Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-05-2020, 04:59 AM   #1
danliveshere
Senior Member
 
danliveshere's Avatar
 
Join Date: Jul 2010
Location: Cairns , Australia
Posts: 739
Default Best rear axle ratio?

Guys a buddy of mine has a newly purchased 36 coupe. It’s running a warm 24 stud flatty, he hasn’t driven it enough yet to know how much power the motor has. Anyway he needs to purchase a new crown wheel and pinion. He has bought 750-16 tyres. Standard 39 transmission. He lives in the country so wants a high ratio, just doesn’t know whether to go with 3.54 or 3.2. With his 750 tyres what recommendation ratio should he aim for? Not sure if he has a 9” or 10” clutch.
Thanks in advance Dan.
danliveshere is offline   Reply With Quote
Old 06-05-2020, 06:50 AM   #2
tub1
Senior Member
 
tub1's Avatar
 
Join Date: May 2010
Location: tasmania
Posts: 221
Default Re: Best rear axle ratio?

dan with those tires 4.11 would be the go
tub1 is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-05-2020, 07:31 AM   #3
Juergen
Senior Member
 
Join Date: May 2010
Posts: 499
Default Re: Best rear axle ratio?

If your choice is 3.54 or 3.2, go with 3.54 as the larger than stock tire size reduces the ratio below 3.54 and 3.2 with 600 x 16 tires is not great in hilly conditions.
Juergen is offline   Reply With Quote
Old 06-05-2020, 08:12 AM   #4
aussie merc
Senior Member
 
aussie merc's Avatar
 
Join Date: Sep 2016
Location: sydney australia
Posts: 1,025
Default Re: Best rear axle ratio?

im running 354s on 600/16s and cant complain about the speed but can be difficult on hill starts as tends to get minor clutch shudder
aussie merc is online now   Reply With Quote
Old 06-05-2020, 09:51 AM   #5
rockfla
Senior Member
 
rockfla's Avatar
 
Join Date: Mar 2014
Location: Jacksonville FL
Posts: 3,925
Default Re: Best rear axle ratio?

We are running a 3:54 in our 32 with the stock 18" rims and tires, on flat land its wonderful, hills...not too bad, mountain's have to be climbed in first gear!!! OH, and "stock" 32 Flathead with stock 32 transmission.
rockfla is offline   Reply With Quote
Old 06-05-2020, 09:56 AM   #6
Mart
Senior Member
 
Mart's Avatar
 
Join Date: May 2010
Location: Solihull, England.
Posts: 8,732
Default Re: Best rear axle ratio?

Sponsored Links (Register now to hide all advertisements)
With the 7.50s I'd go with the 3.54s. It might help if the trans has the 15/29 gearset. I have that combo in my 41 pu with 6.50s and it's fine. I also have 3.54s in my roadster with 7.50s but that is a lighter car. That has the 16:28 gearset.

Mart.
Mart is offline   Reply With Quote
Old 06-05-2020, 10:12 PM   #7
JM 35 Sedan
Senior Member
 
JM 35 Sedan's Avatar
 
Join Date: May 2010
Location: Near Rising Sun, Maryland
Posts: 10,856
Default Re: Best rear axle ratio?

Last summer I rebuilt the banjo rear in my '35 fordor sedan, and installed a 3.54:1, six spline pinion gear set. I also rebuilt the original #48-7006 transmission case using the later style '46-'48 side shift trans gear set with 29 tooth cluster and 15 tooth input gear. This transmission & rear gear combination using 6:00 x 16 tires works perfectly when starting off in 1st gear, on flat, or hilly ground, and climbs hills and mountain roads well in 3rd gear. The engine is a '35 babbitted main bearing, 21 stud, 221 cu in, 85 hp, bored 0.030" over, plus both the deck and heads have been milled for higher compression. This little engine runs amazingly well.
__________________
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; 06-05-2020 at 10:46 PM.
JM 35 Sedan is offline   Reply With Quote
Old 06-06-2020, 05:55 AM   #8
danliveshere
Senior Member
 
danliveshere's Avatar
 
Join Date: Jul 2010
Location: Cairns , Australia
Posts: 739
Default Re: Best rear axle ratio?

Thanks John. My buddy has already decided on a 3.54 ratio based on the above comments. Thanks to all who responded.
danliveshere is offline   Reply With Quote
Old 06-06-2020, 06:06 AM   #9
Tim Ayers
Senior Member
 
Join Date: May 2010
Location: NJ
Posts: 6,141
Default Re: Best rear axle ratio?

Quote:
Originally Posted by JM 35 Sedan View Post
Last summer I rebuilt the banjo rear in my '35 fordor sedan, and installed a 3.54:1, six spline pinion gear set. I also rebuilt the original #48-7006 transmission case using the later style '46-'48 side shift trans gear set with 29 tooth cluster and 15 tooth input gear. This transmission & rear gear combination using 6:00 x 16 tires works perfectly when starting off in 1st gear, on flat, or hilly ground, and climbs hills and mountain roads well in 3rd gear. The engine is a '35 babbitted main bearing, 21 stud, 221 cu in, 85 hp, bored 0.030" over, plus both the deck and heads have been milled for higher compression. This little engine runs amazingly well.
Interesting. I sourced an original 3.54 R& P and may switch over from 3.78’s for a winter project.
Tim Ayers is offline   Reply With Quote
Old 06-06-2020, 06:19 AM   #10
danliveshere
Senior Member
 
danliveshere's Avatar
 
Join Date: Jul 2010
Location: Cairns , Australia
Posts: 739
Default Re: Best rear axle ratio?

I actually have a beautiful original 3.54 in my roadster but that’s being removed to fit a Columbia axle.
danliveshere is offline   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

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:46 AM.