Tranny and rear end oil type?

[hrcollinsjr]

It fills to the level of the hole in all models but the GT. The GT engine is tilted so the correct level is approx. 13mm/.5" below the filler hole.

Harold

[Matt M240Z]

So the only way to drain it is by unbolting the pan on the bottom?

[soybean]

In a word yes. Then you have to replace the gasket etc. The hex head bolt on the drivers side of the transmission about 3 inches above the oil pan is the fill plug. The way Steve described filling it is about the easiest way. The other is the same tools he described, just crawl under the car and use the same procedure, just don't squeese the bottle hard enough to blow the hose off. Hth, Jarrell

[opelnut10]

Some of them have a hex head fill plug and then there are a few that have a allen socket plug. Filling by using the plastic lube bottle and a piece of tubing is the simplest way, just make sure the tubing is down on the tapered fitting on the bottle and that you cut enough off the end of it that you get a good flow without having to squeeze the bottle hard. If you use your pinky finger and stick it in the fill hole and bent it at the first joint, you can feel the lube on the end of your finger and that is the level the transmission requires to operate properly. Also have the car level, wither up on a lift or jacked up on 4 jack stands.

[Matt M240Z]

Ok, just finished changing the gear oil. When I was done, I looked down in the drain pan and saw a metal spring that is 1.5 inches long and has a diameter of about a 1/4 inch. I did a not so smart thing and took the car out for a test drive. Good news, no more noise and it shifted just fine. The spring had a small steel tab at the end of it that looked kind of like a small watch battery. Does this sound like something out of the transmission and if so what does it do?

[asdasc]

Originally Posted by Matt M240Z Does this sound like something out of the transmission and if so what does it do?

hmmmmmm, apparently, not much!

[RallyBob]

Originally Posted by Matt M240Z Ok, just finished changing the gear oil. When I was done, I looked down in the drain pan and saw a metal spring that is 1.5 inches long and has a diameter of about a 1/4 inch. I did a not so smart thing and took the car out for a test drive. Good news, no more noise and it shifted just fine. The spring had a small steel tab at the end of it that looked kind of like a small watch battery. Does this sound like something out of the transmission and if so what does it do?

Yup, there's a check-ball and spring retained by the oil pan. It's for a detent on the shift selector shaft.

[namba209]

I guess that means it is supposed to be in there. Murphy's having a field day today.

[asdasc]

I got around to scraping all the gunk off my differential last night and changing the lube. I pulled the bottom bolt and the fill plug and like everyone said, it drained fine. I have a question, my FSM is for 74, and doesn't cover the GT, is it safe to assume that fluid capacities for the diff are the same? The 74 FSM says 2.5 pints. I put in 2 pints, and it 'seemed' full with the finger in the hole test. I didn't remove the diff cover, so it may not have drained 100% either, but I waited until it stopped dripping.

One other thing, I noticed today that it is leaking a VERY little bit around the drain bolt. There was no gasket on there, but I don't see one in the FSM either. I can cut one out of cork, but wanted to know if anyone else has done that or had that issue.

Thanks,

[OriginalOpelGTOwner]

How did you stop the bolt from leaking? I removed the rear axle cover lower bolt to drain and then refilled with Valvoline 80W-90 durablend gear oil. There is a slight leak now at the bolt. I am just going to remove the bolt and wrap with teflon tape and reinstall.

[paul.catherine]

Redline MTL is hard to beat - I used to race it in supercharged Miatas and it's not only great for the tranny, it made the stick shift like butter....

It's going in my GT now...

Paul
73 Yellow GT
Flagstaff AZ

[Redskinsjbs]

Originally Posted by paul.catherine Redline MTL is hard to beat - I used to race it in supercharged Miatas and it's not only great for the tranny, it made the stick shift like butter.... It's going in my GT now... Paul 73 Yellow GT Flagstaff AZ

Are you going to use the MTL in both the trans and the rear diff?

[paul.catherine]

The top port is the vent, not a fill. The fill is on the port side about halfway up. It's the only way you can measure the proper fill level (when it starts leaking back out you are properly filled)/ You put it in by feeding in the hose from a standard $9 fluid pump found at most auto stores.

Filling through the vent may damage the vent, and you will likely not fill the tranny correctly (overfill)....

This side fill is found on many tranny's (Same setup in my ole Miata and two Lotuses I usta have

Good luck!
Paul

[bert73]

Originally Posted by kent what size are the trany pan bolts ? I lost and need all new

I dont know actually the size of the tranny pan bolts but you could try to search on the search engine your queries..thanks!
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Miata Parts

[paul.catherine]

Originally Posted by Redskinsjbs Are you going to use the MTL in both the trans and the rear diff?

Sorry have not gotten back sooner...I used Redline MTL in the tranny and Redline Hypoid 75W90 I think it was) in the rear diff, almost the same as Redline but a hair more viscous, and more like the OEM weights...

I also did like a few others and welded a drain onto the tranny pan when I had it off. I found an oil drain plug at an auto store, matched a nut to it, and stick welded this to the pan in the back right corner. Welded the nut on the outsided to prevent a lip inside or interference. So far so good!

Paul