I just figured out that i have a 3.08 and realized that that might be the reason why i don't have any power in hills with 285/75's on. I was wondering if any one out there has any input on if the swap is possible without changing the entire axle. Also,i'm switching my speedo gear this afternoon to compensate for the bigger tires, i was wondering if the gear swap would mean another speedo change or what. Thanks Eric

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'97 F150 4X4 Supercab XLT
Rhino Lining
285/75/16 BFG AT/KO
4.6L Triton V8
5 Speed Manual tranny

Coming soon:
K&N air filter
Superchip ( I think)

 

3.08 - are you sure? When I bought my 1997 F150 4x4 new I thought the 3.55 was the only choice. My axle code on the drivers door is H9 for 3.55LS.

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<URL=http://albums.photopoint.com/j/AlbumIndex?u=321294&a=3025856>

Mine:1997</URL> F150, XLT, SC, Oxford white/maroon 60/40 cloth, 4x4 ORP, 4.6L, 3.55LS, 17" ORP wheels w/GY AT/S LT265/70/17, auto, 6 CD,Towing package, alarm, Rhino grill guard w/PICCA lights, dual exhaust. Bought new June '96

Wife: 1999 Explorer Limited,pearl white/tan leather,4.0L,4:10LS,CD,sunroof,towing pkg.,alarm. Bought new Sept. 1999

Next: SuperCrew, 5.4L, 4x4,3:55LS,tow pkg. etc..

Previous: '65 Mustang 289 HiPo, '70 Chevelle SS 396, '70 Vette Conv. 350/350, 72 Datsun PU,'74 Vette TTop, '79 Blazer, '81 F150, '83 Bonneville, '84 Gran Marquis '89 TBird Super Coupe 3.8L SuperCharged, '93 Explorer 4.0L

 

My axle code on the inside of the door says "18" which i have read means a 3.08. The truck was built in canada and that might have been an option. It was leased prior to my owning it so the earlier owner might have wanted the higher gearing, i don't know.

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'97 F150 4X4 Supercab XLT
Rhino Lining
285/75/16 BFG AT/KO
4.6L Triton V8
5 Speed Manual tranny

Coming soon:
K&N air filter
Superchip ( I think)

 

Yes, you will have to change speedo gears again. I went form a 2.73 to a 3.73 on my T-bird and it resulted in about 15 mph difference at 40 mph. I wouldn't think you'd have to change axles.

Goold luck

 

You don't have to change the axle to change the gearing; just the ring and pinion gears, install parts, and labor.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

I am looking at buying a 99 F250 that has a (B6) 3.73 rearend, and if I purchase it I would want to make it a (B9) 3.55 ratio. This truck is an Auto tranny with a 5.4. What would a good estimate for having the pinion gears etc. replaced by a shop cost me? I really like this truck, but I do not pull most of the time and do not want too steep a ratio.

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1990 f-150 s/c
5.0 v8
3.55 rearend
5 spd. manual (m)
147,000 mi.

 

MJVAUGHAN- 3.73 is an excellent gear ratio. The truck you are considering has plenty of top end with that ratio due to the transmission gearing. A gear change is approx. $450-500 per axle. A change to 3.55 will not be a very noticeable change. Usually a change of .5 or more will yield more noticeable results. You could save some money still by just increasing tire height; resulting in the same type of results.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

How about for me. My truck came with 235/70-16 and now i have 285/75-16 with a 6"suspension lift and the 3:55 ls it came with. What size gear ratio do i need to bring me back to stock with my new tires? A little extra push off the line would be nice to, but i also have to drive 40 miles to school.

 

Ryshark5,
New tire height divided by stock tire height equals new new gear ratio. 32.9/28.95= 4.034 The closest gear ratio to bring you back to stock are the 4.10 gears. This will give you plenty of power off the line and still allow you to run at normal HWY speeds.

F's&'B's

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1998 (50th anniversary series) Solid Pacific Green Metallic F-150 XLT Supercab, 4.2L, Automatic (4R70W), 2WD, Limited Slip, 8.8 axle, Tow Pkg, 6' bed, Rear slider

Accessories added:

Performance:
Superchip / 4.10 gears / K&N air filter / Outerwear’s pre-filter / Dynomax Super Turbo muffler

Suspension:
Edelbrock IAS shocks / Hellwig rear sway bar

Other "stuff":
Color keyed outer grill / Stull polished grills / (4) 3A Racing 55 watt driving lights / (2) **** Cepek 150 watt driving lights, all controlled by SPDT switches / Clear corners / Fiberglass hood / Chrome F-150 emblems w/ side indicator markers / Signal mirrors / Driver side grab handle / White face gauges / Husky floor liners / B-Quiet / Carr side steps / 3" rear seat lift / Black Max soft Tonneau cover / Black Max cargo cleats / 3" body lift / OEM Chrome differential cover / Smart Park 2000 / Lighted Ford logo / (2) KC HiLight 55 watt back-up lights / Viper 550 alarm (remote start) / OEM fender flares / Lift lips / BFG AT's 265/75/16 tires / (Custom painted OEM air dam, antenna cover, tailgate handle, slotted taillight covers, all plastic shields under the hood, and stone guards) / 23 tooth speed-O gear.......

Contact me at;
lmaox10@hotmail.com

 

When you say $450-$500 per axle does this mean. This is not 4x4 so I only need one? What does a speedo gear cost? I am just really concerned about gas mileage with this 3.73LS setup. How much taller tires would this mean & what would this do to the overall look and stance of the truck? I don't want it to look like a 3/4 ton truck, but more like a beefed-up 1/2 ton. I really appreciate your response, this truck I think,is at a really good price for what you get and I just want to make sure I don't let it slide without being sure it's not best.

[This message has been edited by MJVAUGHAN (edited 07-23-2000).]

 

MJVAUGHAN- Yes, $450-500 = total cost for one axle; 2 wheel drive. As I mentioned earlier, a .18 gear change should only provide a slight change. The 3.73 ratio is better for towing and quickness. If you don't run at top speeds it is a better gear. The mileage difference is very slight on the highway, and comparable in the city. I personally would prefer the 3.73 gears, but if you don't you should understand that the ratio difference is not substantial and probably not worth the money. It also allows the installer to just screw something up during disassembly. I prefer things left factory/alone if possible. To adjust the ratio using tire size is easier and cheaper. It will not take much or look like a 250 to achieve this. It will not even be noticed; it is not like monster truck tires.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.