Club Cobra Gas - N Exhaust  

Go Back   Club Cobra > Manufacturers, Engine Builders, tools, and parts. > ERA---Speak with Bob Putnam

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

MMG Superformance
Nevada Classics
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Advertise at CC
Banner Ad Rates
Keith Craft Racing
Keith Craft Racing
MMG Superformance
MMG Superformance
September 2022
S M T W T F S
        1 2 3
4 5 6 7 8 9 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30  
  #1 (permalink)  
Old 03-12-2015, 03:10 PM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default Stewart Warner Speedometer

So in short, I am trying to replace my Stewart Warner Speedometer. The old one had the incorrect mileage due to a prior Stewart Warner Speedometer failing. In short, I had a Speedometer shop put the correct mileage on the new speedometer and I put the new one in and it did not work. Ugh. The cable itself came out of the speedometer and it appears warn but ok. But now I will have to pull the transmission tunnel to get at the screw holding it in. Before I do I want to confirm that the gear on the speedometer is correct. I have a Tremec 3550 and the tag on the Jag rearend has a 46/13 division which equals 3.538 rounded equals 3.54. Page 13 of the ERA manual says it is the pink gear. I will check to make sure the gear is correct, but here is my question. The old speedometer seemed to read about 9 mph high. If it is the pink gear, then it should read correctly right? Also, any ideas why the new speedometer would not work. The only thing I can think of is that I accidentally pulled the cable itself out of the transmission and it was not turning. This sound right?

Phil
Reply With Quote
Sponsored Links
Sponsored Links
  #2 (permalink)  
Old 03-12-2015, 03:23 PM
DanEC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2009
Location: Little Rock area, AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,346
Not Ranked     
Default

Phil

Don't know about the correct driven gear but as to why the speedometer doesn't work - one thought comes to mind. I have an Smith speedo and Toploader transmission so I'm not sure that this will apply to you.

Someone here pointed out that the speedometer cable supplied by ERA is a Mustang unit I think - and that there is quite a bit of back and forth play in the inner cable - so much so that if it shifts towards the speedometer, it may be so barely engaged in the transmission plastic gear that it can actually strip out the square drive recess.

I checked mine and he was right - there is a lot of play in the inner cable. I had a box of various size stainless steel washers from Harbor Freight and I found some little ones that fit inside the speedometer end recess and over the cable - it took about 6 or 7 to take up the slack, which pushed the cable back towards the transmission. Instead of washers a spacer could be made from a short piece of aluminum or brass tubing of appropriate size. I think my plastic gear was starting to strip out as it was jumping a lot and after this it has been much better (not perfect but much better).

Something to check - could be your cable is not engaging the transmission plastic gear.
__________________
ERA 782 Running
https://www.youtube.com/watch?v=Cfge...b1-77fqwFRu7c]

Last edited by DanEC; 03-12-2015 at 03:26 PM..
Reply With Quote
  #3 (permalink)  
Old 03-12-2015, 03:37 PM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default

Dan,

That is my suspicion. But now since I pulled the cable all the way through the tubing, I now know that is not the case as you can see I have the cable out.

I am curious as to why the speedometer would read about 9 mph high though.

Phil
Attached Images
 
Reply With Quote
  #4 (permalink)  
Old 03-12-2015, 04:09 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

You should be able to reach up under the dash, and with a little square spacer that fits in to the gauge, "spin it" between your thumb and forefinger and see that the speedometer works. On my thread from this past summer I have shots of the 19 tooth gear that fits in my Tremec TKO and I have a 3.54 rear with 295/15 tires. I have a couple of those gears and they're not all the same color. It's a Smiths gauge but it's within 3 MPH of being correct (and it doesn't bounce).
Reply With Quote
  #5 (permalink)  
Old 03-12-2015, 04:41 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

Another way to test your gauge is to spin the connected cable with your drill. Note that the 19 tooth gear that I have in my drill is colored white. When I was lubing my cable I put my remote wireless camera scope in the cockpit pointing at my speedometer while I spun it from the engine bay.


Last edited by patrickt; 10-31-2016 at 12:07 PM..
Reply With Quote
  #6 (permalink)  
Old 03-12-2015, 04:55 PM
DanEC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2009
Location: Little Rock area, AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,346
Not Ranked     
Default

Quote:
Originally Posted by Large Arbor View Post
Dan,

That is my suspicion. But now since I pulled the cable all the way through the tubing, I now know that is not the case as you can see I have the cable out.

I am curious as to why the speedometer would read about 9 mph high though.

