Center Support
A new center support installed on the H-D 4L80E build.
Free freight shipping to most states in the continental US, delivered to a business address or your nearest freight terminal. Pacific and Mountain time zones plus ND, SD, and NE: add $195 (commercial address) or $225 (residential).
Every Mad Dog transmission and torque converter ships with a 1-year unlimited-mile warranty. No mileage caps, no fine-print games. Extended Silver (+1 year) and Gold (+2 years) coverage available on every unit.
No core charge. Where a core charge applies, you get it back when we receive your rebuildable core — and we make the return freight easy.
Installation is available at our Alpharetta shop. Call (770) 781-0949 to schedule, or have your local shop bolt it in — every unit is a direct bolt-in replacement.
Yes. Every Mad Dog unit is a direct bolt-in replacement for your factory transmission — no modifications. Electronic units ship pre-programmed to your VIN, so there’s no dealer visit and no guesswork.
No. Electronic transmissions are pre-programmed to your VIN before they ship. 700R4 units don’t use a computer at all. If your engine is heavily modified, call us and we’ll set the unit up to match.
Most Mad Dog units have no core charge at all. Where a core charge applies (700R4 Godfather, 4L80E, 6L80E/6L90E) it’s listed plainly on the product page — and on the Godfather 700R4 it’s already included in the price.
Call (770) 781-0949 for current build times on your unit. Every transmission is built to your order — your horsepower, your converter, your options — and dyno-tested before it ships.
Every transmission and converter carries a 1-year unlimited-mile warranty, standard. No mileage cap. Extended Silver and Gold coverage is available if you want more. You deal directly with the shop that built it — not a call center.
Then don’t buy it — call us. We build customs to 1,500 HP, and we’d rather steer you to the right unit than sell you the wrong one. Over 800 HP on a 700R4 platform, the answer is the 4L80E.
The hardware that makes a Mad Dog unit 35–40% stronger than factory.
No mystery parts
A new center support installed on the H-D 4L80E build.
A new filter installed as part of the rebuild.
The full set of Teflon sealing rings replaced as part of the rebuild overhaul kit.
The full set of lip seals replaced as part of the rebuild overhaul kit.
The full set of gaskets replaced as part of the rebuild overhaul kit.
The complete set of steel reaction plates (‘steels’) replaced as part of the clutch pack rebuild.
A 34-element sprag fitted with a hardened outer intermediate race, used on the H-D 4L80E build.
A new round cam direct drum installed on the H-D 4L80E build.
Raybestos’s high-energy friction plates use a friction material engineered specifically to survive the higher clutch-to-steel temperatures that come with performance calibrations and repeated hard shifting — conditions that degrade standard OE friction material over time. The result is smoother engagement that holds up over more cycles than a stock clutch pack.
Roller bearings used in place of factory thrust washers to reduce internal drag and heat generation.
The complete set of internal bushings replaced as part of the rebuild overhaul kit.
A new wiring harness installed on the H-D 4L80E build.
Solenoid(s) controlling torque converter clutch lockup engagement.
Torque converter offered in a range of stall speeds (commonly 1600-2500) selected by the customer at time of order.
New shift solenoids that control gear-shift timing/engagement.
Solenoid that electronically regulates transmission line pressure.
A TCC (torque converter clutch) update sleeve and valve installed to eliminate a common code 1870 condition on the 4L80E.
A steel pressure regulator valve installed to replace the factory aluminum valve, which is prone to binding/sticking at wide-open pressure and causing loss of reverse and 3rd gear.
A worn or undersized stock throttle/boost valve is a common cause of soft shifts and premature band or 3-4 clutch failure in these transmissions. Sonnax’s oversized boost valve increases line pressure across the board in proportion to throttle position, giving the clutches and bands more holding force exactly when the transmission needs it — under load or at higher RPM.
Repeated piston travel wears the 4th accumulator bore in 4L80E cases over time, eventually letting the piston cock and gall the bore — at that point the whole accumulator housing normally needs replacing. This kit presses in a new wear-resistant sleeve along with a pinless piston, restoring proper sealing and shift quality without machining or a case swap.
A new pressure manifold installed as part of the hydraulic pressure system, referenced alongside the Special Valve (GM Code 1870 fix) or independently on the 4L80E build.
An external full manual valve body box, offered as a paid option (approx. $395-$400), that removes the need for the on-board computer; runs on 12 volts and also activates lockup.
Free freight shipping to most states in the continental US, delivered to a business address or your nearest freight terminal. Pacific and Mountain time zones plus ND, SD, and NE: add $195 (commercial address) or $225 (residential).
Every Mad Dog transmission and torque converter ships with a 1-year unlimited-mile warranty. No mileage caps, no fine-print games. Extended Silver (+1 year) and Gold (+2 years) coverage available on every unit.
No core charge. Where a core charge applies, you get it back when we receive your rebuildable core — and we make the return freight easy.
Installation is available at our Alpharetta shop. Call (770) 781-0949 to schedule, or have your local shop bolt it in — every unit is a direct bolt-in replacement.
Yes. Every Mad Dog unit is a direct bolt-in replacement for your factory transmission — no modifications. Electronic units ship pre-programmed to your VIN, so there’s no dealer visit and no guesswork.
