On the door jam of my pickup, it says 16" tires. However, my actual tire size is 265/70/17. I know my speedo is off. It actually registers slower than I'm going. When I order my chip, will they (Mike) actually be able to correct this or do I need some sort of speedo gear? It is a 97 SC 4x4, 4.6.

 

Nevermind...search feature works pretty good here....

 

Hi Jay,

Because your F-150 is a pre-1999 model, you will need to correct your speedometer via the standard method, changing the speedo gear in the tailshaft of the transmission. That is cheap & easy to do, all you need to know is the number of teeth you need on the new speedo gear.

If you'll use the search feature here (just click on the "SEARCH" icon in the top right area of your screen), you can quickly pull up many posts on exactly how to calculate the number of teeth you'll need on the new speedo gear, etc.

What you'll want to do is to make sure you know the exact height of each tire, meaning both the *original* stock tire size and then your changed tire size (the 17" wheels & tires) as well, as you'll need that info to do the math (simply figuring the percentage of difference in height, and then applying that to the number of teeth on your current speedo gear, to give you the number of teeth needed for the new speedo gear). For example, you need to know if the sticker saying 16" tires from the factory was a mistake (not likely), or if someobody put those 17" wheels & tires on there after that truck was manufactured (which is most likely going to be the situation, the odds are 99.9%)

Good luck!

 

Thanks Mike... Only 7 more days until I place my monster order that we've been working on.

Needless to say, I'm pumped!!!

Thanks,
-Jay Waller

 

Hi Jay,

Ahh, I had no idea that was you!

Actually, as I was composing my reply this afternoon, I got interrupted several times so by the time I actually got my response to you posted, you had already posted a note about having used the search feature by then.

Timing is everything, in performance & comedy, or so it seems.

Talk to you soon!

 

Got the speedo gear changed out. Really simple installation. Need to check but i appreciate all the information available from you guys. I feel like an expert on topics after researching them for a couple of days on this website.

-Jay

 

Hi Jay,

Excellent, congratulations on doing the speedo gear change, and on your order as well!

 

Thanks Mike,
I really appreciate your professionalism and especially for the detailed explanations of how these things work. I wish every business was as pleasant to deal with as yours. Did you get the Goodyear serpentine belt added to the order?

Also, my rear pinion seal is leaking and if I can "pull it off" that may require a gear change to 4.10 if you know what I mean (or so that is what I tell my wife). Does that mean I would need to get the chip reprogrammed for the new shift points?

Thanks again for everything! Can't wait to create my signature courtesy of Performance Products!

 

Sounds like you are doing some great mods all at once on your truck have fun when your done.

 

Yeah,
so far this is what my parts list looks like (ordered from Mike):

SuperChip
Airforce One
ASP Pulley Kit
Dual Elec. Fans
Magnaflow X-pipe
Autometer Trans and Coolant Gauges
Dual Pod A-pillar mount
Transgo Shiftkit
Sonnax Valves
Derali Fan assisted tranny cooler
Tranny Temp Gauge
Drain plug kit
Goodyear Gator-Grip Serpentine Belt

Should be pretty exciting!!!

 

Looks like money well spent I wish I had some extra money so I could do a few mods for my truck just have to wait a little longer before I can get some of them mods for my truck.

 

Hi Jay,

You crack me up, better hope your "better half" doesn't read these message boards! I have to be careful, as my wife does read them sometimes, so I can't get away with much.

All kidding aside, a leaking pinion seal is pretty common, one of our trucks was leaking brand new. The service manual does say to replace the pinion nut too when replacing the pinion seal. You don't have to tear into the rear end to replace the pinion seal & pinion nut, that is a simple, quick & easy "external" repair, so to speak. However, it could indeed be used as a good excuse to upgrade to a 4.10 limited slip, especially since it's a 1997 model with some miles on it.

If you change the gear ratio in a pre-1999 F-150, no, we will *not* need to do a custom program to update the Superchip module, as that is controlled by a standard speedometer gear in the tailshaft of the transmission up thru and including the 1998 model year in the F-150. This is a cheap & easy fix, you'll just replace the speedo gear which takes about 10 minutes and less than $20 for the new speedo gear from any Ford parts counter. All you need to know is the number of teeth you need on the new gear to order it, and if you need any help with determining that, give us a call & we'll be happy to go thru that with you.

Yes, you are doing a number of upgrades at one time (and yes, we got the Gatorback serpentine belt added, no problem!), and that will certainly be noticeable in the results. A good bit of it actually can be referred to as maintenance items whose replacement/upgrading can be also expected to result in some performance improvement as a bonus deal.

Thanks for your kind words & have fun!

 

Mike,

I was asking about the chip reprogram not because of the speedo but because of the RPM change due to the lower gear ratio. Since shift points (correct me if I'm wrong) are built into the chip, would the shift points need to be recal'ed because of the change in engine RPMs due to the lower gear?

Thanks in advance.
- Jay

 

Hi Jay,

Ahhh................

Actually, this varies a bit based on model year.....................we take care of *all* of that at the same time automatically in all the 1999 & newer F-150's, we recalibrate the speedometer, the odometer & make any adjustments needed to the shift points. Usually just restoring speedometer accuracy in a number of cases automatically takes care of restoring the shift points.

In the 1997 & 1998 trucks, which have the speedo recalibrated by changing the speedo gear, yes, we can fix the shift points as well. In those cases, what you'll want to do *first* is to correct the speedometer in those model years by installing the correct speedometer gear, and see if we still have an actual shift point deficit after correcting the speedo. If so, then sure, we can adjust the shift points to take care of that.