Urethane IRS trailing arm bushing

Joao,

You must remove the CV joint from the stub axle to gain enough clearance to drop the diagonal arm and replace the inner bushings. You do not need to disconnect it at the transaxle end. Contrary to popular belief, you do NOT need to completely remove the diagonal arm to complete this job. The rear brake line will be just barely long enough to pivot the whole arm down far enough to pry out the rubber from the inner bushings and push the new urethane replacements into place. Do not try to remove the outer sleeve from the inner pivot bushings..the outer sleeve is necessary to support the urethane replacement. Just pry between the outer sleeve and the inner rubber portion of the bushing. Usually they are so shot by the time you get to replacing them that a large screwdriver will pull the inner rubber portion out with zero effort, and then you can install the new bushings.

To answer your other question..to release the spring plate you need to unbolt it from the diagonal arm, put a small floor jack under the end of the spring plate, and then jack the spring plate UP slightly off from the stop, and then use a large screwdriver to guide it down off the stop as you lower the jack. Then you can remove the outer cover and replace the bushings. To preserve the alignment of the spring plate I would suggest scoring a line along the top edge of the spring plate along the lower part of the shock mount once you have removed all of the spring pressure. When you remove the arm and the bushings the line will give you a reference point to put things back as they were during reassembly(unless of course you are going to re-index things if if the rear end is sagging).

Good luck with it.

Chris

Yesterday, I did nothing on the car. Father's day and I was with my family. Remco didn't need a lot of effort to remove the bushing. I plan to make a tool similar to the one he has. The urethane should me easy to put in I guess.

Jo=E3o

Chris,

Thanks for the tips

What do you think of this bushing?

TIA Jo=E3o

The inner bushings are the ones retained by the 17mm allen screw. Originally the VW factory bushings were a two-piece deal as best I can tell from the illustrations in the service manual. The outer metal sleeve was bonded to a rubber core. To remove the outer sleeve required a hydraulic press(at least according to St. Bentley). The new urethane bushings require you to leave the outer sleeve pressed in place, as the urethane seats into the outer sleeve(hence the advice to simply pry between the sleeve and the rubber..they will likely fall apart in your hand with little effort).

The pictures you posted appear to be the outer spring plate bushing, which based on the distortion at the bottom appears to be worn out. Note that there is another bushing behind the one you are looking at here. You have to slide the torsion arm off of the splines to get the inner bushing out.

I would suggest using the original rubber bushings here. I installed urethane spring plate bushings on my 74 super, and while they seem to ride okay, the fit is pretty crappy in my opinion. I noticed that mine already have a sizeable gap visible at the bottom between the torsion arm and the bushing, which is throwing my alignment off. Next time I have it apart I'm going to put rubber bushings back in there.

Chris

Hi Remco,

Yes, I have one washer 1 one left and 3 on the right. I will put 2 + 2 Do you still have your underwater frame camera near you? :-) Could you please post a picture of the outer sleeve? Have you already put the trailing arm on place again?

Regards Jo=E3o

The CV joint is a piece of cake, but you will need a 12-point tool. I bought mine at autozone. You also need to clean out the head on EACH screw prior to trying to remove it, as they get caked up with road grime and then the tool will not seat, leading to the rounding out of the screw. Don't make that mistake..use a pick or a small flathead to clean them out before you apply any torque to loosen them. Once all the screws are out you'll need to rap it a few times with a rubber mallet(at least in my experience) to loosen the CV joint from the stub axle. Then you can just hang it out of the way with a string/wire/whatever.

Chris

Thanks for the reply. I checked the head of one screw and it was clean. The head hole is very deep. I bought new bushing on the way home and the outer looks very different that the one I have. May be the one I have is completely worn or there are tow types of bushing. Also the difference on the high is because the spring plat is out of position. As far as I now it should pass on the middle of the thread hole (red line) Can you confirm this? I also will get some graphite powder to put on the bushing to help them to get in.

Jo=E3o

Joao,

The knobby bushing goes on the inside. You will not see it until you pull the spring plate off of the torsion arm. You need two of each type to do both sides.

You are on the right track here, the red line you added to the first picture is the general idea of what you need to mark so you can put things back the way they come apart. You need to make the line either along the top edge or the bottom edge of the torsion arm before you pull it out off of the splines.

