Chevy 63" 1/2-ton Spring Swap FAQ

63" Chevy 1/2-ton Spring Swap FAQ

By: Philip Melson

A.K.A.: Captain Hardcore, Phil-Fab

philmelson@gmail.com

 

The Engineer’s Adage:

“If it ain’t broke, it doesn’t have enough features yet.”

 

Alright, this is a somewhat complete guide, but better than an FAQ of how-to and not to properly perform a Chevy spring swap onto your Toyota Tacoma. Some of this info also applies to earlier trucks as well, but mention of them past this point will be minimal. ‘Liftedwithleather’ is the original author of the FAQ on the Pirate4x4 boards and he was a very large inspiration for me to do this. Why? I looked all over the damn place trying to find info on doing a spring swap and no one had the answer, in the end, there were a lot of things including some misleading info from others who well, don’t know a damn thing about physics, or trucks in general, much less Tacoma’s. This guide includes ALL aspect you need to address before you start fabricating.

 

The Basics:

 

What year and vehicle do you get the leaf springs from?

The correct years are 1988-1998 1/2 ton Chevrolet or GMC truck. Not a panel van, ice cream truck or Komatsu D65E. Mine are from a ’97 Chevy 1500 w/ an 8’ bed. These are the springs this guide refers to from here on. Anything else is completely up to you. Stuff from a 99’ might work, so use your measuring tape. And if you ask “Wait, shouldn’t I just add blocks instead of all this?”, then you need to go ahead and hit ALT-F4 and go back to your Jeep forum.

 

How are the Chevy springs compared to Toyota springs?

The Chevy springs are 2-1/2" wide and Toyota’s are 2-1/4" wide. Please note on the Chevy's that the sleeve in the bushings at both ends of the spring is 3" wide. That’s why you must use 3.5" x 1/4'” box tube for the front hanger. More on hangers later. These springs are also lot longer than your stock springs. Why is this good? Leverage. With a longer lever, the leaves, despite their increased spring rate, can flex and articulate much more than a standard spring could. Think of it as this, what flexes easier; an eight-foot 2x4, or a twenty-foot 2x4? With the longer leaves, there is much more metal to bend and contort to spread out the change in distance (articulation).

 

Where do I get these springs?

From a junkyard, auto recycler, bone yard, neighbor’s truck, whatever! By the way, buying them new somewhat defeats the purpose of doing this swap. Part of the idea is that this is an easy financial commitment. Not that the idea of throwing money at a perfectly good stock truck is, but whatever. Cheap leaves can be found! Just do a little foot work.

 

Does it matter if it's from a 2WD or 4WD?

No, it does not matter if they are from a 2WD or 4WD truck. The 2WD have 3 leaves

plus an overload leaf, You can use the 4WD but you may have to pull out one leaf. Also some people run add-a-leafs too. Just depends on what you want to achieve.

 

Note: 2WD and 4WD leaves have the same 3 basic leaves, the ONLY difference is that the 4WD leaves have an extra leaf between the #3 leaf and the overload. 2WD leaf packs are not “softer” by nature, however, they can become more pliable with age and use.

 

How much should I pay for the springs?

Pay no more than $100 for the pair. I’m serious on this. I paid $40 for both from an auto recycler.

 

 

 

The big question: How do I mount these springs on my Toyota?

 

Front options:

A new front spring hanger and weld it on the flat part of the frame forward of the stock spring hanger.

 

You can be like some of the crazy fab-shops and French them into the frame, but unless you like cutting up your truck and have a lot of extra time and money, I say just a go with a whole new external mount. Bolts are an option but not a good one. The frame is boxed where the new hanger is theoretically going to sit, which would require drilling sleeveing or tapping, etc… Welding creates much more area on the frame for shear and compression forces to be transmitted and dispersed, rather than a couple holes. Trust me, welding is THE best option, if it’s done right!

 

Design I copied from Erik Bibelheimer:

 

 

Where do I get new front spring hangers?

