Technical Knocking upon deceleration

[hugh w]

Hi all

My car has recently started exhibited a knocking/banging on slowing down (no gas, and I think, no braking) It seems to happen at about 20mph, and is about 7 or 8 knocks.
I've only found very old threads with something similar (I don't think the exhaust is knocking like @stocky recent experience) Older threads point to worn drive shafts or front suspension issues. Im not really sure which direction the sound is coming from.

Not much to go on I realise, but are there at least things I could eliminate or check?

Thanks


HUGH

 

[the hobbler]

Hi all

My car has recently started exhibited a knocking/banging on slowing down (no gas, and I think, no braking) It seems to happen at about 20mph, and is about 7 or 8 knocks.
I've only found very old threads with something similar (I don't think the exhaust is knocking like @stocky recent experience) Older threads point to worn drive shafts or front suspension issues. Im not really sure which direction the sound is coming from.

Not much to go on I realise, but are there at least things I could eliminate or check?

Thanks


HUGH

I would suggest that you DO check the tightness of the drive-shaft-coupling bolts. I am building an engine for somebody, and when I went on a road-test I noticed a sound like very noisy tappets when on the 'over-run'---turned out that ALL the drive-shaft-coupling bolts were loose by between 1/2 and 1 full turn. Tightened them all up and and then took it for another road-test---the sound had disappeared..

 

[hugh w]

Thanks Tom, I'll check that today

 

[hugh w]

I would suggest that you DO check the tightness of the drive-shaft-coupling bolts. I am building an engine for somebody, and when I went on a road-test I noticed a sound like very noisy tappets when on the 'over-run'---turned out that ALL the drive-shaft-coupling bolts were loose by between 1/2 and 1 full turn. Tightened them all up and and then took it for another road-test---the sound had disappeared..

I presume these are the bolts pictured below? (If so, all tight). Knocking continues; any more thoughts?

 

[the hobbler]

No Hugh

I presume these are the bolts pictured below? (If so, all tight). Knocking continues; any more thoughts?

No Hugh, the other end of the drive-shafts, where the sliding part of the coupling (on the drive-shaft) is attached to the alloy/rubber coupling

 

[hugh w]

No Hugh

No Hugh, the other end of the drive-shafts, where the sliding part of the coupling (on the drive-shaft) is attached to the alloy/rubber coupling

Ah ok, I checked those as well and all tight, cheers H

 

[Mike1alike]

any more thoughts?

Check the wheels bearings.

 

[hugh w]

Whats the procedure Mike? I always thought wheel bearings where more like a tube train rumble?

 

[Mike1alike]

Whats the procedure Mike?

Jack up a wheel and spin it, check for play. Feel if any difficulty in spinning and if any noise.

 

[barbubro500L]

Sorry for asking, off topic,
Mike1alike, have you ever had a classic fiat 500?, have you ever repaired a classic fiat 500?? I see that you answer all the questions like a chatbot without knowing how a rear-engined Fiat 500 is built. By answering hundreds of times with answers copied from AI, you mislead the users on this forum and they will no longer enter the forum, and the forum will disappear. I have learned many interesting things here from intelligent and experienced users who have owned and repaired Fiat 500s for many years (I mean "the hobbler", Toshi 975, Bambino, bugsymike,, etc), and I do not want this forum to disappear or for chatbots to appear that answer questions without ever having repaired a Fiat 500 from the 70s. So, please Mike1alike, post a picture of your classic Fiat 500 with Romanian license plates here, or please explain to me what qualifies you to answer technical questions related to repairing Fiat 500s manufactured 50 years ago. Thank you for your understanding. I would like to mention that I have had and still have Fiat 600, 850 and 500 that I have maintained by myself all these years, and yet I do not answer a question posted here when a user like the hobbler or Toshi 975 have much more experience...

 

[blu73]

Sorry for asking, off topic,
Mike1alike, have you ever had a classic fiat 500?, have you ever repaired a classic fiat 500?? I see that you answer all the questions like a chatbot without knowing how a rear-engined Fiat 500 is built. By answering hundreds of times with answers copied from AI, you mislead the users on this forum and they will no longer enter the forum, and the forum will disappear. I have learned many interesting things here from intelligent and experienced users who have owned and repaired Fiat 500s for many years (I mean "the hobbler", Toshi 975, Bambino, bugsymike,, etc), and I do not want this forum to disappear or for chatbots to appear that answer questions without ever having repaired a Fiat 500 from the 70s. So, please Mike1alike, post a picture of your classic Fiat 500 with Romanian license plates here, or please explain to me what qualifies you to answer technical questions related to repairing Fiat 500s manufactured 50 years ago. Thank you for your understanding. I would like to mention that I have had and still have Fiat 600, 850 and 500 that I have maintained by myself all these years, and yet I do not answer a question posted here when a user like the hobbler or Toshi 975 have much more experience...

Someone get out the wrong side of the bed?
Before posting more could you prove your a human by sending pics of birth certificates of your whole family? Or does that sound a bit over the top perhaps? lol

 

[barbubro500L]

Someone get out the wrong side of the bed?
Before posting more could you prove your a human by sending pics of birth certificates of your whole family? Or does that sound a bit over the top perhaps? lol

You're right, I exaggerated, sorry. There's no problem getting advice on repairing a Fiat 500 from someone with experience in Fiat Punto.

 

[Mike1alike]

Get the hell out of here, barbu!
Barbu prostu!
You're just a stupid stupid idiot!
We don't need you here. Fup off!!!

 

[blu73]

OK, you have both gone too far now, either kiss and make up or stop replying to each other.

 

[hugh w]

And getting the thread back on track would be nice

 

[Mike1alike]

OK, you have both gone too far now, either kiss and make up or stop replying to each other.

Agree. It's the second choice there, 100% to me. I let barbu prostu to go the hell.

 

[Mike1alike]

And getting the thread back on track would be nice

Any progress, Hugh?

 

[hugh w]

Any progress, Hugh?

Havent managed to get the car off the ground yet, maybe today

 

[hugh w]

Any progress, Hugh?

Hi all,
Right hand rear wheel seems to have some play in it as in videos. Does this seem like wheel bearing? I did check that wheel nuts were tight first.

Thanks

Hugh

 

[Mike1alike]

Yes, that looks a lot like wheel bearing.
On damaged wheel bearing, play is when you rock the wheel at 12-6 AND 3-9. Yours looks that way so bearing is top suspect there.

Other possible causes, ball joint or tie rod/steering play.
On ball joint play is mostly at 12-6 (top-bottom). You may see the hub move but the arm stays. That is dangerous if worn because it can fail suddenly.
On tie rod or steering play, play is at 3-9 (left-right).