915 Trans

[nwyman1]

Is it OK to use synthetic gear oil in my 915 trans or should I stick with mineral based oil?

[ErrorMargin]

Originally Posted by nwyman1

Is it OK to use synthetic gear oil in my 915 trans or should I stick with mineral based oil?

The consensus is no to any synthetic. Most people use Swepco 201.

[Classic 911]

Do not use synthetic oil, some of the best oils are Swepco 201 for regular driving or 210 for more spirited / hard driving.

[Classic 911]

Here’s some good pointers:

https://forums.pelicanparts.com/porsche-911-technical-forum/524583-swepco-transmission-fluid-question-7.html#post5254487


Sent from my iPhone using Tapatalk

[-Levi-]

Another vote for 201

[pmax]

915 Gearbox Oil

Truck oil works.

[Classic 911]

Originally Posted by pmax

915 Gearbox Oil

Truck oil works.

Something wrong with the link here?


Sent from my iPhone using Tapatalk

[Mike Andrew]

Oh, boy! Here we go again......

[pmax]

Originally Posted by Classic 911

Something wrong with the link here?


Sent from my iPhone using Tapatalk

Link is fine... something's wrong with your phone ?

The key point being made by many in that thread and here is this ....

the more balky it makes your shifting, the better is the oil ...

no wonder folks are confused.

[shoooo32]

We really do need a 915 oil sticky...

Swepco 201 for normal use
Swepco 210 for race/hotrods

No synthetic, no friction modifier, no exceptions

[pmax]

Our host do carry both.







Choice is good.

[Funracer]

Used Kendall last time did not care for it. Went to Swepco 201 a couple of years ago and much prefer it.

[PeteKz]

I used Valvoline gear oil the last time I changed oil in my 915. I'd say it works about as well as 201. And you can get it anywhere.

[pmax]

Chevron lube is what's in the old 915 now, shifts the way a 915 should, never missing a beat.

[Rodsrsr]

Originally Posted by Funracer

Used Kendall last time did not care for it. Went to Swepco 201 a couple of years ago and much prefer it.

I had the opposite. Started with Swepco on a freshly rebuilt 915 and switched to Kendall shortly after. Seemed to shift noticeably smoother with the Kendall. Been using it ever since.

[Matt Monson]

I've been posting this for several years now, and will keep posting this every time the subject comes up. Kendall NS-MP is no longer a mineral based oil. It's not the same oil that many people converted to and started using a decade ago. It is now a a Group V paraffinic based synthetic. Search google for the Material Data Safety Sheet for yourself. LBKN726200 is the number.

Furthermore, I will go on to say that I am not telling you not to use it. Many have mistakenly assumed that because I like and recommend Swepco 201 for the 915 gearboxes, when used for racing. I have only ever argued against the people saying Swepco poorly protects your gearbox. I think it has gotten conflated at times because it's in the middle of one of these patently stupid Swepco vs Kendall argument threads.

I manufacture gearsets and LSDs for Porsches for racing. I see good shift quality and excellent wear characteristics with Swepco 201 and 210 when used with my own products in a racing environment. I do NOT use Swepco in my personal cars for street driving because I live in Colorado and in the colder months is shifts absolutely terrible out of the garage and takes forever to warm up. I mostly use Mobil or Castrol products in my personal street cars.

Regards,

Matt Monson
Guard Transmission LLC

[Funracer]

Originally Posted by Rodsrsr

I had the opposite. Started with Swepco on a freshly rebuilt 915 and switched to Kendall shortly after. Seemed to shift noticeably smoother with the Kendall. Been using it ever since.

My 915 has 111,000 miles unlike your freshly rebuilt one. That may account for some differences.

To Matt Monsons point, I live in Florida and rarely deal with cold weather driving.

[PeteKz]

Matt, if I may ask, what specific Mobil or Castrol gear oil do you use in your street cars? I ask because the next time I change my gear oil (hopefully not for a few more. years), I'll try what you use.

[Rodsrsr]

Originally Posted by Funracer

My 915 has 111,000 miles unlike your freshly rebuilt one. That may account for some differences.

To Matt Monsons point, I live in Florida and rarely deal with cold weather driving.

Tp put more context it was a few years after rebuild but very low miles. They're really tight right directly after a rebuild, but it definitely loosened up nicely after a year, however I experienced what others have mentioned regarding the cold. Sounds like its a non issue for you, just sharing my experience. Good luck with the ride.

[pmax]

I'm sure our OP's all cleared up now.

Or should we direct him to Bob's oil forum ?