Torsion Bar Adjustment
by Pat Walsh
A couple of weeks ago I set out to adjust the torsion bars in my '71 Westy to raise the sagging back end a bit. I'm not going to go over the step-by-step details as they are covered in Bentley and Haynes, as well as an article in HVW a few years back. But there were a few things I thought could use some clearing up. First, the books talk about measuring the angle of the body of the bus (underneath, between the front and rear wheels, along the outer edge) and the angle of the spring plate, then adding or subtracting depending on whether the rear of the bus is higher or lower than the front. This gives you the "spring plate angle". Maybe this is pretty obvious, but they're talking about the angle of the body WHILE YOU'RE DOING THE PROCEDURE, not the normal angle. At first I was thinking of measuring the angle of the bus' body as it sat on it's wheels in the garage and somehow determining how much (in degrees) the spring plate angle needed to change to level the bus. That's not what it's about, though. The angle on the spec. page of the manual is what the angle is "supposed" to be between the spring plate and the body of the bus. In order to determine what YOUR spring plate angle is, you measure the angle of spring plate to the true horizontal and then measure the angle of the bus' body to the true horizontal and add or subtract the values depending on which end of the bus is higher RIGHT THEN. So it doesn't matter if your floor isn't perfectly level, if you've got the back end up on jack stands, etc. In fact, when I was taking the measurements, the rear was actually a little higher than the front because of the jack stands.
The second thing is that in order to adjust the spring plates you don't have to remove the brake drum, disconnect the brake line, remove the CV joints and drive shaft or take off the shocks. (This is on my '71. I would expect it to apply to all '68-'79 but of course I can't swear to it.) You need to unhook the FRONT end of the parking brake cable, either inside the cab ('68-'71) or underneath ('72-'79), then pull the flexible sheath (that goes into the back of the brake drum) away from the rigid metal tube that goes toward the front of the bus. You just need about six inches of slack. Don't try to pull the whole cable through, of course. You'll also need to remove the clip holding the brake line to the front of the diagonal arm and pull the brake line out of the grommet at the rear of the diagonal arm. Support the bearing housing with a floor jack as you remove the four big bolts holding it to the spring plate and diagonal arm (after marking the position as described in the books) and once it is free you should have just enough slack to move it back to clear the spring plate without straining the brake line, etc. I sat mine on a cement block while I did the adjustment.
Next, chances are you're going to find that your current spring plate angle is about what the book says it's supposed to be. That was the case with mine, and the one they did in HVW. Yet the back end of the bus still sags, because even though the unloaded angle is to spec., the bars are old and have a bit more give to them. Also, you're not going to be able to measure down to minutes (1/60th of a degree) like they talk about in the books, either. I was lucky to get within .5 to 1 degree with my Craftsman angle measure-er (or whatever it's called :-) ). My plates started out at about 22-23 degrees, and I rotated them 7 teeth which comes out to 4.67 degrees for my configuration, for a final spring plate angle of about 27 degrees. Different years had different numbers of teeth so therefore 7 teeth = 4.67 degrees won't always be the case. Check your book to make sure. And by "rotating 7 teeth", I mean I turned the torsion bar down 7 teeth on the inside, and the spring plate up 7 teeth on the outside. ("Up" and "down" instead of CW or CCW because it varies depending on what side of the bus you are working on.) Before you pull the spring plate off the torsion bar, put a drop of paint on the end of the bar and on the spring plate. Once you remove the spring plate, paint a mark on the bar and the housing. Don't scratch the paint on the bar as it causes rust. Pull the bar out a bit and rotate it down the number of clicks you've decided on. Then put the spring plate back on, so that its dot of paint is rotated up this same number of teeth from the dot of paint on the end of the bar. Now measure the angle of the plate. It should be 4.67 degrees (or however much you decided to adjust) more than when you started. You should be able to easily tell if the outer end is set up right, based on the paint drops. And if you are off by a tooth on the inner end, it will be obvious when you measure (like 8 degrees or so). If it isn't right, use your paint marks and start over. I think this measuring business is what everyone's concerned about, but honestly it isn't that big a deal. Just take your time and think about what you are doing and start over if you have to and it will go fine. I had more trouble getting the lug nuts off and the bolts out that hold the bearing housing on.
Now you need to raise the spring plate back up a bit so it rests on its lug (support). The books seem to imply that this is going to take some monster amount of force, you might have to have people sit in the bus to keep it from lifting off the jack stands, the spring plate is going to be poised to lop off your hand like a meat cleaver, etc. That just wasn't the case, at least with the increase in angle I was using, and the age of the torsion bars. I just put the floor jack under the end of the spring plate and raised it up enough to clear the lug. Then I used a large socket on an extension, up against the spring plate, and drove the spring plate the rest of the way on the torsion bar. For safety I then used a pair of vice-grips to clamp the spring plate on its lug until everything is bolted up. I used lock-tite (per Bob's recommendation) on the screws holding the cover on, and anti-sieze on the big bolts I had such a hard time removing. Line up the marks you made earlier on the diagonal arm, spring plate and bearing housing and torque everything down. Secure the brake lines to the diagonal arm, put the parking brake housing back in place and connect up and adjust the parking brake and put the wheels back on and you're done.
The bus isn't my daily driver, so I don't have that many miles on it yet since the adjustment, but so far so good. It looks a lot better and I can see out the back window better. I should have taken more precise measurements before I started, but I wasn't sure where to measure. The rear bumper is a bit crooked to begin with on mine, and the front and rear wheelwells don't look like they were SUPPOSED to be the same height, so it's hard to know when you've got it 100% correct. Using a level on the wood floor inside also gave slightly different readings depending on where you set it. But the bus just "looks" better. For one thing, the fender skirt just covers the very top of the sidewall, whereas before it covered over half of it. I'm happy with the results and would recommend the procedure to others contemplating it. If I were doing it over again I might have gone an extra tooth or two, but no more. As it is, it's about 5 degrees over spec. and if you have TOO big an angle, you're putting more of a stress on the bars and they could snap. I'll probably have the bus aligned before too long, too.
