80 series axles+suspension under a first gen Tacoma (11 Viewers)

[theferg]

Posted in the Tacoma section...but maybe it makes more sense in here....

I have wanted 80 series axles under a 1st Gen Tacoma for years and spent a lot of time thinking about this (Even since back in about 2009 when I was in a 3rd Gen 4Runner cause I wanted 80s axles under my 4Runner) but I think it would just about be the perfect setup if the Tacoma had 80 series axles under it and a nice, low-profile, OEM-style coil-link setup. And I plan to do it in the next year or so...already back collecting parts I want to work it with.

I am not satisfied with the huge amount of lift the regular SAS Tacoma builds end up with by doing your off-the-shelf conversions. The trucks are all WAY taller than stock, which I do not care for, and quite frankly, will not work for my type of driving/wheeling/camping. I also do not care for all the custom links and fancy coil-overs, and I absolutely cannot stand a non-toyota axle being used under there. So, long story longer, I'm taking a more OEM-Toyota-setup style approach to it.

Here's the main things I want to accomplish:

• Convert 2003 4WD DoubleCab Tacoma IFS axle and leaf-sprung semi-float, drum-brake rear axle over to 80 series Land Cruiser OEM front and rear disc brake axles with electric locking diffs, utilizing as much of the OEM 80 series coils and links suspension and front steering design and components as possible
• Use as many OEM/original, stock, and off-the-shelf parts as possible from 80 series and other related Toyota trucks including T100 and 2nd and 3rd gen 4Runners in order to optimize ease of supportability and maintainability.

So for years, I've been planning on grafting in the 80 series front suspension and steering as close as possible (seen a few builds done about like this over the years) and then grafting in the 80 series rear (thinking using 3rd Gen 4runner upper link position/setup since the tacoma/3rd Gen gas tanks are about in the same spot under there) and then in order to get the t-case to passenger drop, throw in a T-100 t-case (the one from the 3.4 T-100s will bolt right up with the proper trans tail-housing and output shaft setup--honestly not married totally married to this t-case any more, but one thing to note is that using that same T-100 tail-housing, you can also bolt up the older gen geared case .) (BTW, custom axle housings are not on the table for me. Way too much money, and way too much custom work and design and parts needed--which goes against one of my goals to keep it as OEM ish as possible for ease of replacement and maintenance.)

But now, I've kinda been wondering... why not maybe transplant the Tacoma body and 3.4L V6 and trans onto an 80 series chassis? That way, the suspension and steering and frame are pretty much just money and no need to worry about that part of it.. Would only need to figure out the body and motor/trans positioning stuff. Obviously there's lots to it either way you look at it, but maybe building off the 80 series chassis is... "easier"?

Also, another thing to note is I will also be ditching the factory Tacoma bed and running an aluminum Ute style bed. So pretty much only have to fit up the front clip stuff and the crew-cab body from the Tacoma. ("Only" haha!) So the wheelbase difference is inconsequential and I would only need to line up the front wheel opening.

I'm not totally sure which would be easier. Anyway...I'd love to hear some constructive thoughts and ideas on this...

 

[theferg]

Frame vs frame, for strength and longevity, the 80 series wins hands-down side-by-side as the 80 is fully boxed where-as the Tacoma is not even close, and then you add in all the rust-prone issues the Dana mfg'd Tacoma frames have had... My 2003 frame is really, really clean, but I suspect that it is only a matter of time... :-/ I figure if I'm sticking with the 80 series frame, I will for sure be boxing it in and adding extra frame plates where needed as much as possible.

And would the 80 frame be a lot more heavier weight wise? I mean, I'm sure its heavier, but would it be so much more so that a 3.4L V6 couldnt easily push it around with the Tacoma body on it...?

And another thought on the frames... If sticking with the Tacoma frame and grafting in the 80 series front suspension... and since I care not for the stock Tacoma bed and will be doing a Ute flatbed (though I think this would still work with the stock Tacoma bed anyway), what about chopping off the rear of the Tacoma frame and grafting in the entire back portion of a 3rd Gen T4R frame? I figure this could really help with the upper arms cross-member positioning, as well as the coils, shocks, and panhard bar positioning (I believe the 4Runner frames are more boxed back there too). Just a thought. Not sure how much "easier" or not this would be, but it would allow the suspension geometry/positioning to just drop right in, per se....

Btw, yes, I just need a 4-door 79 series LC pickup.... heh But, alas, I am stuck in the USA where I don't really have that option....

 

[Mace]

Toyota did this in a concept truck a couple years ago. It was at SEMA.

Let me see if I can find pics.

 

[Mace]

80 series front axle and Tcase (possibly the tranny as well I don't remember)
Toyota Tacoma Retro

 

[theferg]

Thanks @Mace. I did see that a while back. Seemed like an ok job, but I think they coulda done it a bit better...

I'm also in a 1st Gen if I didn't mention that... I like the smaller mini truck style feel of the 1st Gen Tacoma over the newer ones...

 

[Tank5]

I would like to see this happen. I have often thought it would be cool if my early double cab tacoma had 80 series axles, suspension, and the V8 from the 100 series.

 

[theferg]

I would like to see this happen. I have often thought it would be cool if my early double cab tacoma had 80 series axles, suspension, and the V8 from the 100 series.

Totally with you! I just had a 2005 GX470 right before this Tacoma... boy do I miss that V8!!! I'm also going to be supercharging this 3.4L in this Tacoma and if that doesn't give me a satisfactory amount of oomph, I will be figuring out a 1uz or 2uz into this thing.

 

[Tank5]

I have the supercharged 3.4L in my Tacoma it has never let me down for what I do. I am sure you will be happy with the SC 3.4L. I saw a SC 3.4L in an fj45 before it looked pretty cool. I never drove that rig though.

I have not measured the WMS on the Tacoma before. How does it compare to the 80 series WMS?

 

[theferg]

IIRC, the WMS is 60" on the Tacoma, where-as the 80 is 63.5". That width is easily made up with wheel backspacing, and I actually would love another 1.5" on each side and what I didn't want of the width could easily be made up with backspacing on some wheels.

But I had just been thinking a bit about the wheelbase between the two... So I went wikipedia-ing. Supposedly Tacoma Xtra/DblCab is 121.9", and the 80 series is 112.2". So a difference of 9.7". That's a pretty good bit... So I see also that the 100 series is listed as the same wheelbase (makes sense since the 105 series is on the same chassis as the 80 series) and I just went out to the garage where I have the 2003 DblCab Tacoma and an 2005 LX470 right next to each other. Got them lined up at the front tire (eyeballed it) and it looked right near 9-10" for sure. Doesn't seem a huge deal, but, the rear wheel opening on the LX would actually get into the back of the cab a bit at that point. I think the rear axle on the 80 series would need to be moved rear-ward a good bit. At least 6" (maybe a couple more) for it to (in my opinion) look and function well. I would imagine you could extend the frame on the 80 that amount. To make it "easy", you would do it in front of the rear lower control arm mounts (or somewhere in the middle section...). But, I was kinda hoping to make this as easy as possible...lengthening a frame is def adding some more complication...

I guess you could *maybe* chop and tub the rear bottom of the cab a bit to get it to fit right in...I'd have to get measuring in order to determine if it would be possible. The Hilux DlbCabs are kinda like this already actually... But whether it would work with the Tacoma is one thing, and whether it actually looks good is another... heh

P.S. - Glad to hear on the 3.4L supercharger. Are you doing any fueling mods?

 

[Mudder]

One concern would be having a title made for it if it is to remain a street vehicle. The vehicle would have to be inspected by the highway patrol and a new vin and title issues. The title could be marked as rebuilt as well.

 

[cruisermatt]

One concern would be having a title made for it if it is to remain a street vehicle. The vehicle would have to be inspected by the highway patrol and a new vin and title issues. The title could be marked as rebuilt as well.

lengthening a frame is def adding some more complication...

These are not concerns for the Hardcore section

 

[theferg]

These are not concerns for the Hardcore section

This is why I came in here... but the most hardcore I've ever done is a spring over on an FJ60 and then later putting an 80 series axle under leafs in the rear on the same 60.

But honestly, it seems having a clean title is always better than a rebuilt...especially since my record is selling trucks when I'm done... (I intend to keep this one though). I'll have to be thinking about this one. If I went this way, I am thinking maybe I won't be starting with the nice super clean, low miles Tacoma I already have, but instead finding a donor with a good front clip and cab...

So anybody with any thoughts on which is "easier" or "better"?

 

[cruisermatt]

This is why I came in here... but the most hardcore I've ever done is a spring over on an FJ60 and then later putting an 80 series axle under leafs in the rear on the same 60.

But honestly, it seems having a clean title is always better than a rebuilt...especially since my record is selling trucks when I'm done... (I intend to keep this one though). I'll have to be thinking about this one. If I went this way, I am thinking maybe I won't be starting with the nice super clean, low miles Tacoma I already have, but instead finding a donor with a good front clip and cab...

So anybody with any thoughts on which is "easier" or "better"?

