Leaking rear main seal due to stationary gear?
 

I had a leaking rear main seal on a recent rebuild I did. After some research on the forum I suspected it was because of Atkins including the RX8 seal in the rebuild kit (I have used this same kit on two other cars without any issues). I pulled the engine and found the RX8 seal completely burped out of the stationary gear. Let's just say it came off with the flywheel (see picture).

I "pressed" in the correct new seal and also installed a new rear stationary gear O-ring. I say pressed in with quotes because it didn't take much effort - I probably could have pushed it in by hand. It ran fine for a few weeks and I noticed it is now leaking again (a lot slower, however). Is it possible that the stationary gear is bad since this is a brand new seal? I recall my other builds require significantly more force to press in the seal.





https://cimg3.ibsrv.net/gimg/www.rx7...3a7aa56768.jpg

Yeah, normally I have to kind of hammer the seal in. Removing it takes a pry bar and ruins the seal removing it.

Did you get the new one from Mazda or from a 3rd party? Wondering if it's an aftermarket seal that isn't the right size.

If the inside lip of the stationary gear is worn so it won't hold the seal you should be able to feel a lip there or something. But, I can't see that lip wearing down - hardened steel vs. a rubber seal.

Dale

I bought the new rear seal and oring from Atkins. I just made sure it was the orange RX7 one. I think it's OEM from their site? I'm not sure.

Some of the parts they have are aftermarket replacements, some are parts (like gaskets) they make themselves.

To be on the safe side I'd get a new gasket from Mazda to double-check.

Dale

Of course that only involves getting to the damn thing. I've never pulled just the trans. Is it easier than pulling the whole thing?

also seem to have trouble with lining up the clutch. I use a clutch tool before I tighten down the clutch cover but it's never centered correctly and I can never insert the transmission. I usually have to keep the cover loose, install the transmission then tighten down the cover through the access hole with the trans in place. Is there some trick I'm not aware of?

Many plastic clutch alignment tools have a nose that's too long - the part that fits into the pilot bearing. I've found that if you cut about a half inch off of it fits way better and centers the disc properly.

You can see if you just put the alignment tool in without the clutch disc - it should almost butt up against the end of the e-shaft (the wider part of the tool).

Sgtblue makes a good point, I have heard of the flywheel surface that the seal rides against being worn down and that causes a leak. Definitely worth checking while you're in there.

Dale

It looks like brown seal and not the orange. I have the same kit, but I ordered the orange seal and I have seen it somewhere in the forum someone getting oil leak due to the brown seal.
look at the difference..
https://cimg3.ibsrv.net/gimg/www.rx7...46ccce3f52.jpg
https://cimg1.ibsrv.net/gimg/www.rx7...e2bb9597ee.jpg

The same thing happened with my engine after a rebuild and it was a giant pain in the ass that put me in tears. I had to pull the engine while it was at a parking structure in DC where there was an incline and the platform shakes. It shook so much that the car bounced off the jack stands and punched a hole through the bottom, almost killing me.

The only seal that I have found that consistently works is the OEM Mazda rx-7 seal. It should be orange and have a NOK stamping. Part #1668-10-556A. I have had every other seal leak on me within 200 miles and will never use one again.. If you have strong hands you can press it in by hand but is should be snug. The oem RX-8 seal can work, but because it is shorter it is possible to press it in too far. Therefore I only use the rx7 seal.

Does anyone know if Atkins supplies OEM parts or 3rd party for the rear main seals? I'm guessing 3rd party as it just comes in a bag with an Atkins sticker and not mazda packaging.

This is a little disgruntling for such a small part and there are threads all over about it. Unfortunately I didn't know it was even an issue until it became my issue. Hopefully the other two builds stay running leak fee but rest assured the seals from Atkins will be going straight into the trash the next time I buy a rebuild kit.

^Yup. I sure will for any required rear main seals in the future. My plan for this one is to drop the trans and put in a new/used rear stat gear with OEM seals.

Atkins produces a lot of their own parts, which is really a cool thing. Going forward I can see them being a great source for discontinued parts that they start making, like gaskets and seals. But, in this case, their part falls short of OEM.

Dale

late to the party, but FYI:

https://jdlmfg.com/products/rear-main-seal-retainer

.

i posted this in 2016:


https://www.rx7club.com/general-rota...rning-1097212/

an additional item of advice re rear main seal:

do not use a flat bladed screwdriver to pry the main seal out around the O D. you will often scratch the mating surface and if you do, you will create a probable leak.

i have found for my needs that Atkins is an excellant supplier BUT i have to stipulate exactly what i want. they have recently started making their own inner coolant seals (compression seals). do not use them. stipulate you want MAZDA.

+1 i got the atkins supplied Rx8 seal to spin and catch on fire. i think maybe Mazda changed the clearance or something, 266,000 Rx8's were totally fine, but in the Rx7 these seals are like 90% fail rate.
the Rx8 seal is more profitable, which is why its the default even though it doesn't work