Hello, Im hoping I finally found a forum that has a lot of info for the 2wd variants of Toyotas. I myself have a 1987 hilux that the rear differential sounds like its about to go out in. I was wondering how I can identify what size the ring gear is without dismantling it and what the highest gear ratio option is for that size. I figured while I do this job I might as well squeeze some more mileage out of it. I think the rear axle assembly is original. I know the transmission is not. What are the places I look on the truck (engine, transmission, rear axle, etc.) that identify these things? The axles are 5 lug if that helps.

 

On the firewall, under the hood, there's a VIN plate. On the bottom of the VIN plate there are some codes. One of them is for your differential gearing. That code will start with an F for a 7.5" differential, or a G for an 8" diff. What are the three numbers after that letter? An F302 is very common, and would be a 3.73.

 

OK, I looked under the hood and didnt see much separation between the numbers but this is what it said:

RN50L-KRA
8A1LL81G662W46

 

That's a G662 differential. Google it quick and you'll see it's a 3.07. Pretty fast already.

(Edited to not ask the obvious.)

 

OK, thats good news. However, the reason I ask is its been clunking like its getting ready to go out on me. All I seem to find online are 4.10s and the like. Is there any place that sells oem?

 

...junk yard

 

Huh. Where in the country are you? I had answered your question sort of at random, but someone here sold me a G662 third a while back. I don't think I'm going to use it. PM me.

 

PM sent^

The reason I didnt look in a junkyard is the junkyards around here in the midwest dont tend to have a lot of 80's Yotas populating them. There are some parts trucks on CL but I have nowhere to put one.

 

Here is the axle code Bible:

http://www.off-road.com/trucks-4x4/tech/toyota-differential-identification-18588.html

 

Not sure but isn't there a good chance that a third out of a 89-94 would fit in the same assuming the ring gear is the correct size?

 

you need to make sure you have a 8" housing and an 8" third member.th 89 -95 2wd are 7.5" the 4x's are 8"

 

Sort of. All 84-95 2 wheel drive trucks with 4 speed trannies have 8" differentials with 3.07 gears. V6 2 wheel drive trucks also have 8" differentials.

An easy way to figure out if you have an 8" or not is to glance under at the axle housing. If the drain plug is on the driver side it's an 8", if it's on the passenger side it's a 7.5"

 

Ah. Seems my 84 has 7.5" at 3.51 ratio or something close to that.

 

This truck started life as a 4 speed and has a code of G662. That is an 8" diff if Im not mistaken.

 

It's funny I guess it depends on where you live.Here on Guam we don't have any 4 speeds after 88.We do have 4cyl 4x4's after 88 and I'm not sure what year they stopped.They typically have a 4:11 ratio and the v6 version has the 4:56
Gearratiosanddiffs

 

Mine's an 87.

 

If the gears have lower ratio numbers (like the OP has a 3.07 and mine is a 4.11) aren't the taller geared than the higher number ones, meaning they do better on the freeway?

 

Yes. My diff would be considered "higher" geared where as your 4.11s are "lower" geared. The higher gears accelerate slower and are not as useful for 4x4 or pulling but they allow the engine to turn less rpms at higher speeds thus getting better fuel economy. I didnt know what mine was until a few days ago when I joined this forum. I just got lucky when I bought the truck.

 

I wish mine came higher geared, the 4.11 with the four speed doesn't like much over 60 mph. I've been trying to find another third member that is higher geared that I can also put an LSD or locker in.

 

Cade. They are out there, one just has to be patient looking for them. I went from a 4.10 to a 3.42, which helped (along with 16 inch wheels and tires) but was too conservative for my liking. I found two 3.07 rears in a boneyard here, of which I purchased one, but have yet to do anything with it. They are out there.

As an aside, I can tow a 2000 pound trailer without stress (in town) with the 3.42/16s. It does require a certain recalibration of both the speedometer, and ones expectations of bottom end scoot, but I do not impede traffic and am presently at 3000 rpm for 72mph (flat ground, sea level, speed measured by GPS)