So who's torn down an RX-7 tranny?

[Mike Spencer]

My donor car is an '86 GTU. I'm DEFINITELY going to "outsource" the motor, but I have to find out which 5th gear I have and if the tranny is even usable.

Anybody have any "words of wisdom" to offer as I tear apart my first 5-speed???

Any comments/suggestions would be welcome.

Thanks!!

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Mike Spencer
NC Region
1986 RX-7 Build In-Progress
1990 RX-7 Convertible In-Driveway

[paulydee]

The break down will require some special long arm pullers to get some of the bearings off. Other than that you need to follow the directions in the shop manual closely. Replace ANYTHING that loks worn (i.e. syncros, shift hubs), and replace all of the bearing if you are going to make it fresh.

Pauly D

[Mike Spencer]

Originally posted by paulydee:
The break down will require some special long arm pullers to get some of the bearings off. Other than that you need to follow the directions in the shop manual closely. Replace ANYTHING that loks worn (i.e. syncros, shift hubs), and replace all of the bearing if you are going to make it fresh.

Pauly D

Thanks for the feedback! I intend to do this right and not have to do it again for a while, so anything questionable gets replaced.

Can you give me a little more info on the "special long arm pullers"? Thanks!

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Mike Spencer
NC Region
1986 RX-7 Build In-Progress
1990 RX-7 Convertible In-Driveway

[paulydee]

The pullers I have used in the past were borrowed from a Mazda mechanic I know. The are special Mazda tools. I don't know if there is a non Mazda equivalent I am afraid.

[ddewhurst]

Mike, I don't have all the answers but might it be more economical to procure a rebuilt trans from one who knows the in's & out's of the trans ? Just as an example a RX-7 trans rebuilt from ISC Racing is $295.00. I have read that a person can spend a bunch of dollars on parts alone. I replace the trans at approx $150 each from the reuse yard (junkyard).

Anyway with respect to the tools. For a 1st gen RX-7 puller needs to be IIRC 8 inches long (Fleet Farm type place for $20) & IIRC the nut socket needs to be 1 5/8 inch (Fleet Farm type place for $7). The nut is metric but the 1 5/8 inch socket works. Ya need to machine out the square extension to fit over the shaft & weld a handle to the side of the socket.

Have Fun
David

[This message has been edited by ddewhurst (edited June 09, 2004).]

[MMiskoe]

I didn't do it, but talked to the guy who did for our Miata. He only commented that the $$ for the special tools is well worth it. Long socket from what I remember him saying. He's a Nissan mech so he may have had some other stuff us other ham fisted guys don't.

[itaracer]

Good subject. I'm wondering if I should replace or rebuild my 1st. Gen transmission. I get a "grind" occasionally in the 4-3 downshift and the 2-3 upshift sometimes hangs.

[Mike Spencer]

Originally posted by ddewhurst:
...Just as an example a RX-7 trans rebuilt from ISC Racing is $295.00...

David -

For that price, I'm probably better off working on other parts of the car!

I've seen their stuff mentioned in IT Car classifieds, but all my internet searches turn up is International Speedway Corporation (i.e. NASCAR). I *know* that's not them.

Can you give me any contact info without violating website advertising rules???


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Mike Spencer
NC Region
1986 RX-7 Build In-Progress
1990 RX-7 Convertible In-Driveway

[Silkworm]

www.iscracing.net

Just bought one from them, just over $800 to my door, no core required. Cleanest thing I've ever seen in my life, so I have a good feeling about them already.

Remember, that 295$ is just labor, gotta add shipping and hard parts into that cost. For me, I needed mine PDQ so I just ordered a 'new' one.

Oh, and the first year of the GTU was 88, so not sure what car you have, but if it's an 86, it's not a GTU. Unless someone's swapped in a GTU tranny, you've got the standard .71 (I think) ratio 5th gear. Doesn't really matter until you get to 4.88 or 5.12 differential ratios anyway, since you'll almost never use 5th with the stock 4.10 ratio.

PaulC


PaulC


[This message has been edited by Silkworm (edited June 10, 2004).]

[ddewhurst]

Mike, sorry about the $295. It's as Paul stated $295 with your trans plus parts. Give them a call for the real details.

Have Fun
David

[C. Ludwig]

Actually the .756 5th gear only came in 89 in the GTUs. That not plural GTU but rather GTUs as in sport. The 86s had a .711 and the rest of the NAs had a .697.

Interstingly the stock 5th gear in a Miata which is a .8-something works out to a .756 when used in the RX-7. The input ratio between the input shaft and the counter shaft is taller for the RX-7 than the Miata. So if you're bargin hunting you can find the prefered 5th gear in a blown up Miata trans for cheap. With my turbo Miata I've created a couple of those.

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Chris Ludwig
08 ITS RX7 CenDiv

[This message has been edited by C. Ludwig (edited June 10, 2004).]

[Mike Spencer]

Originally posted by Silkworm:
www.iscracing.net

Oh, and the first year of the GTU was 88, so not sure what car you have, but if it's an 86, it's not a GTU. Unless someone's swapped in a GTU tranny, you've got the standard .71 (I think) ratio 5th gear. Doesn't really matter until you get to 4.88 or 5.12 differential ratios anyway, since you'll almost never use 5th with the stock 4.10 ratio.

Thanks for the URL.

FWIW, it definitely is an '86. Also, the car has what someone (who I USED to respect ) told me were GTU wheels and it also has the 1.5 pound (well, REALLY light) hood. Also, no sunroof. Perfect donor car!

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Mike Spencer
NC Region
1986 RX-7 Build In-Progress
1990 RX-7 Convertible In-Driveway

[benspeed]

I'll throw in that ISC is an outstanding company to work with. I've bought several transmissions, an awesome race motor, full suspension, complete cooling system and other stuff from ISC. Tracey works the phones and she's always pleasant and Mike will take the time to go over what you need to do.

Cheers,

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BenSpeed
#33 ITS RX7
BigSpeed Racing
[email protected]
NNJR

[C. Ludwig]

I'll throw a thumbs up their way too. I've bought a few things from them and have always been happy. And their prices on the transmissions are outstanding!

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Chris Ludwig
08 ITS RX7 CenDiv