Installing Balloon Seals
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What's a "Balloon Seal"?

If you own an older Mopar with the (in)famous torsion bar front suspension, you have "balloon seals" on those torsion bars. They are a cone shaped rubber piece that fits over the torsion bar and helps seal in the grease that you pack around the end of the torsion bar that mounts to the cars frame - one seal goes on each torsion bar. When you do a front end rebuild, it's a good idea to replace these things. The old ones are cracked, leaking, and generally fall into pieces when you remove the old torsion bar.

 

Why do I care about this?

You need to "slide" the balloon seal over the end of the torsion bar - and that's the problem. For starters, the new rubber seals will be reasonably stiff. Then you have the fact that the end of the bar is large and hex-shaped where it fits into the lower control arm and into the frame. Add in the fact that you have to install the balloon seal while the bar is half-installed and flopping all over the place, and you have the crux of the problem. The seal is very hard to push over the end of the bar, space is limited, and you need someone else to hold the other end of the bar. Blech. While doing this on a friend's car, my friend Jon Class hit on the idea - and it worked so well, we decided to add it to my tech tips page. Hopefully it will help some other people do this job as easily as we did. This information should be treated as an "addition" to the factory shop manual. Follow the rest of the instructions it provides and this will help you get over the one seemingly innocent and easy step that says "slide seal over end of torsion bar".

 

What's the tech tip?

It can be summed up In one phrase - "pre-expand the seal and slide it over the end of the bar". The hard part isn't doing the sliding, it's doing the expanding. If you can pre-expand the seal on something of about the same size as the end of the torsion bar, then hold the whole thing up against the torsion bar, it's pretty easy to slide it from one piece of metal and over the end of the torsion bar.

To do this work, you'll need a 1" socket (that was about the same size as the end of the torsion bars on the car we worked on - your car might differ), a second socket of about the same size (I used a 1 1/4" socket), a shop vice, a socket extension that fits your 1" socket (I used a 10" extension), and a short piece of pipe that will fit over your 1" socket (I used a 3" long piece of thick wall 1 1/4" steel tubing that I normally use on my shop press). You'll also need the grease that you normally use to lubricate the inside lip of the balloon seal.

For reference, the fat/wide end of the balloon seal faces the rear of the car and the narrow end is what seals around the torsion bar. You install the seal fat end first starting from the front of the torsion bar and then you slide it all the way to the back end where it seals against the front surface of the rear mounting point for the torsion bar.

 

Place the 1" socket in the fat end of the balloon seal with the "open" end towards the fat end of the balloon seal. Then hold the other socket in front of it and place the whole assembly in a vice. While making sure the two sockets are aligned with and square to the vice jaws, slowly close the vice. If you do it right (and it will take some pressure, so go slowly and watch closely), the narrow end of the balloon seal with bulge out evenly and then pop over the end of the 1" socket. The other socket is just a spacer to apply pressure to the 1" socket and allow the seal to slide over both sockets without problems. If it bulges unevenly, you don't have the sockets aligned properly and the seal could tear - stop and realign things. Also, don't put any lubricant on the seal of the socket at this point - you want a little friction to hold the seal in place on the socket so you don't have the 1" socket spontaneously pop out. (Warning - if it does pop out, it does so without warning and can fly a good 3 feet in the air... I know because it did it to me - thankfully it was not pointed at me when it popped out.) Look at the photos below to see the seal pressed onto the 1" socket, to see how it fits into the vice, and how the socket fits into the seal.

InstallingBalloonSeals01.jpg (270062 bytes) InstallingBalloonSeals02.jpg (301448 bytes) InstallingBalloonSeals03.jpg (346063 bytes) InstallingBalloonSeals04.jpg (351773 bytes) InstallingBalloonSeals05.jpg (342969 bytes) InstallingBalloonSeals06.jpg (332539 bytes)

 

At this point, the socket will be sitting firmly in the seal with the closed end of the socket being flush with the narrow end of the seal. You want to move the narrow end of the seal about 3/4 of the way down the 1" socket before you attempt to install it onto the torsion bar - that way there is about 3/4 less to push the seal past while you're messing about under the car. You do this by placing the other socket under the wide end of the seal (the same way it was in the vice) and using the tubing piece to push the seal down the 1" socket. It will only take hand pressure, so go slowly. If you go too far, the 1" socket will pop out of the seal and you'll have to start over. Reference the pictures below for the way to do this and to see the final result with the 1" socket sticking up out of the narrow end of the seal.

InstallingBalloonSeals07.jpg (319100 bytes) InstallingBalloonSeals08.jpg (333952 bytes) InstallingBalloonSeals09.jpg (294528 bytes)

 

You're now ready to install the seal onto the torsion bar. Lightly grease the inside of the balloon seal (from the wide end). Put the extension into the socket and loosely place the tubing over the extension as shown in the picture below. Then take the entire assembly to the vehicle, and while someone else is holding the rear end of the torsion bar steady, install the balloon seal by using the extension to hold the socket firmly against the end of the torsion bar and at the same time use the tubing to force the seal over the remainder of the socket and onto the end of the torsion bar. Make sure the socket is centered (it should largely self-center due to the cone shape of the seal, but check and be sure) and do this in one smooth and relatively quick motion. If you are off center, not pressing hard enough on the extension, there is too much grease, or you go too slowly, the seal could go off the end of the socket but not over the end of the torsion bar - and you get to start all over again.

InstallingBalloonSeals10.jpg (366429 bytes)

 

Once the seal is slid over the large hex end of the torsion bar and onto the thinner middle area, you're pretty much done. Follow the rest of the instructions in the factory manual for installing the torsion bars and then relax. Make sure to say "Thanks, Jon!" at least once.


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Page last updated 01/02/2009 01:51:39 PM