FC3S Front U-Joint Damage

This is a classic problem with the 1986-1992 Mazda RX7 (FC3S). The driveshaft is one piece and the u-joints are not replaceable. If the u-joints weaken (afterall, the newest FC will be 16 years old) then you can damage your transmission or cause a bad accident.

Always make sure you keep up with the scheduled maintenance in order to avoid catastrophic damage from aging parts.

Symptoms:
rattling, pinging, metal-on-metal scraping, vibrations from 2500rpms to 3500rpms and also between 40MPH to 60MPH.

You can see detailed pictures of the u-joint damage here:
http://www.rotarycarclub.com/showthread.php?t=3260

If you ever have ANY questions about any rotary powered car, make sure you check WWW.ROTARYCARCLUB.COM

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Category:

Autos & Vehicles

Tags:

• FC
• FC3S
• RX7
• RX-7
• RCC
• rotarycarclub
• rotary
• 13B
• 13BT
• 13B-T
• transmission
• drivetrain
• drive-train
• driveshaft
• drive-shaft
• Mazda RX-7
• Wankel Engine
• Mazda Wankel Engine
• Cars

[JuanPapaNicolao]

im about to replace that shaft again

how much would a shop charge to retrofit u joints to the fc shaft

[PhoenixRX7]

@JuanPapaNicolao I was quoted $300 parts and labor so I decided to go with the Mazdatrix Driveshaft with replaceable u joints for $50 more.

[dpfusion14]

where did you get those u joints? my fc convertible u joints are shot. any help appreciated

[PhoenixRX7]

@dpfusion14 I bought a mazdatrix driveshaft

[musskeeterbump]

i bought the mazda trix driveshaft and man its nice and its considerably beefier than the stock shaft . the stock shaft looks like a toothpick next to the mazdatrix shaft lol

[malatokings]

and before i wasnt able to put it in reverse or drive or the engine would just stall once i raise my rpm to around 2000 all hell breaks loose...any thoughts i need help bad!!!!

[malatokings]

hey i have a 88 fc just bought it its an automatic aswell but i let my friend drive it and he did a neutral drop so now my fc inside is shaking super loud almost sounds like my dash is about to fall off when you get out of the car you dont hear the vibration inthe engine bay but when you touch the engine you can feel it he also blew the belts off of it and overheted the engine (could hear bubbling and such) but park and neutral raises the rpm to 2000 and shakes like crazy in drive shakes at 2000

[APUZER714]

@dpfusion14 what kind of u joints did you order?

[JuanPapaNicolao]

@PhoenixRX7 thanks

[dpfusion14]

@PhoenixRX7

WHAT? thats ridiculous i order front and rear joints for i think $30 bucks a pop? all you have to do is file down the staked-in grooves and they pop in like normal u-joints u should be able to do it for $75 bucks and a few hours of wrench time

[dpfusion14]

thats what i was about to do but i found the u joints at rockford driveline in IL. you just have to file down the groves from the staked in u joint design in order to put new ones in. i put them in about a year ago and many clutch dumps later they still work great