Understand that these are pictures of the torsion arm bushings. The inner bushings are smaller and are behind the 17mm allen screw. There are two in there, and you won't see them until you disconnect the CV axle and wiggle the diagonal arm down and out a little bit. The flexible portion of the brake hose will be just long enough for you to rotate the inner part of the diagonal arm down so you can remove and replace the inner bushings.

Chris

I can see the knobby bushing because I have already pull the spring plate a little out. I only took a picture of one of each. First I will do one side and then the other. I have to reset the high of the suspension so the mark is not very important. Maybe I will have to do a few tries until I can put it right. I have already remove the 17 allen screw, but I didn't remove the CV joint yet. I thought that I could do it last night but I didn't have 1 second for my one. I'm a lithe apprehensive on removing the trailing arm bushing because I have read that a few guy had to burn it.

Jo=E3o

Joao,

If the bushing will not pry out easily then move on to plan B. If it is the original bushing(and there is a good chance that it is...) it

-will- come out with very little resistance.

If it will not come out with the aid of a large screwdriver then cut the rubber part out. The metal 'cup' is the part that must remain, so even if you took the whole arm out and had a shop remove the bushings you would just be taking two steps back because you still need the outer sleeve from the old bushings.

If memory serves me right(it's been almost 2 years since I did this) the inner portion of the bushing(i.e. the part you need to remove) was only attached to the outer sleeve at two points 180 degrees apart from each other. The 'ear' that attached the rubber to the metal sleeve was about a quarter inch wide. You could probably get most of the attachment point cut with a metal box cutter and a new blade. After that..take the screwdriver to it again. It will come free....

Chris

No, I haven't put mine back yet. It will happen after I paint all the parts These are older underwater pictures but show the sleeve & bushings:

Thanks, I will try to put the spring plate in place today with the new bushing. Then I will take care of the trailing arm bushing. It will come out for sure.

Jo=E3o

The metal 'cup' part that I must remain is the one marked with a red arrow? I thought that it was attached to the trailing arm. Remco, thanks for the picture :-)

Jo=E3o

Yes..that part stays when you convert to urethane.

Chris

You know, Jo=E3o, you may want to type up a quick article on how you actually did it and post it in one of those free websites somewhere. Since you had a hard time getting the scoop (luckily Chris was around) I am sure others may need this information as well at some point.

Remco

Yes, but I will do it in Portuguese :-) I never found a website in Portuguese about beetles with technical stuff. I will also put some stuff from others if they let me do it but in Portuguese. Chris helped me a lot. How many people is reading this? :-) More pictures

Jo=E3o

You can see that the bushings were much worn.

I bet quite a few people are interested in doing this, if not now, certainly at some point in the future. Maybe title the page in English and Portuguese so that search engine web spiders can find it. One can always run a page through an on line translator if someone needs it in their language - I do that quite a bit with Spanish and Portuguese. If I pay attention, I can understand quite a bit of it (I speak French, it being in a similar language group), but online translators make life so much easier. :)

Remco

That's a good idea!

Now I have to put everything back in. Do you think that the best way is to buy longer screws? The difference of the high was about 22 mm. If I move only one dent on the out side I will raise the car to much. To get 22 mm do I have to move the torsion bar four dents inside and four dents outside?=20

Jo=E3o

"Now I have to put everything back in. Do you think that the best way is to buy longer screws? "

It would probably be a good idea to have two screws of the same pitch that were longer just in case. The new rubber bushings might be too thick to allow the original screws to catch and draw the cover back over the spring plate. Once you get the cover drawn down a little you can start the original screws into the two remaining holes and then swap out the longer ones for the originals.

"The difference of the high was about 22 mm. If I move only one dent on the out side I will raise the car to much. To get 22 mm do I have to move the torsion bar four dents inside and four dents outside? "

I did not re-index mine but I seem to recall reading that if you increment the outer splines by one(moving the arm DOWN to increase ride height) and it turns out that adjustment moves it too much, you can move the inner splines back to make a smaller adjustment to the ride height. There are a different number of splines on the inboard end of the torsion arm.

Chris