7 or 8 tooth speedo gear? - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 11 (permalink) Old 01-30-2007, 11:53 AM Thread Starter
 
Join Date: Apr 2005
Posts: 25
7 or 8 tooth speedo gear?

i got a 91 xr7 with a 5.0 and there are 2 different part numbers for this model. one is for a trans with a 7 tooth gear and the other is for a 8 tooth. how could i find out? thanks

also the 8tooth is 100$ more.
5.0_Mo is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 01-30-2007, 01:38 PM
Motorboatin' SOB
Headlight Cleaning Guru
 
big mike's Avatar
 
Join Date: Jul 2002
Location: H-town, TX
Posts: 6,910
Send a message via AIM to big mike
do you need a replacement gear? crawl under the car and unbolt the one bolt holding the vss to the tailshaft of the tranny on the driver side. the gear is inside the vss. count the number of teeth.

and how can a little plastic gear even cost $100? hope thats a typo...

2014 GT
1990 300ZX TT
big mike is offline  
post #3 of 11 (permalink) Old 01-30-2007, 03:11 PM Thread Starter
 
Join Date: Apr 2005
Posts: 25
i just realized i forgot to mention the part numbers were for the transmissions then selves but the description said one trans was an 8 tooth and the other a 7 tooth. the 8 tooth trans was 8xx and the 7 tooth was 720
5.0_Mo is offline  
Sponsored Links
Advertisement
 
post #4 of 11 (permalink) Old 01-30-2007, 03:50 PM
Seasoned PostWhore
 
Join Date: Dec 2002
Location: Houston
Posts: 2,233
Quote:
Originally Posted by big mike
do you need a replacement gear? crawl under the car and unbolt the one bolt holding the vss to the tailshaft of the tranny on the driver side. the gear is inside the vss. count the number of teeth.

and how can a little plastic gear even cost $100? hope thats a typo...
He's referring to the drive gear inside the transmission.

It's only funny until someone gets hurt.
Then it's freaking hilarious.


Adventures in ChumpCar Racing
Tobey is offline  
post #5 of 11 (permalink) Old 01-30-2007, 03:57 PM
Seasoned PostWhore
 
Join Date: Mar 2005
Location: Tucson AZ
Age: 49
Posts: 3,726
I don't remember which one my 89 3.8 Cougar had, but the replacement AOD from a V8 mustang was the other one. The tranny shop tried to get it right (pacing the car with a truck with 4 different sized tires, rags stuffed into the fuel fillers, among other rednecky stuff) but I eventually took it to a speedometer shop with a syno to get it right.

Obviously there is another difference that names it 100 dollars difference for the tranny. It would be best to get the one with the same number of teeth on the output shaft if all else is equal. The gear to get the speedometer right is 10-20 bucks.

--
97 Mark VIII LSC/Silver/Gray leather
97 Cougar 4.6 Sport/White Opalescent Tricoat Metallic /Gray leather down but not out?
89 Cougar LS 3.8/Oxford White/Gray velour/HG need replaced AGAIN
00 Grand Marquis LS/Vibrant White/Gray velour
63 Falcon 302/black and rust/shed isn't moving
82 F-150/Oxford White/dumb VV carb doesn't pass emissions
Bangster is offline  
post #6 of 11 (permalink) Old 01-30-2007, 04:09 PM
Seasoned PostWhore
 
Join Date: Dec 2002
Location: Houston
Posts: 2,233
The driven gear is machined into the output shaft of the transmission. Buy the cheaper one. If it's the wrong one, a new driven gear is $20, so you still come out $80 ahead. Go to www.fordracingparts.com and download a catalog. Page 139 has all the speedo gear info you'll need. If you have 3.08 gears and the 7-tooth drive gear, you'll need the 18-tooth driven gear (Gray). For 3.27 gears, you'll need the 19-tooth gear (tan).

Come to think of it, what color is your driven gear, the one on the VSS?

It's only funny until someone gets hurt.
Then it's freaking hilarious.


Adventures in ChumpCar Racing
Tobey is offline  
post #7 of 11 (permalink) Old 01-30-2007, 04:19 PM
Motorboatin' SOB
Headlight Cleaning Guru
 
big mike's Avatar
 
Join Date: Jul 2002
Location: H-town, TX
Posts: 6,910
Send a message via AIM to big mike
Quote:
Originally Posted by Tobey
He's referring to the drive gear inside the transmission.
that aint what the title says

2014 GT
1990 300ZX TT
big mike is offline  
post #8 of 11 (permalink) Old 01-30-2007, 04:55 PM
PostWhore
 
fast Ed's Avatar
 
Join Date: Oct 2002
Location: Caledon, Ontario ... CANADA !
Posts: 1,548
If you're talking about an AOD, the speedo drive gear is machined in the output shaft of the trans ... it's not a separate plastic gear like some other transmissions.

Ford parts catalogue shows an output shaft with a 7-tooth gear for 91 Cougar.


cheers
Ed N.

95 T-Bird SC 5-speed -- SOLD!!
88 T-Bird Turbo Coupe 5-speed
07 Mustang GT 5-speed with some stuff
fast Ed is offline  
post #9 of 11 (permalink) Old 01-30-2007, 05:48 PM
Converter Guy
 
dirtyd0g's Avatar
 
Join Date: Jul 2004
Location: batavia,oh
Age: 42
Posts: 6,617
Send a message via Yahoo to dirtyd0g
91 is a questionable year. The SC's were 8 tooth, what gears does your car have stock? That should be a good clue. It really doesn't make a difference you can change the plastic gear to match. You can use the 8 tooth shaft with up to 3.27:1 gears. The 7 tooth shaft can be used with up to 3.73:1 gears.
Alan
dirtyd0g is offline  
post #10 of 11 (permalink) Old 01-30-2007, 07:38 PM
3rd Gear Poster
 
Join Date: Nov 2006
Location: Bowie, MD
Posts: 164
Quote:
Originally Posted by big mike
that aint what the title says

Yes it does. The drive gear inside the transmission IS one of the two speedo gears.

http://images19.fotki.com/v358/photo...Tbird01-vi.jpg
1994 White (WT) TBird - 4.6 L SOHC with 4R70W

"Sir, if you were my husband, I would poison your drink."
-Lady Astor to Winston Churchill
"Madam, if you were my wife, I would drink it."
-His reply

Rehab progress link
Today's Progress
DScruggs is offline  
post #11 of 11 (permalink) Old 01-31-2007, 07:33 AM
Motorboatin' SOB
Headlight Cleaning Guru
 
big mike's Avatar
 
Join Date: Jul 2002
Location: H-town, TX
Posts: 6,910
Send a message via AIM to big mike
when he says speedo gear, im thinking the one located on the tailshaft.

carry on...

2014 GT
1990 300ZX TT
big mike is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome