Don Plumley

I know this topic was covered at various times on the old board at various times, but I wanted to share my experience with the new board.

Shifting my '87 Carrera from 1st to 2nd was getting very notchy/difficult. No grinding, but at times, it took a fair amount of effort to slide it into 2nd. Not consistent with temperature, not noticable on downshifts. More prevalent with "spirited" acceleration. A pair of p-car mechanics also drove it and confirmed my findings.

I'm worried about $ynchros, etc. So I searched the Rennlist - found some advice about switching to Mobil One synthetic gear oil. I confirmed the PO's mechanic (thanks for the great records!) put Swepco in at the 60K service - 4K miles ago.

This morning I drained out the (very new) tranny oil, and pumped in 3L of Mobil One. (what an easy procedure too - with a gear oil pump and a breaker bar for the 12mm wrench)

I'm back from the test drive and am still smiling. Shifts were as smooth as glass, and the 1st-2nd problem appears to be resolved!

I am a convert - next weekend I drain the dino oil from the crankcase and replace it with synthetic!

Swepco makes great products and I'm told is ideal for 915/901 boxes - so this is not a knock against Swepco, but a very enthusiastic vote to put Mobil One or similar synthetic product in your G50 gearbox.

Regards,

Shifting-Smoother Don

Drew_K

Don,

I had the exact same experience. I had Swepco put into my 92 C2 and it shifted MUCH worse. Balky, especially when cold. I put up with it for a few thousand miles and switched to Mobil 1. Huge improvement, so much so that it now shifts better cold than when completely warmed up with Swepco. I posted a message about this under the old board format, so hopefully you found my message and it was helpful. Either way, your experience confirms that, while Swepco is great in a 915 gearbox, it doesn't seem to work very well in the G50.

Dial 911

The G-50 and 915 use different synchros.
The 915 won't like a synthetic lube like Mobil-1, and the G-50 won't shift properly with Swepco (dino).

Lane

I,m not getting this SWEPCO and G-50 thing? I mean ,I'm not arguing with any one about the fact that their G-50 is shifting better since switching to syn. oil. But I have 201 in my G-50 and don't see a problem at all and it has 122,636 miles on it. What problems were you having with the 201 that the syn. fixed? I mean was it at cold temps,hot temps , shifting at red line , or just a leisurly pace?
Thanks
Lane

Don Plumley

Hi Lane,

For my situation, my sticky shifting was primarily 1st-2nd; was not dependent upon temperature, was much worse under hard acceleration. It was the sort of thing that annoyed me whenever I tried to move quickly off the line.

If I drove leisurely (hard to do in the 911), and/or shifted very, very deliberately, shifting was fine. With the syn oil, shifting is significantly smoother in all gears, under all temperatures. Okay, it's not a US tranny, you don't slam it through the gears, but again, the performance is much better.

I searched the old Rennlist archives and there was considerable discussion about this.

For $21 and 20 minutes, why don't you swap out your oil and see for yourself? You could always put the 201 back in.

Don

Drew_K

Lane,

I was having problems shifting into 1st, 1st to 2nd, and 2nd to 3rd. The shifting was balky, especially when cold and into first gear. I had to double clutch or shift very deliberately into first until warmed up.

Once the car was warmed up, shifting was still balky but less so. It was tolerable, but it didn't feel nearly as smooth as before. The switch to Mobil 1 cleared all this up and the car shifts very smoothly now.

Perhaps (and this is just a guess) you aren't noticing any problems with Swepco because your gearbox is in excellent condition? I'm not the first owner of my C2, and I can tell that the gearbox is not in perfect condition. Maybe Mobil 1 helps to smooth out the imperfections in the gearbox.

If you ever make the change, please let us know. I'd be curious to see if you notice any improvement.

Lane

Don
I'm going to pass on the Mobil 1. I saw a perfectly fine BMW tranny go south after switching to Mobil 1, the gears actually were flaking apart. And as far as Redline goes I know of one individual who has a G-50 and switched from Redline to SWEPCO 201 to improve his shifting at high rpm [track sessions].
Thanks anyway
Lane

Don Plumley

Hey Lane, do I understand correctly from your signature and website that you are a Swepco dealer/distributor?

No real issue for me, as I just wanted to share information. (Though I think you should disclose your business affiliation up-front and no, I have no connection to Mobil)

The old board had lots of support as to how great Swepco and 915/901 boxes work together - and I've heard only good things about their products.

