Trans Fluid Advice

Hi All, I'm thinking about upgrading my trans fluid to smooth out the shifting a little more. What do you recommend?

Swepco!!!

Can you be a little more specific on the swepco?

some light reading (15 pages)

http://www.thesamba.com/vw/forum/viewtopic.php?t=276529

it's up to you. i use redline GL4 and it's fine.

Tom,

What are you upgrading from?

Swepco 201 and Amzoil are both good stuff.

Mike

As with many car topics, there are firm believers on this subject who are at odds with each other. The debate is largely between adherants of GL-4 vs. GL-5. GL-5 contains more of the mystery additives than lowly, old GL-4. The GL 4 and 5 designations are ratings of tranny/diff oils (75, 80, 90W)with different percentages of additives. Some folks worry that the extra additives in GL-5 attack any brass or yellow metal, thus will only use in a diff.

A general rule of thumb is that GL-5 is for the diff and some modern manual trannys, GL-4 for older trannys. That last statement has so many exceptions, however, that it almost swallows the rule. Some autocross guys do a seat time test: try one, listen and feel for shifting differences, then try another. Some mix their own private concoctions. Is there agreement? Shit, no, this is car stuff!

Do any of us want/need to learn fluid dynamics and chemistry? Most of the info is WAY over this guy's head. VW recommends only GL-4 for manual trannys, largely due to the transaxle configuration. Redline seems to be one of the most popular industry standards, making both types above. My recommendation is to do your own research, and make the best choice for you.

OK, my brain officially hurts....hypoid gears, yellow metal corrosion, GL4, GL5, MT1, Dino, synthetic, Swepco., Redline, Amsoil, LAT. After consulting with a local VW engine builder, Carey, the Rancho website, and the CB website, and hearing LAT from all, that's the way I decided to go. I'll report back.

Tom-you started out wondering what kind of lubrication to use to "smooth out" your shifting. I would think your "gremlin" is somewhere between your shifter, linkage, or internals (within the transmission)...
As for lubrication, use the standard gear oil made for VWs of vintage mid-60s to early-70s.
As for additional "research" try the Samba and ShopTalkForum sites. Don't necessarily rule out clutch actuation either.

Scott, my car shifts pretty damn good now. Carey put in a hydraulic clutch in March and that made a HUGE difference. I'm just tweaking now.

GL-4 will will work fine. But GL-5 does offer better protection than GL-4. Any modern GL-5 should also be synchro-safe. The problem is most GL-5 also has friction modifiers that make it too slippery for the synchros to mesh well and causes notchy shifting.

Redline 75W-90NS is a GL-5 gear oil that doesn't have the extra friction modifiers for LSD's so it has the same shifting feel as Redline's 75W90 GL-4 but you get the better protection of GL-5.

Some other similar GL-5 gear oils without LSD friction modifiers that I've seen mentioned: Eneo 75w90, Silkolene Silktran, Motul Gear300, Lubro-moly, Torco RTF.

Both Carey and I contacted different folks at Rancho and they both recommended NOT to use synthetic, but 80/90 LAT or Swepco. I ordered some LAT from their website and got email confirmation from them that that's the best to use. Here's the stuff http://www.ranchotransaxles.com/store/lat-80w90-hp-gear-oil-p-39.html

Yeah, that LAT 80W-90 is a GL-5 gear oil without additional LSD friction modifiers. Just like the Redline 75W-90NS I described above.

Swepco 201 is GL-5 but includes friction modifiers.

I won't get into conventional vs synthetic...

Finally put the LAT in today. Harder than expected. Had to remove the camber compensator to get to the drain plug. A definite improvement, but not jumping up and down. Still, the old oil was pretty dirty and the plug had quite a few filings, so I'm glad that I changed it. I'll report back on cold weather performance at a much later date.

GL4 will not eat up the copper synchros as GL5 will

Tom-good to know that you got the right stuff. A curious question: about how long is it supposed to take before you experience an actual change (improvement?) regarding the shifter actuation?

I use GL-4 synthetic blend and seems to work fine (first I put in Coastal brand; don't recall what I put in the second time I had to change it).

I haven't noticed a large difference, maybe when it's cooler. I ended up adjusting the slave cylinder attachment to the clutch arm (same thing as the wing nut on the cable) and the car finally shifts to my satisfaction. Changing to a hydraulic clutch & adjusting properly was the real improvement.