Helltime

I have a question as to which gear to get to correct my speedometer/odometer. I have a 91 f150 4wd 5spd manual, code for the rear end is 19 (which as far as i have found online means 3.55 gears) and the current tire size on it is 32x11.50r15. My speedometer is off a bit, when it reads 65 i am reading 72 by gps, as much highway as i drive i would like to correct this, not just to keep myself out of trouble but also to log gas mileage and such accuratly. I have looked on other sites after searching this one, when i go to the sites with gears forsale i have no idea what i am looking at, any help would be appreciated, thanks.

f150cam

3.73s will be close but a little low still, 4.10s would be to high. if you can find a set of 3.91s you will be back to stock (or very close) someone else can chime in if im wrong.

Helltime

Sorry i should have worded it better, i ment which gear on the speedometer cable should i go with to account for my change in tire size.

f150cam

never heard of someone fixing the problem like that lol, so hopefully someone else can chime in, good luck.

87f-150

Go to this site and use there speedometer gear calculator to see what gear you need .
http://www.tciauto.com/tc/speedometer-gear-calculator

5Rangers

I have 35s on mine and I put in the purple driven gear, I think its a 14 t.... its pretty close.

The driven gear is really easy to change and they are pretty cheap... get a few different ones and experiment.

Do you know how to change it and do you know which one you have? Your going to want to go with less teeth. Not to drastic. One or two less.

Helltime

I will have the truck in the garage tomorrow, time to change the thermostat, while its in there i will check and see which gear it currently has. Being a 91 with a manual trans, is it located in the transfer case, transmisson or rearend? Keep getting conflicting info, worst case i supposed just follow the cable right?
So dropping 1 tooth on the speedo gear will make the speedo read faster than it does now, correct?

5Rangers

Im pretty sure on the 91 the driven gear is located in the rear output housing of the t case, on the top. If its not there then I am completely out of whack. I think they went to the electronic in 94 or 96. Gurus correct me if I am wrong. Worst case is correct, you can follow the cable (if there is one) to the promised land. Anyway,you will see it if its there. 1 nut to loosen and remove then the gear will pull straight up and out, it has an O ring seal to be careful of. Less teeth will cause the speedo to indicate faster.

Cheers and merry christmas!!