Back a couple of months ago, I got a phone call from Shafi Keisler, owner of Keisler Engineering, about a new 5-speed transmission that had just been released for the C3 Corvette at just $2,195-a thousand dollars less than their current Tremec TKO offering! Well, to say the least, he had my undivided attention. That transmission turned out to be the Keisler T45-RS, which is based on the Borg-Warner T-45 that was used from 1996-2001 in high performance passenger cars including the Cobra and 4.6L Mustangs.
Keisler buys the T-45 from reliable used transmission sources and then remanufactures each transmission in-house with a number of upgrades and custom features that greatly improve the reliability/durability of the gearbox. The T45-RS is a Double Cone transmission with all forward gears and reverse fully synchronized and shares many internal components with the famous T-56 6-speed.
The T45-RS rebuild includes all new upgraded carbon fiber synchronizers, bearings, seals and gears (as required), a new high strength alloy front casting that allows the T45-RS to bolt up to the standard GM bellhousing bolt pattern, and a new super duty input shaft (either standard 10-spline/1-1/16" or optional 9310 chromoly 26-spline/1-1/8"). Keisler also offers a choice of electronic or mechanical speedometer output for the T45-RS and uses a high strength 31-spline output shaft.
The T45-RS comes in two builds, 350HP and 425HP. The primary difference between the two transmissions in that the 425HP version uses the larger 26-spline input shaft while the 350HP version uses the 10-spline input. Both transmissions use the same gear ratio as follows: 3.37 1st, 1.99 2nd, 1.33 3rd, 1.00 4th, .67 5th; 3.22 Reverse which equates to a 33% drop in engine RPM in 5th gear.
The T45-RS uses a custom billet aluminum short throw shifter that has been custom designed to work in all 1968-82 Corvettes. An optional C3 replica shift handle is also available that not only gives you an original look but also places the shifter at the correct height. We used this shifter in this build and as you will see later, it looks, works, and feels great!
Keisler provides the T45-RS in kit form. Their proprietary designs include a crossmember mount bracket, rubber transmission isolator (poly upgrade available), back-up wiring harness, forged quick release slip yoke, driveshaft, 5-speed shift pattern plate, template and tunnel cover, installation hardware kit, and an installation manual. Each T45-RS is 100% spin tested and leak checked prior to shipment and comes with a 6-month warranty (extended warranty available at extra cost).
One of Keisler's key ingredients to their transmission kits is their driveshaft program. Keisler builds all their driveshafts in-house on their Hines driveshaft cell from lightweight high strength steel that is automatically welded and computer balanced with premium solid sealed U-joints. Each driveshaft is then painted satin black, certified and serialized.
Well we have talked enough about the specifics of the T45-RS transmission for now. The result of the initial phone call from Shafi was an invitation to fly up to the Keisler plant for a T45-RS install into a '69 C3 and a test drive. It didn't take too much arm twisting for me to be on a plane pronto to go thrash a hot 5-speed C3 through the hills and dales around Knoxville, Tennessee, so that's exactly what happened. Follow along with us now as we install the tranny in the car and then we will take the car out for a test drive in next month's issue. Let's get to it!
| Difficulty Index - 3 Wrenches |
| Anyone’s Project: no tools required | 1 Wrench |
| Beginner: basic tools | 2 Wrenches |
| Experienced: special tools | 3 Wrenches |
| Accomplished: special tools and outside help | 4 Wrenches |
| Professionals Only: send this work out | 5 Wrenches |
The next step is to cut the...
The next step is to cut the tunnel hump. We used a $35 AmPro reciprocating air body saw to make the job very easy.
This is the Keisler tunnel...
This is the Keisler tunnel cover.
We first need to place the...
We first need to place the cover down inside the tunnel to position it correctly in the new cut tunnel hole. We center the cover in the opening.
Next we use small C-clamps...
Next we use small C-clamps to lock the tunnel cover to the floorboard so it won't move.
We then raise the car up on...
We then raise the car up on the lift and drill out several holes through the new tunnel cover and through the floor board for the new boot trim ring. We use a 1/8" drill bit and will use a 1/8" rivet to anchor the cover.
We then lower the car, remove...
We then lower the car, remove the C-clamps, take the tunnel cover out, run a small bead of 3M Body Sealant in the middle of the plate where it will seal to the underside of the tunnel. Then the cover is put back down through the tunnel hole and the drilled holes are lined up.