If you do this the "easy" way it will not be as good as designing you suspension for your intended uses and with the vehicle weight and characteristics in mind.

I personally think having all stock 80 suspension under a Tacoma is not a good idea.

If it were my project I would design a 3-link for the front (or even custom radius arms, or
Single radius arm/single link) with the 80 front axle and do a lift spring in the rear to get yourself started. And that will be FAR easier then trying to make the Tacoma body work on the 80 chassis, motor mounts, etc. anyways.

 

[Tapage]

I like the axles part and suspension .. but frame wise .. that's another hole story ..

as @cruisermatt said, might be easier to go 3 link on front but I'll do coils in the rear ..

 

[theferg]

Hmm. I understand a completely custom designed and built suspension would arguably be better to some, but that gets away from the root of some of my goals in this project.

Also, Toyota used this same suspension design under 80 series, 105 series, and in the front of 70 series Cruisers. And within the 70 series, there were *many* sub-series that had this *same* radius suspension design. 70/71 series SWB, 73 series MWB, 76/78/79 Wagons, Troopies, and Pickups. Hell, the LC Prado (light-duty Land Cruiser) had this radius arm and coil design implemented the same years the 80 series started up with it and they even went coils and links in the rear on those as well. And the Tacoma/Pickup is very closely related to the Prado platform. Then we go further and see guys that have swapped 60 series bodies onto 80 series chassis. And then look at the design on the Toyota SEMA Tacoma Mace posted... same design. (Albeit, IMO, not the greatest "OEM" looking finish...)

Maybe this same suspension under a Tacoma (or some other Cruiser even) is not 100% *ideal* to some, but I would wager it'll function just as well as it does on all those other trucks its under in the Cruiser platforms as it would under a Tacoma. These are actually some of the same folks who think the 80 series suspension is not an ideal design for the 80 series.

But, I would love to hear more of your thinking on why it might not. (Even though I'm already pretty dead-set on doing it. )

Oh and I realize this is the hardcore corner, but the plan on this truck is *not* a hardcore rock rig. Tires will be 35s max. I put it in here cause I feel you are the folks with the real knowledge most closely related to what I'm trying to do.

 

[cruisermatt]

Radius arms will probably be fine for your build I would just do all custom mounts and actually set them up for your truck instead of doing body swap nonsense.

In fact radius arms front and rear might work pretty well.

I am NOT a fan of 80/100/4Runner rear suspension geometry at all.

 

[Mace]

Why not just leave the rear end leaf sprung? Run the front as a Radius arm with coils/Coilovers and go from there. The front is your primary "ride" feeling anyway.

 

[theferg]

Ya. I think I'm definitely figuring out the body swap idea would probably not be the best idea for where I'm starting from with a complete already running truck. Maybe starting from the ground up with a frame and a body, I might think about just seeing what it looked like with Tacoma body set on the 80 frame, but I'm convinced going with my original plan of setting up the radius arms on the Tacoma is the way to go for me.

As for the rear, I've thought a bit about staying with the leafs...I just really prefer the coil ride over the leaf ride and seems it's easier to find all sorts of different rate and length coils and they're heckuva lot easier to swap around than different leafs (though I've thought perhaps some nice long chevy 63s back there might do wonders over the stiff, thick, extra heavy duty Dakars I've got).

 

[gpfj40]

You are probably on the right track with your front plan, I did similar swapping 80 arms and coils into my 40. The ride is great, flex is ok, the biggest PITA was keeping the castor correct and keeping the back arm mounts high enough to keep them from dragging over obstacles with out reinventing it. I had dreams of a supper low rig, but ran into interference with the diff/pan/frame. I’m finding keeping my latest mini truck SAS low is not easy for the same reason. It will be lower than those front leaf SAS kits out there but not even close to IFS low......be careful planning and measuring before you start cutting in case you can’t get as low as you like. As for the rears, I went OME leafs in my 40 project and the ride is great, had to put a track bar in to keep axle wrap down. If I was going to do the coils out back and wanted to stay stock, I’d through out all stock 4 link brackets and build your own with heims so you can adjust things, you’ll have no axle wrap. With your gas tank it might be easier to do a 3 link in the back...... but leafs are so dam simple, get longer springs, pull leafs till you get the height you want and be done with it.

I’ll certainly follow along as you post your progress.

 

[White Stripe]

Why not just keep the front independent suspension? You can swap in a newer 8" front ifs diff from a fjcruiser or 2nd Gen tacoma and use some rcv chromoly CV axles and wider control arms. The guys from diamond ran such a setup in a 3Rd Gen 4runner with cut fenders, 3" lift and 37s. It did well. And was very streetable