View Full Version : Bye Bye 3.55, Hello 3.73
Railroad
08-22-2021, 12:47 PM
The title says it all. Just got my replacement carrier with 3.73 gears. I have found my Coyote too soft on tq in the lower rpm, idle to 2800. I am running 3.73s in some other cars and have found them just right for my driving.
I guess Ford decided to paint some of the differentials. I saw a lot during my search that were rusty, like my original set. Even the pinion yoke is painted. I feel fortunate to have found such a good looking differential, advertised with 15K miles.
Axle seals look good, but will probably replace them, or not, cannot decide, they sure look good, and Ford OEM is usually as good as it gets.
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richtersand
08-22-2021, 12:52 PM
Nice! I’m also running 3.73 + Coyote so this is particularly interesting for me. I haven’t had the pleasure of driving it yet though. Can you keep us posted on the before/after experience?
Railroad
08-22-2021, 01:24 PM
I will be glad too. I am not getting anything done fast, just hit a lazy streak in my life. The diff sat on the porch for 2 days before I took it to the barn/shop. I turned the roadster around for the lift so the rear will be facing my work table with the diff. I touched up the black and need to put Sharkhide on the alum cover.
I want to pull the present diff without loosing my rear alignment.
Anyway, looking forward to some cruising.
lee82
08-22-2021, 01:42 PM
What's your first gear ratio? 3.27?
CraigS
08-22-2021, 05:39 PM
That will help. It is what is in my wife's 2015 Mustang GT so it should be just fine in a car that weighs 1000# less.
Railroad
08-22-2021, 07:48 PM
What's your first gear ratio? 3.27?
2.87
Alan_C
08-22-2021, 08:00 PM
Curious as to what the connector on the housing is for, maybe fluid level sensor?
tonywy
08-22-2021, 08:00 PM
You'll be happy with those. I'm running them as well but, with a big block. That ratio makes my car fun to drive in any gear. I also ordered my new F150 with 373's, they're just right.
lee82
08-22-2021, 08:44 PM
2.87
Nice. I think 3.73 would be perfect. Maybe even 4.09!
GoDadGo
08-23-2021, 07:00 AM
My C-4 Corvette had 3.54 gears which is why the Redbone Roadster sports 3.73's.
The Higher Revving Coyote I am sure will respond rather well to this little change.
Railroad
08-23-2021, 07:31 AM
Curious as to what the connector on the housing is for, maybe fluid level sensor?
Probably a temp sensor. Too low for a lube level sensor, IMO. Will probably pull and replace with a plug.
Railroad
08-23-2021, 07:34 AM
Nice. I think 3.73 would be perfect. Maybe even 4.09!
I am sure I will be OK with 3.73s. I have a 4.6 supercharged, 99 Mustang Cobra with the same gears. Unreal how many owners run 4.30s in these things.