The Ford Barn

spdway1 · 06-17-2012, 09:10 PM

We changed the rear end ring and pinion, changed the speedometer gear to compensate for the different gear ratio. The speedometer now bounces back and fourth, I took the cable out, it is well lubricated, took the bottom side apart, everything seems ok. At about 33-36 it stops bouncing and reads accurate and at 50-55 it stops bouncing and reads accurate.

Now where do I need to look for a problem? Thank you.

TinCup · 06-17-2012, 09:24 PM

If it is not fully in the head it will do this. I have made a spacer and placed at the end of the cable at the transmission to force the cable to the top. Usually use a 10/32 bolt about quarter of an inch in length.

spdway1 · 06-17-2012, 09:42 PM

What are you calling the head? Thank you.

30Tudor · 06-18-2012, 12:40 AM

Mine dd that. I loosened off the coupler where it screws into the speedometer housing. My theory is that the cable was too long. I have a mitchel overdrive so it is a different setup. However, it might be worth a try.

PetesPonies · 06-18-2012, 08:01 AM

seems the cable is still binding "somewhere". Loosing it could be the ticket is the length is off a little. Also, check the cable along the length for any potential binds.

Mitch//pa · 06-18-2012, 10:00 AM

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Run it at a steady speed with a drill and see if it still bounces to see if it's cable related or head related.

TinCup · 06-18-2012, 01:35 PM

Where the cable connects to the speedometer.

Quote:

Originally Posted by spdway1

What are you calling the head? Thank you.

CarlG · 06-18-2012, 01:41 PM

Quote:

Originally Posted by Mitch//pa

Run it at a steady speed with a drill and see if it still bounces to see if it's cable related or head related.

To get it turning the correct direction, you have to run your drill in reverse.

meteorgray · 06-18-2012, 01:48 PM

I had the bouncing problem after 25 mph. Took the cable off at the trans and used a cordless drill in reverse. All was fine till I put some upward pressure on the cable and it started bouncing. The cable was too long so I cut about 1/4 inch off and that solved it. No bouncing now.

AlanD · 06-28-2012, 08:45 AM

I've had the bouncing speedometer issue for a long time but after reading this thread I too have been working on fixing it. Running it with a drill shows it reading steady. So I will next try the loosening cable trick before I cut the cable.

While I'm under there I'm working on that radius ball (from another thread).

spdway1 · 06-28-2012, 09:10 PM

I loosend the end at the bottom, no improvement.

AlanD · 06-30-2012, 10:44 AM

Same here. I loosened the cable at the torque tube which should relieve binding if it is too long, but that didn't help.
I also noticed that I had the cable clamp on the lower frame rail instead of the upper, so I moved it. Now I know why I put it on the lower, there was a bolt hole there that seemed right and the splash shield is kinda blocking the upper hole - but I got it in.
After all this the speedometer might be worse. It sits on zero alot and jumps up and down from 20-25..crazy thing.
I have the floor board out now and am going to get in there with the drill again.

Has anyone pulled the inner shaft out of the speedometer cable while its in the car? Is that a bad idea?

Tom Wesenberg · 06-30-2012, 07:28 PM

Pulling the inner cable out shoukd be no problem whether it's in the car or out.

columbiA · 07-01-2012, 12:33 AM

The speedo on my coupe would only show about 20 mph even tho I was going about 50,then it would stay at 0 & once in a while jump up & down.Turned out the cable casing had a kink in it & the driven shaft in the"turtle" had the square hole worn out.I think the kink in the hsg put a strain on the cable & wore out the shaft for the cable end.

spdway1 · 07-04-2012, 02:17 PM

The Trip meter and odometer work fine, speedometer still bouncing. ERRRR...

Kurt in NJ · 07-04-2012, 03:24 PM

Too sharp of a bend in the cable, if the cable was bent too sharp and straightened out the inner part can still have a kink ---pull the inside out, clean it off, roll it laid out straight on a table, if there are any bends or kinks straighten them out so the inner cable rolls smoothly across a table, check that the outer part installed has no curve to less than a 7" radius, re-lube the cable

AlanD · 07-05-2012, 10:08 AM

spdway1, have you run your speedometer on a drill and its steady? Mine is, so I reluctantly pulled the instrument panel and then the speedometer. Took the thing apart and lightly oiled it. I noticed before removing it that if I let it rest on zero and start the drill slowly ramping up, it stays on zero until I tap the speedometer or if I gun the drill fast - it's like it sticks on zero. Once it's off of zero, it acts smooth.
I haven't driven the Model A yet to see if oiling the speedometer has done any good. However I did get a free app for the iphone that will measure mph, so I'm ready. Testing it in my regular car shows its within 1 mph.

spdway1 · 07-05-2012, 08:08 PM

My helper will be here this weekend, I am going to try the drill in reverse from the bottom under the car.

