Hitman's Pontiac Trans Am Page | 1978 Pontiac Trans Am
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Rear Leaf Spring


I have a few choice 4 letter words to say about this job. Unfortunately, I won't say them... I said them enough when I was doing this job. Anyway, onto what needs to be done. Once again, raise the car and place it on jack stands. You can't leave it on the jack because of safety reasons and you are also going to need the jack later for the rear end. Once the car is up and secure, take a look underneath the car and look at everything before you start. You need to identify any problem points and work at those first. Most cases the rear shackle will be the sticking point for problems.... at least in my case it was.
The next thing to do is use the jack to support the rear axle to relieve the pressure on the rear spring. I would only do one spring at a time. If you try to tackle both springs at once, then the only thing holding up your rear axle is your brake lines and your drive shaft. If you try to do both at once the rear end will tilt and turn making everything all out of alignment, so concentrate on one side at a time. Start with the rear of the leaf spring, you
will see that there is a lower and an upper shackle bolt that holds the rear of the spring in. Now, they say to remove the lower bolt and slide it out to drop the rear of the spring... Yeah right.... as you can see in the photo to the right, the gas tank is in the way of removing this lower bolt. So much for that idea, it is easier to remove the top bolt and slide it out because it faces the outside of the car and not the gas tank which makes it easier to remove. The manual also shows a car without tailpipes, which I might add, are also in the way.



Once these are removed, you can now remove the 4 (2 stabilizer bolts and 2 spring plate bolts) bolts that hold the spring to the axle, plus remove the bolt that holds the shock to the spring plate. these are all easy to get to and easy to remove. Now you can move to the front of the leaf spring and take that
down. There is a bolt that goes through the center of the leaf eye which attaches to a bracket underneath the car. Don't worry about removing that eye bolt yet. It makes more sense to remove the whole bracket and take that down rather than fight with the eye bolt. There are 3 bolts that hold the bracket in place and also a tab on the bracket which slides into a slot on the frame of the car. Remove the 3 bolts and then slide that tab forward to drop the bracket off of the car.

Now that you have removed the rear leaf spring you can start cleaning up the old hardware to be placed on the new leaf spring. I bought my set of leaf springs from Eaton Detroit Spring which came with a new set of shackle bushings. They also have axle pads and other misc. hardware you might need. Once again.... as long as you have the springs off, you might as well do it the right way and replace the hardware and bushings that are worn. there is no need to do this job twice, so do it right the first time. Once you transfer the old hardware and any new hardware that you bought to the new leaf springs, it is time to put it all back together. When you are putting this all back together, it is a good idea to put some "anti-seize" on the bolts that you are re-installing. It will make it easier the next time you have to do this (if you ever do).
It is almost like doing the reverse of how you took it off, but not quite. Just like when you started, you need to start at the rear shackle and get that on first. With the leaf spring off of the
car, assemble the rear shackle using the lower bolt and get that through the eye and attached. You don't want to tighten this completely because you are going to need to be able to move the shackle back and forth to get it back up into place. Put the rubber bushings in the frame where the upper shackle bolts goes and raise the rear of the spring up into place and slide in the upper shackle bolt and put the nut back on. Don't tighten them yet because the rubber bushings have a lot of play to them and you will be fighting this to tighten them. Go ahead
and move to the front of the leaf spring where the bracket is attached and get that up into place with the 3 bolts that hold it to the frame. You can tighten those all the way down. Now that the front is attached, you can now go back to the rear shackle and tighten those down all the way. With the front of the spring attached, you don't have any play anymore when tightening down the rear shackle bolts.
Now it is time to get the center of the spring attached to the axle. You can lower the axle back down until it is supported by the spring. Now because these are new axle pads, it is not an easy job to get these back into place. I actually had to use C-clamps to slowly bring the center back in the groves enough so that I could then re-attach the spring plate and then use the nuts and bolts to draw the spring tight against the axle. Once it is back in place you can then re-attach the sway bar and the sock to the spring plate. Now that everything is back in place, make sure you go back around and check every bolt to make sure they are all as tight as they can be. Now put the wheel back on and lower the car....
You're done.