knocking/rattle from rear.

Bludge · Post by **Bludge** » Thu Mar 06, 2014 8:04 pm

so its not shock knock. i tried adding the shims/washers and it made no difference. thought it was better at first but as soon as you hit rough road the knocking is back both sides.

i didnt use the exact spec washers as i couldnt get the tools to drill them out, this is what i used, figured the end result would be the same, or at least would change the noise enough to know if i was on the right track.

Now when i took the drives side apart the bush just popped right out, it was sat with the convex side upwards and the flat/concave side down. is this right? as looking into where the bush sits kinda looked like it should be the other way round.

Im hooping i will be able to get the car up on ramps on saturday and will do the arb bushes, although the arb seem pretty tight.
what else should i be looking for when its up in the air? just to retrace i have done the droplinks, driven without the rear bumper, cleared everything from the boot and just tried the shock knock fix. no change.

Mate of mine said he was 100% it would be the subframe bushes, as in the ones where the arms connect. the passenger side toe adjusment bolt is seized inside the rubber, and it was the rubber rotating when i had it tracked. could that be a sign?

Im getting to my wits end with this, and i really want it sorted! any advice to what could be causing it would be greatly appreciated.

I havent looked into the sunroof as im sure it must be something that i changed when i replaced the subframe as it only got really bad after that.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Fri Mar 07, 2014 11:30 am

and it was the rubber rotating when i had it tracked

Can't picture which bit you're describing here (nothing wrong with your description, just I'm not familiar enough with the rear suspension yet

) but...
If that's a normal bush pressed into an arm, the rubber shouldn't be rotating. If it's rotating, that means the bonding has perished and even though it might not be allowing any lateral movement through the bush, the arm will be able to move longitudinally over the bush, so it could be moving in ways it's not meant to and that could be giving you knocking.

Can you put a pic up of the bush/arm in question?

Post by **Merlin** » Fri Mar 07, 2014 11:45 am

Bludge wrote:Now when i took the drives side apart the bush just popped right out, it was sat with the convex side upwards and the flat/concave side down. is this right?

Yes that is correct. The convex side on the top rubber bush should point upwards, the opposite for the bottom rubber bush.

Yeah the camber bushes shouldn't spin when turning the adjustment bolt. That could be the cause of the noise.

Bludge · Post by **Bludge** » Fri Mar 07, 2014 5:43 pm

thanks guys, will have a good poke around when i get it up in the air and will take some pics for you wurly. hoping to use ramps tomorrow afternoon.

how much of a ballache are they gonna be to change merlin? and do i need any special tools to remove or refit the bushes?

Post by **Merlin** » Fri Mar 07, 2014 8:35 pm

It bet it will be a pain in the ass

Bludge · Post by **Bludge** » Fri Mar 07, 2014 11:09 pm

might be easier just to try and get the arms off a breaker then. or are those arms the same on the 4ws setup?? as i could try my old ones to see if it makes any difference.

Bludge · Post by **Bludge** » Sun Mar 16, 2014 2:05 pm

So i realised what i said in the last post was stupid, i was tired! lol. the arms i was talking about would be the steering actuator on the 4ws setup.

Anyhow, i jacked the car and had a poke around today. passenger side rear caliper plastic cover thingy was loose, so thats been tightened. and on the same side i managed to tighten the bottom shock bolt a little, not sure if that will make any difference. also both sets of bushes where the arms meet the subframe look pretty shocking, so they will be on the cards to replace.
I also tightened the subframe bolts a little, although im sure they have gone over the 55nm it states in the manual. will re-check them in a minute.

But im pretty sure the majority of the knocking must be coming from here:

You cant quite see it in this pic, but the exhaust pipe is actually touching the toe arm. so any downward movement is gonna spring it back up against the arm.

Im not really sure what i can do about it though, other then sticking some rubber or something betwixt pipe and arm?
Is that where the pipe normally sits on the 2ws setup??

Those were the only things i could make knock, and im happy that everything is secure enough that the back end of the car wont detatch whilst im driving, so a bit happier to be using it again now!

Post by **Thebusofwoe** » Sun Mar 16, 2014 3:13 pm

Yea but don't forget that the rear arms will lower towards the exhaust when you jack it up. So may not touch when on the floor. Is there any witness marks??

Bludge · Post by **Bludge** » Sun Mar 16, 2014 5:24 pm

forgot about that. lol. couldnt see any. cant drive it at the mo to see if what i have done has made any difference. im guessing if it hasnt then it will be the bushes.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Mar 19, 2014 3:07 pm

Bludge wrote:You cant quite see it in this pic, but the exhaust pipe is actually touching the toe arm. so any downward movement is gonna spring it back up against the arm.

why didn't I think of suggesting this? My UKDM does this sometimes, for that very reason...

Solution is to go to a custom exhaust fitting place and get them to heat/re-bend the pipe away from the suspension arm further.