You can either buy Jeep CJ spring hangers (ick) or make your own out of 3.5" square tube. .250 wall (1/4”) is the best option. Sky Manufacturing, Ballstic Fab (and others now) make hangers developed for this exact type of swap. To me, Sky’s look funny and don’t have a sliding over rocks friendly shape. Go with Ballistic Fab if you don’t want to make your own. Mine were cut (milled) out of 3.5” .250 wall HREW. Remember, the spring is 3” wide at the bushing so my hangers fit perfect.

You can't use the Chevy front hangers as they are just too oddly shaped to work.

 

How far forward do I mount the new front spring hanger?

Okay, here is where it gets tricky, I cannot emphasize enough how much you need to do you homework here. The entire math here is basic addition and subtraction.

 

Okay, don’t get pissed when I say that there is no firm answer on how far you should move your spring hanger forward. There are some various generalities about each generation of truck, but there are a lot of differences. Here is what we know:

 

• On 3^rd Gen trucks (’86-‘95):

(And please, don’t call it a “(insert 3^rd Gen truck year) –Tacoma”, call it a Pre-Taco. They ARE NOT the same truck. Just because Toyota didn’t give your truck a name doesn’t mean you need to muddy the waters and confuse the hell out of the new guys. Not to say they aren’t good trucks, don’t get me wrong. I just don’t call my buddy’s Civic a ’98 CVCC). Anyways, mount the front hanger 9" To 9-1/2". At 9" the axle will sit slightly rear of center and 9 1/2" should get the axle centered.

 

- 1995.5-Early ’97 Tacomas: Mine are at 8-5/8”s forward from stock (center of eye-to-eye) and my axle is just a scooch behind center. ‘Mez’ on the TTORA Forums mounted his 10” forward and his are dead-center.

 

• On 1998-2004 Tacomas mount the front spring hangers forward 7.5 inches.

 

• 2005+ Tacomas: I have no idea; you shouldn’t be cutting up a truck that new anyways.

 

Do I have to remove the gas tank to weld on the driver’s side spring hanger?

No you don't have to, but it would be slightly easier to weld if you did drop the tank. I cut a relief channel in my hangers to tuck the spring eye closer to the frame for clearance issues, which is much better than one of those Jeep rock anchor hangers. The second purpose of the channel was to give me another edge to fillet weld on. Just make sure you keep the gas tank skid plate on and be careful.

 

Rear options:

 

Double Shackle

A double shackle set-up is achieved by bolting the Chevy shackle to the end of the existing Toyota shackle, which is mounted to the frame. Nice because no extra welding is required, just some new mounting hardware. By far the cheapest and easiest option. It gives you a lot of droop but one must be make provisions as to prevent shackle inversion, or rather when the shackle pivots the wrong way and stays that way. On some trucks you must bend a small tab in (I did mine with a large adjustable open-end wrench) in order to allow the stock Yota shackle to lie against the frame. Otherwise your rig will be stuck several inches higher than you want it to.

 

My double shackle setup:

 

 

 

Single Shackle

The name is self explanatory. The picture below shows that the owner decided to move the rear hanger backwards to achieve a proper shackle angle.

 

(stolen from CSR on the Pirate boards):

 

Single Shackles continued: Proper shackle angle at static ride height is between 45 and 55 degrees. That is, the truck has gas, spares, and you in it. Shackle length will vary upon your desired amount of lift, and your rear hanger positioning.

 

What size hardware is required to secure the springs?

9/16” x 5" Grade 8 bolts with Stover -type lock nuts for the spring eyes. 19mm or 3/4 x 5" for the rear factory hanger.

 

 

Spring to axle connection:

 

Can I use Toyota stock U-bolts and spring plates?

Yes; you can use the stock Toyota U-bolt but you will have to grind the springs a little bit to get them to fit. Not the best idea in my opinion; just quit being a cheapskate and make some new spring plates. Besides, the stock plates and bolts are rock anchors.

 

What about a u-bolt flip kit? Can I just flip the factory u-bolts and spring plates?

No. The stock U-bolts are square in profile, not exactly conducive to holding onto a round object such as an axle. You will need new u-bolts and a flat piece of at least 3/8” thick steel plate to mount on top of the springs. Using 1/4” plate and just bending up the ends is kind of dumb.

 

Spring plates:

If a u-bolt flip (or spring plate flip) is desired, you need to be aware of the following:

 

• Since the old spring plates have shock mounts included in their design, you need to make a new mounting point by either by welding mounts to the axle or by including them in the new spring plates.

• New hardware is needed. I used 5/8^th’s Grade 8 u-bolts from Redneck Trailer supply. Be sure to use lock washers at the minimum, better option would be a Stover-type lock nut. Ny-locks are an iffy option in my opinion,

• A drilling pattern for new plates is available here. I enlarged the center hole slightly to allow the 5/8” nut on the end of my new leaf pack center pin to create an interference fit.

 

My plates are 6”x4.5”x ½” thick cold rolled steel. Burly is the key term here. They weigh the better part of five pounds each. This is a better option than using 1/4” or 3/8^ths with the ends bent up. Why? Bending creates stress risers, not that you are going to bust it too easily, but it can’t hurt at all to err on the side of safety. If your really concerned about the corners rubbing on the top of the leafs, spend a couple minutes with a grinder and smooth the edges. Besides, cost is only marginally more expensive, and maybe takes a few more minutes to machine. Plus, you have the added feature of being able to have a nice, thick area to weld or bolt to.

 

Sky Manufacturing and A.O.R. are two companies that sell u-bolt flip kits. Sky has an integrated shock mount.

 

Should I run bumpstops?

No, don’t. You should be fine for “mall-crawlin”. Yes, do so. Make sure that they are tall enough to let the spring flex and articulate without going inverted. I am setting mine up so the touch just before the spring goes flat. (DISCLAIMER: I know you can let some really flat leaves go inverted)

 

Leaf spring pack preparation:

Sure you can just bolt up these natty looking springs, but why? Spend a few minutes and make ‘em pretty, it will be worth it. Replacing the hardware is a good idea since you’ll have everything taken apart.

 

Disassembly:

 

• I used a large C-clamp to hold the leaf pack together while I cut off the old center pin. It was rusted and galled and certainly not worth saving.

• Bend back the clamps on the ends of the leaf with a large adjustable open end wrench, pry bar, whatever, allowing you to further disassemble the pack.

• The spring slider pads were in fair shape, I decided to keep them. One was worn nearly through, so I cannibalized one from one of the lower leaf that I decide to leave out. Perhaps later I will rebuild the packs with full length Delrin sliders for that extra bit of smoothness.

 

Preparation and paint:

 

• Using a 4-1/2” angle grinder, I removed all of the draw/cut marks from the ends of the springs, as well as any burr, nicks or sharp edges could potentially catch on rocks or other obstacles. I even went so far as to slightly taper the ends for a nice, clean look as opposed to the nasty blunt cut edges.

• I left most of paint on and sanded down the bad spots to prevent flaking.

• Dust was blown off with an air nozzle and a quick wipe down with some denatured alcohol to remove grime and dust was all that was needed to be ready for painting.

• For paint I used basic, fast drying enamel. 3 coats on all 4 leaves (8 total) was about 2-1/2 cans. I felt primer was unnecessary due to the very limited amount of rust. Year update: even with salted roads, things still look alright down there, might go back with POR-15 to be safe.

• I left the small galvanized separation plates unpainted. They suffered no rust and are barely visible when the pack is assembled.

 

Assembly:

 

• Again the large c-clamp came in handy to hold the leaves together while the new center bolt was installed.

• If you are re-using the leaf with the clamps, I recommend a MAPP gas torch to heat the clamp only and then use a BFH to push it into place.

• New hardware consisted of:

  • Grade 8 hex-type round-head(Allen) bolt with a total length of 4” (head diameter: 3/8^ths)

  • Grade 8 5/8^ths nut w/ lock washer.

 

Can I still carry heavy loads with these springs?

Yes, especially if you have equipped the overload. Remember, these springs came off of 1/2 ton trucks; so they can support quite an encumbrance.

 

How is the ride with these springs?