AlanD · 07-12-2012, 10:32 PM

OK, I was finally able to watch the speedometer cable turn while the car is moving. I have the floorboard out and the cable loose, and I got my sweetie to drive while I watched. I could see that the problem is the worm gear, which explains why the speedometer acts right when powered by a drill.

So now the question is to find out why the worm gear is stopping - missing teeth?
I could see that it has a lot of end play. Now to dig into it this weekend. Hopefully I can rebuild the little gearbox.

Spdway1 - how are you coming along?

columbiA · 07-12-2012, 11:17 PM

By worm gear do you mean the driven gear in the "turtle"?If so, you could remove the gasket on the turtle and just use a bit of silicone and when you install it,it will fit closer to the drive gear on D S.Best repair is to repair the unit or replace with a better one.

06-17-2012, 09:10 PM	#1
spdway1 Senior Member Join Date: Feb 2011 Location: Chicopee, MA Posts: 1,401	Speedometer Question We changed the rear end ring and pinion, changed the speedometer gear to compensate for the different gear ratio. The speedometer now bounces back and fourth, I took the cable out, it is well lubricated, took the bottom side apart, everything seems ok. At about 33-36 it stops bouncing and reads accurate and at 50-55 it stops bouncing and reads accurate. Now where do I need to look for a problem? Thank you.

06-17-2012, 09:24 PM	#2
TinCup Senior Member Join Date: May 2010 Location: OKC / Tonkawa, Ok. Posts: 1,977	Re: Speedometer Question If it is not fully in the head it will do this. I have made a spacer and placed at the end of the cable at the transmission to force the cable to the top. Usually use a 10/32 bolt about quarter of an inch in length. __________________ Oklahoma City Model A Restorers Group.

06-17-2012, 09:42 PM	#3
spdway1 Senior Member Join Date: Feb 2011 Location: Chicopee, MA Posts: 1,401	Re: Speedometer Question What are you calling the head? Thank you.

06-18-2012, 12:40 AM	#4
30Tudor Senior Member Join Date: May 2010 Location: Calgary, Alberta, Canada Posts: 211	Re: Speedometer Question Mine dd that. I loosened off the coupler where it screws into the speedometer housing. My theory is that the cable was too long. I have a mitchel overdrive so it is a different setup. However, it might be worth a try.

06-18-2012, 08:01 AM	#5
PetesPonies Senior Member Join Date: Jul 2011 Location: South Carolina Posts: 316	Re: Speedometer Question seems the cable is still binding "somewhere". Loosing it could be the ticket is the length is off a little. Also, check the cable along the length for any potential binds. __________________ Pete's Ponies Mustang RUSToration & Performance

06-18-2012, 10:00 AM	#6
Mitch//pa BANNED Join Date: May 2010 Location: Bucks County, PA Posts: 11,454	Re: Speedometer Question Sponsored Links (Register now to hide all advertisements) Run it at a steady speed with a drill and see if it still bounces to see if it's cable related or head related.

06-18-2012, 01:48 PM	#9
meteorgray Member Join Date: Mar 2012 Location: new jersey Posts: 38	Re: Speedometer Question I had the bouncing problem after 25 mph. Took the cable off at the trans and used a cordless drill in reverse. All was fine till I put some upward pressure on the cable and it started bouncing. The cable was too long so I cut about 1/4 inch off and that solved it. No bouncing now.

06-28-2012, 08:45 AM	#10
AlanD Senior Member Join Date: Feb 2012 Location: Louisiana Posts: 117	Re: Speedometer Question I've had the bouncing speedometer issue for a long time but after reading this thread I too have been working on fixing it. Running it with a drill shows it reading steady. So I will next try the loosening cable trick before I cut the cable. While I'm under there I'm working on that radius ball (from another thread).

