hey 64 was originally a 3 speed o/d, how ever it looks as if someone swapped that out for a 3 speed, then finally the PO swapped what he claims is an army jeep t18 4 speed, when my dad got it it had this transmission in it , and upon closer inspection it has a metal speedometer gear/cog , and the speedometer reads 35mph when you going about 55mph...any helps appreciated, would have took some pictures but Ive been busy and it ice storming as of now.....
And while Im at it I also want to know what transmission tops with the reverse light switch i can use, as Ive got the 67-72 reverse lights in and a reverse light switch and pigtail, but still lack the tranny top, switch harness,harness from rear bed to tranny..
its an early t18 ,the transmission gears go: over left up 1st granny, over left down 2nd over up 3rd straight down 4th, and over right and up reverse.

 

If you search abit, you'll come across various posts regarding speedos reading slower/faster than true. I talk about it in my M-250 Build Thread, page 25:

https://www.ford-trucks.com/forums/1...-build-25.html

According to what you've said, you have the reverse problem that I had, your speedo is reading lower than the true value. So I believe you'll need a different driven gear in your t18, one with fewer teeth.

I'm assuming that you can get this, but I don't have the specifics, as I have a New Process 435, 4-speed in my M-250.

You may need to get a pic when it warms up so others familiar with this transmission can confirm if I'm on the right track or not.

 

Is this the speedometer DRIVEN gear at the end of the cable? If so, it may look like TYPE 3.

Count the number of teeth and post it. This gear may have an ID number stamped on it, post that too.

 

thanks for the example and info number dummy, and dank4120, this evening ll go on out and take my speedo cable loose from the tranny to see, been 3 months since it was installed, and report my finding back asap, would be nice to stop messing with the inacurate speed, and get reverse lights.
and ill see if i can get some decent pics of the tranny as well

 

No reverse (backup) lamps were available until 1967.

The backup lamp switch with a 4 speed threads into the shift tower.

Look on the trans case for an ID number that ID's it as either a Warner T-18 or T-98. The T-98 was used thru 1964, the T-18 was introduced in 1965.

AFAIK, the T-18 case will not bolt to a 223/262 I-6 or 292.

 

well i have the 67-72 tailights with reverse installed , and a 67-72 reverse switch with a partial pigtail, im hoping there is a tranny top that will alow me two have reverse lights with this current setup

 

The cog has 20 teeth

 

^ 01T-17271-C .. 20 Tooth Speedometer DRIVEN Gear-TYPE 5 / Obsolete

There are 4 others:

01T-17271-A .. 18 Tooth Speedometer DRIVEN Gear-TYPE 5 / Obsolete

01T-17271-B .. 19 Tooth Speedometer DRIVEN Gear-TYPE 5 / Obsolete

01T-17271-C .. 21 Tooth Speedometer DRIVEN Gear-TYPE 5 / Obsolete

01T-17271-E .. 22 Tooth Speedometer DRIVEN Gear-TYPE 5 / Obsolete

GREEN SALES CO. in Cincinnati OH has 2 = 800-543-4959.

 

ok thanks , so what are you saying about using the 18 tooth gear, are you saying that at 50-55 MPH ,it will read about 40 MPH, or...just clarifying?

-What transmission do i have? a t98 or t18 as i said reverse is over and up, Ive done some research but, it today's light i could not find any numbers through all the gunk , thee where some on the top cover but i forgot to take pic when the hump was off, is there any way to know what it is other than that , its been a while since i looked this up...when i did i was so far away from driving it wasn't something i needed to focus on.

-Now as for changing the top cover to gain a reverse light switch what are my options there, and can this style tooth be changed to use the more regular style.
-thanks

 

I read your original post wrong, I thought you were going 35 MPH but the speedo was reading 55 MPH

Since you're going 55 MPH but the speedo reads 35 MPH then you will need to add teeth. Besides the 21T gear, there is also a 22T gear that I didn't list. I edited it in.

Each tooth will cause the speedo to read approx. 7 MPH different.

The DRIVE gear is on the output shaft, you will have to count the number of teeth it has.

If your truck has radial tires, these are a different shape than the original bias ply tires, so no matter what you do, you will never be able to get the speedo to read correctly.

With radials, the speedo will be off by as much as 5 MPH

 

ok, ill have to check, but if all else fails...i wonder how hard it would be/if it can be done at all, to convert it to the plastic style gear...id hate to chance swaping it for one thats losser than this one...it actually feels pretty tight , as far as the gears,shift cane slack and all...but if have to ive got a '66 np435...have no idea what the wear on it is..id hate to have go knee banger reverse.

 

ok so when i get to counting tat drive gear in the tranny, how ,any variations are there?

 

Starting all over again to see if I can figure out what your original specs would be.

You say the trans is a T-18, but only the T-98 was available thru 1964.

What is the rear axle ratio and tire size?

DRIVEN gear teeth: 18 - 19 - 20 - 21 - 22

DRIVE gear teeth: 6 - 7 - 8

 

The trans in those pics looks like a T98 to me. If it is bolted up to a Y block or a 223/262 six it's a T98. A T18 won't bolt up to either of those.

 

You could add in a ratio adaptor as seen here to compensate for the speedo error: https://transmissioncenter.net/shop/...ratio-adapter/

My 64 was originally a 3 speed on the column w/OD and was converted early on to a T-98 4 speed. The rear end was later swapped out for a 3.25 to 1 ratio, therefore the speedo was not even close. I added the proper ratio adaptor and now I am in the ballpark. I use a GPS on long trips for additional speed readings.

You stated in your first post that your speedometer was only reading 35 mph while your actual speed was 55 mph. If my calculations are correct, then a +61% adaptor as listed above should give you a 56 mph reading at 55 mph. Here is also a Speedometer Calibration program that may be helpful: http://www.bgsoflex.com/speedo1.html Hope this helps.