I'm reading in multiple places that this should actually be GL-3. @cruiser54 @lawsoncl @robsjeep can you chime in?

 

GL-5 is not correct. Any EP oil is corrosive to yellow metal. Use a manual transmission lube such as Pennzoil Synchromesh, Redline MTL, etc.

This is from the 1997 FSM:

 

Thanks for the info. I read that elsewhere online.

I ordered Redline MT-90. I assume procedure is as easy as:
1) Loosen fill plug
2) Remove drain plug
3) Drain fluid
4) Tighten drain plug to spec
5) Fill
6) Tighten fill plug to spec

Is that all? Do I need to replace the washer or can I reuse?

 

The GL5 back in the 90s didn't have the same additives in it as it does today, that's why you shouldn't use it now. I use 15w40 diesel motor oil in mine and it works great.

 

The washer is usually reusable.

 

@lawsoncl I reused both. Couldn’t get the plugs out without a breaker bar aka the nozzle extensions for my shop vac. It’s a shame that the transmission takes something like 3.2 quarts. Now I’ve got a 3/4 full bottle of Red Line leftover.

There was lots of gunk on the drain plug magnet and after the fluid settled in the bucket it was metallic/glittery. I don’t know if this was the original fluid but if it was it’s got 99k miles on it. I assume this is fairly normal?

 

No. First step is to make sure the fill plug can be removed.

 

Yes. I wrote “loosen fill plug.” How could you be able to loosen the fill plug but not remove it?

 

Gold glitter is from worn synchros. How's it shifting?

 

First and second are sometimes a little more difficult than the others. Sometimes has the same feeling as when you put it into reverse without going into first first. No slipping no grinding. It wasn’t gold colored I would say it was silvery.

 

I don't use the fill plug anyway, I take the shifter off and fill from the top.

 

Are you overfilling? I guess if you measure properly you are good. I just fill until it starts spilling out.

 

He probably still pulls the fill plug to know when it's full. It's just easier to pour oil in through the shift tower. Or you use a hand pump to get the fluid up from underneath into the fill hole.

 

overfill slightly I put a gallon in. On bigger manual transmissions like the ZF6, NV5600 and NV4500 I overfill those by a quart.