Inspired by another members install of a 722.6 into a 126ch car I decided to do the same in my 300CE. There isnt anything wrong with the 722.3 currently in the car but I'm covetous of the later trans' .83 overdrive. Not to mention its ability to take a real pounding. I spent a mint building the 722.3 in my turbo 4-matic wagon and it would still barely handle what my builder core is rated for stock.

Future plans for the coupe include an unreasonable amount of boost and having a built 722.6 already behind the motor just seems like good sense. Wanting a good foundation I grabbed up a 722.628. This is the WA580 found behind the M137 in the 220ch. While 580 NM is a goodly amount power handling ability I always subscribe to the more is better philosophy. Hence a thread about building up this trans by increasing the amount of clutches in all of the forward driving gearsets.

First up is the B1 brake. The .628 has 4 friction discs and 3 steels in B1as well as a backing plate and apply plate. Looking for room in the drum I noticed that the moulded apply piston wouldnt lend itself to being clamped in the lathe chuck nor was there much to be gained by trying. .2 ~ .3mm at the most. B1 drums can have the retaining snap ring located at different heights but the .628 is already near the top of the drum. Its tempting to try to cut the groove higher but there is a tricky stress relief cut that I doubt I could duplicate. That leaves the clutch pack itself to find the room. I noticed that the 722.6 versions with single sided cluches dont use the apply plate. That saves 1.8 mm out the box. I also noted that a pair of single sided clutches is thinner than a traditional friction and steel. Lastly I gained 1.2 mm by swapping the backing plate with one of the steels. These changes along with the thinnest selective snap ring allowed me to fit 10 single sided clutches (5 internal teeth, 5 external teeth) in the B1 drum with 1.4 mm clearance.

In the pics you can see the B1 drum on the early inline bellhousing and a closeup of the clutch pack with the new setup.

More to come.... next up K1.

Attached Thumbnails

   

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90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff