The Ford Barn

Phil Gillespie · 05-25-2015, 12:10 AM

Have an overhauled diff. 4:11 with a 10 spline shaft to fit up to a 6 spline drive shaft. Old diff as removed a 6 spline, so the quick swap out delayed a little.
So the 10 spline to 6 spine adaptor will do the job?
This is on a 38 PU. What was the standard set up? is the 6 spline set up for a car and the 10 spline for PU etc? Or is this in the transition period?
Appreciate some advice.
Thanks,
Phil NZ

GEOFFNZ · 05-25-2015, 12:15 AM

Hi Phil. In my experience the 6 spline was in both the car and pick up from 37 on and the most common pickup ratio was 4.11 The 6 spline was with the solid shaft and center bearing.Not sure about the 10 to 6 adaptor.Geoff

Phil Gillespie · 05-25-2015, 12:30 AM

Thanks Geoff, as existing diff with the 6 spline has plenty of play and suspect brgs judging from oil as removed. Have an overhauled 4:11 and thought it was a straight forward swap. Have sourced a 10 to 6 spline from Ajay so hopefully this will do the job.
Thanks Phil

Shadetree · 05-25-2015, 08:11 PM

Here is a picture of the adapter in place:

A good machine shop can do the change out.

One of the best improvements I have made to the `35 was going to a 3.54 from a 4.11.

deuce_roadster · 05-25-2015, 08:13 PM

Oops, read Shadetree's post wrong, thought he went from 3.55 to 4.11.

john in illinois · 05-26-2015, 01:00 PM

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One thing to check on these adapters. I got one that was made in Brazil, and the outside diameter was .008" out of round from the splines. This would not matter if you used it for a coupler,but if you welded it in a tube,you need to center off the splines not the outside when you turn it to fit.

John

Phil Gillespie · 05-26-2015, 02:56 PM

Thanks for advice and info. Will be using it as a coupler.I have learned that the spline size changed from the 10 to 6 in late 1938. these being same for passsenger and PU.
This is the luck with older vehicles until they are actually opened up you dont really know what has been retrofitted over the years.
Phil NZ

05-25-2015, 12:10 AM	#1
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,614	10 spline to 6 spline drive shaft coupler Have an overhauled diff. 4:11 with a 10 spline shaft to fit up to a 6 spline drive shaft. Old diff as removed a 6 spline, so the quick swap out delayed a little. So the 10 spline to 6 spine adaptor will do the job? This is on a 38 PU. What was the standard set up? is the 6 spline set up for a car and the 10 spline for PU etc? Or is this in the transition period? Appreciate some advice. Thanks, Phil NZ

05-25-2015, 12:15 AM	#2
GEOFFNZ Senior Member Join Date: Jun 2010 Location: Oxford New Zealand Posts: 177	Re: 10 spline to 6 spline drive shaft coupler Hi Phil. In my experience the 6 spline was in both the car and pick up from 37 on and the most common pickup ratio was 4.11 The 6 spline was with the solid shaft and center bearing.Not sure about the 10 to 6 adaptor.Geoff

05-25-2015, 12:30 AM	#3
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,614	Re: 10 spline to 6 spline drive shaft coupler Thanks Geoff, as existing diff with the 6 spline has plenty of play and suspect brgs judging from oil as removed. Have an overhauled 4:11 and thought it was a straight forward swap. Have sourced a 10 to 6 spline from Ajay so hopefully this will do the job. Thanks Phil

05-25-2015, 08:11 PM	#4
Shadetree Senior Member Join Date: May 2010 Location: Cottageville, WV Posts: 1,535	Re: 10 spline to 6 spline drive shaft coupler Here is a picture of the adapter in place: A good machine shop can do the change out. One of the best improvements I have made to the `35 was going to a 3.54 from a 4.11. __________________ Son, you will never blow an engine up in high gear.

05-25-2015, 08:13 PM	#5
deuce_roadster Senior Member Join Date: Oct 2011 Location: Shelton, WA Posts: 3,802	Re: 10 spline to 6 spline drive shaft coupler Oops, read Shadetree's post wrong, thought he went from 3.55 to 4.11.

05-26-2015, 01:00 PM	#6
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,185	Re: 10 spline to 6 spline drive shaft coupler Sponsored Links (Register now to hide all advertisements) One thing to check on these adapters. I got one that was made in Brazil, and the outside diameter was .008" out of round from the splines. This would not matter if you used it for a coupler,but if you welded it in a tube,you need to center off the splines not the outside when you turn it to fit. John

05-26-2015, 02:56 PM	#7
Phil Gillespie Senior Member Join Date: Sep 2011 Location: Christchurch New Zealand Posts: 1,614	Re: 10 spline to 6 spline drive shaft coupler Thanks for advice and info. Will be using it as a coupler.I have learned that the spline size changed from the 10 to 6 in late 1938. these being same for passsenger and PU. This is the luck with older vehicles until they are actually opened up you dont really know what has been retrofitted over the years. Phil NZ