Very smooth compared to stock. Firm yet compliant. Perky yet forgiving. Think of it as every positive aspect of breast implants. Enough for that full-bodied feel, while not being to heavy or saggy.

 

Do I need to run a track bar with these springs? What about axle wrap?

No, a track bar isn't necessary IMO. The leaves are plenty thick enough to resist kinking. I’ve heard only a couple folks complain about twisting, and I am fairly sure it was due to 35”+ tires and dual cases. I’ve heard a suggestion involving cutting the overload leaf to resist wrap, which is pointless when you can just leave the whole thing on and not worry about it

 

Can I run these springs under the axle?

Oh schweet! Now I can cut and turn my A-arms and get my new-oh wait…Dude, this isn’t a Ford Ranger for desert running. If you want a spring under, buy a set of Deavers.

 

Can I still run a stock rear driveline with this swap?

Yes. Be wary though, a stock driveline doesn’t have THAT much travel, but you should be okay unless you start trying some really crazy stuff. I think I’ve tested the limits of my d-shaft in terms of extension, and it has not pulled apart. I do recommend that you lower the carrier bearing by an inch to keep the driveline angle happy. I failed to do so and smoked the u-joint at the pinion in about 6 months.

 

Pinion angle:

It can be argued that no change is required to the pinion angle after installation. I feel that if your amount of lift is under 4” and you lower your carrier bearing, you should be fine. I’ve put over 30,000 miles on my current setup with NO issues. That isn’t to say that everyone’s application is the same. Deviating beyond a mild swap will ultimately change things. That is: single shackles and or lifts above 6”.

 

Shocks:

 

Will I need longer shocks?

You will definitely want longer shocks to take advantage of all that new travel you just gained. You could use you stock hardware and mounts, but that would only defeat THE WHOLE PURPOSE of this swap. So please, take the time and fab-up or buy a cross-member. Steve Parks from Parksoffroad.com was one example I borrowed from. My cross member is about 41” inches wide (exact dimensions to come later) with a few 9/16^th’s holes drilled @ 2”, 5” and 8” from the centerline. I used .180 wall 2x2 HREW steel. I made mine a bolt-on application the first time, but later cut off the bolting tabs and welded it in as a new frame cross member. Nothing bad with the old setup, but it gave me a little more room for future growth, along with really stiffening up the frame and providing more bed support. Whether you choose to mount the shocks to the top of the axle or on the front/back is up to you. I mounted mine off the back, in single shear (and have had no problems) but I am going to change to a double shear type of mounting rather, which is arguably much stronger. I use Bilstein 5150’s, of which I am impressed with. Just be sure that if you decide to angle your shocks at a fairly steep angle, (say more than 30 degrees) that you choose a shock with heavier valving as the shocks ability to control movement is decreased when it is angled. My shocks use 255/70 valving, which is a good starting point for a truck that sees some off-road time, while still being very street friendly.

 

For my lower mounts, my helpful machinist buddy cut a couple of chunks from the upper cross member leftovers and milled off the back side of the box to create a U shaped mount. They are positioned about 10.5” from the outside of the box to the drum backing plate which places the shock at around 30° from parallel to the ground at ride height.

 

Travel wise you are only limited by design and imagination. Take measurements at ride height, full droop and full compression. These dimensions will determine your correct length of shock. I can extend my 12” travel shocks to the max, and my lift is fairly mild.

 

My upper cross member, 1^st setup: Bolt in

 

 

 

Now the upper cross member has been welded in tight to the bed for extra support. Currently re-working bump stops. 2 Years salted roads and 30,000 miles later:

 

 

My lower mounts then, note the schweet bent hard line!:

 

 

Not so pretty now, note the scuffs on the shock body from the parking brake cable and rust... I should re-locate the hard-line over the spring plate…*sigh*

 

 

Brake line issues:

 

Flex line:

You will have to change out your 15” factory line for a longer one if you ever plan on using all of this new-found travel. If you don’t, you’ll just rip it out and have no brakes. I bought an Earl’s Speed-Flex 24” line and fittings to go from the -3AN-F ends to the Toyota 10mm x 1.0 factory fittings. You can just buy another stock rubber line to double the length.

