The Ford Barn

my4dv8 · 10-28-2018, 06:23 PM

We have an banjo rear with original 3.54 merc gears and 750 x 16 rear tires.
I have several 19 tooth speedometer turtles. I think 18 maybe the correct number for us, but please correct me if i am wrong . I usually am>>>
Thanks.

ford38v8 · 10-28-2018, 06:37 PM

Quote:

Originally Posted by my4dv8

We have an banjo rear with original 3.54 merc gears and 750 x 16 rear tires.
I have several 19 tooth speedometer turtles. I think 18 maybe the correct number for us, but please correct me if i am wrong . I usually am>>>
Thanks.

No no, no. V8ers are often mistaken, but we're never wrong.

JM 35 Sedan · 10-28-2018, 06:58 PM

I put 3.54 rear gears in my 35 fordor sedan with 600 x 16 tires, and a #18 turtle, w/18 tooth gear. This has the speedometer reading correctly based on what my GPS is saying. With 750 × 16 tires, you might get close to being correct with a 17 tooth gear.

qmdv · 10-28-2018, 09:15 PM

Where can I find a 17 turtle

Charlie Stephens · 10-28-2018, 09:30 PM

Try Bratton's, Bratton's Ford Parts, (301) 829-9880.

Charlie Stephens

Tinker · 10-28-2018, 10:14 PM

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Quick chart, print or save. I need to add it to my photo albums as this comes up about twice a yr and I wouldn't have to look for it. 7.50s x 16s are not there, so no help to you. But maybe others. A 18 will get you close enough to maybe avoid a ticket.

As mentioned: Model a turtle gears 18s will work also. Maybe they have 17s (did ford make 17s????)

https://www.brattons.com/

my4dv8 · 10-29-2018, 12:56 AM

Some folk are saying just fitting a 17 tooth gear wont cut it as the diameter is smaller and when fitted to a regular turtle as the gear mesh is incorrect. Any bright sparks throw some insight on this as fact or fallacy.

deuce lover · 10-29-2018, 01:15 AM

Maybe in a correct #18 turtle it will work..

ford38v8 · 10-29-2018, 01:28 AM

Quote:

Originally Posted by my4dv8

Some folk are saying just fitting a 17 tooth gear wont cut it as the diameter is smaller and when fitted to a regular turtle as the gear mesh is incorrect. Any bright sparks throw some insight on this as fact or fallacy.

As long as the gear mesh is sufficient to prevent gears from slipping cogs, the diameter is of no consequence, as there would still be the same number of cogs to the full circle.

hellmet · 11-17-2018, 01:53 PM

how do you press the gear out ? got a 18 turtle and got new 17 gear.

hellmet · 11-17-2018, 01:56 PM

the 18 turtle I got came off a 47 banjo does that mean it has 3:54 gears in it?

deuce lover · 11-17-2018, 02:04 PM

Its a good chance it has 3.54's.

drolston · 11-17-2018, 03:25 PM

I am using a 17 tooth gear from Braxton in an 18 turtle and the gear engages the worm on the drive shaft okay. I left out the gasket to get it a couple thousandths closer. With 26.5" diameter tires and 3.25 rear end gears, the speed is pretty close to the GPS.

V8COOPMAN · 11-17-2018, 08:32 PM

Quote:

Originally Posted by hellmet

how do you press the gear out ? got a 18 turtle and got new 17 gear.

If you can wait til the morning, I'll post pics. DD

qmdv · 11-17-2018, 11:34 PM

I called Bratton's a few weeks ago. They are using an aftermarket turtle. They use the same turtle for an 18 tooth and 19 tooth. They said that you can buy their bare turtle. They also said that if you put a 17 tooth gear in it it will not engage the drive gear sufficiently. If it is true what I have read on this forum that you can drop one size then I suspect that Bratton's new turtle is a 19. Bratton sells a 17 gear but not a turtle for it.

V8COOPMAN · 11-18-2018, 07:51 AM

Quote:

Originally Posted by hellmet

how do you press the gear out ? got a 18 turtle and got new 17 gear.

hellmet....Here is the picture I promised you last night. Note the little bushing-like piece at the lower right. It starts-out surrounding and supporting the end of the shaft, right next to the threads where the speedo cable goes. Once you carefully pry it out of the housing and off of the shaft, you've got it made. DD

Heavy Duty · 11-18-2018, 01:51 PM

I just went through this and this is what i did and so far it has worked. I bought the 17 tooth gear from Brattons and a turtle from Macks. It had no markings on it but was assured it would work. Surprise it didn't. It promptly ate up the gear. I got a new gear installed it in turtle put grease on both the turtle gear and drive shaft gear took transmission out of gear,spun a rear wheel and took the turtle off to see how they meshed. Then i found some metal pipe of the same OD as the drive shaft, wraped it around the pipe with sandpaper and proceded to sand the turtle. After some time i was able to bring the gear down to make a good match and the turtle retained its original shape.

qmdv · 11-18-2018, 08:02 PM

Quote:

Originally Posted by Heavy Duty

I just went through this and this is what i did and so far it has worked. I bought the 17 tooth gear from Brattons and a turtle from Macks. It had no markings on it but was assured it would work. Surprise it didn't. It promptly ate up the gear. I got a new gear installed it in turtle put grease on both the turtle gear and drive shaft gear took transmission out of gear,spun a rear wheel and took the turtle off to see how they meshed. Then i found some metal pipe of the same OD as the drive shaft, wraped it around the pipe with sandpaper and proceded to sand the turtle. After some time i was able to bring the gear down to make a good match and the turtle retained its original shape.

