Redline Shockproof Heavy?

[mountainkowboy]

Anyone have any insight? Is it ok to use in a stock trans?

[Marc]

I have not tried it myself. Redline doesn't recommend it for synchro-ring applications - they claim that it's so slick it could impair their action - therefore they don't make any claims regarding its corrosive properties, which is reason enough IMO to avoid it for an ACVW.

Look for a GL-4 rating, like their MT-90.


The current GL-5 lubricants which meet the MT-1 spec are definitely better than any old stock which does not, but you can do better.

Never use any lube, synthetic or not, that doesn't meet the The American Gear Manufacturers Association (AGMA) rating D-130. Differentials (like the final drive portion of an automatic transmission or the third member of a conventional drivetrain) do not contain synchro rings made of non-ferrous materials so they can use lubricants with a higher amount of extreme-pressure additives; problem is that when these additives break down into sulfurics which corrode the brass in the old transmissions' synchros. Generally this means you need to avoid GL-5 lubes and look for GL-4, but it's getting harder and harder to find. API GL-5/MT-1 is supposedly safe to use in old transmissions if GL-4 is unavailable - GL-4 is still produced, but not too many places bother to stock it anymore. CRC/Stalube still offers GL-4; NAPA and CarQuest have a GL-3/4/5 which should be fine too.

ASTM D-130 is normally run at 212ºF, but to make the test more severe AGMA increased the temperature to 250ºF. ASTM D-130 is used to determine the corrosiveness of a gear oil’s EP additive to nonferrous metals. A polished copper strip is immersed in the 250ºF oil bath for three hours and the EP additive corrosiveness is determined by comparing the strip against ASTM pre-rated strips.
ASTM rates the test strip as: 1 a or b; 2 a, b, c, d or e; 3 a or b; or 4 a, b, c or d.
Ratings of 1 a or 1 b are the least corrosive.

...If I was putting in a synthetic, it'd be Redline MT-90 GL-4 or Royal Purple Max-Gear 80w90 GL-4/GL-5. Royal Purple meets the GL-5 spec but their "Synslide" EP additive is non-corrosive so it's no threat to the VW synchros. Another choice would be Amsoil, I haven't used it myself but it's claimed to be safe for GL-4 applications...

[mountainkowboy]

Thanks Marc, had some on the shelf from my old Harley and was wondering.

[Pablo2]

I've seen the internals of road racing transaxles that have used Shockproof, and it was not a pretty sight. Yellow, baked on muck everywhere .. a cleaning nightmare.
Shockproof is Redline's attempt to offer a high level of EP protection that their MT-90 and MTL don't provide.

I'd trust this Kendall GL5 over any other oil that I've seen mentioned in this thread .. inexpensive and well tested in older 911 Porsches.
Link: http://images.thesamba.com/vw/gallery/pix/1108417.jpg