T19 Lubrication

[67MercM100]

I'm getting ready to swap out my T18 for a T19.
I've read that 15W50 motor oil works well for lubrication.
Does anyone have any thoughts on that?
Also, any thoughts on synthetic vs. conventional?

[Bullitt390]

80W90 is more than adequate. And being in Iowa the 15 weight isn't needed, Northern Canada or Alaska maybe, but not the mid-west.

50 weight motor oil is equal to about 110 weight gear oil.

Josh

[Eric L]

If I recall correctly... you dont want sulfur in the lube.. I thinks GL-5 is the bad stuff, GL-4 is ok

http://www.mobiloil.com/USA-English/Mot ... izers.aspx

[Bullitt390]

Novak recommends GL5...

http://www.novak-adapt.com/knowledge/t18_t19.htm

Although their 50 weight claim for FASTER shifts is questionable. Maybe they meant 30 weight engine oil, as 50 weight is heavier than 80w90.

Josh

[70_F100]

Although their 50 weight claim for FASTER shifts is questionable. Maybe they meant 30 weight engine oil, as 50 weight is heavier than 80w90.

Josh

Sorry, but NO WAY is 50 weight oil heavier than 80W90.

Those numbers come from running the oil through a viscosimeter, whether it's engine oil or gear lube. The rate at which it passes through determines the numeric value of the viscosity.

Using your logic, 30 weight oil would be heavier than 50 weight.

[fordman]

this is always a fun subject isnt it? i will not state any opinions on what is best or what you should use. i will only say this. on the glove box is a sticker that says use 50w engine oil in your manual transmission. now the matter of opinion about 50w back then vs today 50w i will not comment on.

[Bullitt390]

Although their 50 weight claim for FASTER shifts is questionable. Maybe they meant 30 weight engine oil, as 50 weight is heavier than 80w90.

Josh

Sorry, but NO WAY is 50 weight oil heavier than 80W90.

Those numbers come from running the oil through a viscosimeter, whether it's engine oil or gear lube. The rate at which it passes through determines the numeric value of the viscosity.

Using your logic, 30 weight oil would be heavier than 50 weight.

You know more that the oil companies?

http://www.bobistheoilguy.com/cms/index ... &Itemid=55

Josh

[averagef250]

Interesting chart there.

In a past life I used a viscometer daily, not complicated machines, we worked in saybolt with lube oils for big gearboxes and diesels.

The commercial machine oils I buy to keep my machines going today are all ISO standard. It's funny how in the ISO standard light, medium, heavy medium and heavy actually correlate to specific oil grades (kinda neat to realize that the "old timers" were actually being specific when you thought they were just out of touch with reality).

None of that experience correlates with SAE motor/ gear oils. having a tranny shop for awhile did give me some excellent insight though. 90wt works and works well. You put 50wt motor oil in it it's your choice. I bet it won't work nearly as well as good 90wt, yes I've tried it, and although it did ever so slightly improve the shift quality in a 435, I was replacing all the bearings and the mainshaft 400 miles later (the next day). So, you use motor oil if you think it's a wonderful idea. If you get motor oil near a tranny I built for you you can take the warranty paperwork you got with it and shred it.

standard, reputable manufacture 90wt is the perfect MT lube. You want to blow $20 a qt? then go ahead and buy full syn.

[67MercM100]

I think I'll just let the shop that's swapping the transmissions decide.
After it's done, I'll ask them what they put in and let you all know the outcome.

[67F100-390]

Just curious, what oil did they use... I know this thread is old, hopefully you can remember.

[67MercM100]

Was finally able to talk to the guys who installed the transmission.
They were fairly sure that they just used simple 80/90 gear oil.
Hope that helps. Sorry for taking so long to find out.

Just curious, what oil did they use... I know this thread is old, hopefully you can remember.