So machine down a turtle tell gears get a good mesh. That is what i will try

10-28-2018, 06:58 PM	#3
JM 35 Sedan Senior Member Join Date: May 2010 Location: Near Rising Sun, Maryland Posts: 10,858	Re: Correct speedo turtle I put 3.54 rear gears in my 35 fordor sedan with 600 x 16 tires, and a #18 turtle, w/18 tooth gear. This has the speedometer reading correctly based on what my GPS is saying. With 750 × 16 tires, you might get close to being correct with a 17 tooth gear. __________________ *John* *"Never give up on what you really want to do. The person with big dreams is more powerful than one with all the facts". Albert Einstein* Last edited by JM 35 Sedan; 10-29-2018 at 10:06 AM.

10-28-2018, 09:15 PM	#4
qmdv Senior Member Join Date: Dec 2012 Location: Payette, ID Posts: 935	Re: Correct speedo turtle Where can I find a 17 turtle

10-29-2018, 12:56 AM	#7
my4dv8 Senior Member Join Date: Aug 2010 Location: New Zealand Posts: 1,111	Re: Correct speedo turtle Some folk are saying just fitting a 17 tooth gear wont cut it as the diameter is smaller and when fitted to a regular turtle as the gear mesh is incorrect. Any bright sparks throw some insight on this as fact or fallacy.

10-29-2018, 01:15 AM	#8
deuce lover Senior Member Join Date: May 2010 Location: Southern France Posts: 5,305	Re: Correct speedo turtle Maybe in a correct #18 turtle it will work..

11-17-2018, 01:53 PM	#10
hellmet Member Join Date: Jun 2010 Location: hemet Posts: 80	Re: Correct speedo turtle how do you press the gear out ? got a 18 turtle and got new 17 gear.

10-28-2018, 06:23 PM	#1
my4dv8 Senior Member Join Date: Aug 2010 Location: New Zealand Posts: 1,111	Correct speedo turtle We have an banjo rear with original 3.54 merc gears and 750 x 16 rear tires. I have several 19 tooth speedometer turtles. I think 18 maybe the correct number for us, but please correct me if i am wrong . I usually am>>> Thanks.

11-17-2018, 01:56 PM	#11
hellmet Member Join Date: Jun 2010 Location: hemet Posts: 80	Re: Correct speedo turtle the 18 turtle I got came off a 47 banjo does that mean it has 3:54 gears in it?

11-17-2018, 02:04 PM	#12
deuce lover Senior Member Join Date: May 2010 Location: Southern France Posts: 5,305	Re: Correct speedo turtle Its a good chance it has 3.54's.

11-17-2018, 03:25 PM	#13
drolston Senior Member Join Date: Jun 2014 Location: Williamsburg, VA Posts: 1,627	Re: Correct speedo turtle I am using a 17 tooth gear from Braxton in an 18 turtle and the gear engages the worm on the drive shaft okay. I left out the gasket to get it a couple thousandths closer. With 26.5" diameter tires and 3.25 rear end gears, the speed is pretty close to the GPS.

11-17-2018, 11:34 PM	#15
qmdv Senior Member Join Date: Dec 2012 Location: Payette, ID Posts: 935	Re: Correct speedo turtle I called Bratton's a few weeks ago. They are using an aftermarket turtle. They use the same turtle for an 18 tooth and 19 tooth. They said that you can buy their bare turtle. They also said that if you put a 17 tooth gear in it it will not engage the drive gear sufficiently. If it is true what I have read on this forum that you can drop one size then I suspect that Bratton's new turtle is a 19. Bratton sells a 17 gear but not a turtle for it.

11-18-2018, 01:51 PM	#17
Heavy Duty Member Join Date: Nov 2010 Location: Wadsworth Ohio Posts: 48	Re: Correct speedo turtle I just went through this and this is what i did and so far it has worked. I bought the 17 tooth gear from Brattons and a turtle from Macks. It had no markings on it but was assured it would work. Surprise it didn't. It promptly ate up the gear. I got a new gear installed it in turtle put grease on both the turtle gear and drive shaft gear took transmission out of gear,spun a rear wheel and took the turtle off to see how they meshed. Then i found some metal pipe of the same OD as the drive shaft, wraped it around the pipe with sandpaper and proceded to sand the turtle. After some time i was able to bring the gear down to make a good match and the turtle retained its original shape.