The Complete Guide to Your Rear Torsion Adjuster
Your adjuster is welded in. Now comes the good part: fitting the arms, putting the torsion bars and spring plates back in, and dialing in ride height one turn at a time. Once it's set up right, a height change takes a wrench instead of a weekend.
Why a Rear Torsion Adjuster
On a stock Beetle, the only way to change rear ride height is to pull the spring plates, slide the torsion bars out, and re-clock them a spline at a time. Then you bolt it all back up, set it on the ground, and hope you guessed right. If you didn't, you do it all again.
The Washburn's #CH07 replaces the center section of the rear torsion housing with a pair of splined adjuster arms, one per side. Each arm sits on its own adjusting bolt. Turn the bolt and you twist that torsion bar from the middle of the car. Left and right adjust separately, so you can fix a lean or set the rake you want without touching the spring plates again.
The adjuster is for fine-tuning. It doesn't replace a good setup. Most of the work in this guide goes into getting both spring plates set at the same starting angle during assembly. Get that right and the bolts give you easy, even adjustment for the life of the car. Skip it and you'll spend your time chasing a lean.
§How the Adjuster Works
Before you turn a single bolt, it helps to see the whole chain. The load travels this path from the tire to the adjuster:
The car's weight tries to twist each torsion bar. The spring plate holds the outer end. The adjuster arm holds the inner end, and the arm rests on its adjusting bolt.
Screw the bolt in and the arm rotates, which adds twist (preload) to the bar and lifts that corner. Back the bolt out and the bar relaxes, so that corner drops.
The key thing to understand: the bolt can only push, it can't pull. Only the torsion bar's twist keeps the arm down on its bolt. That's why the bar needs a little preload even when the wheels hang, and it's why Step 9 exists.
§Know the Parts
What you're looking at once the adjuster is welded in and the cover's off:
| Part | What it does |
|---|---|
| Adjuster housing | Welded in where the center of the torsion housing used to be. Holds both bars at the middle of the car. |
| Adjuster arms (L & R) | Splined levers over the inner end of each bar. They're independent, so each side sets on its own. |
| Adjusting bolts (2) | Thread up through the welded nuts and push on the tip of each arm. |
| Jam nuts (2) | Lock each bolt once height is set. |
| Your suspension | Torsion bars, spring plates, bushings and hub covers. They go back in much like stock; only the inner end is different. |
§Fitment & Before You Start
The #CH07 adjusts at the torsion housing, so it doesn't care what's bolted to the spring plate. It does care which torsion bars you're running, so check yours against this table.
| Car | Rear | Stock torsion bar | Notes |
|---|---|---|---|
| Beetle / Ghia 1960–66 | Swing axle | 22mm × 21¾" | Factory spring plate setting 17°30' |
| Beetle / Ghia 1967–68 | Swing axle | 21¾" long (21 or 22mm, see note) | Sources disagree on whether VW went to 21mm with the Z-bar. Measure yours. |
| Beetle 1969–72, Ghia 1969–74 | IRS | 22mm × 24-11/16" | Factory setting about 20°20'–21°10' |
| Beetle 1973–79 | IRS | 22mm × 26-9/16" | Factory setting about 20°20'–21°10' |
Pre-1960 cars use different bars (24-11/16") and a different factory angle. Set them with the angle-matching method in Step 6 and a Bentley in hand.
§Tools You'll Need
Nothing exotic, except maybe an angle finder, and that's the tool that makes the job easy.
Wrench sizes are for stock VW hardware (M10 cover bolts, M12 spring plate bolts, M14 IRS pivot). Check the adjusting bolt and jam nut size on your CH07 before you start.
§The Job, Step by Step
Read it all the way through once before you pick up a wrench. Then begin.
Check the adjuster
Blow out weld spatter and grinding dust. Make sure the splines in both arms are clean, and that both adjusting bolts thread in and out by hand through the welded nuts. Chase the threads if they fight you, then give them a coat of anti-seize. Look over the welds and any tunnel reinforcement one more time. Once the bars are loaded, there's a lot of force going through them.
Bolt threads · anti-seizeSet both bolts to mid-travel
Thread both bolts to the middle of their travel and make them match. Measure the thread sticking up above each welded nut and get both sides the same. Write that number down.
Center adjusters like this have a limited range, typically about 2" at the wheel, which is less than one inner spline. Starting in the middle leaves room to go up and down. Your big moves happen at the splines in Step 6, and the bolts handle the last inch.
Both bolts · equal, mid-travelPrep the torsion bars
- Check the bar body for rust pits, deep scratches or nicks. Per one experienced builder: "If you ever get any scratch/mark… on the centre section, throw it."
- Left stays left, right stays right. Later bars are stamped L and R (part numbers ending 511 115 L / 511 116 R). They're pre-stressed in one direction, and used bars take a set. Swapped bars have broken within a few hundred miles.
- Clean both spline ends and give them a thin coat of grease.
Mark bars on the ends with a paint pen, and never set a bar down on concrete unprotected. Never scribe, punch or grind the bar body. That's where cracks start.
Place the adjuster arms
Set each arm in the housing on its own side, with its tip resting on its adjusting bolt and its splined bore lined up with the torsion tube. The left arm serves the left bar and the right arm serves the right.
Slide in the bars and engage the arms
Feed each bar in from the outer end of the housing. When it reaches the arm, hold the arm down on its bolt tip and rotate the bar until the inner splines drop in. Push it fully home. Work both sides a little at a time so the bars end up centered. Once the bars are loaded they won't budge, so get the centering right now.
Inner splines · 40 (9° each)Index the spring plates, the same on both sides
This is the most important step in the whole job. The bolts only fine-tune what you set here.
- Zero the car first. Put the angle finder on the door sill (or the frame tunnel) and note the reading. Every spring plate reading is taken relative to that number, so the car doesn't have to be perfectly level.
- Read the unloaded plate. Slide the plate onto the outer splines, push it up gently to take out the spline slack, and read its angle. Subtract the body reading to get the setting.
- Pick your starting angle. For stock height, use the factory setting from the fitment table (17°30' swing axle 1960–66, about 20°20'–21°10' IRS). To lower, use less. To raise, use more, but stay within about 9° above stock on stock bars. Every degree of preload you add takes away from the bar's available twist.
- Match left and right to the same reading.
- Use the vernier for fine moves. Pull the plate and bar out together, rotate both one inner spline one way, then rotate the plate back one outer spline the other way. Net change is 50' (0.82°), roughly ¼" at the wheel.
Bushings and hub covers
- Orientation: stock bushings go with "oben" (top) facing up, which puts the thicker side up. On tapered poly sets, the inner goes thin side in and the outer goes thick side in.
- Lube: talc or silicone on rubber, never petroleum grease. Poly gets the grease that came in its kit.
- Draw the cover down: start it with two long M10 bolts (25–35mm longer than stock) on opposite corners. Pull it in evenly in an X pattern, fit the stock bolts in the open holes, then swap out the long ones.
- Seat the plate: with the cover snug, jack the spring plate up past the stop lip (jack chained to the car), then tighten the cover fully and let the plate down onto the stop.
- Torque: 4 × M10 cover bolts to 25–29 ft-lb (34–40 Nm), in an X pattern. Replace spring washers that have splayed.
Reconnect the rear suspension
Jack the axle end up to meet the spring plate. Bolt the bearing housing (swing axle) or trailing arm (IRS) back to the plate, starting the bottom bolt first. Nudge it into line with a rubber mallet, never a steel hammer. If you marked the plate-to-arm position when you took it apart, line up your marks. That's your toe setting on IRS.
Refit the shocks, and check that brake hoses and e-brake cables aren't stretched. Wheels on, lugs torqued.
