swepco gl5, mobil 1 says dont use it...

oc92 · 03-19-2002, 02:20 PM

the swepco site says 201 trans fluid is gl5 rated.
mobil 1 says that although their synthetic gear oil is also rated gl5, you should only use what came dealer installed/approved (liability issues...?) like if it was gl-3, use gl-3. some dealers sell this gl-3 and redline is i think gl-4 ... anyway, the last thing i want is a corroded syncro so let us beat this dead horse one more time so i can make a purchase from pelican and this time keep it in the tranny

Superman · 03-19-2002, 03:06 PM

What kind of transmission? Even before you answer, here's my input. If it's a 915 you're talking about, use Swepco 201. Period. Regardless of what "conventional wisdom" might say. There is no question...no question whatsoever...that Swepco is much better for 915 trannies than anything else. Racers have proved it. Daily drivers have verified it.

tight as a bull's ass · tight as a bull's ass's Garage

Quote:

Originally posted by Superman
What kind of transmission? Even before you answer, here's my input. If it's a 915 you're talking about, use Swepco 201. Period. Regardless of what "conventional wisdom" might say. There is no question...no question whatsoever...that Swepco is much better for 915 trannies than anything else. Racers have proved it. Daily drivers have verified it.

I have GL-5 Mobil 1 Synthetic Gear oil in my 915 transmission.
Shifting is perfect.

Should I be worried?

pwd72s · 03-19-2002, 04:49 PM

Emmanuel...if you're worried, we both should be. I'm using TORCO sythetic with limited slip additive. It's GL-6 rated, I've used it for 4-5 years, and the gearbox shifts much smoother than it did with Swepco. But what the hell, if I break the gearbox by using synthetic instead of dino lube, I'll get it fixed. I'm using synthetic because I'm among those who believe that synthetics do better than dino when things get hot, and they flow better when things are cold. But, I've given up trying to convice those who attend the church of SWEPCO that there might be something better out there. Might as well try to convert the Pope into the Jehovah's Witness believers...

oc92 · 05:44 PM

the applications are:
73 914
74 ghia type 1
1991 jeep (ax-15 trans)

all are brass syncro and the current edition manuals now say use gl-5 but i didnt think gl-5 was around when they were designed. some dealer technitions and some tranny shops use the "old style" gl-3 or 4 stuff yet most just put in the newest synthetic formula. maybe all gl-5's are not corrosive in nature to brass, explaining why swepco is okay and mobil 1 not. shiftwise, by the way, the only oil i have felt a noticable change with was the coastal crap we sell at work that i put in a long time ago. dont even use it on your new vehicles. turned thin and poor shift (yes, same weight, temp, trans and diffs!, etc) soo... back to square one or more info? i have heard mentionings about posi-trac/limited slip additive for manual trans like the above poster states. any more info?

john walker's workshop · 03-19-2002, 06:46 PM

general rule of thumb is don't use synthetic oil in a friction syncro trans. it's too slippery. swepco in 901-915, synthetic in brass syncro G50, etc.

kepperly · kepperly's Garage

red line 75-90 ns

pwd72s · 03-19-2002, 06:53 PM

John...with a LOT of due repect...there is a shop owner down in Sacto...also named John. You might ask him what he runs for lube in the gears of his 3 1973 models,,,"S", "RS", and "RSR". That said, you're suggesting I should go back to Swepco? I mean hell, I'm no wrench...I'll admit that. But I do know wrenches who track drive...and it is synthetic in their 915's....not SWEPCO...

Bobboloo · Bobboloo's Garage

Just to back up John's point. I put swepco in a 915 that has synchros that are nearing the end of their life. After filling with Swepco they no longer functioned. Too slippery for them. The fluidity of the shifter felt great but I could no longer shift into 2nd without grinding.

Bobby

dickster · 03-20-2002, 02:17 AM

Quote:

I have GL-5 Mobil 1 Synthetic Gear oil in my 915 transmission.

is that thinner than swepco??

i have converted to swepco, and although shifting is marginally better its not great.

i have noticed that when the trans is really warm shifting is greatly improved - i have put this down to the oil being thinner when hot?? seems to "stick" when cold??

a bit off topic i know but............

Kahuna · 04:42 AM

I have had both Swepco and Mobil 1 in my 915. Hands down Swepco makes it shift best. I found that especially on hurried shifts the synchros couldn't grab good enough with the M1.

chuckr · 03-20-2002, 03:30 AM

This is really something that some people have to experience for themselves.I have tried Redline tranny fluid, I use Redline oil and I really love Redline BUT in my 915 box it just did not feel right, I put Swepco 201 in and I felt an immeadiate difference, I have 230,000 on my tranny and the syncros for first and second are a bit notchy but it still shifts fine for 230,000, I credit this to Swepco

Early_S_Man · 12:11 PM

There are some factors mentioned here so far that fall into seversl categories ...

1. Rumor/myth/anecdotal evidence from unknown/unnamed second-hand sources ...

2. Observed improvements from credible experienced sources ...

3. Attributed benefits due to factor 'X' ... when factor 'Y' is more likely ...

4. The 'Hawthorne Effect' -- a longitudinal Industrial/Organizational Psychology study done at the Hawthorne Plant of Western Elecric in Chicago from the 1920's thru 1940's (what Wayne calls the Placebo Effect) ... where improvements in productivity by workers were found, no matter what change was made ... lighting levels up or down, temperature up or down, shorter or longer breaks ...

