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Topic: need to change speedo gear (Read 1263 times) previous topic - next topic

need to change speedo gear

I hope someone can give me advice on wich speedo gear I need

running a 8.8 with 3:27 gears and p255/60r15 tires in the rear.
speedometer seems to be around 10 mph off. when the speedometer reads 65 mph it feels more like 55 mph.I am going to verify this with my gps.
If more info is needed,let me know.

wich speedo gear should I be looking for,to get the speedometer back to being somewhat close.

does anyone have the gear I need?
Never drive faster than your guardian angel can fly.
:birdsmily: :birdsmily: :birdsmily::birdsmily: 
  [SIGPIC][/SIGPIC]
:birdsmily: :birdsmily: :birdsmily::birdsmily:
1983 base model,1969 302 (originally a v6),upraded c5,currently 30,441 original miles.


need to change speedo gear

Reply #2
thanks,I just hope I can figure this out............lol.
Never drive faster than your guardian angel can fly.
:birdsmily: :birdsmily: :birdsmily::birdsmily: 
  [SIGPIC][/SIGPIC]
:birdsmily: :birdsmily: :birdsmily::birdsmily:
1983 base model,1969 302 (originally a v6),upraded c5,currently 30,441 original miles.

need to change speedo gear

Reply #3
If you have a 6 tooth tranny gear (inside the tranny),you'll need a 16 tooth speedo gear.

If you have a 7 tooth gear in the tranny,you'll need a 19 tooth speedo gear

An if you have an 8 tooth tranny gear,you'll need a 21 tooth gear.

That's for 3.27 gears.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

need to change speedo gear

Reply #4
Here's another handy chart
http://www.latemodelrestoration.com/page/Mustang-Speedometer-Gear-Application-Guide
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***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
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5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
Pretty much every panel on my 87 is new, rebuilt, or re constructed. :D
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need to change speedo gear

Reply #5
Each tooth less on the driven gear will increase the reading approx 3-4 mph, so you should need one with three teeth less than what you have now...

need to change speedo gear

Reply #6
thx for the help and the links guys.

Turbo
your statement has me confused (not so hard to do).

I need to decrease what the speedometer is reading.
Never drive faster than your guardian angel can fly.
:birdsmily: :birdsmily: :birdsmily::birdsmily: 
  [SIGPIC][/SIGPIC]
:birdsmily: :birdsmily: :birdsmily::birdsmily:
1983 base model,1969 302 (originally a v6),upraded c5,currently 30,441 original miles.

need to change speedo gear

Reply #7
this may help...
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

need to change speedo gear

Reply #8
OOPs I was thinking it was slow, guess I wasn't awake yet... You'll need to add teeth...

need to change speedo gear

Reply #9
TurboCoupe50 was wrong!  Is this a first?  ;)

First time I seen it.

TED (seems to be wrong all the time according to my kids)

 

need to change speedo gear

Reply #10
Quote from: Cad-T-Bird 500;319396
TurboCoupe50 was wrong!  Is this a first?  ;)


I thought I was wrong once, but I was wrong... :hick: