Hey guys,
Looking to swapping 3.73 gears into my 1994 xtra Cab 4x4. According to research, I have the 4.30 gears (confirmed w/wheel rotation test), 8" rear, 7.5" front. My 5VZ swap and 31" tires leaves me with ridiculously fast acceleration in town, and a screaming engine on the highway. I'm already in 2nd more often than not before even crossing the intersection. I've found a 3.73 third member for my rear end, but haven't been able to find info on if a 3.73 ratio is possible with my front diff. I found one page that indicated that the 3.73 gears from a 7.5" rear may be able to be swapped into my IFS front diff, can anyone confirm this?
I do mostly highway driving, followed by light off-roading (shuttling mountain bikes and climbing equipment) so a more highway friendly ratio is what i desire.
Thanks in advance!
Matt

 

anyone?

 

This page says that the carrier and gears in 7.5" rear thirds are compatable with an IFS case: I believe them.

http://home.4x4wire.com/erik/diffs/

I see a couple 7.5" Toyota 3.73 rear third members on Ebay that you might be able to take the carrier and gears from, but I don't find any new 3.73 7.5" ring and pinions offered for sale there.

Have you asked a Toyota dealer about new gears???

 

The 7.5 3rd member is the same on front IFS 4x4 toyotas as in the rear of 2wd trucks, so yes the are "interchangeable".

 

31s are stock size. Rev it out.

I run a 33 and 4.88s and it's perfect.

 

Manual trans would be 3000rpm 4th and 2500rpm 5th at 65.
That should be perfect for 5VZ and DD

Going from 430 to 373 is a 3 point jump (skipping 411, 390)
I would think you will start burning clutch and binding drivetrain and going
on any strain offroading would break something.

What do you consider a screeming engine on the highway?

Maxx here is running a little higher then normal rpm DD setup, 488 and 32.4" about 2750rpm OD at 65, Nice offroad setup.

 

3.73 sounds a little short, even for a 3.4 engine. 3.73 is what Toyota uses in the 4th gens with the 4.7L V8, which has a lot more low-end torque than a 3.4.

4.56 is stock with 31's and a 3.0 with a manual transmission. I don't think I'd go below 4.10 with the 3.4 engine.

 

My tach is right at 3250 when I'm running 75mph. Just checked it today. IMHO, it's right in the powerband.

 

Thanks for the replies dudes! Well based on responses and some thought I've decided on 4.10s - should give me 2500 rpm at 65 or so. My tires are actually 31x10.5 so really around 29.5" real diameter. I just don't see any need to have the engine in its powerband for cruising - flat highway cruising requires few hp. I'd rather just downshift to pass and/or climb a hill. The 5VZ is comfortable revving high but doesn't necessarily need to - I rarely shift later than 2200 rpm.
And I need to work on this truck haha! If I don't do this it could be something way worse! Like #sas2k17
​​​​​​