I'm confused about where to place the jack and jackstands. For jacking up the FRONT END, StealthTL said to place jack at the "frame rail just ahead of the motor." However, where do I place the jack stands? At the outer edges underneath the door sills?


Similarly, if I want to jack up the rear end, where do I place the jack and jack stands?


***Edit: I found the answers at http://www.techguys.ca/howto/floor_jack.html. This website was given in the thread "Best way to jack the car?", which is at https://www.rx8club.com/showthread.p...ack+jackstands.***

My Red Line transmission & differential fluid change
 

Thanks to everyone who has contributed to this DIY.

I changed trans and diff to Red Line yesterday using much of the information contained here. Some additional notes and thoughts for those of you embarking on this project.

For those of you uncertain if you want to change these fluids now or wait until the 30k maintenance interval... this change was perfomed at 9500 miles on my 8. The magnetic plug for the trans had a "dome" of metallic filings at least a quarter inch thick and the fluid drained from the trans was quite "silvery". The differential drain plug didn't have quite as thick a deposit and the fluid was not as visibly contaminated but I feel better knowing that the "break-in" fluid and residues are out.


1. Leveling the car - check the level first before starting to raise it. I used a 36" carpenter level across the door sill with the front and rear doors open. In my garage there is a slight pitch to the garage door so I wanted the level the same once raised.

2. Raising the car - I used Rhino ramps in the rear so started by backing the 8 up the ramps. Easy enough, but now the front was too low to get the floor jack under the front crossmember. I used the scissor jack under the standard lift point at the front to slightly raise the front enough to get the floor jack positioned under the center of the front cross member.

3. Raised the front and placed the jack stands under rear attachment points for the subframe (heavy stamping just rear and inboard of the rear side of the front tires). I do not like placing the jack stands under the rocker panel lift points or the unibody frame rails. Three notches on my Craftsman jack stands and the level was perfect.

4. Loosen the trans and diff FILL plugs first. You don't want to find that you have a stuck or stripped fill plug after draining the fluid. Leave the fill plugs in place, finger tight.

5. Remove the transmission drain plug while holding the drain pan right up under the drain. Once you have the drain plug out and the pan right up under the trans, remove the fill plug. This way you don't have fluid shooting all over the floor and yourself. Do the same when you're ready to drain the differential.

6. Refilling - I used the flotool/hose method. I bought two flotools and cut two 4' lengths of 1/2 inch clear tubing. I bought the tubing at a marine supply store for $1 per foot. It is food grade tubing. I only mention all this because this tubing fit the flotool and the fill openings perfectly. I transferred the Red Line to thoroughly cleaned and dried 2 liter soda bottles. The flotools fit the soda bottles perfectly with no leaks. The reason I used 2 of everything is so that I wouldn't cross contaminate the API4 and API5 products.

7. Place the tube into the fill hole. The fit is very tight. I placed a short phillips head screwdriver between the top of the tube and the top of the fill hole in order to allow air to escape as the fluid was filling. Raise the bottle and squeeze until some fluid escapes from the airgap at the top of the tube. You will probably need to lower the bottle and allow air to reenter the bottle perodically.

8. Don't forget to replace the fill plugs and crush washers. I torqued to 39lbs/ft.

There was a lot of preparation, but it was worth it. Very little difficulty or mess. Only used two small rags for the whole job and that was to wipe off the small overfill on the trans and diff and to clean the magnetic drain plugs.

Please return the used fluids to the local oil change facility or your municipal collection site. (most will take the oily rags too)

Ok someone help. I changed my tranny, oil and rear diff. 2 weeks ago, to redline, except the oil was castrol. No problems with any of it until the other day I started to notice spotting on my driveway. Didn't have time to check it out, and I just jacked the car up today... the rear diff. is leaking. I tightened the bolt, but it was already tight enough, I made sure that I put the correct plugs and washers back in each fill/empty hole. Any suggestions on why this would happen?

Were all the threads clean?
Were the mating surfaces clean?
Did you use NEW crush washers?
Did you torque to 39lb/ft?
Did you thoroughly clean the fins on the differential rear plate? Maybe it's not leaking. Maybe it's just overfill dripping off.

Thanks for the suggestions beachdog. I did all of that, the only thing I didn't do is use new washers, but they weren't damaged or worn at all. It's not coming from the plugs, it's coming from the seal. I spoke to my mother's b/f who is a mechanic and he said that sometimes that happens when the oil is too thin, as redline is. He said the pinion seal won't hold the thin oil because there is some pressure built up in the gearbox and the thin oil is pushed out and will break or pass the pinion seal. He told me to change it back to the factory specs, then see if it still leaks, if so then bring it to Mazda. I have the car jacked up right now and I'm going to change it out, I'll let you guys know what happens. There wasn't any additive that needed to be used in the rear diff. right?

Thanks,
Brian

Hmmmmmmmm, been reading this forum regularly for the past 6 months and have not seen any posts on a leaking diff seal. Many forum members have changed to syn oil in their trannys and differentials with no reports of leaking seals. Did you use the recommended viscosity and spec?

BTW, the washers for the plugs are actually crushable seals that are compressed when torqued down. It's best to replace them with new washers when you R&R the plugs. Depending on how much torque was applied at the factory, the original washer might have already reached it's crushable limit and is now not sealing. Make sure you re-check that again before looking at more serious possible causes for the leak. Good luck and let us know what is causing the leak.

