Author: American Powertrain

BaconShift 2018 Holiday Sale

It’s that time of year again for #BaconShift! Starting Nov 21st through Jan 1st. Get Free Shipping to the lower 48 on all non freight items (TKO 5-speeds ship ground for free!) Get $100 off freight charges for 6-speeds, rear ends and engines. Also any transmission order gets 3 lbs of the best bacon on earth. Benton’s Bacon out of Madisonville, TN. Phone in orders only. 931-646-4836 or you can start your quote by hitting our RFQ link here.


Shifter stuck in gear after your new transmission shows up? Here is the cure…

American Powertrain TKO Shift Assembly Re-alignment Procedure.

Background: Your brand new TREMEC TKO shows up in at your shop or house…You rush out to open it up get it in the shop and it will not shift through the gears! Sometimes your new transmission may get jostled during shipping, causing a misalignment of the shift mechanism. You should shift your transmission through all the gears before putting it in the car and rotate the input shaft to make sure it moves freely.

Note that reverse must be engaged from the neutral position. The transmission has a mechanical reverse lock-out that will not allow a straight shift from 5th to reverse.

If your transmission shifts into all gear positions and the input rotates freely you may proceed with installation.

Should you have a transmission that is locked up due to misalignment you can easily correct the problem with a few simple tools in about fifteen minutes.

Correction Procedure:

Step 1: If you have a clutch disc handy, place it on the input shaft and attempt to turn the disc like a steering wheel. If the alignment issue is minor this will often correct the problem.

If that fails, move on to step 2

Step 2: Remove the four bolts that secure the mid-plate on top of the transmission. This is the flat five-sided plate in the center of the gearbox. See image:


Step 3:  Gently pry the cover off with a flat blade screwdriver or small pry bar.  Work slowly around the periphery of the plate and do not bend the cover.  A chisel punch can be used with a small hammer if used carefully.

Step 4: Under the cover you will find three shift lugs. These lugs should be aligned in neutral position as shown in the image.

Step 5: If they are not aligned use a large screwdriver or small pry bar to move the lugs back to neutral

Note the arrow pointing to the right lug in an incorrect forward position. You may need to move more than one lug. There will be an audible click when each lug is in neutral and you will feel the neutral detent.

Once the lugs are re-aligned the shifter should move freely through the gears and the input shaft should rotate freely. You can test this with the cover off.

Step 5: Now that the transmission is operating properly, remove the gasket sealer from the case and cover plate using solvent and a rag. You may use a razor blade on the case, but do not use a razor on the cover. The sealant will rub away with a rag and solvent. Run a continuous 1/8” bead of grey gasket sealer on the top of the case and around the bolt holes. Then reaffix the cover.

NOTE: Don’t go crazy with the gasket sealer. You don’t want chunks of it dropping off and gumming up the linkage.

If these steps do not correct your problem you will need to contact us for help at 931.646.4836. If your transmission was damaged in shipping we will need images of the transmission and the original shipping carton inside and out. This will allow us to make a claim with the shipping company. Our tech support folks can walk you through this procedure.

Thank you for working through this simple issue. Enjoy your TREMEC TKO.


Swapping a 5-speed into an F-100

Driving a classic truck is fun. It’s even more fun with a stick.

American Powertrain had an F-100 project built by their IT guy Barry. It’s a “pro-touring” like project he has been slowly and meticulously building at home. The truck has good handling and old school looks with a modern EFI 351W under the hood. The parts are a go-to play list for F-100 builds: Panther front end swap, FITech and disc brakes. He knew the final cherry on top would be a TREMEC TKO 5-speed swap. Follow along on the install.


Barry’s 1972 F-100 short bed. 351W with Fitech EFI, Trick Flow heads and mild cam. Even has Vintage Air


The truck came in with no transmission so this gave us a nice clean place to start. The Crown Vic Panther front end swap puts the engine pretty close to stock location so transmission placement was no issue.


The heart of it all is the American Powertrain F-100 Pro-Fit 5-speed kit, using a TREMEC TKO-600. This kit has everything you need to install a 5-speed in a classic Ford truck: crossmember, hydraulic clutch, pressure plate clutch, bell and flywheel.  A custom built driveshaft is also included in the kit. Once you do the install, fill out the driveshaft order form to send in the measurements and your new, custom made shaft will be on its way a couple of days.


The first thing we did was slap the bell housing on with no flywheel or clutch. We hoisted up the trans to see what kind of clearances we had to work with on the tunnel. Turns out we had to do a little hammering just at the vent tube (a common clearance issue on TKO’s). One of the ways American Powertrain gets these larger transmissions to fit into older cars is case minimizing on the transmission. They also offer a fiberglass tunnel hump for F-100. 6-speeds will need a larger tunnel opening.


