How to - What is the Best Way to a change the Transaxle Fluid?

[Nicholas R]

Try for 80W90. Not enough difference to matter. I actually prefer the generic (Super Tech) stuff from WalMart.

Full disclosure, so do I. I may be an outlier, but in the last 6 years or so I've had to drain and refill my transmission four different times, and didn't want to keep paying for the synthetic stuff. I've even got a $60 bottle of Redline Oil 75W-90NS sitting on the shelf that I've never used. I put the supertech in once telling myself it would be for a "break in period" but the transmissions have always shifted great so I've yet to have a reason to use anything else. Several refills later, I'm still running Super Tech.

[David T]

In the world of Lotus, what you use in the transaxle seems to make a very big difference. The Lotus recommended fluid is NLA so not much choice but to try substitutes. RedLine MT-90 seems to be OK for most of us. 85W-90 won't work but it seems just fine in Deloreans. Hard to understand, it is basically the same transaxle. The main problem is how it interacts with the syncros. It has to have just the right amount of slipperiness so it shifts right and it has to have the right lubricity for the differential and can't attack the bronze. The fluids for the differential and the transmission have different, competing requirements. My guess is the ones who have problems with MT-90 (or even 85W-90) probably have worn parts in the shift linkage and/or need a minor adjustment in the linkage.

[Nicholas R]

In the world of Lotus, what you use in the transaxle seems to make a very big difference. The Lotus recommended fluid is NLA so not much choice but to try substitutes. RedLine MT-90 seems to be OK for most of us. 85W-90 won't work but it seems just fine in Deloreans. Hard to understand, it is basically the same transaxle. The main problem is how it interacts with the syncros. It has to have just the right amount of slipperiness so it shifts right and it has to have the right lubricity for the differential and can't attack the bronze. The fluids for the differential and the transmission have different, competing requirements. My guess is the ones who have problems with MT-90 (or even 85W-90) probably have worn parts in the shift linkage and/or need a minor adjustment in the linkage.

I have to wonder how many Lotus owners have actually tried running something less fancy.

[Cone]

That would be a male socket for a 10mm female plug.

For the female socket needed on the male trans drain/fill plugs I think this is the one he was talking about:

https://www.amazon.com/CTA-Tools-204...81&s=hi&sr=1-1

That’s right Mark, that’s exactly the one I got from Amazon.

Here’s a link to the fluid Danny told me that they use at DMC SOCAL https://www.thelubricantstore.com/mo...lus-80w90-12x1

It is for a dozen bottles, but it was cheap so I didn’t really care having enough for a couple changes. I was having an issue with grinding in reverse when the car was warm, this made a big difference to make that go away.

[Ras12]

So I purchased the oil, found a 10mm square female socket and was able to “social distance” myself from my wife and kids.

Excited to begin I took my time, put the socket on the fill plug and it came off relatively easily.

I then moved to drain plug. Previously I sprayed both the fill and the drain plugs with WD40 and Penetrating Oil several days prior.

Needless to say the drain plug won’t budge. See the photos below as I stated rounding off the plug head and stopped.

Any advice on how not loosen the plug?

Thanks

Jason

[WHO1DMC]

Heat usually works. Haven't had to do it myself but others have.


Dave B.

[JETS 81 DMC]

Agreed, heat should work.

What was the brand of the 10mm socket you used?

[Bitsyncmaster]

I have had to weld a nut on the damaged plug. The heat from the welding makes it come off easy. So if you know someone with a MIG welder try to get him to weld on a nut. If you can still grab whats left maybe heat will break it loose.

[Ras12]

How hot? I got it “warm” to the touch but didn't get it cherry red. I have a propane torch maybe I should use that.

I have a Performance Tool - Performance Drain Plug Socket Set - PFM W54287

[JETS 81 DMC]

[QUOTE=Ras12;256348]How hot? I got it “warm” to the touch but didn't get it cherry red. I have a propane torch maybe I should use that.



Yes, use your propane torch. It need to get much hotter than warm to the touch. Heat around the plug in the thread area. You can also tap it with a hammer and spray some more penetrating oil on it when it is still hot and try to remove the plug.

I hope this helps and you succeed. Then replace with a new plug.