[von]

I have traction bars on my car. they were on there when I got it. do they help or are they worthless? Also someone told me there was supposed to be a gap between them and the springs when relaxed. theres not. is that a problem?

[dave-r]

I think I will move this post to 'suspension' as it is more to do with that think.

I am pretty sure I have discussed this before on here but it is worth saying again.

Both the front and rear suspensions on Mopars was the best out of the three main American auto manufacturers at that period of time.

A normal leaf spring has one or more leafs to it and the axle normally sits in the middle of the spring.

Under hard acceleration and with good traction the axle tries to rotate in the opposite direction to the rear wheels. This twists the rear spring into a very slight 'S' shape. This can lead to all sorts of problems like wheel hop. Look at the Mustang Steve McQueen drives in the film 'Bullitt'. There is one shot where he has to reverse a bit and then squeels away burning rubber (with only one wheel too if I remember). If you look at that wheel as it spins you see it is jumping all over the place. That looses traction amongst other things.

Traction bars are there to stop the spring twisting and therefore prevent the wheels from jumping around when it 'unwinds'. You need a gap between the snubber on the traction bar and the spring so that you have some normal suspension movement before the bar hits. Otherwise the front half of the spring is acting like a solid bar of steel!

Now look at a mopar rear spring.

For a start they are not parallel. This helps to make the axle more steady. Now look where the axle is mounted. You see the axle is not mounted in the center of the spring but much further forward. Making the front section of spring shorter than the rear. Also you will notice that Mopar springs have more leafs to them. most of these are concentrated in the front section of the spring. Most noticably on R/T models. This makes the front of the spring very hard to twist into that 'S' shape without loosing normal spring action. This does not make the whole spring to hard though because the long rear section has a lot of flexability to give a nice ride.

But even with springs this good you can get some twisting with a big block Mopar engine and slicks!

So mounted on the front of the diff pinion is a snubber that will hit the floor of the car if the axle twists. On JS models (R/T) this area of the floor is re-enforced to take the hit and you can get a snubber with an adjustable height to hit it early when at the track.

I am pushed for time at the moment but I hope this helps. The bottom of this is that you don't need traction bars on a Mopar. They are made for inferior makes of car!

[VON]

then they are comming off. thanks dave!

[Christer]

I think there is a risk that VON needs to change his rear springs for a new set....I think it is likely this needs to be done when the traction bars is in contact all the time.
This reinforcement above the snubber is new to me. Do you think it is a good idea to do a reinforcement of your own if you change/modify engine in a JH car?

[dave-r]

Just make sure there is no sign of bending or cracks in the spring and it should be ok.

I would only add re-enforcement to the floor above the pinion snubber if it actually showed signs of damage/bending etc.

[Christer]

When I removed the pressure from my hi-jackers, I became aware of how old and worn my rear springs is. The car became really low. Maybe the same thing will happen to VON when he removes the traction bars!?
There is a dent, approximately 5-10 mm deep in that area of my car. Maybe it is a good idea to cover the dent with a little piece of sheet metal!?

[dave-r]

Ah! There you go then Christer. They did re-enforce it for a reason on the JS after all!