A750F Solenoid Kit

This remanufactured seven-piece kit replaces every solenoid on the valve body of the Aisin A750F, the four-wheel-drive version of Toyota's five-speed. It is listed for the 2003-2008 4Runner with the 4.0L or 4.7L, the 2007-2011 FJ Cruiser, the 2003-2009 Lexus GX470 and the 2003-2007 LX470. Owners usually land here with a truck that flares between gears, shudders when lockup applies, or stores a string of solenoid performance codes after the fluid has been neglected.

What is in the kit

The photo shows seven solenoids: four long-bodied linear solenoids and three short on/off solenoids. That matches the A750 layout, which uses SLT for line pressure, SLU for converter lockup, SL1 and SL2 for clutch apply pressure, and the S1, S2 and SR on/off solenoids that stage the shift valves. Replacing all seven at once means every solenoid on the valve body starts at the same condition instead of mixing a fresh part with tired ones.

What the solenoids do in an A750F

The computer combines the on/off solenoids to select a gear, then uses SL1 and SL2 to ramp clutch pressure up and down so each shift is smooth. SLT sets base line pressure from throttle and load, and SLU modulates converter clutch apply. In a 4x4 that tows, climbs or idles hot on the trail, the fluid breaks down and varnish builds in the linear solenoids first, which is why shift feel goes bad well before a hard failure.

Symptoms

• Flare or a slipping feel on the 2-3 or 3-4 shift
• Shudder or surging at steady cruise when lockup applies
• P2757, the SLU (lockup) solenoid performance code
• Every shift harsh because line pressure is stuck high
• Stuck in one gear or a fail-safe mode with the check engine light on

How to confirm before you buy

Transmission Digest covered a 2005 Tundra with the 4.7L and an A750F that kept setting P2757 even after a used transmission went in, which shows the code does not automatically mean the part is bad. Pull the codes, check the case connector for fluid wicking into the harness, and measure each solenoid with a meter using our multimeter solenoid test guide. If the main complaint is shudder, work through converter clutch shudder diagnosis first, since old fluid alone can cause it. Heavy friction material in the pan points to a clutch problem that new solenoids will not fix.

Fitment

The listing names the A750F (and A750E) for the 2003-2008 4Runner 4.0L and 4.7L, 2007-2011 FJ Cruiser, 2003-2009 GX470 and 2003-2007 LX470, plus export models such as the Hilux, Surf, Fortuner and Land Cruiser. It does not name the Tundra or Sequoia. Solenoid connectors and mounting tabs can differ between applications, so compare the connector colors and tab shapes to the photo, check the code on the transmission tag, or send us your year and VIN. Our full A750 range is on the Aisin transmission page, including the LX470 seven-piece kit.

Install notes

• Drain the fluid, drop the pan and remove the filter. The solenoids can be changed with the valve body on the case, but pulling it gives a better look at the bores.
• Unplug and remove one solenoid at a time; the linear solenoids look alike and must go back in their own positions.
• Use new O-rings lubed in fluid and tighten the retainers evenly.
• Fit a new filter and pan gasket, such as the A750E/A760E filter and pan gasket kit.
• Refill with Toyota WS fluid, set the level hot at the check plug, clear codes and reset the adaptives.

If shifts stay soft with new solenoids, worn valve bores are the next suspect; a complete A750F valve body for 2005-2009 replaces them.

What is the difference between the A750F and A750E?

The A750F is the four-wheel-drive version with a transfer case behind it; the A750E is the two-wheel-drive version. They share the five-speed design and valve body solenoid layout, but match your tag before ordering.

Does this kit fix P2757?

P2757 is the SLU lockup solenoid performance code, and this kit includes a new SLU. The code can also come from converter or fluid problems, so test the circuit and check the fluid before replacing parts.

Will it fit my Tundra or Sequoia?

Those trucks are not named in the listing. If your transmission tag reads A750F, send us your year and VIN and we will check the solenoid style before you order.

Should I change the filter at the same time?

Yes. Debris from the old fluid is what usually kills these solenoids, so install a new filter and pan gasket and flush the cooler lines.

What fluid does the A750F use?

Toyota WS ATF. Check the level hot, with the engine running, at the check plug.

• How to Test a Transmission Solenoid With a Multimeter
• Torque Converter Clutch Shudder Diagnosis
• Aisin Slipping Under Load
• Adaptive Relearn After a Valve Body or Rebuild