Spring plate bolts · M12 · 80 ft-lb (110 Nm)IRS pivot · M14 · 87 ft-lb (120 Nm)Shocks · M12 · ~50 ft-lb (70 Nm)The hang check
With the car on stands and the wheels hanging, look at both arms. Each one must still be touching its bolt. If an arm has lifted off, that side has no preload. It'll clunk over bumps, and the bolt can't do its job. Go back to Step 6 on that side and move the plate one step lower until the arm stays down.
"Match the spring plates first. The bolts are for the last inch, not the first two."
§Setting Ride Height
Now the payoff. Set it, measure it, adjust it, and repeat until it sits the way you want.
Set up to measure
Use a flat, level floor, set the tires to your normal pressure, and keep your usual fuel load in the car. Roll it back and forth a few feet and bounce the rear a few times so everything settles. Swing axles especially need this.
Measure the same way, every time
- Height: from the center of the hub straight up to the fender lip. It ignores tire differences, so it beats ground-to-fender.
- Reference points: VW never published a ride height, only a camber spec. As rough guides, a stock car has about 6½–7" between the top of the tire and the fender lip, and sits around 7¾" (20 cm) under the floor lip at the body bolt line.
- Camber: on a swing axle, height is camber. Lowering adds negative camber and raising adds positive. An angle finder on the wheel face is a good second check.
- Aim for left and right within about 1/8–1/4" of each other.
Adjust
- Get under it. The adjusting bolts face down and are reached from underneath the car.
- Unload the bolt. Lift the rear by the frame until that tire just gets light. The bolt is carrying the whole corner, so turning it unloaded is easier on the threads.
- Loosen the jam nut.
- Turn the bolt IN to raise or OUT to lower. Start with two full turns and count them.
- Snug the jam nut, lower the car, roll and bounce it, then measure again. Divide the change by your turns and you know your car's inches per turn. Write it in the log, and every adjustment after that is simple arithmetic.
- To move both sides, give both bolts the same number of turns. To fix a lean, bring the low side up or the high side down. When you're happy, lock both jam nuts down.
On a stock rear, about 3.5° of spring plate angle moves the wheel about 1" (roughly ¼–0.3" per degree on the ~16½" spring plate). Sway-A-Way rates its comparable center adjuster, which has a 5/8"-18 screw, at 0.88° per turn, about 4 turns per inch, with about 2" of total range. Your CH07's exact number depends on its arm length, which is why Step C has you measure your own.
Do the final tweak with the driver's weight in the car, or an equal weight in the driver's seat. A heavy driver can change the rear by a noticeable amount, and experienced adjuster users recommend setting under real driving load, not on the jack.
Ride height log
Write down every change. Future-you will thank you.
| Date | Bolt L turns / thread |
Bolt R | Hub→fender L | Hub→fender R | Notes |
|---|---|---|---|---|---|
§Specs & Torque Reference
Stock VW Type 1 rear hardware. Values are from VW factory torque tables and cross-checked against vendor charts. Where sources disagree, we list the range.
| Fastener | Size | Torque | Applies to |
|---|---|---|---|
| Spring plate hub cover bolts (4/side) | M10 | 25–29 ft-lb 34–40 Nm |
Swing axle & IRS. Not 80. |
| Spring plate → bearing housing | M12×1.5 | 80 ft-lb 110 Nm |
Swing axle |
| Spring plate → diagonal arm | M12×1.5 | 80 ft-lb 110 Nm |
IRS (one chart lists 72) |
| Diagonal arm pivot bolt | M14×1.5 | 87 ft-lb 120 Nm |
IRS |
| Rear shock, upper & lower | M12 | ~50 ft-lb 70 Nm |
Swing axle & IRS (one older manual says 25) |
| Wheel bolts, 4-lug | M14×1.5 | 94 ft-lb 130 Nm |
1966-on |
| Wheel bolts, 5-lug | M12×1.5 | 72 ft-lb 100 Nm |
Through 1965 |
| Rear axle nut (36mm) | M24×1.5 | 217 ft-lb, then up to the next cotter hole ≈300 Nm |
Swing axle & IRS (German tables: 350 Nm) |
Before you drive it
- ✓Jam nuts tight, arms on their bolts. Check both sides one last time.
- ✓Cycle the suspension. No tire rub, and the shocks don't bottom or top out. A stock rear shock is about 16.3" extended and 10.6" compressed. Lowered cars usually need a shorter shock, such as a Monroe 5752 at 8.6" compressed, or a lowered Bilstein.
- ✓Slack at full droop and full bump. Brake hoses and e-brake cables. On IRS, check CV angles and clearance too.
- ✓Get an alignment. Swing axle: height sets camber, and toe is set at the spring plate-to-axle joint. IRS: height sets camber, and toe is set by sliding the diagonal arm in its slotted spring plate holes. Big height changes on IRS can pull toe in.
- ✓Re-check at 50–100 miles. New bars and bushings settle. Re-set height and re-snug the jam nuts.
§Troubleshooting & FAQ
The questions that come up most, and the fixes.
The car leans to one side. What do I do?
I ran out of bolt travel.
There's a clunk over bumps.
Can I raise the car more than the bars allow?
Will the adjuster make the ride softer or stiffer?
The bolt is really hard to turn.
Can I swap the torsion bars side to side?
The height keeps dropping.
What torque for the hub cover bolts? My manual says 80.
Does it work with swing axle and IRS?
§Complete the Build: The Whole Rear End
The rear suspension is apart and everything's within reach, so this is the time to freshen up what's tired.
Torsion Bars · if yours are pitted or nicked
"A pitted bar is a broken bar waiting for a pothole. If yours don't pass Step 3, replace them while the housing is empty."
Bushings & Hardware · new rubber, clean bolts
"Old spring plate bushings are hard as a hockey puck. Fresh rubber and fresh bolts cost less than a tank of gas."
Shocks & Stops · matched to the new height
"Change the height, check the shocks. A stock-length shock on a lowered car tops out, and one that's too short bottoms out."
Parts & Supplies Checklist
The quick cart-builder. The ★ is the star of this guide. The rest is what a complete rear refresh looks like.
★ Rear Torsion Adjuster$265
Spring Plate Grommets$7.50
Spring Plate Cover Bolt Kit$12
Torsion Bars (if yours fail Step 3)$78
Rear Shocks (if lowering)$171.99
§Keep Going
More from the rear torsion housing, and more guides from the bench.
Torsion Raise & Gusset Kit
Need real lift, not just preload? Weld-in raise up to 3".
Swing-Axle to IRS Brackets
Converting your rear? Weld-in trailing arm brackets.
Torsion Tube Narrowing Sleeves
Narrowing the rear for a buggy or custom build.
All Install Guides
Browse every how-to we've written up from the shop.
Get the Part
Everything above is built around the adjuster that turns a weekend job into a wrench turn.
Washburn's Metal Rear Torsion Adjuster
Independent left and right ride height for Type 1 Beetle and Ghia, swing axle or IRS. Heavy-duty and built to take abuse on the street or in the dirt.
$265View the part →Still not sure how to set it up?
Send us a note with your year, swing axle or IRS, and the stance you're after, and we'll tell you where to start.
References: VW factory torque tables (via gw-autoteile.de and German Käfer spec tables); JBugs VW Torque Specs Chart; Volks Conversions torque figures and rear suspension adjustment chart; Bentley spring plate angle and alignment values as quoted on TheSamba.com; Sway-A-Way King Kong adjuster specifications and US Patent 4,094,532; Airkewld, "How To Lower the Rear End of a Classic VW Correctly"; vw-resource.com rear axle and suspension pages; UltimateAircooled.com; TheSamba.com threads on adjuster setup, torsion bar setting, L/R bar identification, spring plate bushings and the hub cover torque typo. This guide is general information for experienced installers. Always follow your vehicle's service manual. Suspension work carries a risk of serious injury.