Question: What do I need to swap the transmission and diff fluids, other than the four (six?) bottles of RP? I saw some "crush washers" on Rosenthal mazda's site, is that the same thing or is that for motor oil? And is there anything else I need?

I was hoping to get this + clear corners + strakes all in one order to save on shipping.






PS: Do not leave the bottles of RP gear lube in your trunk. They will leak, and your interior will give off a subtle petroleum funk every time you get in.

 

There's lots of good information in the DIY: Transmission and Differential fluid replacement thread.

rx8cited

 

See the thread rx8cited gave, but here is a concise list of what you need for diff and tranny refill:

• 4 bottles RP
• 2 lengths of 1/2" clear tubing (5-6 ft.)
• Utility knife, for trimming tubing as needed
• 2x small plastic funnel
• ratchet
• short ratchet extension
• 23mm socket
• 24mm socket
• oil catch pan
• rags, lots of rags
• 2x Crush washers 9956-41-800 (diff)
• 2x Crush washers 2Y601-17-361 (trans)

That is it. Of course, a torque wrench is ideal, but you could probably get by without one. It is only 29-39.7 ft lb. for both drain and fill plugs. With the wrench I was using, I think 40 was the lowest setting. So, you don't have to seriously muscle it.

 

or a little pump, similar to a big shampoo or soap bottle. Super cheap and very easy !



https://www.rx8club.com/series-i-tech-garage-22/changing-fluids-%3Deasy-fun-37600/

 

I used a pump once with my RX-7. It seemed like the pumping to oil movement ratio was like 8,000:1. A whole lotta work...It was probably just a crappy pump, but in any case I found the hose/tubing and funnel to be super easy with no arm workout involved. Some other folks swear by the pumps, though. Different strokes for different folks (pun intended). :D

 

LOL, good one.

It took me about 15-20 strokes for the diff, and a bit more for the trans. Not bad at all

 

Maybe my info is out of date, but a few years ago when putting synthetic in my diff I learned that if you have a clutch type limited slip it was important to use a synthetic designed for limited slip differentials—I believe the term used was “friction modifier.”

Anyway, the concern was the synthetic was so slippery that it would reduce the effectiveness of the limited slip diff by causing too much slip in the clutch packs which need some friction for them to work correctly.

I don’t know what type of limited slip the 8 has or if this info is even relevant with synthetics anymore, but I thought I would throw it out there just in case.

 

Holy bat crap that is hard on the eyes!

 

You have the same part number for both differentail crush washers. The 45 minutes brillo and i spent talking with the mazda parts dept came up with a different answer. Mind you I have not done the work as the crush washers are being ordered.

Part numbers I got where...

2 y601-17-361 for tran
1 9956-21-800 for diff
1 9956-41-400 for diff

 

I looked into this previously: https://www.rx8club.com/showpost.php...&postcount=285

rx8cited

 

I followed David at RP's advice and put in Maxgear on both and what a diference. Tranny is much quieter and feels a lot nicer.

 

Ah, that's exactly the data I was looking for. Thanks.

 

That is interesting. I forgot to compare the old ones before I tossed them (was paying by the hour to use the lift). Has anyone else successfully used the same part# for differential washers? So far, after 2 days of flogging I have aboslutely no leaks whatsoever.

 

When I asked the dealer months ago, I was given the same part # for the differential crush washers. That's what I used (details in the DIY). It's been 7k+ miles now, no problems.

rx8cited