Front end noise back ... again

The biggest mistake people make when trying to diagnose noises like this is to imagine that there is only one source - this is seldom true.

The brake clunk you're hearing is pretty common, and is due to wear in the calipers. It is usually harmless.

As for the other noises, you could guess and guess, but it's much better to just get somone who knows 900s to look at the car - I bet I could spot it in 20 minutes. My first checkpoint would be the balljoints - it's amazing how often they get overlooked, because people don't know how double wishbone setups work. Then I'd look at all the front suspension bushes. Then steering and brakes.

ah... sure? That's what I would check first.

-- MH '72 97 '77 96 '78 95 '79 96 '87 900T8

Does the front bumper rattle up and down?

If it's not bumper (there's a wear point that'll be obvious if you have the problem), then I'd jack up the whole front of the car (crossmember under the engine, floorjack, then jackstands under the a-arm rods. With the weight of the car off the wheels, you should be able to manhandle parts to see what feels loose. Rubber hammer maybe. But, check that front bumper first, it can make very alarming noises when it's loose, which become much less alarming once you know what it is.

Dave Hinz

Thanks for the advice I'll check these out.

--Paul

I'm in the process of getting the confidence up to do a driveshaft replacement on my 1983 900S which has a bad outer CV. 8-) The saga is documented at "

Any broken bushings in the control arms which might be allowing some play in the mountings? The bushings for the control arms in my car are ok at the moment but the shock bushings are up for renewal. I am going to go whole-hog and replace the shocks with Bilsteins and also go for polyurethane bushings. I might replace the springs but I don't see any benefit lowering the car since our yard backs onto a national park and the firebreak is where we park our cars (no direct access off the street into the properly). Already there are some parts where it can't be driven due to the cat converter for the exhaust bottoming out on rocks. 8-)

What about the inner CV's? Apparently if they are worn there can be a fair bit of play and clunking around when driving.

Regards,

Craig.

I took the car to my tire/muffler shop and asked them to look at the brakes. Sure enough the calliper assembly was a little loose. They said they didn't know how to tighten it if it was just loose. Is this an specially difficult/obscure job? For now I'm leaving it alone.

--Paul

That isn't enough of a description to tell, I'm afraid. If the caliper is loose on its mountings, then that is bad, and the bolts should be checked/tightened. However, if the caliper yolk is loose on the piston housing, then as I said before, it's perfectly normal.

I'm worried by the "they didn't know how to tighten it" bit - that suggests that they aren't familiar with the operation of simple sliding yolk calipers.

Those are the same two bolts that are mentioned in the "[Saab_c900] To CV or not to CV - mk 2!" thread. These should be tight as they transfer all the braking force from the caliper to the car.

I prefer my yolk hard boiled.... and yes, my caliper yoke should allow some play for the brake cylinder assembly.

(Grunff; maybe they use brake yolks in your 'other' car? :-)

-- MH '72 97 '77 96 '78 95 '79 96 '87 900T8

I was thinking of writing 'break cylinder ....' to add to the confusion. :-)

-- MH '72 97 '77 96 '78 95 '79 96 '87 900T8

Bugger - I knew that didn't look right, but couldn't think why...

Guess the yolk's on you then...

Well I'm not sure of the terminology but it was the entire visable assembly (including the callipers and the cable & spring part that actuates the callipers) that exhibited the play. Again it was minor and seemed to be radial rather than vertical. Hope this helps.

--Paul