rattle or rumble in rear duiring deceleration

Maintenance advice to keep your Spider in shape.
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piperstan10
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Your car is a: spider 1973

rattle or rumble in rear duiring deceleration

Post by piperstan10 »

While driving at almost any speed under acceleration, the car runs smoothly. Release the accelerator with the car in gear and a very noticeable uniform rattle (about 1,000 Hz) is heard in the vicinity of the rear axel. Sometimes the rattle is heard going over rise or dip in the road. Don't hear the noise while coasting.

It is not in the driveshaft since I just had that balanced and checked - with no change in the noise.

I have inspected the exhaust, suspension (included shocks and springs) all seem to be in good shape. Nothing loose that I can identify.

Any thoughts?
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joelittel
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Your car is a: 1980 Spider 2000 FI
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Re: rattle or rumble in rear duiring deceleration

Post by joelittel »

Could the emergency brake cable be touching the exhaust pipe while under acceleration?
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RRoller123
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Re: rattle or rumble in rear duiring deceleration

Post by RRoller123 »

+1
'80 FI Spider 2000
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piperstan10
Posts: 31
Joined: Sun Jan 06, 2013 1:02 pm
Your car is a: spider 1973

Re: rattle or rumble in rear duiring deceleration

Post by piperstan10 »

Interesting thought, I don't think the exhaust is contacting the brake cable, I will look at that tomorrow but I just put the drive shaft back in and when I reattached the brake cable I inspected and saw no indication of wear/abrasion. I could loosen the parking brake adjustment and see if the noise changes.

I think the noise is likely from the differential?
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joelittel
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Your car is a: 1980 Spider 2000 FI
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Re: rattle or rumble in rear duiring deceleration

Post by joelittel »

I broke my spider gear once, and that created an odd noise coming from the rear of the car. It was very difficult to pinpoint while driving the car and most noticeable under acceleration. Difference here is that I knew I broke something when it happened, but I couldn't tell what.
DieselSpider
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Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: rattle or rumble in rear duiring deceleration

Post by DieselSpider »

That usually happens as the pinion and ring gear wear. Time to get the differential re-shimmed or possibly replaced.
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aevansgatech
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Your car is a: 1982 Spider 2000

Re: rattle or rumble in rear duiring deceleration

Post by aevansgatech »

Could the same phenomenon cause a shake/rattle on an Automatic trans?

Mine makes a decently loud rattle when in reverse (idling OR moving backwards slowly), but not in Drive. I'm wondering if it's differential wear (which I would expect the noise in Drive as well) or just driveline wobble? The guibo joint doesn't have much play in it
1979 Spider 2000 (gone)
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NSFIAT
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Re: rattle or rumble in rear duiring deceleration

Post by NSFIAT »

I had a rattle towards the rear during certain points of acceleration or when hitting a rise / bump. Turns out it was the baffle in the centre muffler - it had rotted away and was bouncing around in the housing. Shaking the exhaust by hand wasn't enough to recreate the sound - needed a bit more force.
DieselSpider
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Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: rattle or rumble in rear duiring deceleration

Post by DieselSpider »

aevansgatech wrote:Could the same phenomenon cause a shake/rattle on an Automatic trans?

Mine makes a decently loud rattle when in reverse (idling OR moving backwards slowly), but not in Drive. I'm wondering if it's differential wear (which I would expect the noise in Drive as well) or just driveline wobble? The guibo joint doesn't have much play in it
When the pinion shaft gets sloppy or the gears in the differential get cupped it can start to clatter in one direction.
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