so im just about to start swaping a 7mgte into my 2wd pickup. i have the engine, r154 trans, all the sensors/wiring, just need to find some 5m engine mounts then i can get things rolling. i have everything planned out pretty good. only a couple things that are a concern. one of which is the strenght of the 2wd rearend. will the 7m just rip it to pieces? i was seaching and i think a lockright will be good for my goals. that is if the ring and pinion can take it. my modified mk3 supra traps 110mph and they have a 7.5 ring. i have 100s of passes on it too. im hoping the 2wd pickup is the same. i swear i read somewhere that you can use the 7.5 ring and pinion from the toyota trucks in the supra diff.


edit: my supra actually has the 8" ring

 

2WD pickups with the 7.5" axle are rated for 1/2 ton. The 7.5" diff is plenty strong enough to handle just about whatever you can throw at it when used in a RWD/2WD setup. It's the exact same size and strength diff the Supra comes with from the factory. So being able to handle the 7MGTE is what it was meant to do.

Why us 4wheelers bitch about it being so weak has nothing to do with how it performs in RWD/2WD applications. You see when you go and put the 7.5" diff in the front axle of a 4WD, it isn't even being used in the manner it was designed to. It's being run backwards on the weaker side of the ring and pinion gears. This leads to ring and pinion gear failures, especially when combined with the added stresses of 4Low gearing(power output x 2.57 = LOTS O' TORQUE)and larger size tires than you'll likely find on a 2WD truck(or EVER on a Supra).

For example...

My 3VZE in 4L puts down ~463ft.lbs. of torque in 4th gear. That's ~1773ft.lbs. in 4L 1st gear. Your 2WD 7MGTE ain't coming anywhere near that. So it's no wonder why, with that amount of power and 35"x12.5" tires, that I've had plenty of trouble busting gears in the 7.5" front axle. But for the most part, suprisingly, they can handle it. I don't bust the gears in the front axle EVERY time I go wheeling, but it has happened more than I'd like it to. And whenever I'm really pulling hard in 4L, I expect to hear the ring gear teeth respond to it with that all too familiar sound of metal fracturing under extreme tension. TANG!!!

So...

Once you put things in proper perspective, the 7.5" diff isn't really very weak AT ALL! It'll actually withstand TREMENDOUS abuse, even being run backwards/on the weak side of the r&p.

 

wow thats great to hear! thanks for the info

i have a extra 2wd rear to. so i'll run those with a lockright till they pop. and if after this winter the motor holds up i might sas it and go 4wd over the summer.

 

If you want a stronger axle, some 2wds came with an 8 inch. Any truck with a G axle code is 8 inch. 4 speed trucks with 3.07 gears (G662) are 8 inch. Turbos, 1-tons, and I think V6s also came with 8 inch diffs. From everything I have read, 4x4 thirds and parts are swappable into the 4x2 8 inch housings. This makes finding lockers much easier.

Ford 8.8 Explorer axles are also suppose to be a fairly easy swap into 4x2s. From everything I have read, they are strong and the leaf springs actually bolt in and they have the same 5 lug pattern. Some of them come from the factory with disc brakes and a posi. Here is a writeup on it:
http://www.toyotaminis.com/forum/sus...-install-5308/

 

so the lockright 1611 is for the front diff on the 4wd. which is the one i need for the 2wd correct? reallly i would prefer to not mess with swapping the rearend unless i have to. im really excited to see how the 7m does in such a light chassie. and i just got a set of 5m mounts!!! should see them next week!

 

the 86+ supras have 8" rear ends, the 84-85 supras have 7.5" diffs.
if your tires ever get any traction, i dont see the 7.5" diff lasting too long
find a 8" 2wd rear axle and swap in a v6 3rd with a lockrite

 

Yep, that's the one.
Seriously? Based on what? They're quite a bit tougher than you think...trust me. It's not exactly easy to break the 7.5" diff in the front axle of a 4WD. As I've stated, it's inherently weaker when used in front axle applications because of it being run on the coast side of the ring and pinion. That's where the myth about it being "weak" comes from. And in 4Low, my rig puts FAR more torque to it than any 7MGTE ever could! So I can't hardly see it having any trouble when used BEHIND one.

8" with a V6 3rd? Dude! That's MASSIVE overkill!!! WAY NOT NECESSARY!!! An 8" maybe, but the V6 third is just dead weight. It's not even necessary in the applications it was intended for(namely a V6 1/2 ton 4WD w/2.57:1 transfer case reduction gears). I've been running a 4cyl 8" diff behind my V6 1/2 ton 4WD PU for years with no problems whatsoever. Why Toyota even bothered on that one is beyond me.

BTW, most folks that have the 7.5" in the front axle(4WD) NEVER have any issues with it, regardless of tire size. The only reason I've had troubles with mine is because I drive my rig like a crazed maniac off-road. NOBODY wheels harder than the MudHippy! If it's breakable, I'LL BREAK IT!!!

Thank god I own a Toyota, or I'd never get any wheelin' done.

 

obviously the 8 inch is way stronger but the gear ratio is what matters, 4.11 are stronger then 5.29s because the teeth are bigger. if your running a 7.5 inch ring gear with 3.__ what ever gears they are gonna hold up, but a 8 inch is gonna be way stronger. say if you were push 40 psi boost and 6 to 800hp but just a measly 300 hp, 7.5 should be plenty.