The often-cited example of Bruce Anderson recommending Swepco 201 is misunderstood by many ... he cited an improvement from ring & pinion lifespan of 40 hours under racing conditions to an ENTIRE racing season for 935 race cars! He also noted longer Porsche-design synchronizer lifespan in both race and street cars as an additional benefit. That there MAY or MAY NOT be an improvement in shifting QUALITY isn't the reason for switching to SWEPCO, and that is the often-cited misconception I see developing here!

In my personal experience more than 24 years ago, I saw a dramatic improvement after changing old gear oil of unknown brand and age in my 915 ... to Valvoline SAE 90 gear oil. Shifting quality improved, especially a 'graunchy' 1-2 shift that disappeared after a few miles with fresh gear oil! Do I attribute the 'improvement in shifting to Valvoline or to fresh gear oil? Most emphatically ... to the fresh gear oil, since it was the factory recommendation back then (and VERY seldom heeded) to change gear oil at the same interval as engine oil, which I did! Since it was observed back in the '70s that 911 transaxle lifespans were often only half that of engines, I took BA's observations on 935 ring & pinion and synchronizer lifespan improvements with Swepco 201 very seriously in the early '80s! But, I didn't note any improvement in shifting quality at the time of the switch!

New gear oil of any brand or type is ALWAYS better than old gear oil in a recently-purchased car ... but I do recommend the 'finger-in-the filler plug hole' test ... just to see what, if any, gear oil is there! That gear oil is one of the most often ignored maintenance items for 911 owners is blatantly clear from all of the complaints here on the Pelican site about 915s!!!

There haven't been any new 915s built in more than 15 years, so the factory's current recommendation of Mobil 1 lubricants doesn't have bearing on what is best for us!

Doug E · 03-20-2002, 12:36 PM

I am glad I didnt' see this thread before I decided to change my tranny fluid earlier this week or I'd be even more confused than before.

I've got a recent threads out there from earlier this week about my experience so I won't repeat it here but the bottom line is that I went with Swepco for peace of mind given the overwhelming testimonials on this board and other sources.

Superman · 03-20-2002, 01:52 PM

I agree with Warren (I've done this a lot of times). First of all, gear oils should be PRESENT in the transmission. Dry trannies shift very poorly and they wear much faster than trannies with gear oil in them. Second, the gear oil should be relatively young and clean. Gear oil does not last the life of the car, as many people appear to assume. And finally, using the right kind of oil helps. Swepco has been shown to be superior compared to other products of its day.

oc92 · 08:44 PM

interesting info so far although i am not concerned so much with shift as i am in the breakdown of internal components in my trans. Mobil 1 website says that don't use their product or any other gl-5 in an older trans. swepco is a gl-5. alldata (factory manual-based tech advisor) says that "...you need gl-4 (or presumably gl3,1) with non-reactive ep additives to prevent syncronizer damage...". most manuals and shops and techs say use gl-5 (incl haynes and chilton), many dont realize the older classifications, those who do are pretty experienced like ase master techs, which is no surprise. so the definitive query is what is the safest for the trans considering all of the odd bits of data? redline (mt90: gl4, 75w-90)is synthetic and non-corrosive so it may be the best bet.

Early_S_Man · 03-20-2002, 10:49 PM

oc,

Your Alldata data is pure BS ... as the factory spec books for '81 thru ''86 915's SPECIFIED GL-5 SAE 90 gear oil!!!

Do you know what a Porsche factory 'spec book' is? Ever read one?

Are you just asking rhetorical questions here for amusement? Try visiting the API website and doing a bit of reading about gear oil specs! A GL-5 gear oil AUTOMATICALLY meets ALL of the earlier GL-1 thru GL-4 specifications, so the premise of your 'concerns' is FALSE!

chuckr · 03-21-2002, 03:49 AM

I am curious.... does anybody have more than 230,000 on an origional tranny ?? I do, and I use Swepco, that is pretty good
evidence of not having a substancial "breakdown of internal components". Information is only good if you understand it!

oc92 · 03-21-2002, 04:06 AM

thank you for the relpy warren.
i will check out that site.
the all data info was for an older jeep, sorry for the confusion... although my real confusion stems from all of the conflicting data. my posting here is merely to seek information. if i gain pleasure from reading interesting tech info than all the better. thank you for your time.

Jim T · 03-21-2002, 07:38 AM

GL-4 and GL-5 are different, and a GL-5 is not automatically better or even safe in a GL-4 transmission. Its not like GL-5 is simply a "later and greater" version of GL-4.

I personally would NOT use GL-5 in a transmission that calls for GL-4, unless the manufacturer has specifically later approved GL-5 for the transmission.

Check the 944 list, I believe their transmissions call for GL-4, and some have reported damage caused by GL-5. Same for BMW.

While it is true that many GL-4 transmissions can safely use GL-5, that is most definately not always the case. GL-5 can damage some GL-4 transmissions, so unless you have specific information approving GL-5 in your GL-4 transmission, you are taking a risk.

Most of the major oil company sites will tell you that.

Here is a start, if you are interested.

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=6260&highlight=GL5