Straight Axle Swap with a Chevy Dana 44 Axle
(Last update: 12/14/04 )

ALSO: Check out the pictures from Ed's 91 4Runner D44 swap

 


Intro-

Jason Wison's
88 V6 4Runner
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This swap was similar to Jason Wilson's swap (AKA "Eight") who helped me out a LOT with the whole project.

Some differences between our swaps:
Jason's hangers are dropped 3" from stock, mine are only 2" drop.
Jason's front mounts are moved forward 2" from stock to use the Wagoneer springs, mine has holes for stock and/or 1" forward.
Jason used stock Wagoneer springs instead of modified Toy springs..
Jason didn't turn his knuckles and perches to point the pinion at the transfer case, mine were turned 12 degrees.

Comparisons to some other swaps:
Mine: front mount is 2" drop w/ a choice of stock or 1" forward, and the shackles are under the frame.
Allpro kit: 1" drop front hanger, choice of stock or 1" forward, shackle hangers through the frame..
DRM's swap:  ~3" drop front hanger, shackles under the frame (Toy axle).
Joe Chacon's swap: 1.5" drop hanger, shackles on edge of frame (Toy axle).
Scott Wilson and Chris Geiger's 4runner swaps: 1" drop, shackles through the frame (Toy axle).
Jack Alford's swap: Duplicates stock mounting method.

 

The Axle-

Narrowed housing and turned knuckles
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Driver's side closeup
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12 degrees of rotation
(see marks)

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I picked up a '72-ish Chevy 1/2-ton (6-lug) 67.5" wide wms-wms (wms = wheel mounting surface)  Dana 44 axle for $150 complete w/ disk brakes, locking hubs, aftermarket steering stabilizer, ~22" stainless steel brake lines, u-bolts and plates, steering arm, tie rod, lug nuts, flat-top knuckles on both sides, and CV style drive shaft. It had 3.07 gears so I needed a new 3.92-up carrier to install 5.38 gears. I also found out later that it has the older small-diameter axle shafts and u-joints, so those were changed out.  The older style axle also used a different type of seal against the spindle than the newer ones, so the spindles were changed out as well.
  • Long side (driver's side) of housing was shortened 4" by Jason and I (mostly Jason, I just helped) so that the axle ended up 63.5" wide wms-wms and uses a Jeep Wagoneer long side axle shaft. Click here for some other width possibilities using stock axle shafts.
  • Knuckles were turned 12 degrees to point the pinion at the transfer case for better ground clearance and driveline angles.  This is not necessary, but it didn't cost anything except some extra time and a shim to do it.
    Driver's side spring pad was moved inboard 4" and rotated 12 degrees to match the narrowed axle and turned knuckles. This puts the spring pads at 27.5" on center (29" is stock Toyota width). My spring and shackle hangers were be built to match this width.
  • Passenger's side spring pad is cast into the center section, so I ordered a 12 degree shim from Roger Brown which was welded on and then used a steel plate welded to the driver's side spring perch to match the added shim height.
  • Perches were drilled for center pin locations at dead center, 1" forward, and 1" backward for different axle location possibilities.  The u-bolt plates had to be drilled to match as well.
  • I bought used 5.38 gears and installed them myself to save money.
    Sean (AKA "GearMan") at River City Differentials traded my old IFS diff for a 3.92-up carrier, a Lock-Right, bearings and install kit, and few tips to boot- very helpful and a great deal. Thanks, Sean!
  • Wheel studs were replaced with 12mm studs. The original 7/16" wheel studs are fairly week and prone to breakage. Jason did some research and found that Dorman 610-264 wheel studs are basically a direct replacement.  They are slightly longer and have larger 12mm threads (same as Toyota uses), so I re-used use my old lug nuts and was able to keep the same lug nuts front and rear.

Update:  I've run the axle now with anywhere from 2-8 degrees of caster.  I've found that I like how it drives best with closer to 2 degrees. With less caster, the steering is easier and more responsive, and there is less bumpsteer felt in the steering wheel.  I also think that too much caster helped contribute to the "death wobble" that I had when I first did the axle swap. 

Update: I changed out the double spindle nut w/ lock washer setup for these cool Ford single locking nuts: Quick Dana 44 Spindle Nut
With these you only have to install/remove one nut and you don't have to play with that pesky lock washer.
I found I had to put a spacer behind this nut though because the tab was bottoming on the back of the slot in the spindle, keeping it from properly snugging down on the bearings and sometimes getting kinda stuck on the spindle. I just used the old lock washer with the tab ground off as the spacer washer. 

Update: On Ed's 91 4Runner D44 swap, instead of using a big, thick shim, I welded some flat bar to the front of the perch, and then ground the flat bar and perch down to the desired angle. This is time-consuming, but works well. It keeps from adding unnecessary lift, and leaves more clearance between the drag link and the springs (and tie rod if you run high-steer). That way you don't have to run extra tall steering arms or spacers. To take out a little lift when I went to 37's, I went back on my axle and ground the perch and shim down to normal height, and removed the spacer on the driver's side perch.

 

Springs-

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I first used stock '84-88 Toyota rear main and second leaves (moves axle forward 2" from stock), plus 4 leaves from a Mazda 2wd pack.  I was able to arrange the Mazda leaves under the Toyota leaves so that the rear of the leaves step down fairly evenly in length and I only have to cut the fronts.  The fronts were cut for about 1.5" steps.
Leaf thicknesses:
Main- .280"; 2nd- .240"; 3rd- .280"; 4th- .240"; 5th- .240"; 6th- .200"

These turned out to be WAY too soft and too tall so I built another pack using Rancho top leaves from a 3" lift pack, and the lower 3 leaves from a stock Toy front pack.  They are pretty stiff, but they still flex decent with the wider axle (more leverage). I plan on changing the springs again soon, possibly using Wagoneer springs.

4/02-  I'm now running a set of used 4" lift Allpro springs up front with the shackle hanger moved from under the frame to through it.  These springs are working great for me.

 

Spring Hanger/Front Crossmember-

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27.5" vs. 29"
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2" drop
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The dropped front spring hanger crossmember is made of 2 x 2 x .25" square tubing (probably overkill, but it was free).  The hangers themselves were cut from 3.5 x 3.5 x .25" square tubing.  I also built a receiver hitch into the center since my tow hook was removed to mount the crossmember..

The hangers are 27.5" on center to match the perches on the narrowed axle.  Stock straight axle Toyota hangers and perches are 29" on center.

The hangers have a 2" drop built into them (4" from the bottom of the frame) compared to a stock straight axle Toyota, but the distance from the front of the frame is the same, about 2". I also drilled a second set of holes 1" forward of those for more mount options.

TIP: To keep the sides of the hanger from getting bent sideways when hit, run a steel spring bushing sleeve. This allows you to tighten the bolt down on the sleeve, and ties both sides of the hanger together, which makes it MUCH harder to bend. Mine have held up great this way.

Update- Ever since the swap was completed, I've run the spring in the 1" forward hole. I also went back and trimmed the excess hanger material under the hole to keep it from hitting rocks and getting the very bottom edge bent in. Now the spring and the bolt are about the only thing that can get hit.

Shackles under:
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Shackles through:
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New shackles:
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Shackle Hangers-
Stock rear shackle hangers were mounted to the bottom of the frame.  The hangers I used are the second set of shackle hangers I had installed with my Chevy rear spring swap.  I removed them and installed a double shackle in the rear instead. It was easier for me to do that than search for another set of shackle hangers.

At first, I planned to use my old stock rear shackles, but I ended up making my own longer ones out of 3/8" x 2" flat bar.

I don't really like how the hangers on the bottom of the frame make the shackles and rear of the springs hang down so low, so I'm thinking of mounting some new hangers through the frame similar to the stock mounting method.

UPDATE 4/02- I've moved the shackle hangers to through-the-frame (duplicated the stock shackle hangers) and changed to some Allpro 4" springs. I'm much happier with this setup and I'd recommend always mounting the shackles this way.
The rear of my springs moved up about 4" which enabled me to remove the shims I was using to correct the caster on the axle, not to mention giving me lots more ground clearance, and I also think it looks better.
There are a couple of possibilities of tubing to use for the shackle hangers- 1-5/8" OD .219" wall (what Toyota uses), or 1-1/2" OD .156 wall. Both have the needed 1-3/16" ID for the Toyota style bushings. I chose to use the 1-1/2" x .156".
The tubes are 3-7/8" long.  I also welded some large 1-1/2" washers around the ends of the tube and frame (similar to how the factory does it) to beef up the mount and spread the load over a greater area.
Since my shackle hangers are in the "stock" location and my springs are inboarded 3/4" on each side compared to stock, the shackles have to make up the difference.  The inner plate is straight and the outer one is bent like stock (3/4" offset), plus there is a 3/4" spacer (a stack of washers for now) to make up the rest of the difference. It looks kind of odd, but works just fine. The shackles are 4.5" eye to eye.
I bought the hard to find 18mm bolts from Nutty.com.  Stock upper bolts are 150mm, and the lowers (and both rears) are 120mm.

Shackles-under vs. shackles-through
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Crossover Steering-

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Pitman arm- Stock IFS pitman arm, end removed and a Chevy- tapered insert from FRORFab ($20) was pressed in.  Although I've yet to have any problems, the pitman arm is probably the weak link in my steering setup, so I carry a spare on the trail.
Flat-top Knuckle- I exchanged my passenger's side flat-top knuckle at Roggy Enterprises for one that was machined, drilled, and tapped to accept a steering arm ($50 exchange), basically a mirror image of how the driver's side came from the factory.  I had to replace the ball joints in that knuckle as well since they were removed for machining.
Steering arm- I used a Roggy Ent. passenger side steering arm ($85).
I re-used the original studs, cone washers, and nuts from the driver's side, on the pass. side steering arm to save money.
Drag Link- is a Rockstomper Rock Rod ($60) using '85 Blazer drag link ends.  Autozone (McQuay-Norris) part numbers are ES2026R & ES2027L for the ends.  Drag link overall length is about 40-1/2".
Tie Rod- A sleeved (3/8" wall) Rockstomper Rock Rod ($75) runs below the springs using an '85 Blazer end (ES2234R) and a '79 Dodge W200 truck (w/ 4500lb axle) end (ES2010L). Tie rod overall length is about 53-5/8".
Total cost for tie rod and drag link ends was just under $120 w/ tax and a "lifetime warranty"

Note: The Toyota pitman arm is very short compared to a domestic pitman arm or steering arm. This means it cant steer the D44 to its full range. To solve this problem, I had the steering arm on the axle re-drilled and tapered about 2" back from the original hole and moved the drag link back to that hole. This effectively shortens the steering arm and makes for a better match to the Toyota pitman. If you run high-steer, you can effectively do the same by running the drag link to the tie rod, which is already mounted in rearward holes. This is known as an Inverted "T" setup.

Also check out Billavista's Dana 44 steering research page for lots of other info & options.

8/02
Steering stabilizer- I added a cheap ProComp steering stabilizer. I found a nice place to tuck it right between the drag link/pitman and the bumpstop.

I've also decided that I will probably not ever switch to high-steer (tie rod above the springs). With the tie rod below the springs, I am free to move my axle forward/backward as I wish and not ever have to worry about the tie rod and drag link interfering and/or needing to move the steering box foward to prevent it. As you can see, the tie rod is actually in front of the drag link as it is. 
The RockRod tie rod has stood up to plenty of punishment (I've come down on it very hard on several occasions) and I'm no longer worried about being down low where it regularly takes some abuse.

9/03- I installed hydraulic steering assist from West Texas Offroad and removed the steering stabilizer. See hydro-assit pictures here.

High-Steer vs. Low-Steer on a Dana Axle
High-steer would have been more complicated and slightly more costly for me to set up. If you look at the top view, you can see that the drag link ended up behind the tie rod, instead of in front of it. It wouldn't be quite as bad as it looks now because high-steer arms move the tie back a bit, but it still would have been a problem. To keep the drag link and tie rod from interfering when the axle moved up, I would have had to move the steering box forward and/or run an even shorter pitman arm. With low-steer (standard crossover) I didn't have to worry about that, and now I can move the axle as far forward as I want without worrying about relocating the steering box. Yes, the tie rod is low and vulnerable, but with the beefy Rockstomper tie rod, I don't have to worry. I have come down on it hard many times, and it has held up fine.

High-steer puts all the steering loads on the bolt-on steering arms and puts extra loads on the upper ball joints. Low-steer spreads the loads between the top bolt-on steering arm and the strong cast arms. Since the cast arms are between the upper and lower steering joints, they distribute the load across both joints more evenly. Either setup will normally work just fine, however under high stress like when adding hydro-assist, the low-steer setup will have a strength advantage. High-steer is a little more likely to tear the arms off the knuckles and wear out the upper steering joints.

My point is, high-steer may be a bit over-rated. Don't shy away from "low-steer" simply because it is "low." That really isn't much of an issue, the axle itself is what limits ground clearance. Low-steer is actually a little stronger, cheaper, and in cases like mine it can be a lot easier to set up.

 

Shocks-

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Bilstein 5100 series 14" travel shocks from Roggy Ent. ($120, part # F4-BE5-6250-HO). They measure 34.90" extended and 20.75" compressed which is longer than the popular Rancho RS9012's (but they have about the same travel), and were mounted accordingly. At rest there is about 5.75" of shock rod exposed.
I like a fairly firm shock and these shocks are fairly soft, so someday I'd like to upgrade to some Bilstein 7100's with custom valving.