 

Hard lines:

That is, the stiff metal tubes roughly 3/16^th’s thick that run along the top of the axle and frame rail. They are easily bent out of the way for adding shock mounts, etc. IF and only IF they are carefully bent. That means only nice, easy radiuses, NO creases.

 

E-Brake:

It’s tough to route everything without the parking/e-brake mounting hardware and cable getting in the way. I removed mine since it lacked the power to hold 33’s and that I am doing a rear disc conversion with a hyro-parking brake. You can be creative and work around it though.

 

LSPBV (Load Sensing Proportioning Valve)

Okay, see that black spaghetti noodle springy looking thing coming from the frame to the axle? That is your load sensing proportioning valve. As your truck shifts its weight; say during hard braking (or if you have 1,860 lbs of concrete because your boss thinks your poor little Yota can haul it), the axle moves farther away from the frame (during hard braking) thus un-weighting the tires and making the LSBPV change the amount of pressure traveling to the rear brakes to avoid lock-up. The flip side of this would be if you had a load of 3/8^th’s minus and you slow at a normal rate, (leaving the distance between axle and frame to be smaller) so the LSBPV adjusts accordingly by increasing the available pressure of the rear brakes to make use of the added weight over the rear axle which provides more traction to better apply braking force without locking up the tires and/or cooking the front brakes. Easy, right?

 

When we start adding things like big tires, lifts, flexy springs, soft shocks, winches, full-width rockwells 2.5 ton axles with pinion brakes, the LSBPV, (which was designed for a stock vehicle), is out of its element and may not apply the correct amount of pressure to your rear brakes as the situation requires.

 

On the cheapest of cheap things you can fabricate a bracket that brings the lower pivot of the LSPV arm up from the axle and “tricks” the LSBPV into thinking that it has returned to normal height. Some folks like Steve Parks make a bracket to manually adjust the LSBPV lever position to keep brake pressure static. This in my opinion works fine for mostly street driven vehicles, and I ran one for quite some time. As long as you take the time to adjust and tune it to your needs, it can work. However, if you want to go that extra mile, you can swap it out for a true proportioning valve as I’ve done.

 

Still, you may find that this little do-hickey is a royal pain to work around when it comes to locating new shocks and mounts, My advice? Unbolt it and use one of the mods listed above; that way you can always return to stock if the need arises.

 

Last but not least: Spare tire mounting…

You can fit up to a 33” tire in the factory mounting, but there are no guarantees depending upon your setup. Factors to watch for:

• Upper cross-member for shocks

• Shock range of motion

• Exhaust (don’t be an idiot like me and cook your spare)

I had to move my tire carrier back about 3” rear ward to clear the shocks comfortably. New holes were drilled and mounting tabs were modified to allow proper positioning. It is very tight in there, but it works.

 

So, how much lift…Seriously?

 

It depends. Newer ¾ ton springs will ride a little higher obviously, while the ones from a clapped-out 1500 W/T will probably be a little lower. Hard to tell until everything is on the truck and it is sitting on the ground unsupported. I say, start small, use only 2 leaves plus the overload and go from there. Mine was exactly 3.5” This matched my 3” ghetto spacer lift quite nicely. You can add blocks, (or not, that would be the best thing to do) or add leaves to gain extra height. There are cases of folks getting 6+ inches from a newer full leaf pack combined with a custom single shackle.

 

Poser flex shots:

 

Stock tires, YAY!

 

 

 

33’s

 

 

 

In these photos, the shocks are in farthest inside position up top and are almost fully extended. The shackles are barely extending and could go quite a bit further. Moving the shocks further out on the upper cross member, while keeping the lower mounts the same (which is what I’ve done recently) can allow more down travel. It’s a trade off, but you get the idea.

 

Thanks to:

Erik Bibelheimer

Great wealth of knowledge, very easy to understand, good articles.

http://home.4x4wire.com/erik/

 

Steve Parks

Good articles, good tech write-ups

http://www.parksoffroad.com/tacomamods/01tacoma.html

 

The Pirate board (duh)