How to identify an IRS vs swing axle?

I am sorry to bring this up again. it has been discussed some time ago, but I am still not sure, if my VS has a rear suspension with IRS or swing axle.

First of all, I always thought it has a swing axle. The previous owner installed a camber compensator to improve handling.

I now ordered a front sway bar and read that IRS pans should have sway bars front and rear (otherwise it can create dangerous driving situations).

So, to be on the safe side, I took a look under the car, but I don't know how to distinguish the two possibilities.

One thing that might help: The VIN is 119 096 852 and the car is based on a 1969 beetle. According to books (John Muir and the Bentley Manual) it is the first year of IRS. Muir describes that if I see two rubber boots (going into transmission??) it is a IRS, if its only one than it is a swing axle. I can only see one, but I might look at the wrong boot.

Please, can anyone post a picture of a typical swing axle or IRS (or both) that would help me to distinguish them. Also, is there any chance that the car originally had an IRS, but that a previous beetle owner or Kirk at VS changed to a swing axle?

Thanks for your help,
Andreas

A swing Axle is solid and swings, hence the term. as a wheel lowers its treads will lose road contact surface. If you jack up the rearend and the wheels cup under its a swing.

Irs is double Jointed on both side with CV joints.Hence Independent Rear Suspencion. the wheels will always be vertical, as it moves up and down.

Andreas,

Take another peek under the car. If you see an accordian style boot (like a round ribbed rubber gear shift lever boot) at the wheel end of the axle, and see another at the end of the axle where it joins up with the transaxle . . . it's an IRS.

The axle has a CV joint covered by a rubber boot at either end.

It will sort of look like a Pep Squad Batton, but with black dirty cone shaped ends on it, not those clean white rubber ones.

Like a metal double ended toilet plunger.

A steel bone with the ends covered in black tool-dip.

A baby's arm holding an apple . . . .

TC

This is a picture of an IRS chassis....

Your car is probably a more sensible colour but it shows the semi-trailing arm locating the suspension and the double CV jointed rear driveshafts with boots at gearbox and hub...

Yes, that's it!

Thank you Simon, mine is an IRS, it looks the same - although not as colorful as yours :(

Thanks to TC I got the picture (English is not my native language, so I usually need more descriptive words than other members).

And Barry: Your suggestion is also easy enough for me to test. I wonder, if the installed camber compensator would have an effect on a swing axle tire and decrease the amount of 'cup in'?

That brings up another question: Having an IRS and an open order for a front sway bar, I should also get a rear sway bar (and keep the camber compensator?). I would be better off with both sway bars, or?

Many thanks,
Andreas

Gotta hand it to you, Simon.....that is one beautifully colourful suspension system.

Hey! We're bring (if the beer store comes through for me) a case of Murphy's Stout to Carlisle.....We'll toast you and your car with some fine Stout!

Gordon

Andreas,

If you upgrade your front sway bar, you HAVE to install a rear sway bar as well.

Only the stock diameter front sway bar will work without a rear bar.

Any upgrade or improvement in the front requires a balanced upgrade in the rear.

Plus. you'll absolutely LOVE the results!!

TC

I second TC's advice. Go with the sway bars front and back. You won't believe the difference. Also, make sure you have some good gas shocks in the back. It doesn't seem to matter in the front.
Ron

A Camber Compensator on an IRS suspension is a big problem. You have a spinning drive shaft rubbing on the Compensator ends. The swing-axle axles are in protective tubes. The IRS axles are exposed.

Remove immediately.

Definately order your front and rear anti-sway bars. You will love the results.

WOW...that changes everything. I guess the previous owner wasn't really sure about the rear suspension as well.

THANK YOU guys - I don't know what to say, but I am so glad I asked!!

Andreas

Their are some good rear sway bar kits out there. I wouldn't know which is best, for the rear.

I like the results I got with 12mm front and 17 mm rear from Bugpack.

It feels very sure footed.

I had to come back:

I made some pictures - that should clarify the issue before I replace the camber compensator with a rear sway bar.

The tires do not 'cup in' when the car is raised, but the camber compensator might hold them. But I don't have a second rubber boot ond the tire side as it is typical for an IRS.

I have some more pictures at: genetics.med.harvard.edu/~eizinger/Car/index_rear.html

Any comments if this rear suspension is a swing axle or IRS are again very welcome.

Thanks for your help!

Andreas

That is a 1968 Swing-axle rear end. Add a front Anti-sway bar.

Looks like your right axle seal is leaking as well. That will foul your brakes pretty quickly.

Hello Andreas! Now that Carlisle is over we should get together!

The car serial number in your first post confused some of us, since the number is for a 1969 T-1 Sedan and SHOULD have an IRS transmission, but yours does not. I read somewhere that they changed over to IRS sometime during the year in 1969 - maybe at under 100K yours might be considered early? Anyway, someone must have replaced it with a swing-axle transmission, but that's OK.....most drivers under normal conditions would not be able to tell the difference.

The camber compensator you have on your car is perfect for the swing-axle transmission/rear end. You do not have to replace it with a rear sway bar, since that is what a camber compensator does. Yes, when you jack up the car the wheels will not "droop" or swing in at the bottoms, because, as you saw, the camber bar holds them up.

You also may not need a vary large sway bar at the front, if you have a compensator at the rear. VS and JPS use normal VW sway bars, but they often mount them upside down for better clearance. Their feeling is that these cars are very light in weight and do not need a strong sway bar for good handling.

Send me an email about what you bought for a sway bar for the front, and let me know when you will be installing it. I may be able to come over and help - they are easy to install. We can also then check to see if Eric is right that your right rear wheel seal is leaking or if it is something else. Best to find the cause of the leak and correct it!

Gordon