how much can the diff take?

I'm on this forum trying to do some research. I've seen a few swapped threads but I had a few questions I didn't see REALLY answered. I don't have a tacoma yet...but I am thinking about it.

For starters I should explain my train of thought. I have a horse and one horse trailer. The tacoma can pull that no problem I'm sure. I also have an 84 celica/supra with a lexus 1uz-fe (4.0L) swap using the stock w58 (rebuilt) tranny and rear end. The car is fun but I need a truck and I don't like BIG trucks that use all their power to move themselves before you even move your load. I would love to swap the v8 into a tacoma and make it a working truck, not a show truck or a hp freak. But a functional tacoma with a v8.

My curiosity is not about how much power I can pump, I'm looking to increase to towing capacity of the truck via engine/tranny swap and seeing what else I will need to do based on the limitations of the frame/suspension.

I know I could boost a tacoma or supercharge but I don't want to go that route. I guess I'm looking for what structural issues will limit the tacoma's towing capacity? I don't want to get into trailer brakes and electronics...etc ...those are things I can find out myself, but the limits of say, the differential, axles...etc...are things I can't find. I know on the honda ridgeline if you go over the towing capacity you will stretch the unibody.

Let's assume first, that I've done these things and these only.

swapped in the 4.0L lexus 1uz-fe, w58 tranny, and using a drive shaft equivelant to the strength of that which is on my 84 c/s.

Still using everything else stock.
I'm assuming the leaf springs and shocks would need to be beefed up in the rear (not as much in the front), but what about the frame, bumper, and differential? What can they take? Would I also need to strengthen the frame? What other things might I not be foreseeing?

I don't know which I would do this on...a first or second gen, I love the first gens but I'm assuming a second gen frame would have a stronger frame.

I hope I'm not being to general, like I said, I've looked over some threads but the folks doing their swaps did them for "ooo" factor and high horsepower. I basically want bigger truck towing in a little truck package


*edit
I should add...the only road time this truck would see is if it were towing something, work truck only...either a car on a trailer, or a lot of building material... or a horse. So a stiff ass wouldn't bother me too much.

 

Putting a V8 into a tacoma is not gonna increase the towing capacity.

Towing capacity is determined by many things - including differential & axle strengh, FRAME, transmission, steering components, and a whole bunch of other stuff.

I'd highly recommend NOT modifying a tacoma under the assumption you can increase the towing capacity. That's not how it works.

If you're gonna go beyond the towing capacity, then get a fullsize truck that is built for it.

 

+1 to what Jan said-By the time you have finished modifying everything to get it to spec for what you want...You've spent a ton of money and have a truck that might act like a fullsize as far as accel goes.

The Tacoma isn't meant to be a huge towing machine...The tow package ones will take 6500#. That oughta get the job done for the stuff you are talking aobut moving....and if it doesn't...Get the right kinda truck for the job....IMO.

 

well to begin with.. if your gonna do a v8 swap why not get a newer 4 runner and use it as a donor truck. i would think that would be alot better engine.... and yes there would be some things you would have to do such as some frame plating. the rear end however i would suspect would hold up just fine under normal driving conditions.

as far as doing the swap to truly increase towing capacity.. well even with the swap and what not i dont think i would tempt pulling to much over the rating. you have to remember that things such as size and weight of the truck play a huge role in its towing capacity. however doing it to make pulling that 6000lbs. easier... HECK YEA!! plus it would just be awesome!

 

Thanks for the response.

Prolly the most important thing I didn't account for...i didn't take into account vehicle weight, that will play a big role in towing safety...and just towing capability period. Thanks for pointing that out...makes perfect since.


Now as to the differential and axles I suppose I should look into those who have boosted the taco...however much power they put through the diff and axles are how much I could push through as well...could just swap a rear diff and axle from a different truck of bigger size...HA HA...too much trouble.

Guess the point is, due to the small size of the truck, even with adequate springs, diff, and axles...it still is just too small to tow heavier loads. SO...change of idea...no more trying to go over the trucks limit...instead...make it tow the limit easier...just my style

IF I wanted to use the tacoma I could simply boost it, or v8 swap, but again, not to attempt to tow more than what the stock truck is rated for, as again...it's just too small to do it....but instead so that I have an easier time towing the tacoma's rated capacity. I like that idea better...especially since it's current capacity should suffice for what I need...be it car, horse, or materials.

Problems with that line of though

 

It's just NOT SAFE. Get a fullsize truck and keep everyone (including other people on the road) SAFE!

Check with your local state laws. It might be illegal to go past the towing capacity.

Here in PA - trucks are rated based on their GVWR and GCWR. The first gen tacomas have a Class I and the 2nd gen just goes past the limit and puts it in Class II. Your truck is registered according to its class. If you are found towing more than the Class specs, you can get a ticket.

Then - in order to change your Class to tow more, you have to go through specific testing/inspections to pass into a higher class. I don't know the details about the tests, but I'm pretty sure....it's not done lightly.

 

well if you plan to stick within the tacomas limits.. which should be fairly easy considering they have a 6000lbs tow rating... then i would say things such as the axle will be just fine. look at it this way, the tundra still runs the same axle as the trd sport or sr5 (8.4) so why wouldnt it hold up to v8 power in a tacoma?? if i were to do it i would leave the axle alone, but do some quality brake upgrades, add a brake controller, weight distributing hitch with sway control and then maybe i would feel comfortable pulling the rated capacity..

 

Why you haven't seen any serious threads on this is probably cause it is to much of a pain in the ass.i just think and i may be wrong that if they thought that a v-8 would work in the tacoma set-up they would have offerd it as an option.It sounds like (imho) that your,e trying to put a flat-top on a destroyer,when they already make an aircraft carrier

 

well i'm not saying its really logical for someone to do a v-8 swap just to be able to tow easier. but what the heck.. its not my truck so if he wants to do the work to make it right then why not.......

 

I agree, it isn't safe to try and tow more than what the truck is limited to.

The limits aren't just based on braking and power and structural issues...but how the truck will actually handle with that much weight behind it.

A little more understanding of my reasoning:
I've towed with 4cyl, 6cyl, the new tundra's (not the 5.7 ), and a newer model ford f-150 (not sure which v8 it had). I don't like BIG trucks...and I LOVE how both tacoma gen's look.

The newer tundra (not the 5.7 ) towed VERY easily, both accel and decel...I could easily forget I was towing. The ford did well. With the 4cyl...forget it...the 6 cyl COULD do it...but good lord it was a pain to get moving. While I know there's more to it than just engine size and gearing, the larger engine does help a great deal.

I guess in all honesty, I'm not REALLY wanting to try and go PAST the towing capacity, I just know the older tacomas don't have the 6500 capacity of the newer trucks. Of course depending on which 2nd gen tacoma you get you have either 3000 or 6500...so as long as I can tow that amount I'll be fine...car, horse, or stuff. Since the two trucks are very similar in size I'm kinda curious what all is limiting the one tacoma to a lesser towing capacity.

I don't want a big truck is what it is. And since I just happen to have a v8... HA HA...

I'll see what's available in my area as to larger trucks. My father-in-law told me the other night he is trying to get rid of his 94 6cyl ranger...I know...a completely different truck than a tacoma...I'll have to find out what it can tow and go from there. Thanks again for the replies!


*added:
one more question...why do the auto's have higher towing capacities? If I shifted right and didn't burn the clutch...why couldn't I tow the same with a manual?