dwyatt321

Hey anyone think this one is broke? lol... Can I purchase a U-joint for an rx-7?? I can't find one on the internet. Thanks

Sgt Fox

iTrader: (3)

84/85 U joints are non replaceable. You will have to either get a new drive shaft or take it to a local drive shaft shop and have them replace them, as the stock u joints were staked in.

jgrewe

iTrader: (1)

Rockford driveline, about $18. They come with instructions, I've used them on my race cars forever.

jgrewe

iTrader: (1)

Here is a link, you're looking for the 430-10A IIRC

http://www.rockforddriveline.com/replacem.htm

datfast1

MazdaTrix should have it.

datfast1

If your car is stock, Mazdatrix should have a stock u-joint replacement. I never had trouble with the stock u-joint until an incident happened on the freeway when the u-joint popped and shattered in half after my motor exceeded 200hp. Then I got me an aftermarket driveshaft with V8 u-joints.

Oneiros

Nice, I have a feeling mine is in a similar condition...

mazdaverx713b

iTrader: (91)

mazdatrix does not sell replacement u-joints for 83-85 RX-7's. the u-joints are not meant to be replaced. the idea is that you will have to buy a new driveshaft. you can talk to a local speed shop or driveshaft shop and ask them if they can order replacement u-joints and replace them for you.

dwyatt321

Hey thanks guys, Ill have to check these places out. I took that U-joint off the driveshaft last night. I was surprised that it actually came out, since everything I have heard is that it's non-replaceable and you have to buy a new driveshaft. It doesn't make sense that it would come out if I can't replace it, why wouldn't it be a sealed unit, with welded caps or something similar? I also noticed in the Haynes Manual that it does have a section explaining how to replace the U-joint on the shaft. So with that being said could someone tell me what it means when they say it's staked in??

Is it necessary to have the driveshaft balanced when done replacing the U-joint? Thanks guys.

The car was vibrating to the point my arms were going numb from holding the steering wheel and the transmission would clunk when I would change gear.

Sgt Fox

iTrader: (3)

Earlier rx-7 used a u joint that had circlips you could remove to replace the u joint. The later rx-7 staked in the joints, which meant they deformed the metal around the joint to act as a circlip.

Read this if you don't believe me: http://mazdatrix.com/g9.htm

dwyatt321

sgt fox, I believe you, but Im going to read the article anyway, might learn something. Well it seems to me then that I dont have an 84 driveshaft on the car anymore. I was able to knock the U-joint out and the inside of the yoke(?) where the U-joint was sitting is smooth, I didn't notice any deformity. So in other words if it was an 84 or 85 driveshaft I wouldn't have been able to remove the caps and U-joint from the driveshaft at all??

I did have the driveshaft replaced when I had my 85 GSL-SE LSD rear axle installed on the car, the mechanic said my old shaft wouldn't mate up or fit with the new rear so he installed the one I have now, I have no clue as to what year shaft it is.

datfast1

I was able to replacement mine cause I got a 1981 drive shaft.

datfast1

1983 to 2004 RX7 you can't replace the u-joint. You need to look for the 1982 and older drive shaft, hopefully in good condition those you can replace the u-joint. If you can remove your old broken u-joint there is a change you got the old school driveshaft and the picture you have looks like the groove is for a C clip to hold the u-joint. You know its a Mazda u-joint just start with the 1979 to 1982 RX7 u-joints. Then compare your old broken u-joint to your foreign car part as long as the bearing cap that goes in is the same diameter and shape your good to go. You can alway return and get your money back if its not the right size. Good Luck!

jgrewe

iTrader: (1)

Guys, hate to **** your knowledge cheerios but you can replace them very easily. Two tools make it very easy. I use a torch to make the center part disappear and tap the caps in toward the center. Then use a die grinder to smooth out the bores the caps go into. The replacement caps have clips on the inside part of the joint.

Does 150mph at Daytona count for testing to see if this works? It does.

datfast1

Nice link jgrewe. According to this link you can buy a replacement u-joint.
Just in case if any rotorhead want to check this link for replacement u-joint and instructions.
http://www.rockforddriveline.com/replacem.htm

Sgt Fox

iTrader: (3)

Yes, the later drive-shaft's u-joints are replaceable, but not in the traditional sense. As I said earlier you can take it to a driveline shop and have then replace them, or perform the same procedure yourself.

dwyatt321

well i ordered a 1983 U-joint to look at it because it looked the same as the U-joint I had removed from the driveshaft and it ends up being the same U-joint. So I have replaced the one and have ordered another U-joint to redo the rear axle U-joint. Might as well since it's off the car. Thanks guys.

kenneth_ugalde

I replaced both U-joints on my 86 with 430-10A 2 weeks ago. This night as I was leaving the office, I made a fast start (not a burnout !!!) to clear the intersection and WHAMMM !!!
Big clunk from under the car and no movement. Almost got hit oon the side by on coming cars.
Pushed back to the street I was coming out of and got under the car. U-joint snapped. When it broke, the driveshaft hit the shifter extension housing and broke that too.

Needless to say that I am very upset. If I had abused the car I'd be honest about it. But I just made a quick launch. Nothing the OEM part didn't survive.
I have seen this before on parts where the material is of lesser quality.

I'll call Rockford tomorrow and see what I get.

Just thought I'd share my experience. If someone knows of another replacement, I'm in to try it.