Replace diff gearing in automatic with manual

Automatic Tacoma's have 3.909 gearing while the manuals have 4.30. with the difference being close to 10% I'm thinking it could be a cost effective mod.

Does this make sense? Has anyone done this?

 

depends on load......weight.....driving environs.......towing

if U could find 1 cheap at a salvage yard

otherwise its only a few hundred rpms.........a fun knuckle bustin weekend tho

 

You won't see more than a 100-150 rpm difference

 

Don't forget the torque multiplication.

Cost effective, yes.

 

Aren’t the differentials different sizes? I’m pretty sure they are

 

Some 4 cylinder automatics received the 8" 4.30 ratio.

 

Did you miss a 0 from that? Think It’ll be closer to 1500 rpm.
(Edit. No you didn’t. looks like 300rpm, my maths was bad).

That would probably be perfect for people running 33” tires. V6 auto gearing, can barely handle stock size tires 30~31”, so assuming it fits and is cost effective ( I have no idea on either), seems it would be good for people running 33”.

 

I've done gear changes in quite a few vehicles I've owned . I went from.3.73's to 4.10's and noticed a 300 rpm increase . I've also seen going from 3.90 gear to 4.88 gear a increase of 500rpm


Just recently I went from a 3.73 gear to 3.89 gear in my Camaro and had increase of 200rpm

 

Any more information on this thread!! Would love to learn more as I have an option to throw in a rear diff from a manual and swap it with the auto I just bought

 

Not much to add. If the diff is the same size you could install it but not really worth the seal and oil to replace imho.

 

Might as well get some aftermarket gears installed, there is no telling what you get from the bone-yard.
Also, if you have 4wd, you need to do the front differential.

 

thank you for confirming. Seems like a hassle but I’m only doing 33’s max. I just have 2 tacomas right now ones a manual but the manual is being sold

 

You are looking at a few hundred to set the gears up in the diffs. Ring and pinion need to be swapped, that’s new seals, shims and crush sleeve. Then the time and and a new setup labor.

 

41201-79485 - Front Ring & Pinion, 4.30:1 Ratio
41201-09C30 - Rear Ring & Pinion, 4.30:1 Ratio

Jeff