The 45RFE is a heavier-duty transmission. That said, the 42RLE isn't exactly being overworked by the 3.7L. Properly maintained it should last many miles. The 45RFE was replaced by the 42RLE halfway through '03.
AFAIK there isn't any real difference in the suspension for the Liberty, 02 to 07. However, early '02 models are an inch higher. Jeep lowered them after concerns were raised about stability.
ABS wasn't standard, I think, until '06. It was optional before that.
All Liberties have the Chrysler 8.25" rear end and a Dana 30a front end. The 30a is an aluminium IFS axle, and is not parts-compatiable with the steel Dana 30. JeepinByAl makes a steel Dana30 housing for the Liberty that can be geared much lower (I've heard it's a standard Dana 30 modified to work in an IFS).
3.7L Liberties will have a 3.73 gear ratio, and may or may not have a limited slip installed from the factory, as long as they are pre-06. 06+ uses the ESP and did not come with a Trac-Lok option.
The 'Towing Package' adds an upgraded alternator, an engine driven cooling fan on top of the electric one, an external transmission cooler, and a power steering cooler as well as a trailer hitch. The 45RFE transmission cooler is integrated with the radiator, whereas the 42RLE is an external unit.
2002 Liberties get the transmission and power steering cooler without the towing package.
All Liberty packages (Sport, Limited, Renegade, Rocky Mountain) have the same exact suspension. Don't let someone tell you the Renegade is taller. It's not.
'05+ Renegades have a different grill and hood package, which is flat across the front instead of curved.
Power seats sit higher in the cab than manual seats. While I think they are more comfortable, I wish it was half an inch to an inch lower.
There is a microswitch in the rear hatch that controls the rear glass 'pop' when you pull the handle. It'll probably need to be replaced, meaning the only easy way to open the rear hatch will be to pop the glass using the remote first. It's a $15 part.
There is a good chance that whatever Liberty you buy will suffer from what is called the, "Fuel Burp", plague. Basically, if you let the pump run until it shuts off, gas will come out of the filler! Not cool. This is due to a bad valve in the gas tank, and Jeep will want to replace the entire tank with a part that will also probably fail (ethanol in the gas causes the problem). There is a cheap fix on the 'How To' section that actually works great, and costs about $40 if you have to buy tools.
The front ball joints suck. Hopefully you won't have to replace them before you do a lift. If you do lift, get JeepinByAl upper arms, which have replaceable ball joints, whereas stock requires a whole new arm.
The radiator has plastic end caps, with an aluminium core. The heads are aluminium, and the block is Iron. You must use the specified coolant or else you'll get corrosion. Also, the plastic end caps on the radiator are known to suffer from 'microfractures' as they age (over a lot of heat cycles, they'll start to crack). This is pretty common of newer vehicles with this style of radiator (which, I think, is all of them by now). If your Jeep leaks a little coolant when hot, but stops once it cools down, this is probably the reason.
The 3.7L has a timing chain. 0 maintenance unless it starts making noise!
I believe the '06+ Liberties did not have a Trac-Lok option and instead used a 'Brake Assist lock'. Basically, it used the rear brakes to apply braking force to the spinning tire. Not optimal, but something that can be worked around. The Electronic Stability Program on the '06+ is, from what I've heard, pretty invasive.
In 2005, Jeep moved the Manual Tranmission Liberties to a 6-speed unit. Earlier units were 5-speed.
There were three transfer cases used on the Liberty. The NV231J and NV241J (used on 6-speed manuals) Command-Trac cases were both Part Time units with 2WD, 4WD HI, Neutral, and 4WD LO options. They should not be used on the road or where good traction is available. The NV242 is the Select-Trac unit is a Full Time unit with a 2WD, 4WD Hi Part-Time, 4WD Hi Full-Time, Neutral, and 4WD LO selection. All transfer cases were 2.72:1 in LO range.
There is a TON of information in this forum. :gr_grin:
