Chevy spring swap Pics, and further advice wanted

[kytann]

I've mostly got the Chevy spring swap complete.
I've got a 1996 V6 Regular cab 4x4, so the truck is pretty light.
Anyway, Here's what happened to start the project.


Notice I was running without overload leafs? That, combined with the Daystar shackle lift and lots of 4x4ing during my Colorado vacation conspired to overstress the short Tacoma springs. They started sagging when I left Colorado and broke in South Dakota, right near my girlfriend's father’s house, who happens to know how to weld, have a good welder, and lots of experience with welding. Convenient, eh? Pricing replacement Toyota springs vs. aftermarket vs. boneyard Toyota versus boneyard Chevy's cinched the decision for me. My only concern was that JohninDenver has close to the same truck as I do and got much more lift than I wanted, and than everyone else seems to want.

I got some front spring hangers for free that were cut off of a Jeep CJ by a local custom shop around here.
I measured a difference in spring length (from front eye to center leaf pack bolt along the arch) between my short Tacoma springs (early regular cabs had super-short springs) and the Chevy's (which are from a 1998 Chevy 1500 4x4) as 9.75". We decided to mount the spring hangers 10.5" forward from stock, so that I wouldn't over-extend my driveshaft. If I get any rubbing issues on stuff I'll just trim my fenders.


They're not quite as ramped as some of the aftermarket options, but I needed the parts immediately, not in a week or so, and you can't beat free.
I flipped them upside down to give me more surface area to weld them on with, and dropped the gas tank prior to welding.


As you can see, there's a small amount of room between the spring and the frame. With the aftermarket low-profile hangers I would only end up about a finger and a half closer to the frame, which would make ~1/2" difference in ride height. Not much, and I don’t have any regrets..

I was able to re-use my stock shackle hanger location, and the Daystar shackles had to be modified to widen them. I doubt this'll affect their strength appreciably considering the thickness of the metal they are constructed from versus the thickness of the frame where it's attached.

As you can see my shackle angle is a bit past 45 degrees, so I tried cycling the suspension with only one leaf in the pack



I can go completely flat and into negative arch without any binding of the shackle.

Still quite a bit of up-travel room left. I'm going to need longer bump-stops. It’s a shame, as I’d like to use all of the available up- and down-travel I’ve got.


Here it is partially put back together. No shocks and my taillights are zip-tied to the frame for my test drive. Still sitting pretty high. With myself and my girlfriend simulating the weight of the bed I'm measuring ~3" of lift (~13" from the spring perch to the bottom of the frame)


Here's my static shackle angle.


I ended up running with the two longest of the three stock Chevy leaves and the Chevy overload turned upside down. I disassembled the whole thing and sanded off the rust, repainted all of it, and applied Anti-seize in between the two upper leaves. I also shaved down the Chevy springs to work with my stock u-bolts and shock mounts. I didn’t have to remove much material to get it to fit, just basically the rounded portion of the side of each spring. I'm going to need longer shocks though. Tomorrow I plan on going down to Burnsville Off-road and use their RTI ramp to figure out my minimum and maximum lengths for the shocks.


Had to chop off my exhaust. Which leads me to a question. With the exhaust in the stock location, I sometimes could smell it wafting back up towards the cab of the truck. This made me want to run it straight back, though I know I'll smash it on a rock if I have it going back under the bumper. Any ideas for exhaust placement?

Sorry about the dark pictures, those were taken just this evening. I've still got to install my longer rear brake line and figure out what to do with the rear brake-proportioning valve.

On my test drive I had zero driveline vibrations even with it sitting so high. With the bed and the spare tire in place it’ll put the pinion at an even better angle. Not much traction though, and it rode pretty weird without shocks.

I still think it sits too high. Though I'll have to see how it looks with the Spare tire, truck bed and toolbox back on there. Bouncing it by hand it seems like a lot lighter spring rate than my front springs are (which are OME N91s with stock springs, btw)

One thing I was thinking of doing if this turned out too high (and I still am considering it) was to cut the stock rear shackle hangers off, and re-weld them on top of the frame. Kind of like this idea

Then make longer shackles to connect them to my springs.
A lot of work, and i figure I would only end up losing about 2" in ride height, after having to add shims to correct the pinion angle and making sure the shackle is long enough not to hit the frame on full compression.
Since my rough guess now it I'm sitting 3" higher than stock, than I'd only be sitting 1" higher than stock. Guess I'll have to see how well it flexes...

How does it look? Any advice, comments, questions?

[synovus]

I noticed you said you're running stock coils with OME shocks up front. Are you planning on lifting the front? Seems to me you'd have to do some tricky things to get the rear low enough to match or approximate the front as it currently sits.



For example, in that pic, that's quite a bit of forward rake. I think lifting the front 2.5" or so would really level it out, or at least reduce the rake considerably. Also, just running 2 leaves, it seems you'll likely experience a good bit of axle wrap. A traction bar may be needed.

Originally Posted by kytann

With the exhaust in the stock location, I sometimes could smell it wafting back up towards the cab of the truck... Any ideas for exhaust placement?

That's interesting. I haven't heard other regular cab owners complaining of smelling the exhaust. Are you positive there's not a leak somewhere along the way? Most people just cut the exhaust, pretty much like you already have yours.

Originally Posted by kytann

I've still got to install my longer rear brake line and figure out what to do with the rear brake-proportioning valve.

The easiest thing to do is the standard extended BPV bracket that you can make yourself using stuff you can find at any Home Depot. Something like this. Or, you could get an aftermarket adjustable unit, like this.

Originally Posted by kytann

One thing I was thinking of doing if this turned out too high (and I still am considering it) was to cut the stock rear shackle hangers off, and re-weld them on top of the frame...Guess I'll have to see how well it flexes...

I considered possibly having to do the same thing with mine, but I heard that going with that type of shackle reduces flex a little. How much, I'm not sure, but that may be something to look into before you commit to going that route.

It's interesting that you seem to be looking to retain stock height even though most people report 4"-5" of lift by going with the Chevy's. I know I'm going to be having issues trying to get no more than about 3" out of mine, so you're most likely going to have a lot more work/creativity ahead of you to acheive what seems to be your desired goal. Looks like you have a pretty good idea of what you're doing, though, and I look forward to seeing how your install progresses.

I would definitely suggest switching out that front spring hanger at some point. That thing looks like it'll chomp down on a rock and not let go. BudBuilt has some very nice hangers for the Chevy swap that you might want to check into, and his include a nifty skid plate to complement the long, sloping design of the hanger. I'm not positive, but the design of his may actually reduce the amount of lift you're getting out of the springs a little bit, too. Please keep us updated with your progress, and keep the pics coming!

[zosimov21]

Would the suspension cycle normally with the hangers way up there like that? What about using the stock shackles to connect the rear to if your not wanting to be too high. Will they work?

[ATLRoach]

Your rear shackle mount needs to be moved back 2" . That is the difference from the 95.5-97 and the 98-04 leafs.

Also frenching in the front hanger will lower the rear some.

[kytann]

Originally Posted by synovus

I noticed you said you're running stock coils with OME shocks up front. Are you planning on lifting the front? Seems to me you'd have to do some tricky things to get the rear low enough to match or approximate the front as it currently sits.



For example, in that pic, that's quite a bit of forward rake. I think lifting the front 2.5" or so would really level it out, or at least reduce the rake considerably.

Well, I don't plan on lifting the front.
You see, whenever I go 4x4ing because of my location it's almost always combined with a camping trip. So the rear is usually loaded down with a lot of stuff, even though we keep trying to pack lighter each year (seems the more camping gear I leave behind the more tools I end up bringing with me...). With the stock Toyota springs I was running a little lower in the back than the front when it's all loaded down for the trail / camping. The new springs are softer due to the longer length of the springs acting as a longer lever arm, so if I'm at the stock height, I'll end up sitting a little lower than I'd like. So to get the right height when laden with gear, and a softer spring rate, it seems I'll have to be taller when unladen.
If that means I'll look like a 60's muscle car when I'm not carrying a load, I don't have a problem with that.
As long as it's not too tall when I am carrying stuff so that it raises my center of gravity. When 4x4ing it already seems like my truck is more tippety than most of them out there. Or I'm just paranoid :-).

Originally Posted by synovus

Also, just running 2 leaves, it seems you'll likely experience a good bit of axle wrap. A traction bar may be needed.

I don't think so. Remember, each Chevy leaf is not only wider, but also thicker. I've still got one intact Toyota leaf in the garage, and it measures 0.830 inches thick for the 3 leaf pack. My 2 Chevy leafs measure 0.815 inches thick. 15 thousandths of an inch isn't much difference in strength. Combined with the wider set of the Chevy’s I think it's a wash for leaf strength.
The stock overloads are super curvy and in a negative arch, so they don't come into play until the springs are almost completely compressed. The Chevy overloads, even upside down, will come into play a lot earlier than the 'Yota ones. Adding to my resistance to axle wrap.
Now the Chevy’s are longer, which, as I said before, gives them more of a lever arm. This is why they feel softer, even though they are thicker. But my understanding of axle wrap (which may not be complete) is that the whole axle twists, putting most of the twisting stress on the portion of the leaves directly adjacent to the spring perch. Which is just about as thick and strong as stock.
So with that, I'm not too worried. Then again, that is exactly where I broke my stock springs…
Though if I do have axle wrap I should be able to feel it, right? What, exactly, does it feel like?
I don't drag race my truck, and I like crawling over rocks, not roaring up them full throttle. In fact, with my locker up front, I'm always very soft with the gas pedal when 4x4ing so that I don't snap a CV. In 4lo I never really want for more power, just more control, so the only time I'll experience axle wrap is when in 2wd accelerating or towing. What exactly does it feel like then? Or what can I watch out for?

Originally Posted by synovus

That's interesting. I haven't heard other regular cab owners complaining of smelling the exhaust. Are you positive there's not a leak somewhere along the way? Most people just cut the exhaust, pretty much like you already have yours.

Well it's the propane-ish smell that a lot of Toyota owners complain about that occasionally wafts forward. Especially when under heavy throttle applications (like when towing) and the passenger window is open. I’ve also noticed the same thing on my dad's '97 4runner with the same 3.4 V6 I have. I've also had an exhaust place check it out and they did not detect any sort of leak.
Maybe my catalytic converter is just getting old.

Originally Posted by synovus

I considered possibly having to do the same thing with mine, [...weld the shackle hangers on top of the frame...] but I heard that going with that type of shackle reduces flex a little. How much, I'm not sure, but that may be something to look into before you commit to going that route.

Why would it reduce the flex? A shackle has two pivot points. Beyond that, it doesn't know what the frame is doing. You'd have to fabricate a longer shackle, which should theoretically give you more droop, thus more travel, not less.

Originally Posted by synovus

It's interesting that you seem to be looking to retain stock height even though most people report 4"-5" of lift by going with the Chevy's.

In my research, most of it done on Pirate and a little here, it seemed like most people were getting 1.5"-3" of lift, with JohninDenver the main person I recall getting more than 3". Maybe I didn't search around enough. Like I said earlier though, if my static ride height unladen is tail high that's OK with me, as long as it's fairly flat when laden for the trail.

Originally Posted by synovus

I would definitely suggest switching out that front spring hanger at some point. That thing looks like it'll chomp down on a rock and not let go. BudBuilt has some very nice hangers for the Chevy swap that you might want to check into, and his include a nifty skid plate to complement the long, sloping design of the hanger. I'm not positive, but the design of his may actually reduce the amount of lift you're getting out of the springs a little bit, too.

Well that'd require cutting the ones I've got off. And they're welded really solidly into the frame. Like I 'd probably have to cut the frame. Which is a lot of work. It would allow me to French in the front hangers, so that is something I’d still consider.
Anyway, I could get some of the same effect by shaving down the bottoms of those hangers and welding ramps that'd connect the two halves and strengthen it. Seems like I'd get pretty close to the same result as the Budbuilts without having to chop these ones off.
If you're planning the project, there's nothing wrong with the Budbuilts. I just had to get my truck back on the road and us home in a very limited time, so I worked with what I had available. I basically had one day in the cities to collect my parts and information before getting a ride back out to my truck.

[kytann]

Originally Posted by zosimov21

Would the suspension cycle normally with the hangers way up there like that?

You mean with them above the frame?
Like I said, the shackle doesn't know where it's attached. As long as it can move far enough rearward to allow the spring to completely go flat, and far enough forward to not limit droop.
They did a similar thing in the off-road.com Tacoma build-up

located Here

Originally Posted by zosimov21

What about using the stock shackles to connect the rear to if your not wanting to be too high. Will they work?

No. The stock shackles aren't long enough, they would limit the backtravel of the spring, unless I moved the rear shackle hanger.

[kytann]

Originally Posted by ATLRoach

Your rear shackle mount needs to be moved back 2" . That is the difference from the 95.5-97 and the 98-04 leafs.

Are you just repeating what everyone else has done or have you looked at my specific setup?
With the front hanger moved .75" forward from normal and the Daystar rear shackle (which is slightly >6.25" eye to eye) I'm able to completely compress the suspension without any sort of binding or limiting. And when crawling over rocks they will allow a small amount of further droop.

If I moved the rear shackle hanger location 2" farther back the only difference from now would be that the shackle would sit more upright when at static height, wich would slightly raise my static ride height and slightly limit the amount of suspension droop that I get.

Though with a more upright shackle I would end up with less spring compression for a given amount of upward wheel travel.
So I'd get more stuff and less downtravel, and a higher ride height and a softer effective spring rate. None of which I really want.

Unless there's some other reason shackles should be within a specific angle range (like effecient transfer of spring forces? Though I can't see how the angle would make a difference) I plan on leaving it just as it is.

Originally Posted by ATLRoach

Also frenching in the front hanger will lower the rear some.

Sure would be nice. It's alot of work though. Wanna come down and do the grinding for me? I'll buy the beer...

[Deserttaco]

I would try to move the shackle hanger back an inch or so, then trying to run the stock Toyota shackle. That should bring your ride height down a little, but that stock shackle will give you roughly the same suspension cycle you had before...

[synovus]

Originally Posted by zosimov21

Would the suspension cycle normally with the hangers way up there like that? What about using the stock shackles to connect the rear to if your not wanting to be too high. Will they work?

Looking at the shackle angles with that daystar shackle, I think if he put a stock shackle on there it'd be almost completely flat against the frame. Not good. Frenching the front hangers like Kyle suggested would be a good option.

[az250r]

you don't have to move the rear hanger....on that gen...i had a reg cab and when we put the chevies on we moved the front 10 or 10.5 forward and my 35's stuffed nicely

[Deserttaco]

Originally Posted by az250r

you don't have to move the rear hanger....on that gen...i had a reg cab and when we put the chevies on we moved the front 10 or 10.5 forward and my 35's stuffed nicely

That's the thing, He doesn't want to run 35's... He want's it stock height and run stockish tires... I'd look into moving the hanger back (shackle hanger) and running a stock length shackle.

[zosimov21]

Since they would too short wouldn't work anyways. The chevy springs are more of a U shape so I think some lift cannot be avoided vs the flat taco springs.

[synovus]

Originally Posted by kytann

Though if I do have axle wrap I should be able to feel it, right? What, exactly, does it feel like?

Yeah, you should be able to feel it to a certain extent. On the road, when accelerating, it should feel like the rear end is squatting down a good bit. I forgot that you're running the overload which most people I've seen opt out of for improved flex and ride. Maybe you won't have any problems with axle wrap. I'd certainly keep an eye on it, though. Axle wrap will ruin a set of springs with a quickness. I don't know that you'll only have to watch out for it in 2WD. Even if you're not heavy on the throttle in 4WD, it could still come into play. If you find that the rear end starts bouncing when trying to crawl up rocks/obstacles, that's a good indication of axle wrap. After it happens enough, the springs will start to form and "S" shape. If they get to that point, it's time to replace them.

Originally Posted by kytann

Well it's the propane-ish smell that a lot of Toyota owners complain about that occasionally wafts forward. Especially when under heavy throttle applications (like when towing) and the passenger window is open. I’ve also noticed the same thing on my dad's '97 4runner with the same 3.4 V6 I have. I've also had an exhaust place check it out and they did not detect any sort of leak. Maybe my catalytic converter is just getting old.

Well, I dunno what to tell ya. I doubt extending the exhaust a matter of inches to the rear is really gonna do much for ya, though.

Originally Posted by kytann

Why would it reduce the flex? A shackle has two pivot points. Beyond that, it doesn't know what the frame is doing.

