Continuous Rear Main Seal Oil leak
 

Hello guys,

I am really fed up of replacement this Rear Main Seal!!!:rl: this is the 6th time I am changing the seal, why? all the time the garage is asking me to replace the seal... I am tired :(

Anyone knows what is the cause? please help :(

Thanks :)

Sometimes the part can be confused between the RX-7 and the RX-8. They look similar but the RX-8 seal is thinner and does not seal well.

See this thread for pictures. Ask to see the rear main seal they pulled from the engine. If it's the incorrect seal they should pay you back for the last 5 jobs.
https://www.rx7club.com/general-rota...rning-1097212/

Also... the old seal can wear a groove into the flywheel where the seal rides. If the seal is installed in the same place it will continue to leak. The seal can be installed further in or out, or the flywheel replaced and it should fix the problem.

Hmmm... ahaaa, now I see the reason why, I buy the rear seal from Atkins Rotary and it seems that they were shipping me all this time the dark color one, which is for RX-8. I always get the dark color from Atkins, but this time I ordered from Tasca Parts, Part no. 1668-10-556A for the rear main seal.

I guess this clears my problem, let's try the original seal from Tasca and see.

Thanks a lot :)

I have also had this issue from the Atkins rear main seal.
Got a new one from Mazdatrix and no leaks thus far.

Sucks having to pull out the tranny for a ~$10 part...

^Yup, someone needs to contact Atkins and tell them to stop sending that part like yesterday.

A local buddy of mine has to fix the exact some problem for the exact same reason.

While the design is slightly different, the two seals are interchangeable. If you have a leak it is most likely from installation error. The orange rx7 rear main seal is a bit wider than the maroon rx8 seal. Because of this the rx8 rear main seal can be installed too far in. The eshaft can have corrosion or other blemishes and since the seal is now sitting further in, it can sit on those imperfections and not seal. Both seals need to be installed flush with the stationary gear base, not recessed. It is also a good idea to hit the surface of the eshaft that rides on the seal with fine emery cloth to make sure its smooth. While I have used both seals, I prefer to use the correct part for the given application.

I recently installed a RX8 rear main on my 13bt. It sealed with no problems.

OP, are you sure its not leaking from the rear stationary gear?

Someone should look into hand modeling :naughty::hahano:

https://www.rx7club.com/attachments/...325_143336.jpg

"If you have a leak it is most likely from installation error."

"OP, are you sure its not leaking from the rear stationary gear?"

it is certainly possible to install a rear seal in such a manner that it leaks. it is great that tips were shared such as seal depth.

cleaning/polishing the contact surface on the crank is essential as is adding a small amount of lube to the journal... same for the front hub seal contact surface.

cleaning the mating surface between the stationary gear and seal is not to be taken lightly.

my seal leaks clearly came from the O D of the seal, not the stationary gear/rear iron mating surface or the I D.

pretty simple stuff here.... why would anyone use a 5 mm contact surface over a 10 mm.

as to the hand modeling... maybe i will have to clean my fingernails...

Howard

The sealing surface of both seals is approximately the same, even though the outside of the rx-7 seal is thicker.

Only the ID sealing surface is the same. The outside, which is the area the OP said was leaking, is 5mm thinner/thicker.

I have the same problem.. ordered rear main seal from Atkins and apparently they are undersized? Why the f would they do this crappie. Pisses me off.

A second suggestion to look at the flywheel. I've seen a couple FW's whose surfaces were either deeply grooved or damaged...somehow, with pitting.

FWIW, I've ordered a few things from TASCA, a door light switch and right side defroster vent among them. No complaints. :dunno:

in the midst of replacing rx8 seal from atikins, started leaking a couple months after install.

The stock rear main seal seems to still be available new, and it doesn't cost that much. I would just get the right part.

IMHO there's no good reason to use the RX-8 seal. Get the right part, do it once, do it right.

If that's what they want to bundle with their seal kits, that's fine, just order another seal and pitch the RX-8 seal. It's not like they're horribly expensive.

Dale

......they should stop this practice, immediately.

Not sure why this is an issue---- it's not like the correct part is no longer available.

I can't help but wonder if the leaks aren't caused by install error, rather than seal design.

Just thinking out loud, but wouldn't this be a known/recall item from the rx-8's if it were a result of only the seal? Or perhaps its due to mixing an 8 seal, with an FD gear and an FD e-shaft...

I'll be firing mine up this fall and I built my engine with 8 stat gears and an 8 e-shaft.. hoping they work better together..

My RX8 rear main seals fine. Going on about 6 months now.

Quote from Ray Crowe......

"Hell no! Why would I sell you an RX-8 part for your RX-7, when the RX-7 parts works perfectly fine and is still available from Mazda? Hell No!"

Anyone who knows the man will be laughing, because that's exactly the way he talks :rofl:

Lol! Well damn... he had no qualms about selling me the e-shaft and both stat gears for my mutt build (FD irons/housings, s4 NA rotors/stack, rx8 e-shaft/stat gears) :dunno: granted.. I also got all three pieces for what I would spend (less probably) on a new FD e-shaft alone.

Is the oil pressure (base and max) that different between an FD and rx-8 that the later design would be that prone to failure?

^right, you did that for a reason..... i.e. possible performance gain.

I mean, what's next? FB tension bolts, rx-2 corner seal springs?

Mostly it was because my stock eshaft was toast, and I didn't trust the gears afterwards (mass oil loss + toasted rotor bearing). So they NEEDED to be replaced :(

:rofl: