Porsche Gear Lube?

I am having the transmission re-built on my 99 C4 (I will post an update and pictures when the job is complete). I have been searching for the proper gear lube 999 917 546 00 to fill the trans when it arrives back from Powerhaus in the next few days. When I called, the parts departments at three major dealers in Chicago have all told me that I DO NOT need the Porsche Approved transaxle lube. They recommended going to Autozone and buying regular Mobil 1 75W-90 synthetic (one dealer said 80W-90). I know there has been discussion on this in the past as I have searched the board, but has there been a sudden change in thought? Certainly I would love to save the $$$ but I am defiantly willing to spend whatever it takes to protect the new transmission. I never expected to hear this from the Porsche parts counters..... Thanks, Jeff

You can get 3 liters of the shell lube from the dealer for less than $90. Use it. It seems to work best.

I certainly don't mind the $90 or using the approved fluid - it would be my preference. However, it seems that our local dealers only stock it in bulk as opposed to the liter containers that I need. It was when I inquired about special ordering the fluid that they informed me I "didn't really need" the approved fluid.

We put the Mobil in a buddy's Porsche and ended up changing it to the Shell because of noise and stiffness of gears. Part Number 999.917.546.00. Dealer can order. They do not have to order the 20 liter container which is a different part number.

I am sorry about "highjacking" Jeff's thread but since it is on the transmission fluid topic, I would like to ask the experts what is the recommended maintenance interval? Manual says 90k miles, but is that too long? Is it better to do it every 30k or 60k miles? Thanks... Cheers,

IMO, it is better to change the lube more frequently than 90,000 miles. It definitly will not hurt. I just changed mine a few weeks ago and the improvement in gear movement and LSD was very noticable.

1999Porsche911. Thanks for the advice - I'll take a pass on the Mobil 1. I found 3 liters of the lube at a dealer that is a little out of the way. They are charging me $37 a liter. Jeff

The Mobil 1 available at Autozone is a gear lube, not a transaxle fill. It is the wrong lube. It will owrk, but is not optimum. This is what you want to use: http://www.lufteknic.com/Merchant2/m...ode=lubricants

Thank you very much for the link. I placed a call to them and they are checking on the differences between the SHC and PTX in terms of lubrication. They couldn't be nicer on the phone - if this works it will save me nearly $100 for the fill.

I would suggest NOT to use the Mobil. As I mentioned above, my experience after using it (same exact product) was the the gears did not mesh as well as with the Shell nor the LSD lockup as smoothly.

Call Jeff Clark at Sunset Imports in Oregon. IIRC I paid $19/liter a few months back. At first he said he didn't think he could ship fluids, but after checking he was able to use UPS.

Actually, last week I did ask Jeff at Sunset Imports about these fluids and he also told me that they cannot ship fluids out??? Maybe their policy has changed? I don't think it's a safety regulation thing, bc I ordered transmission/differential fluids even engine oil from Bavarian Motorsports on the East Coast for my BMW without any issue. So what's up?

It could be either UPS or Sunset have changed their policies, or that Jeff has forgotten that it is (was?) allowed. At the time I asked him to check and he discovered that UPS ground allows motor oil, but not coolant. Remind him that at least a couple of months ago, UPS had an exception for motor oil and he was able to ship it then.

Actually, there is a tremendous difference between Mobilube SHC and Mobil 1 gear oil (Autozone stuff). SHC has the synchro additives and LSD additives that make it the right fluid. Mobi1 Autozone stuff is gear oil, not transaxle fluid. Been using SHC all season. Never shifted better.

Great, thanks Pazzo... I will ask Jeff again because I kinda like to order from Sunset Imports. Cheers,

The last two transmission rebuilds I had done by Brian Copan came with Mobilube. Brian told me not to use the Autozone stuff. I trust Brian.

I second Brant's comments. I replaced the factory fill in my '95 993 with Mobilube SHC a few weeks ago (at 41,000 miles). The shifting is very smooth, whether cold or hot. I also purchased from Lufteknic. Andreas

Just got my GT3 back after having the trans gears upgraded to lower ratio Cup gears in 3rd, 4th, and 5th. The trans shop, which spealizes in Porsches only, swears by Havolin 75-90 synthetic. They claim it is the best for steel syncros. I'm only relaying what I heard. I would have picked Mobil or Motul. We'll see if the new gears like it or not.