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Fri May 11, 2007 7:07 pm

How do I know if I need to replace my CV joints and what is a spring plate? :D

Fri May 11, 2007 7:55 pm

CV joints will last a very, very long time if they are well maintained. Unless you hear some "popping" sounds from the rear rear suspension, they should be OK. I most important thing is to make sure the CV boots are intact. These are the rubber accordians at each end of both axels. Check for tears, cracks, or brittleness. The boots are important because they seal out dirt and water from getting into the CV joints. They also keep the grease inside the joints. Changing the boots is not a difficult job, but it is a very messy job!

Fri May 11, 2007 8:19 pm

Mine are REALLY gooy greasy, thats why I asked...I posted a pic of one of them on my myspace (www.myspace.com/vwthings). If anyone wants to have a look and tell me if it looks ok...?

Fri May 11, 2007 8:57 pm

There's supposed to be gooey and greasy. But if you can see the goo and grease then your rubber boots are shot.

Ok, I took a look. the joint shouldn't be that dirty. Might want to clean them off. Heaven knows how long thats been caked on. Grease should be contained by the boots

Fri May 11, 2007 9:11 pm

give 'em a tug and yank (the axles), fore and aft, there shouldnt be any slop. port and starboard should have some give but thats it.

Sun May 13, 2007 12:01 pm

Kherome wrote: what is a spring plate?

A spring plate is part of the rear suspension. If you look under your car (like, if you're under there cleaning grease off of CV boots :wink: ) you'll see that the CV goes into stub axle that is mounted in a diagonal arm that supports the rear wheel. The diagonal arm is affixed to the car at two pivot points. The inner pivot has a fat hex bolt near the transmission. But out near the wheel, you'll see that the arm is held onto another pivot with 3 bolts. Those bolts connect the diagonal arm to the spring plate.

You can see the spring plate installed here. See that tube to the left of the picture, just behind his fender? That's also part of the spring plate - that part slots over the torsion bar to provide spring to the back end. The torsion bar is a fat bar of metal that twists when the car is pushed down, it's a twist-spring. The spring plate, pushed down by the torsion bar, transfers that down-push to the diagonal arm.

On older swing-axle transmissions, the spring plate had to flex a lot because as the wheels went down, their angle changed and they towed inward. It doesn't have to flex much on our IRS suspensions (the wheels go pretty much strait down and the CV moves in and out), but it still does have to allow some flexing as the wheel travels up and down.

Also in this picture, you can see a trapezoid shaped metal cover holding the spring plate in position. That's the spring plate cover. They hold the spring plate onto the torsion bar and keep the spring plate centered. Another job of the spring plate is to keep your rear wheels strait. There's two fat rubber doughnuts called rear bushings, one on each side of the spring plate - one just behind the spring plate cover, and one between the spring plate and the body. These are squished together by the spring plate cover. When they wear out, the rear wheels don't sit strait anymore. When I pulled mine off a few months ago, they were oval!

If they haven't been replaced in over 10 years (and the probably haven't) you should plan on replacing the rear bushings. It's not an easy job and you have to be very cautious because the spring plate is being pushed down with a LOT of force - if it simply let's go, it could break your arm.

Here's a good article on replacing the spring plates with adjustable ones to raise the rear:
http://laudeman.com/bug_spring_plates.html
(it's where I borrowed the above picture)

I'm taking pictures of the process of pulling apart my rear suspension, and I'll write an article on how to disassemble and reassemble it. It's a bit more complex on a Thing than a bug because there's no where to clamp a spring-plate-compression tool to gracefully raise and lower the spring plate. So, in Tom's article above, when you see that black threded rod that holds the plate in position, know that you can't do that with a Thing (I tried, hard, and it just doesn't work with the body on the pan).