The Ford Barn

MII · 03-29-2018, 12:22 PM

my 49 F1 is 3:92.1, and I'm thinking of changing to 3:08.1
the transmission is heavy duty 3 speed on the floor
has any one done that and with good results?
it is an 8BA built by Walt

JSeery · 03-29-2018, 12:51 PM

Depends on what your objectives are for the truck. Trucks are typically geared lower than a car. To me that would be a very high gear, is it going to be mostly a highway vehicle?

MII · 03-29-2018, 12:58 PM

mostly highway and around town

estout81 · 03-29-2018, 01:40 PM

I have a '48 F=1 with the same gear ratio. I run 235/75 tires on the rear with no undue strain on the engine. I have run interstate highways to Charlotte motor speedway!

Fordestes · 03-29-2018, 01:46 PM

Expect to stay in the box,(Aphrase used by truckers who constantly have to shift up and down) I tried it here in flat land oklahoma and it resulted in rotten fuel milege and a lot of shifting, mine was a 3:25. you my get better results , the rear diff is still on the shelf collecting dust. I had to run about 65 + mph to keep her from lugging down, also hard on the engine being in a hard pull at lower speeds. Lots of luck!

estout81 · 03-29-2018, 01:53 PM

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I forgot to say, my fuel mileage is 16-18 depending on how hard I drive it. Also, performance is very good. The engine is 276 ci.

MII · 03-29-2018, 02:03 PM

thanks estout81 and Fordestes now I am totally confused, I have a 239 over .060
my rpm will b 2000 at 55 mph, I am looking at Speedway for the parts, is that the right place?

MII · 03-29-2018, 02:09 PM

I forgot to add the tire size is P215/75 R16

estout81 · 03-29-2018, 02:10 PM

What parts are you looking for?

AnthonyG · 03-29-2018, 02:22 PM

Like estout81 I compensated for a 4.11 rear in my '35 by going with a bigger diameter tires on rear, also wen with radials (love them). If your not concerned with a stock look it works well ( & looks cool ). Mine had 600 16's which I believe were approx 26" went to 235X85-16 approx 30 3/8" & believe reduced the 4.11 by 17% or approx to equivelent 3.50 rear. Runs great at highway speeds now.engine doesn't scream like it did at 60 to 70, just purrs now

MII · 03-29-2018, 02:23 PM

I am new at this, but I think carrier, gears, shims, I assume the bearings will interchange, but new seals the axles should fit they are 19 spline

expavr · 03-29-2018, 02:43 PM

Quote:

Originally Posted by MII

I am new at this, but I think carrier, gears, shims, I assume the bearings will interchange, but new seals the axles should fit they are 19 spline

If you’re looking for some input on parts for your differential I’d recommend you contact Chuck at Chucks Trucks. https://www.chuckstrucksllc.com/ He sold me a set of new gears for the tonner and handed out a lot of free advice on how to remove and set them up.

estout81 · 03-29-2018, 03:06 PM

If there is nothing wrong with your rear end other than the ratio, I'd think long and hard about changing the gears. Unless you have experience at rear axle work you best leave it to a professional. Pricey!

rotorwrench · 03-29-2018, 03:51 PM

Stuff is available for the Dana 44 with the 19-spline axles. If it's a Dana 41, I don't know. They had a different carrier but it might work on the taller ring gears. It depends on the size of the bolt circle.

slowforty · 03-29-2018, 04:01 PM

You could also swap in a Ford pick up rear end from the late 60s or 70s

TJ · 03-29-2018, 07:00 PM

The later 9" Ford rear end from '58 up to '72 will fall right in on your springs. You can buy a good used pickup rear a lot cheaper than changing the gears in your existing rear end. I did this swap for a friend and even used the brakes from the '52 rear end on the 9" rear end.

MII · 03-29-2018, 07:23 PM

thanks TJ I will check on a different rear

MII · 03-29-2018, 07:25 PM

I wonder which ratios are available, my tire dia. is 29 3/4

TJ · 03-30-2018, 07:57 PM

In the 9" there are many different ratios. There's usually a tag on them if nobody removed it. With your tire size and 3 speed trans. I would think something in the 3.50 range would give you a good highway cruising speed.

rick r · 03-31-2018, 08:45 AM

I would look long and hard at replacing the trans with a t5 5 speed. With a 3.90 rear you will be in the rpm range in 5th on the freeways and 4th will be good up to about 50 mph. You will still have the option of playing with rear gears if you feel it is necessary. Am running 5 speeds behind a flathead and a nailhead. Just my 2 cents worth.

03-29-2018, 12:22 PM	#1
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	change rear ratio my 49 F1 is 3:92.1, and I'm thinking of changing to 3:08.1 the transmission is heavy duty 3 speed on the floor has any one done that and with good results? it is an 8BA built by Walt

03-29-2018, 12:51 PM	#2
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: change rear ratio Depends on what your objectives are for the truck. Trucks are typically geared lower than a car. To me that would be a very high gear, is it going to be mostly a highway vehicle?

