Overview

This site is mainly for me to keep track of things regarding this transmission that I might referenced later but I figure someone else may get some use out of this data too.  Described by many as a "replace" and not "rebuild" trans, I want to show that people can actually use these transmissions with their builds and that replacement parts are readily available.  Although they've been described as not surviving well above 300 ft lbs of torque, I've been using one with ~317 ft lbs of torque under very harsh driving conditions and with reasonable success.  The 012 trans, and it's 01A AWD variant, were installed in many different vehicles and with varying gear ratios including the VW Passat 1.8t and 2.8 V6, the Audi A4 1.8t and 2.8 V6, as well as the 97-08 Boxster and Cayman.

VW / Audi Self Study Program

SSP location if you can't see the embedded PDF below:  http://www.volkspage.net/technik/ssp/ssp/SSP_74.PDF

Gear Ratios

The following table shows the gearing differences between the EHV (Passat 1.8t), the 00-04 Boxster (G86.01), and the 97-99 Boxster (G86.00) transmissions.  

Stub Axle Flange Info

3 different sizes

• 90mm

• 100mm - Boxster 2.5/2.7 size

• 108mm - Passat 1.8t/911 SC/996/Boxster S 3.2 size

90mm and 100mm flanges use M8x1.25 size bolts while the 108mm flange uses M10x1.5 size bolts.

Stub Axle Flange Removal

The stub axles are held in place internally by a clip.  The easiest way to remove them is to use 2 long bolts with the same thread size and pitch as the stock axle bolts.  Thread the bolts into the stub axle and tighten them against 2 scrap pieces of metal so that it is between the base of the bolt and the transmission housing.  Then tighten both bolts equally until the stub axle is free, going about 1/4 turn per bolt.  Do not tighten the bolts against the diff cover or trans housing directly!  

Below is the special tool from VAG is shown below.  It can be found on eBay for around $160.

CV Joint

The Boxster uses a GKN 15 CV joint with 28 splines, both inner and outer.  There is no known substitute for the outer cv joint, yet.  

It appears that sometime between 01 and 03, Porsche switched inner CV joints. The axle bolt holes on the earlier ones had an 8mm diameter hole while the newer ones had a 10mm bolt hole and used a hybrid bolt with M8x1.25 threads but with a 10mm shoulder.

Axle half shaft

The 012 in a 986 uses different length half shafts. 

Porsche switched the axle shaft size in 03 and 04 to a larger diameter shaft.  The shafts are still 28 spline.

97-98 part numbers:

• Left - 986 332 024 04

• Right - 986 332 024 03

99-02 part numbers:

• Left - 986 332 024 07

• Right - 986 332 024 06

03-04 part numbers:

• Left - 986 332 024 09

• Right - 986 332 024 10

Limited Slip Differential Options

Kaaz 1.5 way clutch type LSD

According to Kaaz, it fits all 97-08 986/987 5 speed transaxles but it will need to use the 97-99 diff cover on all 00-08 transaxles due to the later trans use a larger bearing on the diff cover side.  

In my experience, the diff I received accepts a 50mm bearing on the left (diff cover) side, not a 46mm bearing as I was told by Kaaz.  My diff has a production year of 2020 so maybe this is the way they will be going forward.  What this means to me is that 97-99 diff that use the smaller bearing on both sides will need to use a diff cover from a 2000 and later trans with the larger bearing.  SEE PHOTOS BELOW

Carrier Bearing Sizes

46 x 75 x 18 - Bearing and Race P/N - LM503349 / LM503310

50 x 80 x 20 - Bearing/Race P/N - 32010X (VW/Audi/Porsche P/N - 012 409 123)

012 409 131 H - diff cover with the smaller bearing.

012 409 131 L - diff cover with the larger bearing.

97-99 Boxster used the smaller bearing on both sides of the diff.  2000 and later used the smaller bearing on the right side and the larger bearing on the left (diff cover) side.

Setting Lash

Shown below is an 01E but the same process applies to the 012.

Transmission Code / Manufacture Date

Known Failure Modes

Failed ring gear

• 2003 Boxster with 131k miles ( ~500 miles with Audi 4.2 V8 swap and only autocross/track days)

• Very noticeable wear on ring gear.  Internal magnet completely covered with fine steel dust.  Lots of play when grabbing both stub axles by hand and rocking the diff back and forth.  Very loud whine associated in any gear.

• Might have had excessive wear before engine swap.  Was only using 75w90 gear oil and not 75w140 gear oil.