ws6transam.org - Dan's Performance Page

Installing the Steve Spohn Adjustable Torque Arm

Updated: February, 2002


I've installed the Steve Spohn suspension onto the Trans Am back in 2000. It really made a huge difference in terms of traction! If you have ever listened to my sound byte called "zero to 65", you will hear a VERY slow shift to second gear. Now, this isnt a slow shift: It's wheelspin. After I finished the modifications to the L69 305, (affectionately nicknamed the "feeble305"), I found that the 5800 RPM shift to second gear would spin the tires so badly that the speedometer would bury itself, then stabilize at 60 MPH and begin climbing from there. I found that the installation of the torque arm BY ITSELF is not the straight path to traction. You must also include upgraded lower control arms and a panhard rod. These two parts installations are not covered in this install page. I only cover the torque arm here. 

Now,  Are you considering the installation of one of these torque arms yourself? If so, here's some pictures and tips on how to do it. The total installation time took about 3.5 hours due to a couple of unforseen problems. If you read to the end, then you ought to be able miss these problems for an easy, trouble-free installation. Don't forget: If you are considering the order of one of these pieces, dont buy it first. Buy Steve's lower control arms, his panhard rod, weld-in mounting brackets, and THEN the torque arm. If I would to do it a second time, I would order it all at once.

Also note: The torque arm shown here is an early design, built when it was just Steve and his dad in the shop. He has been very responsive to customer feedback (such as this page), and has greatly improved the fitment and design of the torque arm. Long-tube Hooker header owners beware: This design is not (at present) compatable with long-tubes that are installed to Y-pipes and Mufflex systems. At least, I dont think it is! Call Steve Spohn for the latest details.
 --Daniel Burk

Steve's adjustable torque arm relocates the torque arm mount off the transmission tailshaft and onto the transmission crossmember. This reduces forces from the axle onto the transmission tailshaft. I have dents in my transmission tunnel where the tailshaft smacked into the tunnel when the OEM mount broke. 

1) Notice the ramps. I jacked the car up, put it on jackstands, then jacked it up some more. I then slid the ramps under the front tires, and jacked up the rear. I measured the fenderwell height to the floor and matched it in the rear. I think the fenderwell is 36-inches up. Normal ride height is 27 inches. Be careful with ramps: When you jack up the rear-end, be sure the car doesn't slide down the ramps and through the garage door! In retrospect, I should have turned them around.

2) The yellow jackstands support the transmission. This lets me remove the crossmember. There is a 2 x 4 between the jackstands and it supports the oil pan.
 
Steve's design is nice; although my safety loop had this hex bolt that is used as a rivet: It was tall enough that it hit the bracket when the rod-end is positioned straight-up. I got me a nice sharp bastard file and filed it down to fit. I also could hear the "clack! clack!" of the safety loop on the bracket, and I worried that it would be noisy under the car. Thus, I got me some 1/16" mylar-backed closed-cell neoprene with adhesive and stuck it to the inside of the bracket. Steve has since revised his design and opened up this bracket to remove any interference.
One difficulty I ran into was the old torque arm bolts: they couldn't slide out the top withut running into the floorpann of the car. A jack with a 4X4 block was perfect: I raised the chassis temporarily in order to slide the bolts out. I left the body raised until I had the new torque arm in place. Once I slid the bolts through the holes, I removed the jack to restore proper height. One note: I have four jackstands, and a hydraulic scissor jack. I used them all on this project. I also have an Ingersoll-Rand impact gun: It made removal of the torque arm bolts a piece of cake.
Uh Oh! 
I ran into problems with the safety loop crunching into the speedometer cable. I was scratching my head as to what to do at this point. I even considered slotting the crossmember holes, as well as the transmission mount. In the end, inspiration struck while drinking a cup of stale coffee the next afternoon at work: Back out the rod end! There's no reason why you can't simply back out the rod end until it just touches the safety loop. This effectively relocates the safety loop rearwards in relation to the crossmember mounting points. It worked. I now have .125" clearance. It's still tight, but plenty of clearance. 

Steve has since changed his crossmember design to alleviate this potential problem. 
You'll want to remove that old torque arm bracket. I found that the easiest thing to do was take the top mounting  bolt and reattach the nut & screw it down, rather than try to tip the whole transmission out of the tunnel. In addition, one of the bolts is riveted to the torque arm bracket. I couldn't get it out without tipping the transmission a lot, so I got out my cutoff wheel and chopped the bolt in half. I replace the bolt with a 4-inch 3/8 Stainless bolt, and a lock nut. The bolts are required to hold the catylitic converter hangar in place. 

Mike Metzler has an alternate method that he claims is even easier:

There is a much easier way to remove the torque arm mount than what is in your article. The method I use is to remove the driveshaft (piece of cake), then remove the tailshaft housing (4 bolts, another piece of cake). You will lose a small amount of tranny fluid, so have a pan ready. Once the tailshaft is off, you can easily get the bolts out of the mount.

That would also be a good time to elongate the holes in the bracket for the CAT. By making the holes a little larger there and on the part of the bracket that bolts to the cat, you can gain up to a 1/4 inch of clearance between the cat and your subframe connectors. 
Steve Spohn has a nice web site. He's very accessable and has his own tech forum. If you need suspension upgrades, look here.
Some other observations: Removal of the original torque arm can be made easier if you first loosen up the bolts on the differential. These are, I think, 13/16". You'll need the boxed-end wrench at the top, and an impact wrench or big breaker bar on bottom.

Next, you'll need a 15MM boxed-end wrench, a 15MM socket and half-inch drive ratchet. There are two nuts at the top of the mounting bracket that you must remove in order to open the clam-shell. Pivot the transmission downwards out of the tunnel a little bit to gain access to these bolts. Be careful not to go too far and bust off your distributor or oil sending unit...

Finally, don't forget to buy a new transmission mount. I replaced mine in 1993 with a new OEM dealership mount, and it was really cracked up six years later. I bought an Energy suspension polyeurethane mount from Summit Racing Equipment for $22 or so... I got a nice bright red one for the heck of it. I was worried about the height of the transmission tailshaft, and the fact that it was sitting higher than the original installation. My torque converter rattles on the subframe connector now. I was a little concerned that perhaps the tailshaft/driveshaft angle was incorrect, with the new crossmember. Well, I checked it, and found that the angle was half-a-degree or less. Perfect!  I guess my old transmission mount must have sagged over the years, and the use of the Spohn crossmember and Energy Suspension poly mount corrected the angle.

I'll leave the alignment tips to Steve Spohn. He provides several pages of documentation on how to measure the relative angles between the driveshaft and the pinion. As it turns out, the angle of the car body with respect to gravity is not as important as I thought it was. The most important detail is that the rear axle be at proper ride height. This means that you'll want the weight bias to be as if the car was parked on pavement. In other words, weight on the front tires. Don't put the car on jackstands on the front subframe. It will uncompress the rear springs and mess up your angles.

My adjustable torque arm was pre-adjusted, I guess. I wanted 1.5 degrees of negative pinion angle, and the torque arm as delivered hit right between 1.5 and 2 degrees. I played around with it for laughs, but returned it to the original setting.
 
Adjusting the torque arm using the angle finder. 
Place the angle finder on the flat portion of the torque arm, and record the angle.  I've since modified my procedure to read the angle directly from the Universal joint bearing cap face. I glued a flat machinists magnet to a piece of flat bar stock, upon which the angle finder is mounted. The 3/4" magnet is then fixed to the pinion end of the universal joint, and the angle recorded. It is a more direct measurement, but yields the same results. At least to the accuracy of this angle finder, which is +-0.5 degrees.
Measurement on the driveshaft.
This measurement is a bit more suspect because we try to attach a flat magnet to a cylindrical object. Again, by reading directly at the U-joint, the accuracy is not in question, assuming the bearing cap end is true. Mine yielded the same results.

 

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