#1  
Old 11-08-2022, 03:28 PM
dpoltzer's Avatar
dpoltzer dpoltzer is offline
Chief Ponti-yacker
 
Join Date: Dec 2012
Location: Now in Ormond Beach, FL
Posts: 941
Default What color are my teeth? Speedo gear.

I need to purchase the correct speedo gear for my 1970 T/A with an M-20, 3;55 rear gears and 25.5 inch tall tires (15" rally 2s). Looking at George Pearsons Speedo gear chart I need either: Blue with 20 teeth "WB code, or Green with 22 teeth "WL" code. I do not know what the "WB" or "WL" codes refer to. Anyone here know what speedo gear I need for an accurate speedometer reading? Thanks.

__________________
1970 T/A
  #2  
Old 11-08-2022, 04:57 PM
bhill86's Avatar
bhill86 bhill86 is offline
Chief Ponti-yacker
 
Join Date: Jul 2021
Location: NW Ohio
Posts: 520
Default

You’d also need to know the number of teeth on your drive gear (on the output shaft inside the tail). You should be able to remove the driven gear housing and will be able to see what color it is but I’ve seen a few variations as in, the same number of teeth being two different colors. You could raise the rear axle and spin the tires to turn the output shaft and count the number of teeth.

Lastly, this kit come with several driven gears you could easily swap out till you get one that works for you.

https://www.ebay.com/itm/13265705988...mis&media=COPY

__________________
1977 Trans Am 400/4speed (swap)

Brian
  #3  
Old 11-08-2022, 05:11 PM
dpoltzer's Avatar
dpoltzer dpoltzer is offline
Chief Ponti-yacker
 
Join Date: Dec 2012
Location: Now in Ormond Beach, FL
Posts: 941
Default

I believe there are 8 teeth on the drive gear. Dave

__________________
1970 T/A
  #4  
Old 11-08-2022, 05:25 PM
bhill86's Avatar
bhill86 bhill86 is offline
Chief Ponti-yacker
 
Join Date: Jul 2021
Location: NW Ohio
Posts: 520
Default

I believe you’d need a 22 tooth driven gear then. You can find online calculators to help you if you search for speedometer gear calculator.

__________________
1977 Trans Am 400/4speed (swap)

Brian
  #5  
Old 11-08-2022, 05:36 PM
Held for Ransom's Avatar
Held for Ransom Held for Ransom is offline
Ultimate Warrior
 
Join Date: Mar 2000
Posts: 8,912
Default

WB is the wide ratio. WL is the close ratio. There should be a metal tag (with PN and pick code) on the transmission side cover bolt denoting such. Also stenciled on the transmission.

__________________
So long, farewell.
The Following User Says Thank You to Held for Ransom For This Useful Post:
  #6  
Old 11-08-2022, 06:42 PM
unruhjonny's Avatar
unruhjonny unruhjonny is offline
Ultimate Warrior
 
Join Date: May 2004
Location: Calgary, AB, Canada
Posts: 6,232
Default

/\ HFR nailed it;
I have rarely seen the stencil, but if the tag is missing, the Muncie code should be stamped.

According to the MPC I have here:
the WL w/3.55 gears (and F60/15 or F70/14* tires) used a green 22 tooth gear (#3860345)
the WB w/3.55 gears (and F70/14* tires) used a natural 19 tooth gear (#3860342) with an adapter
the WB w/3.55 gears (and F60/15 or E78/14** tires) used a blue 20 tooth gear (#3987920) with an adapter

* = Formula availability only
** = base or Esprit only

__________________
1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.


1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
  #7  
Old 11-08-2022, 06:54 PM
dpoltzer's Avatar
dpoltzer dpoltzer is offline
Chief Ponti-yacker
 
Join Date: Dec 2012
Location: Now in Ormond Beach, FL
Posts: 941
Default

Green gear with 22 teeth it is then! Thanks again everyone I really appreciate your help. Dave

__________________
1970 T/A
  #8  
Old 11-08-2022, 07:16 PM
Sirrotica's Avatar
Sirrotica Sirrotica is offline
Ultimate Warrior
 
Join Date: Jan 2005
Location: Catawba Ohio
Posts: 7,190
Default

Green Teeth, there was a 1973 Charlie Daniels song, Uneasy Rider that had a character named "Ole Green Teeth". He might also had 22 teeth, they never reveal that in the song.....

After reading the thread i just had to go to You Tube and play it once, funny song, I haven't heard for many years.


__________________
Brad Yost
1973 T/A (SOLD)
2005 GTO
1984 Grand Prix

100% Pontiacs in my driveway!!! What's in your driveway?

If you don't take some of the RACETRACK home with you, Ya got cheated

The Following 2 Users Say Thank You to Sirrotica For This Useful Post:
  #9  
Old 11-09-2022, 02:02 PM
Formulabruce's Avatar
Formulabruce Formulabruce is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: North East of AMES PERFORMANCE, in the "SHIRE"
Posts: 9,363
Default

From the factory speedometers tended to read high by up to 5 mph at 60. This was allowed. Reading too low was NOT allowed. Accuracy from 0-35 was not good.
Also Bias ply tires sit a little taller than their radial counterparts.
Only Police cars had certified speedometers at this time, and not many dealers certified them, and GM didn't till much later.
So... don't expect exact speed to show..

__________________
"The Future Belongs to those who are STILL Willing to get their Hands Dirty" .. my Grandfather
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:32 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017