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Re: Rear end noise

Posted: Wed Aug 14, 2019 4:53 pm
by MikeGreer
Jody, based on tire size alone there isn't much difference, about 0.3 mph. Something else is responsible for your speed difference. Maybe there was a speedo swap, or tranny swap, I think different years had different drive gears for the speedometer. I think If it was the rear end, there would be more difference.

Re: Rear end noise

Posted: Sat Aug 17, 2019 1:59 pm
by vandor
jfarr wrote:
Sun Aug 11, 2019 8:59 am
I've noticed my speedo reads about 4mph slow at 60mph. I wonder if I don't actually have the stock diff in this car.
In my experience that is normal for a Spider, every time I measure a stock setup the speedo is optimistic.

Re: Rear end noise

Posted: Sat Aug 17, 2019 2:00 pm
by vandor
kgfiske wrote:
Sun Aug 11, 2019 8:48 am
The 4.1:1 differentials were used on the 124 Coupes.
AFAIK the Coupes used the same diff ratios as Spiders. 4.1 with the 1438 engines and 4.3 afterwards.