I recently went from the Firestone A/T 265/70/17 to the ProComp 33x12.5x17 -- Love the tires -- how do I figure out what tooth gear to get, where can I get it, and is there somewhere which tells me how to change it out? Thanks!

 

Go here to find the gear you need: http://www.finer.com/internet/pages/speedo.htm

If you have an auto, then the drive teeth is 8.

To buy the gear, you can go to your local dealership. I paid about 8 bucks apiece for the 2 that I bought. Also, while you're at the dealership, ask them to show you a diagram of the VSS assembly and where it goes on the tranny. Hope this helps.

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TRUCK:
1997 F-150 Supercab 4X4,Royal Blue,4.6 V-8,Tow Package,3.55 LS

MODS:
K&N FIPK,Performance Accessories 3" body lift,
Superchip,Bosch Platinum +4 Plugs,
True Dual Exhaust w/ Flowmaster 50 Mufflers,
Smitty Nerf Bars,3.55LS Swapped For 4.56LS,
16X10 Eagle 589's, 315/75-16 A/T's,
Rancho RS5000 Shocks,Rancho Steering Stabilizer,
Alpine CD,Alpine 5 Channel Amp,PPI 5 X 7's,
Boston 10" Sub.



Pics at: http://www.f150world.com/loknload/

 

Did you run those on a stock 4x4?? If so, do they fit pretty well. How 'bout some pics??

 

Assuming you have a '97-'98 F150 with the 3.55 gears, I'd say probably an 18 tooth gear. But now that I read your 265/70/17 original tire size, you could have a 3.73 gear? Also, I think '99 and up does not use a speedo gear, it uses the computer?

Really depends on what gear came in the rig. Mine had a 20 tooth originally. I went from an installed 235/70/16 to 265/75/16. About a 2.5 inch difference. Only had to change to a 19 tooth gear. But, my door sticker said the rig was supposed to have 255/70/16's?? Anyway, the 19 tooth worked great for my config.

Your original 265/70/17's are about the same size as my 265/75/16's and are about 31.5" tall. I'd check out what your current speedo gear is (if you have one) and go down 1 tooth. They only cost like $12 and take like 2 minutes to swap out. It's more trial and error then scientific.

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1997 F150 4x4 XLT, SuperCab, Short Box, 5.4, Royal Blue/Silver, K&N, Gibson SS, LT265/75/16 Wild Country APT's, Hellwig Progressive Springs (LP-25)

 

What do you do if you have a 99-up?

kev

 

It's a '97 F150 4x4 -- I bought it used last year, so I'm not sure of the gearing...I think I read where it shows what it is on the door sticker. I'll check it out and see what I can find. Is it easy to explain where the speedo gear is and how to swap it?

Dargo- Yes, it's just a stock 4x4 -- no lift or anything. They fit and look great...I'll try and get some pictures tonight and post them in the morning.

Thanks for your help guys...

 

I think you have to, somehow, reprogram the computer! Not sure on the details, but I'm sure there are other posts on that subject.