This will take you to the main site where there is history, technical information and other information on these cars.
This takes you back to the main page of the forums.
This is the control panel to change your password, information and preferences on this message board.
Click here if your lost your password or need to register on this message board. You must be a registered user to post. Registration is free.
Search this board for information you need.
Click here to buy cool Squarebirds mechandise.
Click here to support Squarebirds.org. For $20 annually receive 20mBytes webspace, a Squarebirds e-mail address and member's icon on the message board.
  #1  
Old 08-24-2007, 05:15 PM
Bill Grove Bill Grove is offline
Newbie
 
Join Date: Jun 11 2007
Posts: 11
Bill Grove is on a distinguished road
Default speedometer

Hi;

I have a 59 OD that needs a drive and driven gear. I am trying to calculate what I need but I'm having a problem finding out how many revolutions/mile on the speedometer.
Anyone know?

thanks
Reply With Quote
  #2  
Old 08-24-2007, 08:50 PM
JohnG's Avatar
JohnG JohnG is offline
John
 
Join Date: Jul 28 2003
Posts: 2,229
JohnG is on a distinguished road
Default

Bill, you're referring to the gears in the transmission? (as opposed to the gears involved in the speedometer)

John
Reply With Quote
  #3  
Old 08-26-2007, 04:56 PM
tbird430's Avatar
tbird430 tbird430 is offline
Super-Experienced
 
Join Date: Jun 18 2007
Posts: 2,616
tbird430 is on a distinguished road
Lightbulb

Yes. He needs the one on the transmission shaft (inside tailhousing), and the one on the end of the speedometer cable. Good luck is all I can honestly say.
Reply With Quote
  #4  
Old 08-27-2007, 01:37 PM
Bill Grove Bill Grove is offline
Newbie
 
Join Date: Jun 11 2007
Posts: 11
Bill Grove is on a distinguished road
Default

Hi;

What I have currenty is a bad drive gear(7 tooth) and a 18 tooth driven. What I was trying to find out is how many revolutions of the cable input to the speedomenter per mile. There are some variations, but 1000 rev/mile seems to be more common. Knowing this lets me look for the right gears.

thanks
Reply With Quote
  #5  
Old 08-27-2007, 10:38 PM
byersmtrco's Avatar
byersmtrco byersmtrco is offline
Administrator
 
Join Date: Sep 28 2004
Posts: 1,611
byersmtrco is on a distinguished road
Default

Give me your final drv ratio and your tire size and I'll get you the corr tooth count (18T does not sound right)
__________________
John Byers
1960 Convertible (Orig owner)
Pic of car with my son Justin (15 Y/O 6'1")
Poss 3rd Gen T/B owner
Reply With Quote
  #6  
Old 08-29-2007, 11:36 AM
Bill Grove Bill Grove is offline
Newbie
 
Join Date: Jun 11 2007
Posts: 11
Bill Grove is on a distinguished road
Default

Thanks BYERSMTRCO.
The tooth count I come up with is a 20 tooth driven (cable) gear for 3.73 rear end with 14" tires. But that assumes that the odometer needs "1000 revolution per mile" to clicck up a mile.
I am trying to confirm that ratio because it effects the readings.
Reply With Quote
  #7  
Old 08-29-2007, 12:46 PM
tbird430's Avatar
tbird430 tbird430 is offline
Super-Experienced
 
Join Date: Jun 18 2007
Posts: 2,616
tbird430 is on a distinguished road
Unhappy

I see that only 1 new replacement driven gear is even available now for our original 1958-60 cruise-o-matic trannys. Even if u find out which combo of drive/driven gear teeth u need, how on earth are u going to find a proper set?

I hope I didn't burst ur bubble any, but u may never have the right combo in there when u do figure this tooth count out...
Reply With Quote
  #8  
Old 08-29-2007, 03:03 PM
Bill Grove Bill Grove is offline
Newbie
 
Join Date: Jun 11 2007
Posts: 11
Bill Grove is on a distinguished road
Default

Hey tbird430;

Surprisingly enough, I have found all the gears for the T-85 transmission. Something I thought was impossible. My best source to date is Northwest Transmission. They are looking for the gears. (drive and driven). The driven gear shouldn't be that hard since they are plastic. There are a couple of places on the net that deal in the plastic gears. The drive gear on the OD shaft is metal and may be problematic.

thanks
Reply With Quote
  #9  
Old 08-29-2007, 04:39 PM
tbird430's Avatar
tbird430 tbird430 is offline
Super-Experienced
 
Join Date: Jun 18 2007
Posts: 2,616
tbird430 is on a distinguished road
Thumbs up

That's good news, I will have to add them to my Tbird Roladex for future reference.

That's right I forgot about the drive gear which slid onto my 430cid cruise-o-matic trans shaft was steel also...
Reply With Quote
  #10  
Old 08-30-2007, 12:05 PM
byersmtrco's Avatar
byersmtrco byersmtrco is offline
Administrator
 
Join Date: Sep 28 2004
Posts: 1,611
byersmtrco is on a distinguished road
Default

A J code car "should have" a 2.91 rear end ratio.
W/14's I'd try a 17T. If it reads to fast, go to 18. (the smaller the driven gear, the faster the speedometer will read.
__________________
John Byers
1960 Convertible (Orig owner)
Pic of car with my son Justin (15 Y/O 6'1")
Poss 3rd Gen T/B owner
Reply With Quote
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

vB 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 11:19 AM.

Driving, racing or working on cars can be hazardous. The procedures and advice on this website including the message board are opinion only. Squarebirds.org and its webmasters and contributors do not guarantee the correctness of the advice and procedures. The Squarebirds.org and its webmasters assume no liability for any damage, fines, punishment, injury or death resulting from following these procedures or advice. If you do not have the skills or tools to repair your car, please consult a professional. By using this site you agree to hold harmless the Squarebirds.org, its authors and its webmasters from any resulting claim and costs that may occur from using the information found on this site.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Any submissions to this site and any post on this site becomes property of Squarebirds.org . The webmasters reserve the right to edit and modify any submissions to this site. All material on this is site is copyrighted by the Squarebirds.org. Reproduction by any means other than for personal use is strictly prohibited. Permission to use material on this site can be obtained by contacting the webmasters. Copyright 2002-2016 by Squarebirds.org.