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Rear end, Good or bad?


shinrich's Avatar
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MD

04-29-03, 08:58 AM   #1  
Rear end, Good or bad?

I have a 1985 Mazda RX-7, 12A engine, 5-speed with a bad rear end. It used to make a horrible noise when it worked. Now the differential input shaft won't turn and the wheels, when jacked up, will only turn in opposite directions (one spins forward, one spins backwards).

So I need a replacement rear end.

I have found one at a "U-Pick-it" type of junk yard for $35. There is absolutly NO guarantee, so if I pull it and it does not work, it is a $35 paperweight.

When I jack it up, the differential input shaft spins freely, no loud noises and the axles seem to have little play. The only thing is that when I spin the differential input shaft, only one wheel spins.

Is this because the differential is giving the power to the wheel with the least resistance (which would be fine, I guess) or is something wrong?

Thanks

 
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shinrich's Avatar
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04-29-03, 09:03 AM   #2  
One more thing - I can't get the parking brake cable out of my old rear end.

I have disconnected the cable from the brake hardware and there was a little clip on the cable as it exited the rear plate, but the cable does not budge. It does not spin, nothing.

Is it just rusted on there or is there another clip/connector that I have missed?

How do you remove the parking brake cable from a 1985 Mazda RX-7?

Thanks

 
Joe_F's Avatar
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04-29-03, 09:07 AM   #3  
Joe_F
If it were my car? I would source OEM parts and bring them to a reputable driveline shop and have them install it and set it up. Let them deal with it.

It takes specialized knowledge and tools to set the rear end up correctly.

 
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04-29-03, 10:07 PM   #4  
knuckles
New OEM Mazda rear diff parts will likely exceed the value of this 18 year old car.

IMHO, $35 and a few hours time isn't a very big gamble. Just make sure the ratio of the replacement rear end assembly is the same as the existing unit. Change the fluid too.

The parking brake cable is probably rusted to the backing plate. Give it a few shots with PB Blaster. Let the Blaster soak in for an hour or so & give the backing plate a few taps with a hammer as you attempt to twist or pull the cable free.

 
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04-30-03, 06:27 AM   #5  
Joe_F
True. If you can verify it's possibly good, you'll save some time and effort .

 
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