915 tranny LSD and non-LSD - newbie question

86FLATSIX · 05-19-2015, 06:32 PM

Based on on my frunk sticker, I have option 220 which is LSD. Since I am not sure if it really has LSD or not (why coz I also have option 241 which I don't think I have a short shift kit either), thus, can I:

1. Assuming I have LSD, can I put gear oil without LSD additives?
2. Assuming I have a non-LSD tranny, can I put gear oil with LSD additives?

Sorry if I sound stupid but I have 8 qts of Kendall (4 with additive and 4 without additive) that was given to me

MikeD · 05-19-2015, 06:45 PM

Your 87 will have a G50 not a 915. Why do you doubt the option sticker? Do you think the gearbox has been changed? I would use the correct lube for a G50 with LSD.

86FLATSIX · 07:14 PM

Hi MikeD,

Sorry for the confusion. My signature should had been 86 Carrera instead of 87. Signature corrected. Apologies. With regards to doubting the sticker, not sure though but it caught my attention when option 241 says short shift but I swear the throw wasn't short. The rest looks consistent like sport seats color code.

Matt Monson · 05-19-2015, 07:27 PM

Is this your first 911? Even without a short shifter, the '86 is the shortest throw of a 915 gearbox. And even with the short shift it will be longer and looser than many modern gearboxes. It's never gonna shift like a BMW M3.

You can use either gear oil, or mix them. LSD additives make the LSD chatter less and run smoother, but not lock quite as well. I also feel that LSD additives tend to be a but too slippery for the Porsche proprietary synchros in a 915. Others will disagree with me. Opinions are like a... As they say.

midnight911 · midnight911's Garage

lift rear and spin one tire then you'll know? what am i missing?

Cevan · 05-20-2015, 04:01 AM

The search function is your friend.

915 Transmission --- LSD

I am also a newbie 911 owner of an '86. On mine, there was a "12" stamped in the middle of the trans serial number. I also confirmed the rear wheels turned in the same direction when one was spun.

spuggy · 05-20-2015, 09:55 AM

Quote:

Originally Posted by Matt Monson

Is this your first 911? Even without a short shifter, the '86 is the shortest throw of a 915 gearbox. And even with the short shift it will be longer and looser than many modern gearboxes.

LOL! That takes me back; right after buying my 911:

Me: "so, think I'd like a short shift kit".
Wrench: "already has one".
Me: "Seriously?"
Wrench: "Yup, no doubt. Pretty sure it's a factory kit."
Me: "Wow....."

(thinks for a bit)

Me: "What the heck is it like with the standard shift?"
Wrench: "Longer throws."
Me: "How can that be? 2nd's almost in the seat cushion"

Wrench just smiles and shrugs...

Bill Verburg · Bill Verburg's Garage

just use Swepco 201 in all 915s w/ or w/o lsd, you will be fine

the wheel test doesn't work well when the lsd friction disks are worn out or the lsd has little or no preload. In case the wheel test doesn't work plan on an lsd rebuild, if it was originally in there it probably is still in there, people rarely take them out.

wolds · wolds's Garage

+1

Quote:

Originally Posted by cevan

the search function is your friend.

915 Transmission --- LSD

i am also a newbie 911 owner of an '86. On mine, there was a "12" stamped in the middle of the trans serial number. I also confirmed the rear wheels turned in the same direction when one was spun.

Geary · 05-20-2015, 02:32 PM

Since the OP says he's a newbie, he doesn't really know this car's history. The trans code is certainly no guarantee that an LSD is still there.

I know of one unscrupulous dealer mechanic who would steal OE ZFs, exchanging them for open diff in about an hour. (Same guy would spray a new car's oil drain pan with WD-40, making it appear as though he'd performed that critical 1st oil change.)