EMan 928

Hi everyone,

New to the group as of today, and I wanted to post a question. I am looking at a 96 993 Cab without the LSD/ABD option. Is it possible to install a LSD, or did the car have to come with the option from the factory? How about the ABD, or is that the same?

Thanks in advance for your help.
Eric

Bill Verburg

lsd - yes, easily
abd - no at least not w/o a lot of work starting w/ the ams pump and plumbing

EMan 928

Thanks Bill. Is ABD an important option to have?

Bill Verburg

IMHO, no

GrantG

I'd rather have LSD without ABD...

Slow Guy

What could you expect to pay for adding LSD, parts / labor? A '97 if that makes a diff.

Bill Verburg

It's not going to be cheap, the best is a Guard asymmetric unit ~$2300, then the labor to install it.

The common factory ones have a deficiency of plates and material so are prone to wearing out quickly not worth any price IMO.

Geoffrey

You can very often find the LSD on ebay for $500-$700. Any of the 964 or 993 LDSs will fit. The insides of the diff can be upgraded or replaced with factory or Guard parts. Personally, I favor the Porsche Motorsport LSD over a Guard unit, both of which are billet. The street LSD is cast and sufficiently strong enough for your car. My recommendation is to find a used one, inspect and replace any parts that are worn and install it. The Guard or Porsche Motorsport units are overkill for a street car. FWIW, I have a 1997 993tt cast LSD in my race car.

Bill Verburg

IMO installing any of the 2 plate versions is a waste of time

Geoffrey

"IMO installing any of the 2 plate versions is a waste of time"

I agree that the stock 2 plate insides don't last a long time which is why you rebuild it with Porsche Motorsport insides. My point was that the billet housing is not needed.

Bill Verburg

Can't disagree w/ that

TCallas

It is a good idea to have a Limited Slip Differential (LSD) in your gearbox IF you do aggressive street or any sort of track driving. I like the factory, Porsche motorsport and Guard units if upgraded with Guard Transmission (Paul Guard Transmission 530-878-4499 or gears@gte.net) friction plates. That usually will run you $1500-$2000.00 for parts and shipping depending on what you choose. The labor/installation is another charge. You need to find a good shop/mechanic that can fit/install the differential without removing your gearbox. This involves careful measurements of the removed differential and your existing gearbox parts and will run you around $500-750 plus a small amount in seals, gaskets and gearbox oil. As for gear (transmission) oil, I recommend Swepco, Redline, Mobil-1 and Neo synthetic gear oils not to forget replacing your gearbox oil shortly after running the LSD due to the debris from these plates when they are new. Your total estimate should run around $2200-3000.00 plus tax.

Martin S.

His advice is Rennlist Gold. He writes, "You need to find a good shop/mechanic that can fit/install the differential without removing your gearbox. This involves careful measurements of the removed differential and your existing gearbox parts and will run you around $500-750 plus a small amount in seals, gaskets and gearbox oil."

There are very few shops that will attempt this job without gearbox removal. When the gearbox is removed, the cost goes up dramatically. Installing a LSD is not for the shade tree mechanic, as I have been told.

In case you are not aware, Tony runs a world class shop in Torrance, CA, Callas Rennsport. Tony does not self promote, so let me promote for him. If you are on the Westside of LA or the Southbay, Callas Rennsport is a shop to seriously consider. He also works on BMW cars. Tony is also a professional crew chief having crewed Reiser Callas Racing back in the 90's. They ran a very successful privateer team. Google Reiser Callas Racing and you’ll get the picture. Note they were running 993 RSR cars…as a result, Tony knows 993 cars like few others I have ever met.

Thanks Tony for jumping on the thread and sharing your expertise.

JasonAndreas

What type of grease are people using to pack between the dust lip and the sealing lip of the halfshaft oil seal? Porsche specifies "Silubrin S" but Kluber will not import it to the USA because of the heavy metal content. "Petamo GHY 133N" looks to be a possible alternative?

The only problem I ran into when removing the LSD with the transmission and engine still attached and in my 964 was that the left side heat exchanger blocks the side transmission cover so I had to remove a stud from the bellhousing to get the thing out. For a backyard mechanic it is a lot easier to just pull everything.

TCallas

John, are you talking about the oil seal at the gearbox (Halfshaft output flange seal)? Mostly all standard oil seals should be installed with a light coating of either motor oil, Vaseline or an assembly oil. I have even used wheel bearing grease in the past. I would not be too worried about this as long as the seal does not run dry and gall.