Spohn 921 User Manual

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Spohn Performance, Inc.

494 E Lincoln Ave Myerstown, PA 17067

1-888-365-6064 www.spohn.net

Part #921 – Pro-Series Rear Anti-Roll Bar

1982-2002 GM F-Body

USE OF THIS PRODUCT IS ACCEPTANCE OF SELLER’S DISCLAIMER OF WARRANTY!

By their very nature, competition components are cons ta ntly pus he d to their limi ts . While o ur com po ne nts
are designed to withstand intense race co nditio ns , it is imposs ible to control the quality of installation or
the varying conditions in which they are used . It is for this reason that absolutely no warranty or
guarantee is either written or implied. Ne ithe r the selle r no r the m anufacturer will be liable for any loss,
damage, or injury – direct or indirect – arising from the use of or inability to determi ne the use of any
product. Before using, the user should determine the suitability of the produc t for its inte nd e d use , and
the user shall assume all responsibility in connec ti o n the re with. Sp ohn Performance, Inc. makes no
guarantee as to the legality for any specific class. Sp o hn Perfor m anc e , Inc . makes no claims, nor do es it
intend its products to be used in street driven vehicle s . Spohn Perfo rma nc e , Inc . reserv es the right to
make changes in design or add to or improve on their product without incurring any ob lig ation to install
the same on product previously manufactured . The Buyer agree s to inde mnify a nd hold Spohn
Performance, Inc. harmless from any claim, ac tion or demand arising out of or incident to the Buyer’s
installation or use of products purchas ed fro m Spohn Performance, Inc.

INSTRUCTIONS

1. Remove your stock rear sway bar, end links, and upper end link mounts (on rear sub-frames).

2. Jack up the rear of the car and place jack stands under rear end housing. Let jack down so the weight
of the car is on the rear housing. This will place the rear suspensio n at ride height. (N o te: Place j ack
stands in the area of the LCA mounts so they do not interfere with sway bar installatio n.)

3. It’s time to prepare the sway bar for installation. Note that when or ie ntating the sway bar, the center
bend faces down. Remove the poly bushings from their shell. Us ing the supp lie d greas e pack s apply
silicone grease liberally to the insid e of both sway bar bushings. Install the poly bushings onto each end of
the sway bar, and re-install the bushing shells.

4. Note: From here on out, this is a two person job as the amount of things that need to be done exceed
two hands, not to mention the weight of the bar! Place a u-bolt on one end of the rear housing. Now slide
a spacer saddle over the u-bolt and hold it in place. The second person can now hold the sway bar in
position. Slide the bushing shell onto the u-bolt. I ns tall the flat w as her s and the n the lock nuts, o nly make
hand tight at this time (start them as far as you can by hand). Now you can let this end hang down until it
rests on the u-bolt. Repeat the same procedure on the other end of the sway bar.

5. Tighten all four of the u-bolt lock nuts until you have them barely snug, do not fully tighte n. Now you
want to make sure the sway bar is centered on the rear side to side, and front to back. Position the sway
bar side to side until you have the same distance from the outside of the bar to the shock on both ends.
Position the bar front to back so that the bar runs along the center line of the botto m of the axle tube s .

6. Next you want to install the upper end link mounts (plate with bolt weld ed to it). The se bolt in place
where the OEM upper end link mount was located on the sides of the rear sub-frame. Re-use the stock
bolts (two per side) to mount these.

(Note: If you have a base model car that was not factory equipped with a rear sway bar, your car stil l has
these mounts in the frame, but you will need to get the four mounting bolts. You can obtain them fr o m a
donor car, or call us, we have these GM bolts available for purchase)

7. Next you want to install the rod ended end links. We have already set them at the proper le ngth (7.5”
c-c), do not change the length. Keep the end link mounted to the sway bar as shipped. On the top mount,
install the zinc coated spacer sleeve onto the bol t, then ins tall the to p rod e nd onto the bolt. Now you can
install the lock nut and fully tighten. Fully tighten the bottom bolt where the end link is mounted to the
sway b ar.

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8. With both end links installed and tightened, you can now fully tig hte n the loc k nuts on the u-bolts. Do
not over tighten the u-bolts or the bar will not rotate prope r ly. You should be able to rotate the bar by
hand with force.

9. Jack the car up and remove the jack stands, place vehicle back on the ground.

10. Now we’re going to adjust the sway bar and set it with the proper pre-load. Place the jack under the
front of the car, make sure the jack is perfectly centered on the front c ro ssme mbe r . Jack the front of the
car in the air until the front tires are BARELY

11. Check your rear tire pressures and make sure you have the exact same pressure in both rear tires.
Set your rear tire pressure to whatever psi you run them at when racing at the track.

12. Whoever will be driving this vehicle now needs to sit in the driver’ s se at of the car, shut the dr ive r ’s
door. (Simulate driving the car).

13. Measure from the lower rear corner of both the driver’s and passeng er’ s sid e door jam to the ground
(car should be on a level surface, ie. cement). We’re looking to have the driver’s side 1/16” lower then the
passenger’s side.

14. Adjust the passenger’s side end link (by lengthening or shortening) until you achieve the above
setting. Tighten the jam nuts and re-check your dimensio ns. Onc e you have the adj us tment pro perly set,
tighten all four jam nuts on both end links. Note: We recommend using remov able s trength Lo c tite on the
threads to keep the jam nuts tight on a street driven car.

15. With this sway bar set up, if you were previously running an air bag in your spring , remove it. You
also want to run the same rear spring rate on both sides of the car.

Important: While we have designed this kit to allow you to fully ins tall it as a bolt in assembly , we highly
recommend that you have the upper end link mounts welded to the rear sub-frames. We designed the kit
to bolt in for two reasons, so you know where to properly locate the components , and s o you c an do the
complete installation yourse lf, and then drive the car to a shop and just have them do the welding. We
also recommend putting a small weld on the top of the u- bolts to the housing to prevent the poss ibility of
them turning under load.

Tech Note: Our sway bar is 37.50” wide. The factory rear is 38.75” from the inside of the shock mount to
the inside of the shock mount. That gives 5/8” clearance betw e e n the sway bar and the shoc k mo unt. If
you have an aftermarket rear end and you do not have shock mount clearance please talk to the rear end
manufacturer as their rear should be built to factory dimensions!

off of the ground, stop there.

**** Enjoy your straight launches and down track stability!! ****