Now place the boot trim ring...
Now place the boot trim ring and the 1/8" spacer (placed on driver side of hole) on the tunnel cover and secure with multiple C-clamps. Make sure the boot trim ring, spacer and cover are lined up properly. Drill the 1/8" holes for the boot trim ring screws. You can now remove the clamps and boot trim ring for now.
Now place the boot trim ring...
Now place the boot trim ring and the 1/8" spacer (placed on driver side of hole) on the tunnel cover and secure with multiple C-clamps. Make sure the boot trim ring, spacer and cover are lined up properly. Drill the 1/8" holes for the boot trim ring screws. You can now remove the clamps and boot trim ring for now.
Now the tunnel work is complete...
Now the tunnel work is complete for now. It's time to install the tranny.
Now raise the car back up....
Now raise the car back up. The first thing to do is to seam seal the tunnel cover from the bottom of the car and then you can paint to make the underside look clean. The next step is to dial in the bellhousing.
Here is the T45-RS ready for...
Here is the T45-RS ready for the install. You should have done all your preparatory steps that Keisler dictates in their install literature and the tranny should be ready to go at this point.
Lift the transmission assembly...
Lift the transmission assembly up (preferably on a tranny jack) to the back of the bellhousing and insert the input shaft into and through the clutch assembly. The lower left mounting bolt (arrow) is partially captured in front transmission case and requires an open end wrench. Make sure the back of the transmission is supported until the crossmember is installed.
This is the original crossmember...
This is the original crossmember with the new crossmember bracket and E-brake pulley assembly that Keisler manufactures in-house for this application.
This is the optional exhaust...
This is the optional exhaust hanger bracket that also is used in conjunction with the crossmember for rear exit exhaust equipped cars. Our install did not use this bracket since our car had sidepipes.
Next, the crossmember is lifted...
Next, the crossmember is lifted into place.
Note the new rear mount location,...
Note the new rear mount location, a Keisler Engineering exclusive.
Next we install the E-brake...
Next we install the E-brake cable pulley assembly.
The driveshaft is now ins...
The driveshaft is now installed.
Next we install the Keisler...
Next we install the Keisler billet U-joint caps to the forged quick release slip yoke. Keisler only uses Neapco HD sealed solid hub U-joints.
Now the slip yoke is asse...
Now the slip yoke is assembled.
A new speedometer cable is...
A new speedometer cable is provided, including the calibrated driven gear for your tire size and rear differential ratio.
All of the original mechanical...
All of the original mechanical clutch release linkage is reassembled.
The lower left bolt is partially...
The lower left bolt is partially captured in the front casting due to the shape of the T45-RS maincase. The bolt is set to the transmission and tightened as the transmission is joined to the bellhousing. No big deal.
The reverse light switch is...
The reverse light switch is built into the transmission and Keisler provides the wiring harness that connects to the factory harness.
The transmission is now in...
The transmission is now in and the assembly is now complete so it's time to button up the shifter up top.
The transmission is ready...
The transmission is ready to receive the new shifter.
First, RTV sealant is applied...
First, RTV sealant is applied to shifter sealing surface.
Next we set the shifter tower...
Next we set the shifter tower assembly to the T45-RS.
Tightening down the shifter...
Tightening down the shifter tower.
Next we assemble and tighten...
Next we assemble and tighten the lower shift boot retainer screws.
Apply Loctite Blue to shifter...
Apply Loctite Blue to shifter handle bolt.
Assemble shifter handle to...
Assemble shifter handle to transmission.
Reassemble console...
...assemble fiber optic p...
...assemble fiber optic panel...
...and re-install the cigarette...
...and re-install the cigarette lighter.
Re-install the console top...
Re-install the console top plate with the trick Keisler 5-speed pattern plate.
Apply Loctite Blue to shifter...
Apply Loctite Blue to shifter knob thread prior to installing the shifter ball.
The T45-RS install is now...
The T45-RS install is now complete. Stay tuned for next month when we drive the C3 with this new tranny!
Get out of the slow lane!...
Get out of the slow lane! At just 2200 RPM you will be cruising at 68 to 83 MPH depending on what rear axle ratio your Corvette is currently equipped with. Check out this T45-RS speed table at www.keisler auto.com to dial in your own Vette!