Shock towers- '88 F250 shocks towers (part number E5TZ-18183A) purchased from Harold Ford in Sacramento ($10.85/ea).

I left part of the old IFS bracket on the frame rail where the shock tower is now welded. This made for less junk to cut off, and kept me from having to re-box in the motor mount support. And, since the IFS bracket is very strong and spread over a large area of the frame, I didn't need to brace the tower to keep it from tearing off the frame.
The shocks are angled back slightly at the top.
The lower shock mount is simply a 1/2" bolt welded to the front of the axle tube.

5-04- I swapped out the Bilsteins for Poly Performance BBCS shocks. These are firmer and I like them better. They are also longer, so I moved my lower shock mounts down a couple of inches.

 

Brakes-

1" bore master cyl
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Brake Upgrade
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The easiest way I've found to adapt the Chevy calipers to the Toyota brake lines is buy custom lines from Tony at Rock Equipment. Tell him you need some lines to go to the D44 under your Toy, he'll ask you how long you want them and whether your calipers have 3/8" or 7/16" banjo bolts. In a couple of days you'll have exactly what you need.

I also installed a 1" bore V6 brake master cylinder from a '92 pickup in order to be able to push enough fluid for the large Chevy calipers. This helped, but the pedal was still pretty soft and mushy.

UPDATE- I found a way to fix the mushy pedal and dramatically improve the brakes over all.
Go to the BRAKE UPGRADE page to read about it.

 

Drive Shaft-

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High-Angle
Driveline

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I used receiver tubing to build a cheap, home-made, long-travel drive shaft.
I used the pinion end of my IFS drive shaft at the transfer case (transfer case flange was redrilled) welded to some 2x2x1/4" tubing. I chopped off the shaft leaving about 1" to slide into the square tubing.  I had to grind small flat spots into the round tube until it could be pounded into the square tubing and then welded.
The Chevy pinion-end yoke was also chopped off with about an inch left and I tack welded sheet metal chunks in four places around the tube to help it fit snug and center itself. Then I filed those down until the yoke was a tight fit into the receiver tubing and welded it up.
Both yokes and tubes were pre-heated with a torch and then MIG welded.

The receiver tubing was $7.50/ft at S&K Steel and I used about 18" worth.

The price of the square driveshaft compared to a new long-travel one is definitely worth it for a rockcrawler.  It works great for rockcrawling, but not surprisingly, vibrates at speeds over 25mph.  Part of that is due to having a lot of angle on the t-case u-joint, and no angle a the pinion joint.  A CV (double cardan) joint at the joint will help cure this part of the problem.
Another source of vibration is that there is a  lot of play between the two tubes.  I've heard of people tack welding strips of sheet metal along the 2" tube to take up some of the slack.
The other sources of vibration are that it's not balanced, and it may also not be centered very well since it was all built by hand. The vibration isn't that big of a deal, but I figure I might as well get rid of as much of it as I can while I'm at it.

UPDATE: I won a High-Angle Driveline on the Marlin Crawler website. 
So I decided to install dual transfercases so as to not have to get it re-sized later. The dual cases add about 6.5" to the length of the front shaft, and it turned out that the square shaft that I made was still plenty long enough to use, and I did use it until I ordered the new shaft from High Angle.
The High Angle RockCrawler shaft uses an IFS CV (double cardan) joint up top, clearanced for more angle, a 13" coarse-spline slip yoke, and a standard 1310 style u-joint at the bottom to mate up to my D44. This thing is NICE. Very heavy-duty. I highly recommend it.
I can drive on the highway with the hubs locked up to about 75 mph and notice only minor vibrations. This was not possible with the square drive shaft. This will work well for snow driving in the winter.
Thanks Jesse!

 

Anti-swaybar-

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Tacoma sway bar
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To help reduce body roll on my daily-driven commuter/rockcrawler 4Runner, I installed a swaybar.  I used a thicker one with shorter arms from a '90's V6 Toy truck, flipped over so that the bend went up and over the driveshaft instead of under it.  The new swaybar frame mounts are several inches farther forward on the frame than the originals, so they were custom.  I also made some disconnects using heim ends, similar to the Rockstomper disconnects.
The only real swaybar problem I have is that if I bottom out fairly hard, the driveshaft hits it.  I think using one from a Tacoma will solve this problem since the bends are the same on both sides as well as sharper and deeper.
The disconnects also rattle on rough roads when installed, but that's not a big deal.