I'm no expert on suspension/shackle technology. But Puckett did some interesting CAD predictions before jumping into his spring swap and modeled that shackle design. In his model, it resulted in slightly less travel. Here's that thread. You seem to be approaching the spring swap from a different desired result than most folks. Most folks do it to maximize flex/travel, but you say you'd rather have greater strength and don't mind giving up some flex. Maybe that type of design would work great for you.

Originally Posted by kytann

You'd have to fabricate a longer shackle, which should theoretically give you more droop, thus more travel, not less.

Yes, but it would also give you more lift, which you say you don't want.

Originally Posted by kytann

In my research, most of it done on Pirate and a little here, it seemed like most people were getting 1.5"-3" of lift, with JohninDenver the main person I recall getting more than 3". Maybe I didn't search around enough. Like I said earlier though, if my static ride height unladen is tail high that's OK with me, as long as it's fairly flat when laden for the trail.

That's interesting. I know Mez, who has lift up front (not sure what his setup is) got a considerable amount of lift out of his (here's his thread). He ran 2 leafs with no overload at first, to minimize how much rear lift he was getting (if I remember correctly), but ended up adding a third leaf (still no overload) after getting some axle wrap. Zosimov got about 5" of lift from his. Like I said most people I've read about who've done the swap got anywhere from 3"-5", with most being closer to 5" than 3". It's definitely one of those things where every individual gets something slightly different, though.

[zosimov21]

Originally Posted by synovus

Zosimov got about 5" of lift from his. Like I said most people I've read about who've done the swap got anywhere from 3"-5", with most being closer to 5" than 3". It's definitely one of those things where every individual gets something slightly different, though.

I am using a 2" lift shackle. If I replaced my rear shackles with something a little different I'm sure it would bring the rear down. So I'm sure your measurements and methods will differ when only wanting to be a tad higher in the rear.

[kytann]

Well I drove it down to the local shop today and ran it up the RTI ramp that they have.
I did this as it currently sits, with no bed or weight in the back-end. I shoulv'e brought my camera, but I forgot.

Anyway, for my shock mounts, I measured a minimum length of 18" on each side and a maximum of 26". While this is without any weight I'd imagine I'd get a bit more than this for both measurements with wieght but that's have to wait for another day.

I also made it 71" up the RTI ramp( backing up it) before the rear tire came off of the ground.. Is that good?

It didn't look like as much flex as I thought it would. And the wheel that was at full stuff wasn't even completely touching my overload leafs.
I'll have to put the bad back on, and put the motorcycle in the back too to simulate 4x4ing wieght, and try again on Monday.

[az250r]

Originally Posted by Norcalvp

That's the thing, He doesn't want to run 35's... He want's it stock height and run stockish tires... I'd look into moving the hanger back (shackle hanger) and running a stock length shackle.

I agree in this situation he should move the rear hangers back a little...my post was to ATLRoach that stated,

"Your rear shackle mount needs to be moved back 2" . That is the difference from the 95.5-97 and the 98-04 leafs."

b/c thats not true....

[synovus]

Originally Posted by az250r

my post was to ATLRoach that stated, "Your rear shackle mount needs to be moved back 2" . That is the difference from the 95.5-97 and the 98-04 leafs." b/c thats not true....

If that's not true, then what is the difference between the 95.5-97 and 98-04 leafs? Everything I've seen says to move the rear shackle hangers back on the 95.5-97's, not just move the spring hangers forward.

[Deserttaco]

The shackles are in roughly the same place, It's the front spring mount that is in a different place. I have chevies on my 97, and did not move the shackle hanger back. I am however using lifted toyota shackles and my angle is about 40 degrees.

[AngryAndy]

Originally Posted by Norcalvp

The shackles are in roughly the same place, It's the front spring mount that is in a different place. I have chevies on my 97, and did not move the shackle hanger back. I am however using lifted toyota shackles and my angle is about 40 degrees.

Here is a pic of my stock (unused) spring perch and the new bentup rear spring perch SAS mount: with chevy springs on a '97...

The difference is dead on 9" forward.

Look closely and you can see it is welded to bolt on sliders....

And my shackle angle is just like Steve's. I have AOR 1.5" lift shackles in the rear. Angle is about 40-50 degrees.