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I decided to try and find out what my differential ratio is. I should have 3:45 being FI but I belived it to be 3:9. The number under the diff case is RKC0100. I couldn't find the number they usually refer to (CH1 etc. ) in the bottom LH side. The RH side was number 0391 poorly cast and difficult to read. When I turn the marked wheel one turn I get two revolutions of the marked drive shaft which is 2 to 1 give or take a bit. I thought I was possibley loosing motion at the other wheel so I jammed it with no difference. According to video on the web this is the way to do it (except they did it 10 wheel turns to make it easier accurately calculate the ratio. What am I doing wrong?



TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

The CL or CH etc. numbering to identify the gear ratio is actually in the middle of the bottom of the differential housing. The numbers are stamped and not cast. You will need to degrease the area to find the markings.

Michael
1980 TR8 FHC/Works Rally Project

If it is broken then fix it....if it is not then make it faster!"

What I'm thinking (somebody please correct me if I'm being dumb!) is that the rotation of the prop-shaft would normally turn BOTH wheels, so if the drive is directed only to a single wheel, it will turn twice as far.

In other words, you have to take the result of turning a single wheel and multiply by two to get the correct answer.


Sondar

Hi,
If all else fails, whip the cover off and count the number of teeth on the crown wheel and divide by the number of teeth on the pinion, the result is your ratio. Also dont do any harm changing the oil at the same time.
Cheers John

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