T56 Billet Reverse Lockout Solenoid Delete Kit

If you dropped a T56, T56 Magnum or TR6060 into a swap car, or moved an LS or Hemi build onto a standalone engine controller, the reverse lockout solenoid is usually the loose end. Leave it unplugged and you have to shove the lever hard to the right and back to get reverse. Pull it out with nothing in the hole and there is no resistance left between fifth and reverse. This billet delete from Michigan Motorsports (MM-RLODELETE, engraved 6033) fills the solenoid bore with a spring-loaded plug, so reverse takes a deliberate push again without any wiring.

What the reverse lockout solenoid does in a T56 and TR6060

On these six-speeds reverse sits in the gate next to fifth. A quick 4-5 upshift with a little too much right-hand pressure could end up aimed at reverse, so Tremec put a solenoid on the side of the case that blocks the shift lever from entering the reverse gate. Modern Driveline's write-up on the T56 Magnum explains that the solenoid blocks the gate when it is de-energized and opens it when it is powered, and that the factory setup lets the engine computer use vehicle speed to decide when reverse is allowed. A swap harness or aftermarket ECU often has no output for it, so the solenoid just sits there locked.

The delete replaces that electrical gate with a mechanical detent. The plug seals the bore and the spring pushes back on the shift mechanism, giving you a firm step you can feel before reverse. It is honestly described by the maker as not a lockout: a driver who pushes through the step will still get reverse.

Symptoms that point you to this part

• Reverse takes far more force than it should, or you can only get it by slamming the lever, on a swap where the solenoid is not wired.
• The lockout connector is cut, missing or unused because your controller has no reverse lockout output.
• The solenoid was removed and the bore plugged with a bolt or tape, and now the lever drops into reverse with almost no resistance.
• A leaking or cracked solenoid body weeping gear oil from the side of the case.

How to confirm before you buy

First decide whether you actually want a delete. If your car still runs the factory computer and the lockout circuit is intact, a hard reverse usually means a wiring, fuse or speed-sensor input fault, and fixing that keeps the true lockout. Check that the solenoid gets power and a switched ground at a standstill. If you are running a standalone ECU or a swap harness with no lockout driver, the delete is the simple route. Our manual transmission repair cost guide is worth a read if the box also has grinding or worn synchros, since forcing reverse for months is hard on the shift rails and detents.

Fitment

The listing and the maker cover the Borg Warner and Tremec T56, the Tremec T56 Magnum and the TR6060 six-speed. That spans the factory T56 in F-body Camaro and Firebird, Corvette and Viper applications plus the swap market, and the TR6060 behind later Camaro, Challenger and Mustang performance models. The solenoid boss and bolt pattern are shared across these units, but confirm your case has the side-mounted lockout solenoid held by a single bolt before ordering. If you are unsure which six-speed you have, read the ID tag or send us the year and VIN. More manual transmission parts are on our hard parts page.

Install notes

• Shift into neutral, unplug the solenoid connector and remove the single bolt holding the solenoid to the case. Expect a little gear oil to come out with it.
• Clean the bore and the sealing face. Fit the new O-ring onto the billet plug and lubricate it with the same gear oil the transmission uses.
• Drop the spring into the bore, seat the plug and install the supplied M8x1.25x30 bolt. Snug it evenly; one buyer on the maker's page reports a very tight fit, so do not overdrive the bolt into the aluminum case.
• Two springs come in the kit. Start with the standard spring; use the lighter one if you run a short throw shifter that makes reverse feel too stiff, such as our F-body T56 short throw shifter.
• Top off the fluid to the fill plug and test reverse selection with the engine off before driving.

If the transmission is coming apart anyway, our T56/TR6060 5th-6th gear puller and the T56 concentric slave cylinder are the other parts swap builders most often need at the same time.

Will this delete stop me from accidentally hitting reverse?

It adds a firm spring step before reverse, so a normal upshift into fifth will not slide into reverse by accident. It is not a positive lockout; deliberate pressure will still select reverse.

Does it fit the TR6060 in a Challenger or Camaro?

Yes, the maker lists the TR6060 along with the T56 and T56 Magnum. Confirm your case uses the single-bolt side-mounted lockout solenoid before ordering.

Do I need to unplug anything in the computer?

The solenoid connector is simply left unused. Some factory computers may log a lockout circuit code with the solenoid removed; on standalone and swap controllers with no lockout output there is nothing to change.

Which spring should I use?

Start with the standard spring. If you run a short throw shifter and reverse feels too heavy, swap to the lighter spring included in the kit.

Do I have to drain the transmission?

No. Keep the car level and work quickly; only a small amount of gear oil escapes when the solenoid comes out. Top it back up to the fill plug afterward.

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