03-29-2018, 12:58 PM	#3
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio mostly highway and around town

03-29-2018, 01:46 PM	#5
Fordestes Senior Member Join Date: May 2010 Posts: 886	Re: change rear ratio Expect to stay in the box,(Aphrase used by truckers who constantly have to shift up and down) I tried it here in flat land oklahoma and it resulted in rotten fuel milege and a lot of shifting, mine was a 3:25. you my get better results , the rear diff is still on the shelf collecting dust. I had to run about 65 + mph to keep her from lugging down, also hard on the engine being in a hard pull at lower speeds. Lots of luck!

03-29-2018, 01:53 PM	#6
estout81 BANNED Join Date: Jun 2010 Location: Utica, Ohio Posts: 522	Re: change rear ratio Sponsored Links (Register now to hide all advertisements) I forgot to say, my fuel mileage is 16-18 depending on how hard I drive it. Also, performance is very good. The engine is 276 ci.

03-29-2018, 02:03 PM	#7
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio thanks estout81 and Fordestes now I am totally confused, I have a 239 over .060 my rpm will b 2000 at 55 mph, I am looking at Speedway for the parts, is that the right place?

03-29-2018, 02:09 PM	#8
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio I forgot to add the tire size is P215/75 R16

03-29-2018, 02:10 PM	#9
estout81 BANNED Join Date: Jun 2010 Location: Utica, Ohio Posts: 522	Re: change rear ratio What parts are you looking for?

03-29-2018, 02:22 PM	#10
AnthonyG Senior Member Join Date: May 2013 Location: Pa. Posts: 2,174	Re: change rear ratio Like estout81 I compensated for a 4.11 rear in my '35 by going with a bigger diameter tires on rear, also wen with radials (love them). If your not concerned with a stock look it works well ( & looks cool ). Mine had 600 16's which I believe were approx 26" went to 235X85-16 approx 30 3/8" & believe reduced the 4.11 by 17% or approx to equivelent 3.50 rear. Runs great at highway speeds now.engine doesn't scream like it did at 60 to 70, just purrs now __________________ Nomad

03-29-2018, 02:23 PM	#11
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio I am new at this, but I think carrier, gears, shims, I assume the bearings will interchange, but new seals the axles should fit they are 19 spline

03-29-2018, 03:06 PM	#13
estout81 BANNED Join Date: Jun 2010 Location: Utica, Ohio Posts: 522	Re: change rear ratio If there is nothing wrong with your rear end other than the ratio, I'd think long and hard about changing the gears. Unless you have experience at rear axle work you best leave it to a professional. Pricey!

03-29-2018, 03:51 PM	#14
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: change rear ratio Stuff is available for the Dana 44 with the 19-spline axles. If it's a Dana 41, I don't know. They had a different carrier but it might work on the taller ring gears. It depends on the size of the bolt circle.

03-29-2018, 04:01 PM	#15
slowforty Senior Member Join Date: May 2010 Location: Tinley Park Ill Posts: 1,062	Re: change rear ratio You could also swap in a Ford pick up rear end from the late 60s or 70s

03-29-2018, 07:00 PM	#16
TJ Senior Member Join Date: May 2010 Location: Napa,California Posts: 6,037	Re: change rear ratio The later 9" Ford rear end from '58 up to '72 will fall right in on your springs. You can buy a good used pickup rear a lot cheaper than changing the gears in your existing rear end. I did this swap for a friend and even used the brakes from the '52 rear end on the 9" rear end.

03-29-2018, 07:23 PM	#17
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio thanks TJ I will check on a different rear

03-29-2018, 07:25 PM	#18
MII Junior Member Join Date: Aug 2011 Location: Veazie, Maine Posts: 29	Re: change rear ratio I wonder which ratios are available, my tire dia. is 29 3/4

03-30-2018, 07:57 PM	#19
TJ Senior Member Join Date: May 2010 Location: Napa,California Posts: 6,037	Re: change rear ratio In the 9" there are many different ratios. There's usually a tag on them if nobody removed it. With your tire size and 3 speed trans. I would think something in the 3.50 range would give you a good highway cruising speed.

03-31-2018, 08:45 AM	#20
rick r Senior Member Join Date: May 2010 Location: Woodville Ontario Posts: 227	Re: change rear ratio I would look long and hard at replacing the trans with a t5 5 speed. With a 3.90 rear you will be in the rpm range in 5th on the freeways and 4th will be good up to about 50 mph. You will still have the option of playing with rear gears if you feel it is necessary. Am running 5 speeds behind a flathead and a nailhead. Just my 2 cents worth.