Thanks that sounds logical. Where can I get new washers?

Your dealership or on-line at Rosenthal.

Thanks, I think the differential is ok though, haven't seen spotting since I did the switch back to stock, time will tell now.

Did you change your washers when you switched back to stock? Also, did you notice exactly where the fluid was leaking from (was it the fill or drain plug)?

Nah, he said it was leaking from the pinion seal, which is at the front of the diff. I told you, those crush washers will last forever!

Doh! Thanks, he said it here: https://www.rx8club.com/showpost.php...0&postcount=30

Interesting that this is the first one that has leaked.

I'll give you guys an update over the weekend, the weather is horrible right now and the cover is on my 8.

I changed my trans/diff oil today with the Redine MT/75w90. I also installed RP's short shifter at the same time. Shifting is now perfect.
I couldn't believe how many metal flakes were on the magnetic drain plugs. It looked like it couldn't hold anymore and the old oil was very muddy looking.
Very helpful DIY thread.

I changed my tranny and diff fluids this weekend. There were NO crush washers on either of the drain plugs - only the fill plugs... Anybody else have this issue?

On another note, I can't believe how the Redline improves the synchro meshing. I can now easily shift into first gear going 25mph. Before, I was lucky to get it into first going <10mph! Wow! What a difference!

You might be able to do it, but I'd strongly recommend that you stop doing that! You're putting a huge load on the synchronizers when you downshift to first at 25, and they can and will wear out. Downshifting to first at 25 mph will definitely cause the 1st gear synchro to wear out prematurely.

Regards,
Gordon

c'mon... Its just a way to judge how different the Redline is from the stock stuff. Besides, in 2nd gear @25 you are turning 3500 RPM - hardly in the power band - hardly out of the range of 1st gear. Before changing the fluids, if I pulled-out and then saw the need for rapid acceleration after already shifting into 2nd, then I'd have to slam the gears - or get run over while waiting for the car to get the RPMs up out of the bogged-down range. Now, the synchros are lubed well enough to slide right in. I'd venture to say that the amount of effort required to get it into gears in proportional to the damage being done. So, since it goes right into first now, I doubt I am doing anything detrimental to the synchros. Hell - its a machine. If you drive it, it will wear out.

c'mon, hell, like any other machine, if you abuse it, it will definitely wear out faster :rolleyes: .

Okay okay! Sheesh!! :p It's not standard operating procedure for me. I was just extoling the rheological virtues of this stuff through an illustrative example. I still can't believe how much better it lubes the gears than the stock fluid. One of the biggest differences is cold-weather performance. The stock fluid felt like shifting through bubble gum if the tranny was cooled down to 40 deg. F or so. The Redline is -way- less viscous at lower temps. I'd bet its also more well behaved at higher temps. :D

-Shift-on, Brothas!

I can't wait to do this. Excellent DIY. I read it twice however and somehow I missed the correct Red Line products to use. Is it MTL or MT90 for the tranny ? Redline mentions Mazda's specificaly for MT90 although the DIY seems to link to MTL .... Similarly did everyone use 75W90 in the diff with friction modifiers? I have the Sport Package. Thanks for clarifying.

Below is what you need.

Thanks, that helps.

Ok here's my update sorry it took so long. My pinion seal was broken from the thin oil it wasn't the washer, thank god Mazda covered it. I did speak to a mechanic and he told me that it was from the thin oil, he said he's seen it happen on a few cars, not 8's though. So that's my story, remember it is possible that I overfilled the rear differential, I thought I had my measurments correct, but I do make mistakes. If I overfilled it, I would guess that the pressure would be too much and that could have caused for a broken pinion seal.

Break the pinion seal from using too much liquid ? I doubt. Cannot fill the differential completely, the filler port is lower than the top of the case. Can put in a little extra, if car is tilted to the front. Now, from that extra amount, to go from a safe pressure to a huge one capable of breaking a seal, seems too extreme to me.

Redline MT 90 - 75W90 Trans and Diff oil change
 

Well, I had never changed transmission and differential oil before. It was a great project to do with my son. We had access to a 9K lift so we were able to walk under the car... a real advantage.

Things we learned.

• We ordered new drain plug crush washers from Rosenthal but when we compared them the ones on the car, the factory installed washers were thicker. We reused the original washers. Your choice.
• Getting oil into the fill hole is tricky. We had planned to use a syphon unit for draining gas but could not get the oil to move. I had also bought a funnel that had a shut off valve at the base. I patched together the hoses from both systems and we filled the tranny by feeding the hose down from the engine compartment, by the oil stick.
• The differential was worse. Our tubing did not reach to either side of the car. We finally got it done by filling the funnel, raising it up into fender well behind the rear tire and feeding the tubing along the half shaft. Took some time, but worked.

In the end, my son and I spilled a little but it was a fun project.

The end result....
After some cautious laps around the garage, we took it on a run that combined city and highway speeds... up to 90. The tranny is quieter. There is a 20% drop in shift effort. The car goes into reverse far easier. The gear noise in fourth is significantly less. Gear noise at 90 is almost noexistent and... while it may be just my imagination, I think the car is quicker and requires less throttle to maintain 80 mph.

I will be checking for leaks over the next week, but we are really satisfied. Now I have to do the same on my wife's 8. Should go much quicker.

Thanks to all for all the information and insights. You made this an easy and fun saturday morning project.

Dave