Rear Suspension Refresh Questions

[TCMoto]

Hi, I have a 2004 3.0 (12/2003) with 129,000 miles on it. I'm collecting parts and tools to totally refresh the rear suspension and all things rubber in the rear end. Should I consider replacing the springs as well? Nothing appears to be wrong with them but recently I was reading about an M5 suspension rebuild and they recommended replacing the springs which got me thinking I should do the same.

Also, I have a clunk coming from the rear end when taking off from a stop. If I'm smooth with the accelerator it doesn't happen or if I have a load it doesn't happen. The clunk is somewhat loud and can be felt at the same time. I'm thinking rear diff, rear bushing?

Thanks,
Alex

[srmmmm]

I wouldn't worry about the springs unless you're bottoming out the suspension all the time. My rear suspension rebuild wasn't necessary until about 240,000 miles when I finally couldn't get the rear camber set correctly anymore.


I would inspect the guibo and driftshaft bearing carrier for play as the source of your driveline clunk.

[X5chemist]

Mine just went through a suspension refresh. Knowing what I know now, I would do the front first. The rear was still okay on mine. Fresh giubos and carrier bearing made a difference. Replace the shocks and see how it drives. Replacing the rose ball joint does require a special tool. I'm glad I spent money buying one. Replacement was easy. The rear shafts were still good. I could have left them on. A complete refresh is time consuming. Especially with trying to align all the parts back up to tighten it up.

[TCMoto]

Originally Posted by X5chemist

Mine just went through a suspension refresh. Knowing what I know now, I would do the front first. The rear was still okay on mine. Fresh giubos and carrier bearing made a difference. Replace the shocks and see how it drives. Replacing the rose ball joint does require a special tool. I'm glad I spent money buying one. Replacement was easy. The rear shafts were still good. I could have left them on. A complete refresh is time consuming. Especially with trying to align all the parts back up to tighten it up.

I was able to do the front suspension a couple of years ago. I replaced everything including the struts but used the old springs. I did not replace the front shaft guibo. Probably should have since I did everything else. I'm not familiar with the rose ball joint. Did you mean rear ball joints?

[X5chemist]

Originally Posted by TCMoto

Did you mean rear ball joints?

Yes, you are too far away or I would lend you the tool.

You can find pics of my refresh here: https://xoutpost.com/bmw-sav-forums/...an-gasket.html

[TCMoto]

Originally Posted by X5chemist

Yes, you are too far away or I would lend you the tool.

You can find pics of my refresh here: https://xoutpost.com/bmw-sav-forums/...an-gasket.html

Thanks for offer. I have the tool and joints squirreled away for the future.

[nick325xit 5spd]

The clunk that you describe is most likely failed rear subframe bushings. Which at that mileage, you can absolutely assume are completely trashed.

The good news is that you can do the subframe bushings on the car with almost no disassembly in an hour (if you work fast), or two (if you're slow). This does require the special tool.

If you are on a time and money budget, the bang for buck items are:
front thrust arms
rear subframe bushings.
front control arms

I would try to do more than that, but that's the absolute minimum.

[TCMoto]

Originally Posted by nick325xit 5spd

The clunk that you describe is most likely failed rear subframe bushings. Which at that mileage, you can absolutely assume are completely trashed.

The good news is that you can do the subframe bushings on the car with almost no disassembly in an hour (if you work fast), or two (if you're slow). This does require the special tool.

If you are on a time and money budget, the bang for buck items are:
front thrust arms
rear subframe bushings.
front control arms

I would try to do more than that, but that's the absolute minimum.

My subframe bushings do look tired as in old and they seem like they have shrunken/contracted (dried up). I bought the tool awhile ago for fear they would become unavailable at some point. I was planning to drop the whole frame and replace the diff bushings too. I think I can see a crack in the rear one.

I've read that you have to heat the subframe up to extract the old bushings. Do you know if a standard heat gun would work or if it's even necessary?

Thanks

[nick325xit 5spd]

Originally Posted by TCMoto

My subframe bushings do look tired as in old and they seem like they have shrunken/contracted (dried up). I bought the tool awhile ago for fear they would become unavailable at some point. I was planning to drop the whole frame and replace the diff bushings too. I think I can see a crack in the rear one.

I've read that you have to heat the subframe up to extract the old bushings. Do you know if a standard heat gun would work or if it's even necessary?

Thanks

If you're using the correct tool, no heat is necessary.

If you are not, you need a torch. You have to melt the rubber on the outside of the aluminum sleeve. (Note: This means heat the subframe.)

[haigha]

Originally Posted by nick325xit 5spd

If you're using the correct tool, no heat is necessary...

Interesting, I thought that you needed to heat the supports for the exhaust system, to bend them out of the way, in order to remove the rearward one on each side. Do you not need to bend them if you're using the tool, or you did you bend them without heating?

I ended up not doing the rear bushings after getting the tool and bushings, because my mechanic friend inspected them and showed me the rubber was still fine. He looked at the front and a few components are beginning to wear, though not in urgent need of replacement. (04 4.4i, 43k orig miles, garaged)