06-28-2012, 09:10 PM	#11
spdway1 Senior Member Join Date: Feb 2011 Location: Chicopee, MA Posts: 1,401	Re: Speedometer Question I loosend the end at the bottom, no improvement.

06-30-2012, 10:44 AM	#12
AlanD Senior Member Join Date: Feb 2012 Location: Louisiana Posts: 117	Re: Speedometer Question Same here. I loosened the cable at the torque tube which should relieve binding if it is too long, but that didn't help. I also noticed that I had the cable clamp on the lower frame rail instead of the upper, so I moved it. Now I know why I put it on the lower, there was a bolt hole there that seemed right and the splash shield is kinda blocking the upper hole - but I got it in. After all this the speedometer might be worse. It sits on zero alot and jumps up and down from 20-25..crazy thing. I have the floor board out now and am going to get in there with the drill again. Has anyone pulled the inner shaft out of the speedometer cable while its in the car? Is that a bad idea?

06-30-2012, 07:28 PM	#13
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Speedometer Question Pulling the inner cable out shoukd be no problem whether it's in the car or out.

07-01-2012, 12:33 AM	#14
columbiA Senior Member Join Date: Nov 2011 Location: B.C. Canada Posts: 1,746	Re: Speedometer Question The speedo on my coupe would only show about 20 mph even tho I was going about 50,then it would stay at 0 & once in a while jump up & down.Turned out the cable casing had a kink in it & the driven shaft in the"turtle" had the square hole worn out.I think the kink in the hsg put a strain on the cable & wore out the shaft for the cable end.

07-04-2012, 02:17 PM	#15
spdway1 Senior Member Join Date: Feb 2011 Location: Chicopee, MA Posts: 1,401	Re: Speedometer Question The Trip meter and odometer work fine, speedometer still bouncing. ERRRR...

07-04-2012, 03:24 PM	#16
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,158	Re: Speedometer Question Too sharp of a bend in the cable, if the cable was bent too sharp and straightened out the inner part can still have a kink ---pull the inside out, clean it off, roll it laid out straight on a table, if there are any bends or kinks straighten them out so the inner cable rolls smoothly across a table, check that the outer part installed has no curve to less than a 7" radius, re-lube the cable

07-05-2012, 10:08 AM	#17
AlanD Senior Member Join Date: Feb 2012 Location: Louisiana Posts: 117	Re: Speedometer Question spdway1, have you run your speedometer on a drill and its steady? Mine is, so I reluctantly pulled the instrument panel and then the speedometer. Took the thing apart and lightly oiled it. I noticed before removing it that if I let it rest on zero and start the drill slowly ramping up, it stays on zero until I tap the speedometer or if I gun the drill fast - it's like it sticks on zero. Once it's off of zero, it acts smooth. I haven't driven the Model A yet to see if oiling the speedometer has done any good. However I did get a free app for the iphone that will measure mph, so I'm ready. Testing it in my regular car shows its within 1 mph.

07-05-2012, 08:08 PM	#18
spdway1 Senior Member Join Date: Feb 2011 Location: Chicopee, MA Posts: 1,401	Re: Speedometer Question My helper will be here this weekend, I am going to try the drill in reverse from the bottom under the car.

07-12-2012, 10:32 PM	#19
AlanD Senior Member Join Date: Feb 2012 Location: Louisiana Posts: 117	Re: Speedometer Question OK, I was finally able to watch the speedometer cable turn while the car is moving. I have the floorboard out and the cable loose, and I got my sweetie to drive while I watched. I could see that the problem is the worm gear, which explains why the speedometer acts right when powered by a drill. So now the question is to find out why the worm gear is stopping - missing teeth? I could see that it has a lot of end play. Now to dig into it this weekend. Hopefully I can rebuild the little gearbox. Spdway1 - how are you coming along?

07-12-2012, 11:17 PM	#20
columbiA Senior Member Join Date: Nov 2011 Location: B.C. Canada Posts: 1,746	Re: Speedometer Question By worm gear do you mean the driven gear in the "turtle"?If so, you could remove the gasket on the turtle and just use a bit of silicone and when you install it,it will fit closer to the drive gear on D S.Best repair is to repair the unit or replace with a better one.