No. Electronic transmissions are pre-programmed to your VIN before they ship. 700R4 units don’t use a computer at all. If your engine is heavily modified, call us and we’ll set the unit up to match.
Most Mad Dog units have no core charge at all. Where a core charge applies (700R4 Godfather, 4L80E, 6L80E/6L90E) it’s listed plainly on the product page — and on the Godfather 700R4 it’s already included in the price.
Call (770) 781-0949 for current build times on your unit. Every transmission is built to your order — your horsepower, your converter, your options — and dyno-tested before it ships.
Every transmission and converter carries a 1-year unlimited-mile warranty, standard. No mileage cap. Extended Silver and Gold coverage is available if you want more. You deal directly with the shop that built it — not a call center.
Then don’t buy it — call us. We build customs to 1,500 HP, and we’d rather steer you to the right unit than sell you the wrong one. Over 800 HP on a 700R4 platform, the answer is the 4L80E.
The hardware that makes a Mad Dog unit 35–40% stronger than factory.
No mystery parts
A new center support installed on the H-D 4L80E build.
A new filter installed as part of the rebuild.
The full set of Teflon sealing rings replaced as part of the rebuild overhaul kit.
The full set of lip seals replaced as part of the rebuild overhaul kit.
The full set of gaskets replaced as part of the rebuild overhaul kit.
The complete set of steel reaction plates (‘steels’) replaced as part of the clutch pack rebuild.
A 34-element sprag fitted with a hardened outer intermediate race, used on the H-D 4L80E build.
A new round cam direct drum installed on the H-D 4L80E build.
Raybestos’s high-energy friction plates use a friction material engineered specifically to survive the higher clutch-to-steel temperatures that come with performance calibrations and repeated hard shifting — conditions that degrade standard OE friction material over time. The result is smoother engagement that holds up over more cycles than a stock clutch pack.
Roller bearings used in place of factory thrust washers to reduce internal drag and heat generation.
The complete set of internal bushings replaced as part of the rebuild overhaul kit.
A new wiring harness installed on the H-D 4L80E build.
Solenoid(s) controlling torque converter clutch lockup engagement.
Torque converter offered in a range of stall speeds (commonly 1600-2500) selected by the customer at time of order.
New shift solenoids that control gear-shift timing/engagement.
Solenoid that electronically regulates transmission line pressure.
A TCC (torque converter clutch) update sleeve and valve installed to eliminate a common code 1870 condition on the 4L80E.
A steel pressure regulator valve installed to replace the factory aluminum valve, which is prone to binding/sticking at wide-open pressure and causing loss of reverse and 3rd gear.
A worn or undersized stock throttle/boost valve is a common cause of soft shifts and premature band or 3-4 clutch failure in these transmissions. Sonnax’s oversized boost valve increases line pressure across the board in proportion to throttle position, giving the clutches and bands more holding force exactly when the transmission needs it — under load or at higher RPM.
Repeated piston travel wears the 4th accumulator bore in 4L80E cases over time, eventually letting the piston cock and gall the bore — at that point the whole accumulator housing normally needs replacing. This kit presses in a new wear-resistant sleeve along with a pinless piston, restoring proper sealing and shift quality without machining or a case swap.
A new pressure manifold installed as part of the hydraulic pressure system, referenced alongside the Special Valve (GM Code 1870 fix) or independently on the 4L80E build.
An external full manual valve body box, offered as a paid option (approx. $395-$400), that removes the need for the on-board computer; runs on 12 volts and also activates lockup.
Free freight shipping to most states in the continental US, delivered to a business address or your nearest freight terminal. Pacific and Mountain time zones plus ND, SD, and NE: add $195 (commercial address) or $225 (residential).
Every Mad Dog transmission and torque converter ships with a 1-year unlimited-mile warranty. No mileage caps, no fine-print games. Extended Silver (+1 year) and Gold (+2 years) coverage available on every unit.
No core charge. Where a core charge applies, you get it back when we receive your rebuildable core — and we make the return freight easy.
Installation is available at our Alpharetta shop. Call (770) 781-0949 to schedule, or have your local shop bolt it in — every unit is a direct bolt-in replacement.
Yes. Every Mad Dog unit is a direct bolt-in replacement for your factory transmission — no modifications. Electronic units ship pre-programmed to your VIN, so there’s no dealer visit and no guesswork.
No. Electronic transmissions are pre-programmed to your VIN before they ship. 700R4 units don’t use a computer at all. If your engine is heavily modified, call us and we’ll set the unit up to match.
Most Mad Dog units have no core charge at all. Where a core charge applies (700R4 Godfather, 4L80E, 6L80E/6L90E) it’s listed plainly on the product page — and on the Godfather 700R4 it’s already included in the price.
Call (770) 781-0949 for current build times on your unit. Every transmission is built to your order — your horsepower, your converter, your options — and dyno-tested before it ships.
Every transmission and converter carries a 1-year unlimited-mile warranty, standard. No mileage cap. Extended Silver and Gold coverage is available if you want more. You deal directly with the shop that built it — not a call center.
Then don’t buy it — call us. We build customs to 1,500 HP, and we’d rather steer you to the right unit than sell you the wrong one. Over 800 HP on a 700R4 platform, the answer is the 4L80E.