Trans/Axle Oil

[Dirty Marty]

Greeting Pelicans,

I recently had my trany rebuilt by Joe Legg's Shop in Escondido. ( Great Local Porsche Shop if you're in the San Diego Area} and it's bone dry right now......I know that back in its day they recommended a certain type of gear oil in it. Is there a newer/better type to put into it or should I go with the original......It's a 1970 T 5 speed. Any suggestions would be appreciated as I'm about to put the car back together after almost a year with the car disassembled in my garage.

Thanks,

Dirty Marty
Fallbrook, CA

[Solamar]

I've been really happy with the Kendall gear oil in my 915. I don't remember the exact spec, but if you search pelican, it's pretty common. I buy it from Pelican.

Joe Leggs is a great local Porsche shop, lucky to have him close by!

[Solamar]

Kendall 80W-90 GL-5

Swepco is the other favorite. Some say Kendall shifts smoother.

[faapgar]

Lubrication Engineering is the only oil to use.Good for LSD.Ciao Fred

[bigo5552000]

Originally Posted by Solamar

Kendall 80W-90 GL-5

Swepco is the other favorite. Some say Kendall shifts smoother.

Does the 915 use the same weight?


Sent from my iPhone using Tapatalk

[winders]

I have run 10 race seasons using a 915 in front of a 3.6L engine of some type. The last 2 with over 430 HP at the crank. My R&P still looks great and is still quiet. Why? Because I use Swepco 210.

[Cairo94507]

Just did a transaxle service on my car and filled it with Valvoline 85/140 GL4/GL5 rated oil. Took just over 3 quarts- it's a 901.

[EC900]

Specification is 90 weight oil. A 85W-90 is a winter/colder climate formulation. Swepco seems to be the favorite here and like a new engine, In any event the oil you choose for the break-in period will need to be changed out after the recommended break in interval.
Then changed again but at the service life recommendation (30k), though once a year or every 6,000 or so miles is added insurance like engine oil depends too on driving style and conditions.

[winders]

Transaxle are not engines….you don’t need to use break-in oil or change the oil after “break-in”.

[fetus]

I've tried both Swepco and Kendall. Kendall is easier to shift than Swepco. But as mentioned earlier, most shops that race all use Swepco because its supposed to be better for wear and tear.

[G450X]

Originally Posted by winders

Transaxle are not engines….you don’t need to use break-in oil or change the oil after “break-in”.

Being a mechanical device, wouldn’t there potentially be some metal fragments from the wear in of various new & old parts? The magnetic drain plug should pull much of the metal particles out, but I think a full change would be even better to protect a newly rebuilt gearbox.

I think that is the general thought, although not under the enhanced stress of combustion…

[winders]

What is the major wear item in a 915? It doesn’t have rings and no plain bearings exposed to the transmission oil. It is the synchros. Guess what, the synchros wear from day 1 to the day the transmission is taken out of service to be rebuilt.

You want to change the transmission oil after breaking in a 915, go ahead. But you are wasting time and money.

[DaytonaCoupe66]

After reading what seemed like hundreds of oil threads, with numerous opinions offered, all of which I'm sure are well informed, I went with Swepco, Dr. P's original choice in my newly rebuilt 930 4 speed.

Don't overthink it.

[Marc Bixen]

+ 1 for Kendall. Swepco in a pinch, or for track use.

[Zuffenwerker]

Back in the day when penzoil sponsored Porsche racing they had penzoil barrels filled with swepco for a reason! It’s very handy that it’s blue too makes it easy to identify a leak

[winders]

I am pretty sure Porsche ran the red Swepco…

[PeteKz]

Originally Posted by winders

What is the major wear item in a 915? It doesn’t have rings and no plain bearings exposed to the transmission oil. It is the synchros. Guess what, the synchros wear from day 1 to the day the transmission is taken out of service to be rebuilt.

You want to change the transmission oil after breaking in a 915, go ahead. But you are wasting time and money.

+1 on what Winders said. You don't need to "break in" a manual transmission, and synchro wear is a constant over the life of the transmission. As for what oil to use, I've used the SWEPCO and Valvoline mineral based oil (not synthetic). I can't tell the difference in a 915 in a street-driven car. The shifting still sucks, compared to more modern designs.

[Schulisco]

Follow the specs Porsche has given for the gearbox in the older days. On a 915 they always recommended a mineral only (neither part nor full synthetic!!) gear oil with SAE90 GL5!!! specification (and no GL4!). Mineral oils do have a drag torque which is necessary to perform the Porsche patended synchronization mechanism in the 915 gearboxes. Synthetic oils doesn't have this and this causes worse shifting after being warmed up.
Today Porsche recommends a 75W90 for almost everything, this makes storageing much easier for them, but my experience told me to go back to the old fashioned gear oils they recommended first. In the very last hint on the last page of the PDF they're saing that you can still use the old fashioned SAE 90 mineral oils on the 915 etc. gear boxes...



...with manual transmission types 901/902/905/911/914/915/925/930... the previous SAE90 GL5 (MIL-2105 B) approved for these transmissions can optionally continue to be used.

My experience with the SAE90 mineral oil: Far better shifting when warmed up, a bit worse when cold, yes, but hey - I don't use the car to do daily business.

Thomas

[Matt Monson]

The Kendall that everyone loved a few years back is no longer made. It was a mineral oil. The oil they now sell under a similar name is now synthetic.

[deemsriddle]

I have been using Swepco 210 for 45 years. None better.