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View Full Version : Anyone using RX-7 Mazdatrix replacement driveshaft?



mbuskuhl
08-18-2008, 11:47 AM
As you know, the OEM driveshaft has non-replaceable U-joints. Is anyone using the OEM equivalent RX-7 Mazdatrix replacement?

I know it probably works fine for street cars but have heard conflicting information for high speed racing applications.

Thanks.

tom_sprecher
08-18-2008, 02:45 PM
I don't know the specifics but there is an OEM drive shaft for a certain year that is rebuildable. Try Googling it.

callard
08-18-2008, 03:27 PM
Dave Lemon owns Mazdatrix and successfully races an RX-7 nationally. Ask him if he uses the driveshaft.
Regards,
Chuck

mbuskuhl
08-18-2008, 04:17 PM
I don't know the specifics but there is an OEM drive shaft for a certain year that is rebuildable. Try Googling it.

I have heard you can get the OEM retrofitted but it was designed with non-rebuildable U-joints. This is true for '83 on. Even the driveshaft shops all have told me we just build you a new one instead (must be easier).



Dave Lemon owns Mazdatrix and successfully races an RX-7 nationally. Ask him if he uses the driveshaft.
Regards,
Chuck

Yes, but he runs the EP car and doesn't use the stock box so it's a custom driveshaft. I hear he runs the aluminum version of the OEM equivalent he sells in his drift car but did not run it in his EP car when he had a stock box with Miata gears. Mazdatrix may also be a little biased in their opinion, after all they are selling the parts.

I'm just wondering if the OEM equivalent he sells (steel version) will hold up in racing conditions just as good or better than a true OEM one from Mazda. The Mazda OEM (comp pricing) one is about $50 more than the Mazdatrix OEM equivalent he sells. Not a big difference on price normally but I got a hookup to get a Mazdatrix OEM equivalent at a nice savings off list.

I can't decide what to do on a driveshaft and only want to make one purchase and definitely want it to stay intact.

Mazda OEM
Mazdatrix OEM Equivalent (steel)
Mazdatrix aluminum - Not IT legal so don't expect anyone to even know about this option.

Surely not everyone is still using a driveshaft that is now 17-22 years old.

Mazmarc63
08-18-2008, 05:14 PM
Surely not everyone is still using a driveshaft that is now 17-22 years old.

Actually, mine's 22 years old. Never an issue. Ever. Been a race car for 12 years.

I know I shouldn't answer a question with a question but...

Why do you think you need a new one?

IMO (experience with half-shaft boots) go with OEM.

mbuskuhl
08-18-2008, 06:08 PM
Actually, mine's 22 years old. Never an issue. Ever. Been a race car for 12 years.

I know I shouldn't answer a question with a question but...

Why do you think you need a new one?

IMO (experience with half-shaft boots) go with OEM.

I think I need a new one as when I pulled my shaft there is a little play in the U-joints. Also... I like to replace things before they fail, I'm always rebuilding and replacing parts.

Good advice on the half shaft boots, wish I would have known that a few months ago. Recently I had them rebuilt not knowing and they used non OEM boots, subsequently both boots tore and spit grease everywhere. Someone else recently told me OEM was the only way to go on the boots as well. For now they have silicone patches but will be changed out.

tdw6974
08-18-2008, 09:19 PM
http://www.thrashdriveshaft.com/

seckerich
08-18-2008, 09:32 PM
I have run new Mazda factory driveshafts for 10 years with no problems. That said if you want rebuildable for the race car give Dave at Mazdatrix a call. He has better things to do with his day than lie to you about his products. If it works for racing he will tell you. Easier than wondering on a forum.:rolleyes:

mbuskuhl
08-18-2008, 10:15 PM
http://www.thrashdriveshaft.com/

I talked to them. Same price if not more both for steel and aluminum than Mazdatrix. There is also that story about the EP guy at Daytona who had a shaft built by a circle track shop, the shaft was not balanced to spin over 10k RPM apparently even though requested, long story short the car caught fire.


I have run new Mazda factory driveshafts for 10 years with no problems. That said if you want rebuildable for the race car give Dave at Mazdatrix a call. He has better things to do with his day than lie to you about his products. If it works for racing he will tell you. Easier than wondering on a forum.:rolleyes:

I called them last week, didn't speak to Dave but he was in the background and the guy on the phone said his driveshafts would work.

Just looking for anyone with real world experience on these. Too many conflicting opinions and I've made enough mistakes already.

joeracerx95
08-19-2008, 01:03 PM
I need to ask a question, are you talking about a 1st gen or 2nd gen? '83 up was mentioned but your signature says you drive a 2nd gen.

Here's my experience with a 1st gen. When I changed to ITA I switched out my final ration to a 4.88. Doing the math this means my driveshaft is spinning around 9,000 RPM in 5th at the fastest track I run. I had HUGE vibration problems. I tried a couple different used shafts. Indexing one of them made the vibration tolerable until I can afford a new one. I talked to numerous people that I consider an expert on Mazda's. They uniformly recommended only using a driveshaft from Mazda. YMMV.

mustanghammer
08-19-2008, 02:14 PM
For what it worth I called Mazda Trix and they advised me to buy a new shaft from Mazda for my first Gen instead using one of their rebuilds. So I purchased a new early style shaft because they are repairable. It was expensive but worth it - much better than any of the used shafts I had been using.

I have also noticed the condition of the tailshaft bushing has allot to do with vibrations. Pressing in a new bushing can improve this problem.

tom_sprecher
08-19-2008, 02:39 PM
I have also noticed the condition of the tailshaft bushing has allot to do with vibrations. Pressing in a new bushing can improve this problem.

Or have the tail shaft machined to accept the MazdaSpeed roller bearing and hardened yoke that is required with it.

Is that against the rules? Can driveshafts be balanced to that speed?

dickita15
08-19-2008, 03:55 PM
Is that against the rules?

yes but then again so is a non oem driveshaft. :)

JeffYoung
08-19-2008, 04:09 PM
Functional equivalent replacement parts ok?

Meaning, can't you have a driveshaft shop make an identical (weight, dimensions, material, etc.) duplicate of the stock driveshaft?

joeracerx95
08-19-2008, 05:43 PM
Functional equivalent replacement parts ok?

Meaning, can't you have a driveshaft shop make an identical (weight, dimensions, material, etc.) duplicate of the stock driveshaft?

Of course you can.

2008 GCR

"Stock replacement parts may be obtained from sources other than the manufacturer provided they are the exact equivalent of the original parts. "