UPDATE: I've installed a Tacoma sway bar. The bar is stiffer than the old one and works very well. It has a deeper/wider bend that gives the driveshaft lots of clearance as I had hoped. However, the bend is deep enough that it also hits the transmission, so the bar had to be spaced down from the frame about 1-3/8".  That worked fine until I moved my shackle hangers to through the frame which made it so the springs hit the sway bar mount brackets when the springs are compressed. Its not too bad though. They hit just after the bumpstops do, so I have to bottom fairly hard for them to hit. It hasn't been enough of a problem for me to bother fixing yet. If I plan on flying around at high speeds where I'll be bottoming out a lot, I just remove the whole sway bar.

 

Misc. Pics:

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Contact Info for Parts Sources:

River City Differential, Rancho Cordova, CA, (916) 852-7109
Roggy Enterprises, Placerville, CA (530) 626-9451 (Bob Roggy of the Pirates of the Rubicon 4wd club)
Rockstomper, Firestone, CO (303) 833 1431
Front Range Off-road Fabrication (FRORFab), Fort Collins, CO (970) 481-6508
Roger Brown- "4Crawler", Santa Clara, CA
High-Angle Driveline
, Paradise, CA (530) 877-2875
RockEquipment.com, Lincoln, CA (916) 434-7887
West Texas Offroad, San Angelo, TX 1-87STEERING (1-877-833-7464)
Parts Mike Parts
, Auburn CA (530) 885-0673

 

 
Chevy Dana 44 width possibilities using stock length axle shafts:

(Axle widths are, WMS-WMS - wheel-mounting-surface to wheel-mounting-surface. Perch widths are center to center)

69" wide, 31.5" perches- stock Chevy 8-lug
68.75" wide, 31.5" perches- Chevy axle with Ford 5-lug outers
67.5" wide, 31.5" spring perch centers- stock Chevy 6-lug

65" wide, ~29" (Toy width) perches- long side cut down 2-3/8", use 70's Ford long side axle shaft
64.5" wide, 29" (Toy width) perches- long side cut down 3", use late 70's Wagoneer long side axle shaft
63.5" wide, 27.5" perches- long side cut down 4", use 80's Wagoneer long side axle shaft
62" wide, 29" (Toy width) perches- long side cut 4", short side 1.5", use 80's Wagoneer long side, Dodge short side. See Ed's D44 swap for an example of this one.

Wagoneer axle dimensions-
60.5" wide, 31.5" ??? perches, passenger's side diff, spring-under, late 70's Wagoneer
60.5" wide, 31.5" ??? perches, driver's side diff, spring-under, 80's Wagoneer
The wide perch width of Waggy axles means that big tires easily hit the springs, limiting steering radius. Perches can be narrowed, but the diff side is difficult because of the cast center section (u-bolts end up in front of diff cover bolts?). The passenger's side diff Waggy has the diff offset 1" closer to center than the driver's side diff Waggy. Narrowing the perches on a driver's side Waggy to Toy width may not even be possible.

Warn's axle shaft application page has some useful (but limited) axle shaft length info.

Stock Toyota front axle measurements for comparison:
55.5" wide, 29" spring perch centers, '79-85 Toyota trucks and 4runners, and most Landcruisers
63.5" wide, (set up for coil springs) 90-97 FJ80 and FZJ80 Landcruisers
'86-95 IFS front end is about 58.5" wide
'93-98 T100 IFS front end is about 65" wide

Toyota Rear Axle Widths:
55" wide, '79-85 trucks/4runners
58.5" wide, '86-95 trucks/4runners
60" wide, '95.5-up Tacomas/4runners
66.75" wide, '93-98 T100 trucks (Tundra is the same?)

 

Cost Breakdown at time of swap-
Complete used axle- $150
Axle shim- $20
Short and long side axle shafts- ~$50
Pass. side knuckle machining- $50
Pass. side steering arm- $85
Drag link- $60
Tie rod- $75
Steel- $35
Chevy shackles- $10
Mazda Springs- $35
Pass. side ball joints- $45
Tie rod and drag link ends- $120
Pitman arm insert- $20
Shocks- $120
Ford shock towers- $25
Brake master cylinder- $??
Brake line fittings- $10?
3.92-up carrier- $45?
Gear install kit- $100?
Lock-right- $250?
5.38 gears- $48

Total: $1333
Lock-right, install kit, and carrier were traded- subtract $398
Sold lift kit- subtract $300
Sold IFS parts (CV axles, hubs, idler arm)- subtract $120
Which means I only spent about $515 out of pocket for the swap...

 
Since my 4Runner is my daily driver, I got as much as I could ready before the actual swap took place so that it could be finished in one weekend.  I didn't get as much done beforehand as I had planned, so it was an extremely busy weekend.  However, I had lots of friends stop by to help get everything done.

 

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