150 XLT, SC, SWB, 2WD, Pac. Grn., 4.2L auto, 4.10 gears w/ LS, Tow Pkg., BFG AT's 265/75/16, K&N air filter, Dynomax muffler, Superchip, Edelbrock shocks, Hellwig sway bar, 3" body lift, signal mirrors, ...tons of cosmetic products

 

nomo, well I did forget to mention that I did take the front diff out of the truck and take it to them, which you are right, makes it quite a bit cheaper. Sorry

[This message has been edited by Squanto804 (edited 01-26-2000).]