Vintage car "non-hypoid" SAE 80 GL-4 gear oil?

[Whitewolf]

Has anyone considered that a UTTO might fit the application? They are generally about 9.4 cSt kv 100c and are 'GL-4' rated.
Just a thought.

 

[Olas]

The first link on google..

http://www.amazon.co.uk/Liqui-Moly-1401-GL4-Transmission/dp/B004FPQYW4

Sae 80 gl4 non hypoid. Seems its pretty easy to get hold of

 

[440Magnum]

Originally Posted By: Beem
Originally Posted By: 440Magnum
Redline makes a GL-4 product line in various weights- MTL, MT-85, and MT-90. I would have ZERO qualms using any of those fluids in a 60s vintage transmission (let alone 80s) . Even though they are synthetic they're pretty much made for the purpose.

http://www.redlineoil.com/Products.aspx?pcid=7


If you want non-synthetic, your best (pretty much only) option is an ordinary engine oil. Use the viscosity table on the main BITOG page to determine what weight to use- SAE 40 engine oil is roughly equivalent to SAE 90 gear oil.

http://www.bobistheoilguy.com/viscosity-charts/


Despite some opinions, every vintage vehicle I've put synthetic oils in develop leaks very soon after use. Some people claim to get away with it, I never have. Can't fool me four times.

Maybe motor oil is an option as it is also noted as an option in the manual but that opens a whole new can of worms. Modern oils do not have zinc and phosphorus that the classic oils did. So a motor oil would probably need to be an old spec oil to be safe.


Thanks for the chart link. Looks like 30 wt is in the ballpark. I'm thinking before an SM rating might hit the mark.


I wouldn't worry about ZDDP content for a number of reasons- a transmission doesn't have the extreme sliding contact pressure points that a flat-tappet cam engine does. Besides, the modern (SN) levels of ~800 PPM for xw30s and 1200 PPM for xw40s are just fine. 800 PPM may be a problem for breaking in a flat cam, but its enough for sustaining one after breakin. People back in the "old" days weren't that aware of ZDDP, and it was rarely more than 1400 PPM in older oils anyway- it only became an internet phenomenon when engine builders tried to break in new cams, or run very very aggressive cams with monster valve springs with modern 800 PPM oil and ran into trouble.

As for the manual specifying "non-synthetic," I'd ignore advice given 40 years ago based on 40 year old oil technology COMPLETELY. Synthetics and conventionals behave pretty much exactly the same with respect to seal materials these days.

 

[Whitewolf]

The seal materials in his vehicle may not get on well with 'synthetics' though.

 

[Greasymechtech]

What unknown European vehicle for the 80's is not compatible with synthetic?

What owners manual in the 1980's state not to use synthetic, which was pretty uncommon at the time? Picture please.

Most that I've owned/seen usually offer options and other grades too.

If it is cold enough for you to use SAE 80, I'd just use the Pennzoil/Valvoline synchromesh fluid. If you want a 75w90, use the Ford conventional GL4..... XT-4-QGL

https://www.fcsdchemicalsandlubricants.com/main/quickref/mantrans.pdf

And, you could always use the 75w85 GL4 from Hyundai/Kia/Nissan. I heavily doubt that there is any excess of Group 4 or 5 in those Asian MT fluids.

http://www.penngrade1.com/Products/Gear-Lubricants/GL4-SAE-80W90.aspx

http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/en_1401.html?Opendocument&land=de

http://www.liqui-moly.de/liquimoly/produktdb.nsf/id/en_1403.html?OpenDocument&land=de

http://www.crcindustries.com/ei/product_detail.aspx?id=SL24239

http://www.millersoils.co.uk/automotive/tds-automotive.asp?prodsegmentID=226&sector=Car

http://www.penriteoil.com.au/products.php?id_categ=4&id_products=379

http://www.nulon.com.au/products/Gear_an...d_Transaxle_Oil

http://www.commaoil.com/passenger-vehicles/products/view/537

http://www.motorex.com/index.cfm?oid=204...;eintragId=2820

 

[440Magnum]

Originally Posted By: Whitewolf
The seal materials in his vehicle may not get on well with 'synthetics' though.


Its the owner's choice if he wants to play it safe and I can agree with that choice. But from an engineering perspective I personally don't believe that should be a big concern anymore for a manual transmission. If this were first-generation synthetics, or 1930s vintage natural fiber seals... yeah, then I might have a real worry.

As for 80s owner manuals recommending against synthetics in certain applications- I definitely believe that. I had a 93 Chrysler product (42LE transaxle with a divorced differential sump that needed GL-5 fluid) which prohibited synthetic gear oil. I have no idea why, but it was right there in the manual. I assume the concern was related to the possibility of gear fluid mixing with the ATF+3 in the transmission sump, and we all know how snarky ATF+3 transmissions were about fluid friction characteristics. Chrysler had no prohibition on synthetic fluids in their rear-drive differentials.