Arctic White 91 RS

I've decided to post this on TGO because the T56 Magnum transmission can be swapped into a 3rd Gen fbody, typically with an LSx or LTx engine swap. My 99 TA needed a transmission and clutch upgrade for before the new engine gets installed. The stock T56 and clutch were borrowed time after 15 years and 128,000 miles behind a heads and cam package. They also had ~30,000 hard miles when the car was a bolt on car.

I'm posting from my cell phone so please excuse the edits and typos.

I considered a T56 rebuild like the level 2 from Hawk's that's in my 91 RS and initially discussed that with RPM Transmission. Some will wonder why I picked RPM this time instead of Hawk's and there is a very simple answer: Logistics

The TA was here in Indiana in the middle of getting upgrades when the stock T56 started having issues shifting gears and vibration problems. There are only a few shops in my area I'm comfortable with to work on the car. Mike Norris Motorsports was booked solid and the car would have to sit until Mike can do the scheduled motor swap. We could get the transmission issue fixed then. Hawk's was 600 miles away and I really didn't want to try to do much driving with TA gear shift issue.

RPM Transmission seemed the logical choice.

Visiting Hawk's with a friend, Bruce and I discussed the TA's issues. He felt it was most likely the pilot bearing / bushing and possibly the pressure plate. He suggested considering an upgrade to a Magnum T56 from Hawk's or RPM Transmission.

Tyler at Hawk's let me shift thru the gears in his Magnum T56. Even with the car parked, I was shocked at the precise short throw shifting. I was sold on the Magnum even if the motor swap had to wait. Every time the my TA is driven the driver interacts with the transmission. I couldn't think of a Mod that would improve the driving experience more than the Magnum and Hawk's 8.8 rear end.

Given the logistics with the TA, I called RPM Transmission to discuss Moving from an RPM Level 5 to the Magnum.

Arctic White 91 RS

Jeremy at RPM Transmission was fantastic at every step of the process. We discussed the various options for the Magnum like the gear set ratios. The chart below gives an idea of the choices.



With the TA having 4.10's in the Hawk's 8.8 rear end, the 2.66 1st seemed the best choice. The 0.80 5th and 0.64 6th seemed perfect. I upgraded to the Magnum.

Rounding out the part selection a new clutch was in order. My criteria: The clutch had to drive like stock, be able to hold up to 600 hp and survive a 6000 rpm side step on slicks. While I probably won't abuse the drive line that severely, I like to over build and not worry. Jeremy suggested the McCloud RXT Twin Disc with supporting McCloud pressure plate, small 9 inch fly wheel and new hydraulics.

Jeremy asked if I the stock drive shaft needed to be upgraded too. I've always wanted to try a carbon fiber drive shaft. Jeremy said the Drive Shaft Shop could have one ready in a week or so. He confirmed the stock length and correct yoke to use with the 8.8 rear.

The parts were all ordered. I've condensed the discussion and process for the review. Jeremy was outstanding at every step in the process.

We scheduled an install date and everything was on had ready in a timely manner. I planned to wait on the car at RPM while the install was done. We planned to start at 8 am sharp.

Arctic White 91 RS

Details:

TREMEC T-56 Magnum 6-speed manual transmission, was the long awaited and highly anticipated replacement for the original T-56.





Based heavily on the TR-6060, the all-new Magnum took the best of TREMEC’s current OEM design and manufacturing technologies and combined them with the most popular features of their intensely popular TKO 5-speed. The result is the smoothest shifting, greatest driving, strongest and most versatile 6-speed aftermarket transmission TREMEC has ever produced.


Features & Benefits

Features & Benefits:
85mm center distance.
700 lb-ft effective torque capacity.
Fully reversible ‘TKO-style’ OEM-grade die-cast aluminum shifter for smooth, positive shift action.
Dual ‘speedo’ pick ups to accommodate both electric and mechanical type speedometers.
Built-in mid-shift provisions under inspection cover for simple, pain free mid-shift conversions.
Triple cone synchronizers on gears 1-4, double cone synchronizers on gears 5-6, as well as reverse.
Accurate, smooth, high-rpm shift capabilities.
26 Spline input shaft
31 Spline output shaft

RPM Level VI upgrade

Level VI $5495.00
All of our LEVEL VI MAGNUM six speed transmissions include:



*Media blast transmission case

*Hand fit sliders and hubs

*Assembly to our specifications

*Bronze fork pads on all gears 1-6 including reverse

*Micropolish by Performance Metal

*Bronze shifter bushing when applicable

*Carbon blocking rings





Optional upgrades include:

$350.00 - cryogenic tempering

$250.00 - Powder Coat Case

SFI Bellhousing Call for pricing

If getting a package install of clutch and transmission RPM Transmission offers a package deal.

The TA's new Magnum

Arctic White 91 RS

The two hour drive to RPM Transmission had me wondering if the old T56 going to shift several times. A little before 8am arrived at RPM Transmission.




Lucky for me there was a nice waiting room with plenty of car magazines, TV and comfortable couch. I spend most of the wait time checking out the cool items in the show room and taking pictures of the installation.

Arctic White 91 RS

The car went back for the install and the install started immediately.




About to pull transmission.





Drive shaft out of the car.




The pilot bushing looked pretty nasty and was toast.
The stock clutch had got hot

I think I had the best stock LS1 clutch with this car. It survived lots of abuse for a long time. I learned to drive straight drive all over again on it, taught my girlfriend's son to drive straight drive on it too.
After almost 160,000 miles it was time to upgrade.

Arctic White 91 RS

Bruce of Hawk's Motorsports was correct the pilot was trashed.








Ready for the McCloud RXT Twin Disc.



One of those little red clutch by McCloud.

Arctic White 91 RS

Talking with the staff at RPM Transmission was lot of fun. Jeremy is also a Third Gen fan owing a couple of them, including a cool yellow 87 IROC. The technician doing the install on the TA is a Z06 owner. There were a lot of Sweet cars at RPM getting upgrades. Here is my favorite.

Arctic White 91 RS

The stock drive shaft and it's carbon fiber replacement.




The RPM Magnum



Installed.

Arctic White 91 RS

The entire install took about eight hours from arrival to loading the old T56 in the back of the TA. RPM Transmission was so kind to drain the oil and place the old transmission on several sheets of cardboard. They also loaded the old T56 in the back of the TA.

Driving the TA is a delight. The McCloud RXT clutch drives like the stock clutch. Pedal pressure might be a hair lower. Engagement point is perfect in the middle. The friction point is smooth, the clutch can slip without chatter. Jeremy suggested the ideal clutch for my application.

The carbon fiber drive shaft seems to dampen some of the typical noise and vibration a 4th Gen six speed car normally has. I want one for the white RS now.

The Magnum lives up to the hype and exceeds it. The close ratio shifting is Precision and it's a delight to drive. The Pro 5.0 shifter that's been on the car since 1999 shines in a new light. The shifter pulls to Center perfectly for fast 2nd to 3rd shifting. The feel is incredibly easy to describe - perfection.

After 18 years the TA is a true joy to drive. The new rations for 5th and 6th are fantastic. The hint of spark knock my TA would show at 55-60 mph in 6th is all gone with the new lower 6th gear ratio. The old 0.50 was too steep. The new 0.64 6th gear is ideal. At 70 mph the rpm is up from ~ 2000 to ~ 2500 so mph may decrease a little. The car is far more lively in 6th on the interstate at 70 mph when going to pass another motorist.

High rpm shifting is also much improved in all gears. The shift to 5th at WOT is clean and fast.

I think the Magnum is best manual for I've driven and my sampling includes Honda, Chevy Ford, Pontiac, Dodge, Porsche and probably a few others I can't think of right now.


Highly Recommend
RPM Transmission for tech support
RPM Transmission for parts
RPM Transmission for install
RPM Transmission for fast turn around time

Magnum T56 Level VI for gear shifting driving fun.

Beater79TA

I see the one you had installed was converted to a FBody tailhousing. We have a similar unit in out 88 GTA. For anyone looking to put a Magnum in their car, I highly recommend this conversion on the Magnum. It allows you to use 4th gen 4 bolt shifters, it puts the shifter through the floor in the correct position, and it allows you to retain the stock torque arm mounting.

Hopefully the output shaft seal on yours lasts longer than many of the others in circulation. Ours seems to be good for about 12 months before starting to leak from there. Same is true of 2 other cars. But a 3rd friend has one that uses the same seal and has never leaked from it in 5 years.

Arctic White 91 RS

Appreciate the heads up on the output shaft seal.

Arctic White 91 RS

Update - the tail shaft seal started leaking on my Magnum T56. It held up for about six months and ten thousand miles. In November there wasn't any fluid under the car. The car was at a shop for the winter for an unrelated issue.
​​​​
This May the leak was discovered. While under side of car was soaked. Had to add two quarts of transmission oil and return car to ship for repair.

Will update with repair details.

A friend also bought a Magnum T56 after driving mine. Within two months and two thousand miles the tail shaft started leaking.

The Magnum shifts fantastic but I'm not sure if I will upgrade my 91 RS with a Magnum anymore. The Hawk's level 2 T56 doesn't leak or have any issues.

Beater79TA

Have them also check the output shaft bushing. We ended up with a major leak from ours after 18 months and it was a result of the bushing having moved inward. It's been solid since they repaired that.

Arctic White 91 RS

The shop said it was just the tail shaft seal that was bad. No burrs on shaft or nicks on their leaking seal were found. It's been fixed two weeks and so far seems good. Took a little while to get the seal.

Edit - fixed for ~ 12 weeks and no leaks.

Note: On my 99 TA the rear springs (Eibach Pro) are sagging after 18 years and ~150,000 miles. The springs seem to be losing their rate and will have to be replaced. I suspect the rear end has moved around and bottomed out more than normal with some of that energy going back up the driveshaft and possibly damaging the rear seal on the Mac from excessive movement.

I plan to replace the springs with a set from Strano in the spring of next year since the car is parked for the year.

Arctic White 91 RS

Update - no leaks

Update- no leaks 5-31-19