Phil
I'm not sure I'm following you but your statement in your OP - "The only thing I can think of is that I accidentally pulled the cable itself out of the transmission and it was not turning. This sound right?" - would seem to support that the cable wasn't engaged in the tansmission gear. Thus the speedometer wouldn't work. Because of the short cable length, connecting it to the speedometer didn't necessarily result in it engaging in the transmission. I would get the speedometer working before changing the transmission gear - it could be that the original SW speedometer was not calibrated correctly.
__________________
ERA 782 Running
https://www.youtube.com/watch?v=Cfge...b1-77fqwFRu7c]
Reply With Quote
  #7 (permalink)  
Old 03-12-2015, 05:05 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

Quote:
Originally Posted by DanEC View Post
would get the speedometer working before changing the transmission gear - it could be that the original SW speedometer was not calibrated correctly.
Spin your cable with a drill and have the brightest member of the family sit in the car and tell you if the speedometer gauge moves. If it does, the gauge works.
Reply With Quote
  #8 (permalink)  
Old 03-12-2015, 07:54 PM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2012
Location: Bay Area (Peninsula), CA
Cobra Make, Engine: ERA 427, 427/487 side-oiler
Posts: 1,248
Not Ranked     
Default

The calculations and guidelines ERA supplied didn't work for me. I had to experiment with a few gears until I got it close. I *think* I used the pink one, but I bought the white and black ones too. BTW I calibrated it with two different iPhone GPS speedo apps, which essentially read the same.
Reply With Quote
  #9 (permalink)  
Old 03-13-2015, 05:13 AM
DanEC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2009
Location: Little Rock area, AR
Cobra Make, Engine: ERA Street Roadster #782 with 459 cu in FE KC engine, toploader, 3.31
Posts: 4,346
Not Ranked     
Default

Quote:
Originally Posted by patrickt View Post
Spin your cable with a drill and have the brightest member of the family sit in the car and tell you if the speedometer gauge moves. If it does, the gauge works.
Yes, but the old one may have lost it's calibration in the process of slowly going off to the great speedometer graveyard in the sky. There is some chance the new one will read correctly when hooked up.
__________________
ERA 782 Running
https://www.youtube.com/watch?v=Cfge...b1-77fqwFRu7c]
Reply With Quote
  #10 (permalink)  
Old 03-13-2015, 11:36 AM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default

Ok, so I confirmed the cable itself pulled out of the end of the gear plug going into the transmission. Is this however the right gear for my setup? The ERA manual says it should be the pink gear. Am i missing something hear?

Phil
Attached Images
 
Reply With Quote
  #11 (permalink)  
Old 03-13-2015, 11:39 AM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default

Here is my gear.
Attached Images
 
Reply With Quote
  #12 (permalink)  
Old 03-13-2015, 11:54 AM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

This is the speedometer gear that I have in my TKO: http://www.summitracing.com/parts/SDK-C0DZ-17271-B

Note that it is a C0DZ-17271-B it says that it's "Pink," but when it came, it was "White."
Reply With Quote
  #13 (permalink)  
Old 03-13-2015, 05:10 PM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default

I picked up the Ford replacement today at a transmission shop and it was pink. It matched the white/tan one that came out. I put it in, connected the cable and started it up and ran it in first gear and it worked. I had to have pulled the cable out of the transmission. Its back now. If the weather clears tomorrow I will give it the street test. I am still thinking that I will be about 9 mph fast. I am wondering what the gearing is on mine. The aluminum tag on the rear is 46/13 which would be 3.54. However I am wondering if it that is correct. I am running 295-50-15's. Any thoughts on what the difference might be?

Thanks for all the comments and advice. This novice appreciates it very much.

Phil
Reply With Quote
  #14 (permalink)  
Old 03-13-2015, 05:20 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

Quote:
Originally Posted by Large Arbor View Post
The aluminum tag on the rear is 46/13 which would be 3.54. However I am wondering if it that is correct. I am running 295-50-15's. Any thoughts on what the difference might be?

Thanks for all the comments and advice. This novice appreciates it very much.

Phil
Easy to check. Just jack up the rear so both wheels are off the ground, mark your tire and your drive shaft with some chalk, then rotate your wheel and count the drive shaft rotations.
Reply With Quote
  #15 (permalink)  
Old 03-13-2015, 05:30 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,377
Not Ranked     
Default

If you want to be really accurate, have someone under the car count the driveshaft rotations as you rotate your wheel ten times. They should report that the driveshaft rotated 35.4 times. And I'm sure you have a limited slip in there.
Reply With Quote
  #16 (permalink)  
Old 03-15-2015, 12:48 PM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2013
Location: Columbus, OH
Cobra Make, Engine: ERA 714
Posts: 713
Not Ranked     
Default

Ok, I did not yet do the driveshaft count but the Speedometer is in and working. I had to raised the cable where it goes into the speedometer and now its much closer on the actual speed. Thanks for all the advice. I am pretty sure the rearend is a 3.54, but will verify next time its up in the air.

Phil
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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 01:03 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy
Links monetized by VigLink