Good luck,

Don

Jake

My 79 915 was very balky in first and second, both into and out of the gears. I went to the Swepco fluid and have since put on about 500 miles. No real change as of yet. Is there a milage marker out there when I should see some improvement from the Swepco? 1000 miles from the fluid change? 2000?

Will

Don,

I have an '87 Carrera, too, and the 1-2 shift is similarly balky. I'd like to try Mobil 1, and you make it sound like an easy procedure. Can you explain how it's done, or point me to a book or other resource that might help me tackle this?

Thanks. Will

Lane

Yes Don , I'm a dealer for SWEPCO and I have disclosed that info in many of my other posts. But I really don't think that it matters in our discussions of what works and what doesn't work. That's why I said earlier that I,m not disputing your smoother shifting with Mobil 1. And believe it or not the results of Mobil 1 in the BMW tranny , and my use of SWEPCO products was well before I became a dealer for SWEPCO.
As we all should know there is no miracle cure for shifting problems in a tranny and for some reason it does seem to help when we try different oils , but in most cases worn parts are the culprit. Bruce Anderson found that SWEPCO 201 eliminated the ring and pinion failure in the transmissions of the 935s that they raced [don't recall anything about smoother shifting]. And thats my main concern, long life in my tranny , and if it shifts smoother then great.
Lane [owner]

Don Plumley

Will,

Changing the tranny oil is a simple procedure. There are many others more experienced out there than me, but here goes:

Put the car up high on jack stands, helpful if it is level (e.g. 4 stands). This is a topic worth a thread on its own.

Using a 10mm socket bit, open the filler plug up on the side of the case. Always open the filler plug first. It's not good if you drain out the oil and can't put in new stuff. These have a tendency to get pretty tight, I had to use a long torque wrench as a breaker bar. You could use a 10mm hex key and a wrench, but I bet you wouldn't get enough leverage and risk rounding the plug.

Using the same 10mm tool, open the drain plug and drain out the oil. The drain plug has a magnetic thing, clean and inspect. If you see lots of bits of metal that's probably bad.

I jacked the front of my car up a bit to try to get all the oil out. Then put it back on the stands before you back under the car.

Wipe all around the filler and drain plug.

Replace the drain plug. I tightened to 18 ft-lbs, which is not too tight.

Using a gear oil pump (about $4 at the local auto-parts store), begin pumping in the new new stuff. There's no room to tip a bottle up there, the pump makes this easy. My pump did not fit into the Mobil One bottles, but the hose fit over the bottle tip - just sucked the lube out.

Pump in 3 liters (just over 6 pints) of lube, it should just start running out of the filler plug. As mine was nearing the top, it pushed out the last of the old oil, when I saw nice clear new oil emerging, I stopped.

Tighten the filler plug, check for leaks, lower the car, smile.

After the test drive/a few miles, I think it would be wise to check the fluid level again.

Well, that's about it. I would really appreciate it if anyone else reading this would jump in and elaborate/correct/update my procedure.

Don

KLehmann

I agree with the hand pump method. Works quite well if you transfer your quarts of gear oil into a clean milk/windshield washer gallon jug. The type I have is made by either Sta-Lube or CRC and is made of plastic with a threaded body that screws onto standard gallon jugs (bought at Sears Hardware or Pep BoyZ). I think it's $4-5 and good for once in a while use.

Warren from Pelican BB recommends: A good idea is to replace the alumnium fill/drain plug with a steel one. I agree wholeheartedly as when I tried to remove the filler plug from my trans., the plug would not budge a bit. So I decided to muscle up and push on the tool (with my feet braced up against the motor) instead of pull. When that plug finally let go, I smashed my elbow on the car SOOOOO hard it was like I was smacked with a bat. I thought for sure I broke my elbow. One more example of always pull the tool, don't push!

Probably is a good idea to also replace the aluminum sealing washers for the drain and fill plugs.

cwlovell

On my '86, I had the 915 oil changed to Mobil 1. I immediately experience a much more balky shift out of third to forth or second. Al other shifts seem okay but not improved from pre-change. This forum was the first I've heard of staying away from Mobil 1. thoughts?

Gary J. Spinella

My 88 Carrera with the G-50 shifts much better after switching from Swepco to Redline. The 1-2 shift has improved greatly although the improvement is felt through all gear changes. Prior to the switch, I spoke with two factory trained techs. Both agreed that the G-50 performs best with a syn grear oil.