The trans on the left is a stock out of the box TREMEC TKO. The trans on the right has been “minimized” by American Powertrain. You can see the corners on the top cover of the trans were CNC milled and new cover plates installed for better tunnel clearance. Doing these mods yourself will void the TREMEC warranty. APT works with TREMEC on approving these mods and offers a two-year warranty. The shifter has been replaced with a White Lightning short throw shifter that also serves as forward shift position to clear a bench seat.


Once the tunnel clearance’s was checked and shifter location set up, we installed the X-Factor universal adjustable crossmember. American Powertrain has these in 3 sizes that adjust to fit frame widths from 20” to 34”. We used the widest one that adjusts from 32”-34”. This allows you to set height for the right driveline angle, and uses a standard GM transmission isolator. The crossmember also allows adequate exhaust clearance for lowered trucks. Simply slide the plates to the frame, mark your holes and drill, using the supplied grade 8 hardware



Set the crossmember to the right driveline angle. Plus or minus 3 degrees are the specs that TREMEC calls for to avoid vibration.  A cheap angle finder makes this pretty easy.



Now the real fun begins.  Once we did the mock up and took out the trans, it was time to start the install. One of the critical procedures is to dial indicate your bell housing. This is very important to make sure the bell is centered on the engine so the input shaft lines up straight with the crank. This is critical for transmission longevity. American Powertrain has videos and instructions on how to get this right. 


Once the bell is checked, take it off and start installing the flywheel and clutch. Make sure to torque everything down to spec!


Now its time for more math! This time it’s for the hydraulic clutch bearing. Once the bell and clutch were installed, we had to measure the distance from the pressure plate fingers to the back of the bell. Then from the face of the trans to the face of the bearing. This difference tells us how far the bearing is sitting back from the clutch fingers.


The Hydramax Hydraulic Clutch Kit allows many different clutch combinations. The key to this is making some measurements and setting the depth correctly for the set up you have. The specs are .150” air gap between the bearing and the pressure plate fingers. Once you get the measurements this will determine the number of shims you need to set it correctly for long clutch and bearing life. Once again, American Powertrain has all the instructions and videos to make this pretty easy.  A digital caliper is all you need.


Install the trans and the bearing together. Make sure to run your lines out of the bell and away from the exhaust.



Barry’s truck already had a clutch pedal. These are fairly easy to find for Fords in a junk yard or any of the restoration catalogs.


Next up mount the patented Hydramax master cylinder bracket on the fire wall. This requires a about four holes to be drilled. The bracket has a backing plate to prevent firewall flex. You may have to drill an additional hole higher up on the pedal to get the clutch rod ratio set correctly. We had to lengthen out the mounting point using a piece of flat stock to get the correct angle. American Powertrain will have this added in to the kit for F-100’s as soon as research & development approve the new component.


Finished install is now ready for a new drive shaft. Do a few simple measurements on the included driveshaft measurement form then send it in to American Powertrain. In a couple of days your new driveshaft will show up, ready to install.


We had plenty of room for a bench seat with a double bend 18” shifter handle. APT has tons of shifter handles, shifter knobs and boots to finish up your install. We finished it off with one of their gunmetal gray billet shift knobs to match the wheels of the truck. No more boring automatic!



American Powertrain also now offers an F-100 fiberglass high hump tunnel replacement for F-100s. TKOs and T-5s fit the truck with slight massaging. Magnum 6-speeds will need more clearance. But if you want all the room you can get grab one of these to finish it out.

TREMEC discontinues production of all Magnum 6-speeds with a .50 overdrive gear.

If you want a .50 6th gear call now because when they’re gone … they’re  gone

We still have a few in stock. If you want one give us a call!

Tremec will still offer the 2.97 first gear option previously offered with the .50 6th, but it will now only be available with the .63 6th .

YES – that is correct you have 2 choices of 1st gear that are only .31 apart but no factory option for the .50

After the supply of factory built .50 6th gear  Magnums is gone American Powertrain will be able to custom build a new Magnum with the .50 6th gear for an additional charge. Call for details and pricing.

931-646-4836 or shoot us an email

TUET11009 MAGNUM for GM   2.66/.63
TUET11010 MAGNUM for Ford  2.66/.63
TUET11011 MAGNUM for Ford  2.97/.50  Discontinued
TUET16884 MAGNUM for Ford  2.97/.63  NEW MODEL
TUET11012 MAGNUM for GM   2.97/.50  Discontinued
TUET16885 MAGNUM for GM   2.97/.63  NEW MODEL
TUET11430 MAGNUM XL for Ford 2.66/.50  Discontinued
TUET16886 MAGNUM XL for Ford 2.66/.63  NEW MODEL
TUET11940 MAGNUM XL for Ford 2.97/.63
TUKT12019 MAGNUM XL + Mustang install kit 2.66/.50  Discontinued
TUKT16901 MAGNUM XL + Mustang install kit 2.66/.63  NEW
TUKT12021 MAGNUM XL + Mustang install kit 2.97/.63