80W90 Gear Oil in Tranny? (Guess I'm not very good with WIKI search)

[rbastedo]

Is it OK to put 80 W 90 gear oil in the transmission?

I've got an A15 motor with a 4 speed manual transmission.

Thanks!

[datzenmike]

Make sure it's labeled GL-4 and NOT GL-5. GL-4 is recommended but hard to find. The 80 W 90 is good to about 100F. If your summer heat exceeds this then go thicker.

[rbastedo]

Thanks, good to know.

I'll go find some GL-4 and put that in.

Does it hold 2 quarts?

[datzenmike]

The transmission and rear end oil should be changed every 30,000 miles. If you don't know... do it.

 

Two quarts should be close. Remove the drain bung at the bottom if you haven't and clean it off. It's magnetic and collects ferrous metal particles. Vehicle level, fill through the side bung until it won't take any more. Good to go. Use a piece of garden hose and a funnel from a dollar store. Run the hose down from the engine compartment and into the tranny.

 

While you are at it check the rear end. Pop the fill bung and the oil level should be up even with it. If draining clean the magnetic bung.

[rbastedo]

Thanks again!

I have one of those pumps so I can pump it in.

 

Neither plug had any stuff on it so I guess that's a good thing!!

 

What would happen if I could only find GL-5? You using CAPS when you say "NOT" makes me think the gearbox might explode if I use GL-5.

The auto parts places around here only carry GL-5. Next I'm going to go over to the True Value and see what they have. They do carry motor oil and gear oil.

[datzenmike]

GL-5 is used in newer car rear ends and transmissions and contains more of a certain additive to prevent wear on the gear teeth. GL-4 has it too but to a lesser degree. This additive is not good for brass/bronze parts like the balk or syncro rings used in our older transmissions. Seems like the GL-4 is slowly being phased out and it's hard to find. Some say you can use GL-5 some say that it will chew up the brass. Nissan manuals say to use GL-4 but dealers probably use GL-5 and say that it's ok, hoping any problems from it's use will be far down the road. If you were to tell them that you are aware of the controversy and will be back for a new tranny if it goes bad I bet they would change their story fast.

 

All I can say, until it's been proven one way or the other, is to use the factory recommended GL-4 oil as in your owner's manual.

 

Try one of those jiffy lube places. They may have some of the old GL-4 laying around. I know a guy that got 4 gallons for $6 for his 720.

[rbastedo]

Ah, now I see.

I'll look. I suppose if worse comes to worse there will be somewhere online where I can order the GL-4.

[ggzilla]

For a Datsun 210 transmission, the kind that came with A15, Nissan recommends: API GL-4 75W, 80W, 80W-90, 85W, 90 or 140.

 

80W-90 is a good choice. It works per spec at -20 up to 100F.

 

 

Shuck's

* 80W-90 is only $3.69 for 32oz

* 85W-140 is only $5.69 for 32oz

[HRH]

"Typically, a GL-5 gear oil will have about 2 times the active additive level

of a GL-4 product. This additional additive can cause problems with yellow

metals like brass or bronze."

 

I just pulled this from some other guy's letter from Castrol. My question is whether a transmission that has been rebuilt would have replaced brass and bronze parts?

 

The head shop replaces bronze guides stock in Datsun heads with steel due to not running leaded fuel anymore, maybe it's the same for transmission rebuilds?

[HRH]

Hmm, Redline MT-90 (75-90) gear oil is GL-4. I think that will be going into the racecar transmission when I replace it.

[HRH]

Check out what I found on Valvoline's website regarding ZDP:

 

http://www.valvoline.com/downloads/2008-003a.pdf

[rbastedo]

I have been running Valvoline VR1 since I bought the car.

 

It would be nice if they would also make something specifically formulated for the older gearboxes.

Edited January 21, 2009 by rbastedo

[HRH]

Hey, is that VR1 synthetic or regular oil?

[rbastedo]

Regular oil with a higher amount of zddp. Works good in my old cars!

[ggzilla]

That's fine for engine oil, but we are discussing manual transmission oil here.

What's needed for engine to replace lead additive is not what's needed for gearbox.

 

Since oil manufacturers still create GL-5 and GL-4 both, maybe there is something to be said about it. To be safe, just get GL-4 and ... no worries.

[rbastedo]

I've researched here, on other old car sites (Citroens, Mustangs, MG's of course) and the general consensus is to use the GL-4. (makes sense)

 

However, it's also true that the same things that are in GL-5 that are bad for the yellow metals are present in the GL-4 but in a lesser amount. This means that it will eat the metal but take longer to do it.

 

Maybe some synthetics get around this problem by using a different formulation, that's what it seems like I am reading.

 

Yesterday I went over to Joe's (formerly GI Joe's) and looked at their oils.

Royal Purple, Amsoil in both GL-4 and GL-5, and of course the Valvoline and Pennzoil GL-5 stuff. I was tempted to go ahead and grab the Amsoil GL-4 but I've also read about some people getting a leaking problem after going synthetic.

Is that likely with my Datsun transmission?

 

Oh - I've even read that going with a Marine grade gear oil could be good because of their anti corrosive anti-rust additives.

[datzenmike]

Very likely. I change the $5 rear seal whenever I put a tranny in so no problem with it. The transfer case began leaking at the top input...$26 seal and ok. The rear pinion leaked and I didn't see it and lunched the rear end. I had a spare and put a new seal on before installing and it been just fine. These trannys are 25 to 35 years old! I don't doubt the seals are worn and would leak.

[ppeters914]

I've also read about some people getting a leaking problem after going synthetic. Is that likely with my Datsun transmission?

 

I remember a lot of discussion on this a couple years ago. Lotsa controversy and theories, but the one that makes sense is that the original seals (at least prior to 1980? 1970?) were not quite compatible with synthetic oil. That, and being old and worn meant leaks....and thus automotive lore is born.

 

If the seals have been replaced in the last 10 years or so, they should be compatible with synthetic oils.

 

I think I saved the info and links, but that's all at home.

[imtb]

What size is the drain plug ? Is it allen plug?

[ggzilla]

60-series transmission drain plug is a square stud, I think it is 14mm (9/16").

[datzenmike]

The square end of a 1/2" ratchet or extension fits perfect on the fill and drain plugs on tranny and rear end.

 

For $5 change the rear seal.

Edited February 5, 2009 by datzenmike