I bought a 98 F150 used and it has to be the best truck I've ever owned. It has an aluminum drive shaft and i put a K&N FIPK on it and the truck just blows other F150's away. The axle code is 19 which means 3.55 n/ls, although it won't pull one leggers. It either spins both are none at all. I was wondering if anybody could tell me how i could check to see if the gears are different or what. Also I'm turning 2000 RPM @ 65 MPH with 265/70R16's. Any help is apreciated.

 

Hi it sounds to me like whoever had the truck before you had the gears changed to either 4.10 or 4.56 gears but cant be sure till you go in and count the teeth and calculate them to find out for sure. that is the only way i know for sure!

Bigern

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ok, This test is not 100% but it will give you an idea. Make a mark on the tire and a mark on the pinion yoke of the diff. have someone under the truck watching the pinion yoke and someone to spin the tire. Spin the tire one full turn and count how many times the pinion yoke turns(make sure the trans is in nutral). If the pinion spins about 3 1/2 times it will be a 3.55:1 gear, if it goes a little over 4 turns it will probably be a 4.10:1 gear. so on and so on for 3.73:1 and 4.30:1......you get the idea I hope.

 

thanks for the reply. this is the first time i really used this board other than reading other posts. Thank you for the information.

 

And if it lays 2 stripes of rubber on dry pavement, it's not an open diff.

 

and it looks mighty good when ou lay down two dark as coal strips, LOL

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97 Ford F150 XLT 4x4 4.6L auto, Std cab/Long bed, 3.55LS rear axle, PW,PL, and PM, captian chairs w/arm rests
Sylvania Cool Blue Bulbs, Ford logo hitch and license plate, tinted windows, blackouts front and rear(w/ford logos on front blackouts),ventvisors all around, painted logos on door sills and under hood, 55w backup lights, K&N Filter, custom 4x4 emblems,and much more to come


thomaswright5714@hotmail.com