[AFineRide]

Just when I thought my car was running perfectly....

Started today. I had to get to the brakes quick...holiday shoppers... And I hear a CLUNK!

I test by applyng slow brake pressure and I hear/feel nothing. Everything normal. I apply quick hard pressure....CLUNK!

Sounds like it's coming front the right front of the car.

Any ideas?

Larry

 

[miami592]

How are your motor mounts?

 

[144]

Check the lower A-arm bushings.

 

[AFineRide]

Motor Mounts...could be. Lower suspension done less than a month ago. Unless they screwed up the install... Thanks for the leads...

 

[Norseman50]

carrier bearing or rubber bushing

A clunk when braking or starting from a dead stop can also be caused by a worn or broken carrier bearing, or the rubber bushing that holds it in the carrier bearing frame. The rubber bushing will wear out in time and develop a circular or semi-circular tear that is fairly easy to see. Climb under your car and grab the prop shaft right next to the carrier bearing assembly. Push the shaft up and down and side to side. Is it real sloppy? If you can see light coming through anywhere inside the carrier bearing frame while moving the shaft around, the rubber is cracked or torn and should be replaced. You will need a press or a gear puller to remove the old bearing from the shaft.

 

[AFineRide]

A clunk when braking or starting from a dead stop can also be caused by a worn or broken carrier bearing, or the rubber bushing that holds it in the carrier bearing frame.

Got it. Would it be a safe assumption that if the clunking does NOT Happen from a start, thats its NOT the carrier bearing or bushing? I can test that on my way to work this morning.... Won't be able to get under the car until this evening...

 

[Alfar7]

Clunk

If it happens during braking or bumps, it most likely is the upper caster ball joint mounted on the front chassis (with 2 bolts) they are a common failure point.

 

[Norseman50]

Got it. Would it be a safe assumption that if the clunking does NOT Happen from a start, thats its NOT the carrier bearing or bushing? I can test that on my way to work this morning.... Won't be able to get under the car until this evening...

Whether it occurs during take off depends a little on the style of the driver. Some drivers are more aggressive on starts than others. You can make a couple of "jackrabbit" starts (really put the pedal down or pop the clutch quickly) from dead stop to see if the clunk happens then too, but the best way to check the condition of your carrier bearing/bushing/frame is to wiggle it and look at it. It should be fairly snug in all directions, without more play one way than another.

 

[veloce430]

Clunk on braking

A couple of times I have found that one or more of the lower A-arm bolts were not as tight as possible and caused a clunk. This has only occurred on early 2-bolt front a-arms. Try removing the cotter pin and trying to tighten one more flat and replacing the cotter pin. Very possible the shop didn't get them tight enough when the re-installed the lower a-arms. I had this clunk on hard braking on both a Super and a Duetto that I had purchased, and that was the cure..
Stu

 

[Abbassato]

I would suspect the caster arm bushings. Usually, the new upper control arms come through with the earlier style bushing. Those bushings require the plastic insulating washers (with plastic tangs) installed above and below bushing. With no washers, the bushings quickly tear themselves up, allowing clunks as well as unwanted caster changes. I usually just install the later 2.0L bushings before assembly unless the it's an early care and we want the stock appearance.

 

[AFineRide]

Well, you guys are certainly giving some great check points. Raining today and need to get the car out of the garage to work on it....will get her jacked up tomorrow or Wed. at the latest.

 

[Jim G]

The castor bushing in the upper are. Pull the bolt out move the arm out of the way. Push on the metal sleeve. It will probably fall out.

 

[AFineRide]

Update / Conclusion

The answer is: not what was making the noise!

The problem was two fold; (I think)

1) right side motor mount collapsed. Left side, cracked but not collapsed.

2) I think that the noise is created by the oil pan banging against the metal oil pan protector. The oil pan protector had taken a few hits in its day and protected the oil pan as best it could. It's ( the steel grate) dented up and is real close to the pan. But, I'm thinking that when the mount finally collapsed, the "gap" between the pan and guard shrunk.

Therefore, when I braked hard, the engine momentum would shift and the pan would hit the grate.

Anything wrong with my theory?

I checked all arms, bushings, drive line shaft bearings/bushings....

They all looked great. No shimmy or looseness.

I'm going to replace the mounts, remove the grate and see if I can bang it back into shape and see what happens.

 

[Vintre]

I hope that this fixes the issue.

Changing motor mounts is a right of passage for an Alfista.

Good luck, especially with that passenger side!

Vin

 

[Norseman50]

After re-reading your initial post, and noting that the sound was coming from the right front of your car, I have to agree with your latest conclusion. Good luck changing the mounts. I'm in the process of doing that right now, and the passenger side mount is not too easy, even if you have removed the plenum chamber (which I have)!

The removal of the plenum chamber (intake manifold) is not too difficult - just remove the radiator overflow reservoir, the windshield wash reservoir, and the main rubber air tube (after labelling the hoses so you can put them back in the same places). You will also need to un-bolt the start valve from the manifold. Once all that is done you will have fairly easy access to the bolts on the manifold bracket to remove the plenum chamber. I actually found it easier to get at the bolts from below using a socket on the end of several long extensions, but you can probably get to them from the top too.

Once the plenum chamber is out, and the sump guard removed, you can put a 2x4 on a floor jack and lift up on the oil pan or the front pulley to get the mounts out. Oh, one more thing - don't forget to unbolt the fan shroud before you start lifting the front of the motor, and keep an eye on the top radiator hose as you do it.

 

[Gubi]

Note that it's a '91, so no fan shroud to worry about and the wash reservoir is on the other side. Not a fun job but I've done worse. IIRC there's a decent plenum removal procedure in the Cardisc manual. Helps to have extra joints in your arms.

Yes, it's reasonably easy to remove the oil pan guard and bang it back into shape. I usually whale on it for a while on the ground with a hand sledge hammer.

 

[AFineRide]

Yep, after reading Edward and Tom's post, I'm thinking that motor mounts is a 5-6 hour job assuming everything goes smoothly and Murphy isn't hiding in the bushes....BIG assumption.

I may, for the short term gratification just remove the pan guard and try to reshape it.

The rear bolts looks easy to get to but the front ones look like they are tucked under some other components, making removal more difficult. For those of you who have removed this guard, is it straight access to front bolts or is it one of those "gotta remove 10 things to get to 1 bolt" things.... Hard to see how I get to them...