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Tremec T56 Six-Speed - Transformulation
Get New Life and Better Performance Out of Your Tremec T56 Six-speed
Sep 1, 2012
Red Line Synthetic Oil
Benicia, CA 94510
Plymouth, MI 48170
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Tremec T56 Six-Speed - Transformulation
1. Dropping the stock T56 from under the fourth-gen was a snap. We just racked the car in our tech center, dropped the exhaust, and unbolted the trans from the bellhousing.
2. Over at Anaheim Gear in Anaheim, California, technician Joey Rodriguez started tearing down Black Betty’s problematic T56 on their autopsy table.
3. One good sign was that there was relatively little metal on the two magnets located at the bottom of the trans. Joey told us that he occasionally finds surprising things stuck here.
4. Now for the bad news. To us, Sixth gear looked fine, but Joey pointed out that the inner teeth were pretty rounded off, and if not replaced, the gear would only degrade further over time.
5. We also found the main cause of our shifting problems: the plastic pad on our 3-4 shift fork was toast, and barely hanging on. A typical cause for this occurring is hard driving, but editor Licata refused to take the fall alone and blamed the previous owner.
6. A cure for this problem is replacing the plastic pads with bronze versions. The pads for the 1-2 and 3-4 forks are the same (PN BS14B, $64 per pair). We also replaced the aluminum 3-4 fork with a more durable steel piece (PN TNEC0843, $81). A bent 3-4 fork is a common problem in early T56 transmissions that are hard-shifted on a regular basis.
7. The stock inserts (referred to as dogs) are stamped steel and prone to breaking, which can lock your trans in Third or Fourth gear. These new billet dogs are indestructible and will never let us down (PN BS47, $116).
8. Starting in around 1999, all T56s were upgraded to carbon blocker rings since the older paper-based designs didn’t hold up. Our rings looked OK, but since we were in this deep already we had the carbon-fiber friction rings, along with the 1-2, 3-4, 5-6, and brass reverse blocker rings replaced with new ones (PN SY 396, $280).
9. Everything had seemed about normal for a trans with 120,000 miles on it until Joey removed the input shaft and main cluster. He found that the gears were burned up (and Sixth gear was worn), and would need replacing. We asked Eric Skillman about this and he said it often happens due to heat caused by low or dirty fluid. Anahiem Gear recommends that manual transmissions get serviced every 15,000 to 20,000 miles. This may sound excessive, but fluid is cheap and transmissions … not so much.
10. Since the original trans had well over 120,000 miles on it, we went ahead and had all the roller bearings, races, and seals replaced (PN TK 396, $170) with quality Timken parts.
11. Thankfully, the guys over at Tremec stepped up and helped us out big time by sending over a brand-new cluster, input shaft, and Sixth gear! These parts would have set us back over $800, so we really appreciated the assist. This means our finished T56 will be as good as new when done. Scratch that. It’ll be better than new! We considered doing the stronger Viper-style output shaft, but given our power levels and how we drive the car, we felt it was an unnecessary expense.
12. Joey then went ahead and installed the new bronze pads on all of the shift forks. Like the stock 3-4 shift fork, the 1-2 fork is also aluminum, but according to Eric, it’s bigger and well gusseted, so it doesn’t have the problem like the 3-4 fork.
13. One nice bonus you get at Anaheim Gear is that they tumble the aluminum transmission cases rather than just rattle canning them or hitting them with a high-pressure washer. This gives the case a very clean, and slightly polished look. With a squeaky clean case in hand, Joey started putting the T56 back together again. This isn’t an easy task, but he’s rebuilt so many of these, he made it look as if it was.
14. Before testing the trans, we filled it up with three quarts of Red Line trans oil. We’ll also take Eric’s advice and change out the fluid on a more regular basis.
15. Once assembled, the final step was to run the trans on Anaheim Gear’s testing dyno stand. Here, technician Juan Dalvan makes sure everything is shiftin’ like butter. It’s also where they ensure there are zero leaks or noise issues.
1. We decided to take this opportunity to try out Centerforce’s new super-lightweight twin-disc DYAD clutch and also modify our clutch master by doing what’s known as the “drill mod.” This is where you remove the restriction, which was put there to slow the movement of hydraulic fluid and thus the clutch operation. The theory was that this would reduce shock to the driveline, but the cost is poor clutch operation in performance driving. This restriction cuts down the line I.D. by about 50 percent. By drilling it out with a 1⁄8-inch drill bit, you get quicker pedal response. You can see complete blow-by-blow details on how to do this simple mod over at YouTube.com by looking up “2002 Camaro Hydraulics Drill Mod.”
2. Aluminum flywheels are great for saving weight and getting those revs up quickly, but they have downsides in terms of expansion and durability. Centerforce’s solution was to lighten up a steel flywheel. By removing weight from the outer edge, the flywheel gains much of the benefit found in an aluminum offering. As Centerforce’s Will Baty relayed, “The entire assembly weighs 44.8 pounds, and although the flywheel is made of steel, it has a low-inertia steel design. Centerforce removed 6 pounds of weight from the outer edge of the flywheel, drastically reducing the inertia, allowing the flywheel to have the same inertia as an aluminum flywheel.” While our old dual-friction clutch called for GM torque-to-yield bolts, this one came with high-strength ARP fasteners.
3. Will also told us, “the DYAD DS is a ‘true sprung’ hub design with the main drive disc built from chromoly steel. The drive disc also has over an inch of spline engagement for stability and strength. The six outer lugs on the driven disc drive the second ‘floater’ disc for positive, but smooth engagement.”
5. This is the part we thought was really cool. The floating disc is held by six drive pins rather than on the input shaft of the transmission. What this meant for us was that aligning the clutch parts was a breeze.
4. The floater then goes on and is held in place by the three lugs on the flywheel. Centerforce marked both of these parts with machinist’s ink to let us know their proper orientation. This is important since the pieces are balanced as an assembly.
6. With all the discs in place, we went ahead and installed the pressure plate and secured it with the included high-strength fasteners. Normally, a twin-disc clutch is challenging to align, but since all the parts are carried on a common splined shaft, it wasn’t any harder than doing a single disc.
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