5spd & LSD gear lube?

[panchovisa]

Does anybody have favorite weight/ brand/ GL spec for their gear lube?

I've got one 4 speed, one 5 speed, two R-180's (one welded, one open), and one LSD R-200 to change lube soon.

Petro based, or Synthetic? Any additives?

Thanks,

Pancho

[frank13]

Hey David, for just changing gear oil I use the regular (conventional) 80w-90. But if the tranny or rear end has been treated like a redheaded step child after you change with this weight it will feel smoother, but since it was abused the internal clearence for the gears will have increased. Leading to failure, even with freash oil. Changing the oil might actually lead to the failure sooner than latter being that all the tinny metal dust is suspended in the old used oil filling the extra clearence where it once was. In this case you will need to step up to thicker gear oil.

A lot of companies are now offering blended (conventional/synthetic) and pure synthetic lubes. The Blends being down the middle road in price. But still offered in the same weights. They offer better protection in the form of being harder to break down. And smoother flow regardless of temp. Usually for a LSD when using Conventional type gear oil an addative is used, the Diff might have a tag attached to one of the cover bolts or the FSM will have(should) that information. I don't remeber off the top of my head but I seem to remeber that some LSD's were using Synthetic oils(late models), and the early types used an addaditve to fight the oil from breaking down due to added shear forces internal to the LSD assembly. I believe you might be able to use striaght synthetic in a LSD. IF I am mistaken someone please correct me (thanks) Hope this was of help Panchovisa.:devious:

[panchovisa]

Thanks Frank.

Both the 5 speed (direct drive option #2) and the welded R-180 and the LSD 4.37 R-200 where used in competion. So based on your advise I should probably go with full synthetic and heavier weights.

What about the GL-4, GL-5, etc. specifications? The guy at two different parts stores had no idea what that spec was. Someone told me that GL-4 was usually for trannys, and GL-5 was usually for rear ends. Whats the real deal?

[frank13]

David i'll look up the GL ratings tommorow and see if i have the conversion table some where around the shop or in one of the newer manuals lying around. Then i'll get back to you on this thread. Cool. :devious: .

[jmortensen]

The synchros in the Comp transmissions are Porsche synchros which are the same as the synchros in the "915" box from 911's. I would use what they use. Overwhelmingly people who race 911's with the steel synchros use SWEPCO 201, which is an 80W-90 weight gear lube designed for heavy tractors and machinery.

I gave a buddy a close ratio comp box with the .8 overdrive, and he tried a couple different lubes in it, and was about to take it out when I gave him some SWEPCO. He is a believer now.

It works well in clutch style LSD diffs too, and in brass synchro transmissions as well, especially when mixed 50/50 with ATF. It is a GL5 rated lube.

Swepco used to have a website but I have been unable to find it recently, but you should be able to find a bunch of suppliers online. If not pick up a European Car magazine and look for a vendor who sells Porsche parts. They will have it.

It is expensive but definitely worth the $$$.

Jon

[panchovisa]

j, thanks for the info. By the way the video of your autocross was awesome! I tried to save it but failed.

I had to get my diff in the car today so I bought Mobil 1 full synthetic 75-140 wt (GL-5) and some CRC limited slip additive (compatable with synthetic). Pricy lube at $19.00 a quart! Well if it doesn't work it's not because I was cheap.

[jmortensen]

Thanks for the compliment on the video.:classic:

I'm sure that the lube you got will work fine for the diff (a bit on the thick side though). Get the Swepco for the tranny, though. Take my word on that one. The difference is amazing on the Porsche synchro'd transmissions.

Or run what you've got, then swap for Swepco and see the difference (expensive experiment but worthwhile). I definitely envy your ratios regardless. That would be a very cool transmission to have on a big track.

Jon

[frank13]

David I could not find the information I wanted to share with you about the gear oil classifications. And What I got from useless SAE sites and the likes was nothing but the impression that GL-#'s can apply to diferent weight oils.?. I pertty sure I had this information once somewhere. I must have it in storage. Sorry. The Mobil one is pertty trick Stuff. Synthetic oils are cool because it'll have the shear properties of 140w, but not flow lick a conventional 140w. Also if any body ever gets a deal on ?Honda oils take it. Honda oils are made by mobil. The honda they sell at the parts dept is Honda synthetic is Mobil1. :devious: .

[panchovisa]

frank, you would be amazed at how little the "professionals" know about gear lube. The local Nissan service head honcho didn't know if they put synthetic or normal gear lube in LSD'S. He also had no idea about the weight or GL- spec's.

At Rapid Oilchange (Valvoline) the kids new that tranny's nad rear ends took gear lube. But it was the same for each and every car/ truck/ moped/ space shuttle that drives in. "Lube is lube man".

And two auto parts stores both knew slightly more than the dealer.

Thank goodness there are people here that know about our cars!

[240ZX]

Use SWEPCO 201.....you won't regret it!!!

[peterc]

Hey guys,

Thanks for the info. This was exactly what I wanted to know. Now, lets see if I can locate a dealer up here that sells SWEPCO 201.

Cheers,

Peter