 

and u base this info on your 4wheeling background?
i have killed a few 7.5 diffs with my 84 2wd yota with a sbc 283, and finally switched to a 8" housing with a 4.10 v6 diff and had no problems after that. i (with experience)would not recomend a 300+ hp supra motor in front of a weak 7.5" diff.

 

Negative. Please see Gary Curmi:
http://www.gtepowered.com/index.php?...mi/profile.php

LOL, sorry, I had to. In no way, shape, or form, is this normal 7M power though. Most common street driven 7m's are topping out at around 700-750rwhp, and those are scarce because that costs money.

I'm just messin' with ya Hippy, though the 7M is a very capable motor in the right hands, those power levels aren't going to be achieved for a street car or pickup.

Edit: he's posted videos before, you can search youtube for user mibrum I believe.

 

Love this quote

 

i'd rather it be Overkill than "MAYBE" enough.

why do people upgrade to Longs in their SAS's..because of the POSSIBILITY that they MIGHT break a shaft one day, Longs will PREVENT that.

 

the swap is done!!!! i've been driving it for a couple days now and i really like the extra power. running stock boost for now. the sound and rumble of the 7m makes people think wtf is going on with that little truck lol! just the small amount of time driving it i realized how much it needs different gears. low rpm in 5th is like 85-90 mph! way to fast to cruise. i'm set with finding a front 3rd member out of a 4x4 but i don't know what to pay. i don't want to get ripped off. the local salvage yard said 175 for one. they have a good amount of mid 90s 4runners but not many trucks. i would like to get between a 4-4.5 to 1 ratio. what models have that range? are the autos ratio much different from the manual? how much should i pay? or is there a place to get a good deal on a new r&p for mine? sorry im such a noob with this stuff. and heres a pic of the 7m in there. its a tight fit!

 

so i did end up killing the 7.5 rear end. it lasted like 7 months. just the other week i got an aussie locker for it and 4.56 gears. i went to put the gears in and one of the side gears was siezed in the diff housing so i decided to weld it since it was on its way out anyway. drove around with it for a couple day then went to the riverbar this past weekend. got in a nice little grassy area and unleased hell lol! did like 10-15 doughnuts and as i came down from this little hill with back all sideways it jumped off a little hump. when it landed it snapped the axle....

so now im back to the drawing board. ideally i would just get a 2wd v6 rearend but im finding out that those are like finding a needle in a haystack!!! then theres the ford 8.8 but that seems like overkill and way more work than the 2wd v6 rear. i did find a slavage yard in sac that has one but they want $525 shipped for the complete rearend. i was wondering what if i just buy the axles and put them in a 4wd rearend which is extremely common. is that even possible? i open to whatever at this point. i just don't want different lug pattern because i have a ton of wheels for the 5 lug

 

I did a bunch of research a while back and discovered that the 4wd and 2wd shafts are about 1 inch difference, so they will not fit in different housings. 4 speed trucks with 3.07 axle ratios have an 8 inch axle with 5 lug shafts. These do not have the stronger V6/turbo third, but will get you an 8 inch housing. If I remember correctly, a 4x4 3rd will fit this housing, so you can get a V6 4x4 third for it.

Pick-n-pull is probably going to be your cheapest source. You can take apart axles so you can get the housing and shafts from one truck and a third member from another. Check all the VIN tags on 2wd trucks for a G axle code. 4 speed trucks and I believe some 1 ton pickups do not look any different than all the other trucks, but will have an 8 inch housing. 1 tons might even have the V6 third. I sold a Toyota RV axle once and it had a V6 third even though it was in a 4 cylinder motorhome.

 

I FOUND A V6 REAREND!!!!


so i just want to make sure that i can use my current driveshaft with the v6 rearend. are they the same? thats the only thing im unsure of. other than that it seems it should be a direct swap.

 

May or may not have the same flange bolt pattern. If the same, it should bolt right up. If the patterns are different, some options are to re-drill the flange using the old flange as a template for the new holes, drill in between the existing holes:





Or swap the flange from your old diff. to the new one.

Or pick up a triple-drilled flange from Marlin/TrailGear/InchWorm/etc. and slap that on there. That is assuming the 4WD flanges are the same as the 2WD (I think they are).

 

so i was about to buy this v6 axle from redding for 375 shipped. then today i had to go to the salvage yard and thats when i saw it!!! they finally got one at our local yard so i got it right away. i pulled it which was a breeze so it was only $150! i measure my ds and the v6 ds and theyre the same. the flange is too! the only thing i need to do to it is supra lsd (which i have laying around) or locker still can't decide yet, 4.56's, and im thinkin i'll do new bearing to freshen things up. now my new question is 85excab said how the v6/turbo third is stronger. this came out of a v6 so shouldn't that mean this one has the larger bearing and what not?

 

so after looking at it closer it has the 4 cylinder 3rd. tomorrow im gonna see if i can get a v6 3rd. also i want to run a shimmed supra lsd instead of a locker because it will drive way better on the pavement.

 

You do not need a V6 third. Since you are going to put a different differential and gears, a 4 cylinder housing will hold up just fine. Also the 2wd 3.07 3rd member is a dedicated 3rd meaning you cannot regear it due to the offset pinion so that housing is scrap. My advice is to put a Ford 8.8 in the back since parts are plentiful, cheap, huge aftermarket and they are way stronger than an 8" Toyota rearend. Heck you can probably find a Ford 9" if you are serious.

James