MTR

I was working on my C2 yesterday and wanted to remove some of the unused engine undertray mounts which are bolted to the transmission. One of them was held on with 2 bolts (see picture, not my transmission). There is a gasket here so I want to make sure I have the torque value correct, but I can't seem to find it in the manual. Anyone have any idea?

Also, what is this port used for? I'm assuming an external transmission cooler, but want to know for sure.

Thanks.

Gus

This is the location where a counter measure adjustment fitting goes for a factory LSD. You have a cover plate that is a blank. You remove this and install a counter measuring tool that helps you adjust the LSD using the counter bearing bolt which is located at the 11 o'clock (relative to the drive hub) position on the transmission you posted a picture of The counter measuring device has a reading in mm and you set it at ( 30 or 31 mm ) after installed and adjust the counter bearing .
Hope this answers your question.

MTR

Thanks Gus. I learned something new today.

Have any idea of the torque value? 15-20 ft-lbs, or should I just snug them up?

Mike

Gus

Mike -
Can not find specific torque for that one location. However think it falls into this area -

Hexagon nut for gear and transmission case, side transmission covers, transfer case, immediate case and tension plates

The torque for these areas and bolts is Nm - 23 / Ft lbs - 17
Bolt size should be a M8 - Other option would be to look up torques spec for bolt size.

Gus

This sis chart I found -
Note "( )" is inch pds

Metric Bolt Torque Table
Estimated with clamp load as 75% of proof load
as specified in ISO 898-1
Property
Class 8.8
8.8 10.9
10.9 12.9 Socket Head
Cap Screw
12.9
Minimum Tensile
Strength MPa M6 - M16: 800
M20 - M30: 830 1040 1220
Nominal Size
and
Thread Pitch Bolt Torque Specs in Foot Pounds or (Inch Pounds)
Dry Lubed Dry Lubed Dry Lubed
M5 x 0.80 (54) (41) (78) (59) (91) (68)
M6 x 1.00 (92) (69) (133) (99) (156) (116)
M7 x 1.00 (156) (116) (222) (167) (260) (195)
M8 x 1.25 (225) (169) (333) (242) (377) (284)
M10 x 1.50 37 28 53 40 62 47
M12 x 1.75 65 49 93 69 108 81
M14 x 2.00 104 78 148 111 173 130
M16 x 2.00 161 121 230 172 269 202
M18 x 2.50 222 167 318 238 372 279
M20 x 2.50 314 235 449 337 525 394
M22 x 2.50 428 321 613 460 716 537
M24 x 3.00 543 407 776 582 908 681
M27 x 3.00 796 597 1139 854 1331 998
M30 x 3.50 1079 809 1543 1158 1804 1353
M33 x 3.50 1468 1101 2101 1576 2455 1842
M36 x 4.00 1886 1415 2699 2024 3154 2366
Lubed means cleaned dry bolts lubricated with a standard medium viscosity
machine oil. Lubricate all contact areas of the bolts and washers. Lubricating
the bolts is the suggested method.

MTR

Thanks Gus that was a big help.

hockenheimr

So if you add a LSD to a non-LSD G50, is there anything you need to do with this box thing?

Gus

Box thing ????????
As long as the LSD is not an original Porsche LSD that required setting up using the box thing - then the answer is NO
Like a Guards or Quife

hockenheimr

You know the box thing with the plate lol

I have a 996 GT3 LSD

MTR

How much are those LSDs selling for? I started looking into Guards LSDs but haven't pulled the trigger yet. Can you educate me on the GT3 alternative?

hockenheimr

I paid $750 off a Rennlister, he says the discs are in good condition but worst case I change them for $1,000-$1,500 labour included.

MTR

And it's a direct bolt on with the G50 transmission?

hockenheimr

Yea, but I'm going to have a shop do it.

I could potentially have a 993 LSD for sale if your interested.

MTR

Sent you a PM.

GTgears

No such thing as a direct bolt in when it comes to differentials, though a lot of hack shops just slap them in there. Afterall, they won't be around 5-10k mi later when your ring and pinion goes bad because it was mis-meshed. These days that kind of mileage is several years. They are taking a chance that the owner won't put 2 & 2 together then the box eats itself. To do it properly, with the factory tools, the gearbox must come out of the car and the ring gear backlash and bearing preload must be reset.

Also, a GT3 LSD does not have the holes drilled in it to mount the tone ring for the speedo drive on a 964. If you use a factory GT3 LSD in the car you will lose your speedo.