Castrol Syntec 75w-90?

RPM-Junkie88 · 10-29-2009, 11:24 PM

Is this okay to use in my tranny? I know most reccomend redline or motul or OEM. What about lucas 80w-90 dino oil?

man show · 10-30-2009, 12:04 AM

Just about any brand is probably going to be just fine. Personally, I wouldn't stray from the recommended weight - unless it's Andrewtech's cocktail.

RPM-Junkie88 · 10-30-2009, 05:34 AM

Okay, is synthetic the best to use are far as gear oil?

RPM-Junkie88 · 10-30-2009, 05:38 AM

oh and in the rear diff i've heard that lucas HD oil stabilizer is good to use as a diff fluid, i love the stuff, u can use it in any application. What do you guys think bout using half or all lucas in your rear diff? I mean lucas oil is top quality oil

man show · 10-31-2009, 12:36 PM

If it helps, I'm currently using Redline 75W-90 NS in my transmission and Redline 75W-90 in my rear differential. I think the next time I change the fluids, I'm going to use the Andrewtech cocktail in my transmission (Redline Shockproof and Motul Gear 300 75W-90) and I haven't thought about what to put in the rear differential yet, but I'm thinking Motul Gear 300 for that too.

Lucas oil is probably ok if you want to use that. I don't think too many people on this site are using that, so you might be one of the first to try it out and tell us what you think. In general, synthetics are best and most people seem to use Redline, Royal Purple, or Motul products.

The only thing I would really suggest you avoid is Uncle Scotty's Cocktail in your transmission because it has been proven to turn acidic over time and that's not good for your internals.

basco · 10-31-2009, 01:44 PM

I run the AndrewTech Cocktail in my tranny and have for the past ten thousand or so miles with absolutely no issues...and I run full Motul in my rear diff.

airplnmdls · 11-02-2009, 12:02 PM

I haven't put it in yet, but I got Subaru 75W-90 Extra S from fredbeansparts.com...gonna probably try to do that within a week...