Top Jeep 42RLE Transmission Problems & Preventative Maintenance Tips

To understand the top Jeep 42RLE transmission problems and tips, let’s look at a little history. This 4-speed auto transmission shares DNA with the sideways-mounted 42LE and was released in 2003. It was a watered-down rear-driven cousin of the 42LE with a modified bell housing and casing to allow longitudinal installation. It was initially redesigned to be used in the Jeep Liberty.

Jeep 42RLE Transmission Problems

To keep up with the times, the transmission was also showered with numerous electronic upgrades, like the transmission control module or TCM. A device that enabled it to monitor and analyze a driver’s habits via an adaptive memory and entirely electronic shift control. The electronically modified converter clutch employed in the torque converter assists in hard shifts by absorbing latent energy.

Having been in the Liberty and several Wranglers, some 42RLE transmission problems have shown themselves across the board. Some owners cite its quirky problems as a result of an overreliance on electronic systems. The type of transmission fluid used has been a subject of banter in Jeep circles too.

Top Jeep 42RLE Transmission Problems and
Preventative Maintenance Tips

Lagging or failing to shift gears

The four-speed automatic 42RLE had a universal issue with delayed and abandoned gearshifts. This scenario presents itself under two circumstances:
○ While shifting up from one through to third gear.
○ When going from third to fourth,

Causes for this include a worn-down or tethered governor pressure solenoid, inhibiting it from sustaining adequate fluid pressure. This mainly interrupts first to third gear shifts. Checking the 42rle transmission pressure sensor location and diagnostics may rule on a defective sensor or cabling issue causing wrong readings on the solenoid position.

The second is a tired overdrive solenoid that acts as a pressure builder engaging with the overdrive gear. This will thus only affect the overdrive (fourth) gear. A worn-out solenoid will not maintain the liquid transmission pressure required for optimal functioning. To prevent this, replace your dirty transmission filters often and closely monitor your transmission fluid levels.

Overdrive and torque converter problems

Especially in production after the year 2000, models tended to have periodical torque converter clutch and overdrive interlocking failures. You should see a CEL when this occurs.

A common cause for this is a shattered cover plate holding the pressure boost valve at the base of the 42RLE valve body. This was an infamous flaw as it was a defect from the manufacturer. It led to the retaining bracket holding the lockup breaking off. Here the cure is prevention as well.

There are upgrade kits available that can keep the plate from shattering in the first place.

Shifting solenoid malfunction

The transmission shift solenoid’s job is to simply change the gears for you. The transmission control unit gathers data from the motor, speed sensors, and other instruments to compute gearshift timing. The transmission control unit will send power signals to the intended shift solenoid, causing it to open and allow the transmission fluid to flow into the valve assemblage, which then shifts the gear.

Shifting issues are also indicative of a defective solenoid. Coupled with a check engine light or a transmission warning light, you can be sure it is the solenoid. The check engine light also comes on when you have a problem with the transmission. To be sure it truly is a problem, you should get an error code of P0700. This code is indicative of an issue with the transmission control.

Methodologies Associated With Increasing the Transmission’s Lifespan in General and Addressing the Common Problems Before They Make Themselves Known

Regularly check your oil levels

If you think your transmission is low on oil, just go ahead and top it up, as it is not worth the risk of potentially damaging the transmission bychecking fluid levels when they are very low.

The optimal fluid recommended for the 42RLE transmission is the ATF+4 Synthetic 9602 Type. Do not purchase oil with any additives, whether sold together or separately.

To ensure the longevity of your fluid, replace the filter regularly. Irregular replacement of the filter can result in:
○ Noises. When the filter is carrying debris around, it tends to make contact with
the housing and make inexplicable sounds. When you hear rattling sounds from
your transmission it may be past time to change your filter.
○ Contamination. When the filter is not sieving out particles effectively, small debris
enters the transmission system and causes undue stress. If using the wrong fluid
could ruin your entire transmission system, imagine what solid debris would do.
○ Smoke or smoldering smell from the engine. Congestion of the filter to the point
of saturation sometimes results in a burning smell, and when left unattended,
eventually black smoke appears from the engine.

Replace the transmission pressure sensor every 30,000 to 60,000 miles

The pressure sensor, true to its name, measures the amount of pressure built up within the transmission housing as fluid makes its way through a maze of sections to facilitate smooth gear changes. Because the 42RLE transmission pressure location is beneath the car, it is affected by extreme conditions. It is very easy for a unit to fail due to its
environment causing it to send inaccurate data and ultimately making the transmission work inaccurately.

When this instrument breaks, there will be a couple of indicators to look out for if you want to catch the problem early and avoid having to look for a rebuilt 42RLE transmission:
● The vehicle enters limp mode.
● The car has trouble shifting gears.
● Changing gears at higher RPM than normal is evident.

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