Here's my story: my RE730's were running bald, so I decided to get a new set. Now that I have left California and it's car-friendly environment, I found that my choices for tire sources in Texas are extremely limited (well, at least for tires that aren't taller than my FC, as part of a vehicular compensation for groinal inadequacy that seems to run rampant in these parts - maybe it's the water). So I took the car to a local Firestone operation for a new set of shoes. When I left, there was a distinct wobble/shimmy in the rear end. I thought it might be an out-of-round tire, or maybe a flat spot, or even an unbalanced wheel. So I decided to let it go for a while, hoping that it would heal itself. Less than a week later, my speedometer cable fell off on a freeway - the cable backed off the transmission, and the center flex shaft snaked out from the speedo, never to be seen again. Less than 100 miles after I let Firestone touch my car, what are the odds? And the shimmy got worse. So I took the car back to Firestone, and told them of the problems. They seemed unconcerned about the speedo cable - I guess that happens a lot down here, so I'll be doing all my own work from now on, thank you very much. But even rebalancing and rotating the wheels did not good. Oh well, Firestone didn't care. Even in the follow-up customer survey, which consisted of questions like "Was the coffee warm enough? Did you enjoy the old magazines in the waiting area? Do you like tires?" and not something meaningful like "Did our low-rent deadbeat employees sabotage your car?"
I got under the car, replaced the speedo cable, checked for obvious damage to the half-shafts, differential, rear hubs & bearings, and back of the drive shaft. Nothing I could see. The shimmy continued, and got worse. Finally, a few months later, it got so bad, that I got under the car again, and found slack in the driveshaft. Criminy, I'll have to replace the u-joint bearings, what a pisser. So I read up on the operation, and looked for a local source for the bearings. Then, I dropped the drive shaft, and this is what I found:

(Bigger pictures at: http://www.16paws.com/rx7/driveshaft/ )

No point getting new bearings for this drive shaft. Ever so fortunately, I had a spare FC NA driveshaft in the garage. Oh, how I miss Pick-n-Pull and Pick-your-Part; there are NO self-service junkyards in Central Texas, as far as I can tell. However, you can legally marry your sister.

So here is my question: does this look like reasonable failure for a driveshaft on it's own, or does it look like it was helped? The U-joint is just a few inches from where the speedometer cable some how loosened itself; so I find it suspicious that I have two failures in the same area minutes after visiting an unfamiliar low-rent tire dealer in a new town. Either way, I would sooner poke my eyes out with a red hot iron poker than return to a Firestone franchise anywhere in this galaxy.

And now I think I have to tighten up the transmission bolts because it seems to be loosing lube; I'm worried that I may have damaged its rear bearings.

 

I saw two driveshafts in the back of a RX n/a at Apple recking in Mansfield Tx. That's just on the east side of Ft Worth Tx. The name is Apple. I'm not sure if there's more to the name than that.

What part of Central Tx are you? Waco isn't that far away.

 

When I had my Jeep, I had driveshaft failures that put that one to shame. But yes.. after a certain amount of miles, and if a u-joint goes bad, or throws a cap, it can damage the yoke's if say.... LEFT ALONE FOR A LONG AMOUNT OF TIME... You SHOULD have had it inspected or done it yourself right away instead of driving on it hoping "It'll work itself out". Typically if something is wrong...... SOMETHING IS WRONG...

Anyways... griping aside, glad you had a replacement. Oh and thanks for the scattered humor in this post... Texans are weird.

 

YEs it is. Too much abuse, i've gone through two N/A driveshafts in 7 months.

If your going to be beating on yur car alot, i recommend getting the corksport(?) driveshaft i think it was. THey have replace able u joints.

 

Sigh, I'm in Austin. The drive to the DFW area isn't so bad (when I'm in my FD) it's the morans that choke the major highways around the DFW metro area that suck-diddley-yuck. I have literally spent more time stuck in traffic just outside of town than on I35 between there and Austin (not counting fuel stops for the thirsty beast). I have not found any self service junkyards around here. I really miss "junkyard Saturdays" in the South/East Bay (SFBay Area) when we'd hit up to 5 yards in one day since P-n-P had the "pay once, get in all day" stamp technology. And half price days, when I'd come home with a motor, or transmissions or hood.... sigh. You'd be surprised what a 5 gallon tank of compressed air and a 1/2" impact wrench will do for you in a yard. Flywheel nut? No problemo. Rear hub nut? Natch!

What I find suspicious about this failure is (a) the timing (as I drove away from Firestone), (b) the locality (i.e. just one ear of the u-joint), (c) the inexplicable failure of the speedo cable and (d) the failure position on the driveshaft. The end cap (outer bearing race) is still intact, where Mazda staked it in place close to two decades ago. Now, I have torn an NA FC driveshaft in half before, on this car as a matter of fact. It ripped apart at the differential end as the tube tore radially. All I knew was one second I was peeling out of a Taco Bell parking lot into heavy cross taffic, the next second the car was rolling to a stop perpendicular to four lanes of traffic and the motor was revving. But the u-joint was fine. That's why I concentrated on the rear end but didn't find anything. So I'm now on my third driveshaft in 240K miles on my reliable old '87 base model, that I bought new off the dealer lot 20 years ago.

 

that **** looks like it could've gone @ any moment. lol. mine broke on the yolk in the same exact place. but i was driving when it did. lol. not fun... especially right when school lets out.