42RLE Quirks?

[Jeepin05]

Hey guys, quick question on the 42RLE ******. I did a search for this and found a little info, but figured I'd open a thread to learn more.

When I am slowing down and the ****** is downshifting to 1st, it seems to thud a little. It isn't always noticeable but sometimes it is, not incredibly concerning...yet. I'm just a little worried it's going to get worse, but I know this ****** has some known quirks. Have others had this issue turn into something more serious than a light thud?

Also, would others mind listing their "quirks" dealing with this ******? I know it tends to jump into OD a little sooner then preferred, and I think mine also will drop into second occassionally too soon (not very often).

Again, I'm not too concerned about the thud yet as I know this ****** acts a little goofy sometimes but generally is considered to be reliable. To note, I had a ****** flush done by the dealer about 6 months ago, perhaps I should have them check that the computer is up to date?

As always, appreciate the info.

 

[HoosierJeeper]

Most Jeeps have somewhat clunky trannies.

 

[Atrus]

Mine does the clunk sometimes too and I also just hope it's normal.

 

[HoosierJeeper]

With my old WJ the ****** started to clunk pretty bad, so we called the dealer and they said, "It's a Jeep thing...you really wouldn't understand." The ****** worked fine, but was a little noisy. The KJ's reminds me of it.

 

[JeepJeepster]

Normal.. What your talking about sounds like the slack in the drive train rather than the ****** downshifting. The ****** downshifting can make this happen but simply letting off the gas and getting back on the gas too fast can also cause it to happen.

 

[Jeepin05]

Thanks for the info, it definitely could be the drivetrain as I seem to get the same effect when getting off and on the gas.

It's nice to hear logical explanations, I know it's not a race car or a bmw.

I'm a former driver of a Talon, Lesabre and a Grand Prix...completely different (not in a bad way ).

 

[Treyz02KJ]

Thanks for the info, it definitely could be the drivetrain as I seem to get the same effect when getting off and on the gas.

It's nice to hear logical explanations, I know it's not a race car or a bmw.

I'm a former driver of a Talon, Lesabre and a Grand Prix...completely different (not in a bad way ).

I've also come to understand the computer relays information from the speedometer to the transmission in some manner? And that tire size can also cause unusual transmission behavior.

 

[Powerslave]

There is a difference between a BUMP shift, than a clunk... A clunk generally comes from inside differentials, and U-joints, or lose torque converter... A bump shift is different, it's when the 2nd gear clutch is left on slightly too long when the other one engages for 1st gear.

Try this: Down-shift to 2nd gear MANUALLY at 35mph, then come to your full stop. If you do not hear the Clunk, go back to drive. Then the next time you are to come to a stop, do NOT down-shift manually, see if you hear it. Do this pattern a few times. If you hear it ONLY when you stay in drive, there can be a 2nd gear bind-up, which WAS common in earlier ultradrive transmissions. This can be caused by a cracked valve, or bad seal, that is causing a 100% duty cycle during downshifts. They used to make the valves in these valve-bodies (inside the trans) out of plastic. If they cracked, fluid would bypass the valve slightly, so the pressure would have always be high, the TCM compensates with 100% duty cycle. My Dodge Avenger did this all the time, since the day I bought it. When I manually went to 2nd, it would NEVER do it, only when downshifting from on its own from Drive.

Now, it was said here in the forums that these transmissions were REDESIGNED by Mercedes, BUT, it is still based off the same flawed ultradrive design. They only changed a few things, I did a little research. I could not tell if they went with Metal valves in the valve-body. There were always upgrade valves you could buy to change them to metal ones.

Anyhow, this may not be true of these new transmissions, HOWEVER, with all this computer controlled crap, it could be almost anything. I liked the old transmissions, that did not require anything but what it has inside to shift it. You now have input and output sensors, and they ARE plastic, and if any one of them goes, the TCM goes into limp mode, when the transmission is still quite capable of shifting on it's own at this point. It's all stupid, and redundant if you ask me. The only way a trans should get put into limp is if a clutch is bad, a valve breaks, or a solenoid won't work, a major failure not a stupid I/O sensor. There is too much crap on these transmissions now days.

 

[JeepJeepster]

True.. Wish they had the aw4 like the xj's..

And those sensors are there to make sure a valve, solenoid, or clutch isnt bad. They stuck those in there to try and keep the ****** from killing itself but as you said, the sensors go bad sometimes..

 

[AlexKJ]

True.. Wish they had the aw4 like the xj's..

I beg to differ... The reason I finally didn't buy a 2001 XJ Classic was b/c they have an AW-4... I think they aren't precisely good transmissions... For an example, read this

The AW4 is a light to medium-duty transmission. Ours, our callers' and customers' experiences with the AW4 are less than stellar. They have a tendency to generate excessive amounts of heat, and are known for unnecessarily consuming more engine power than some other automatics. The shift points in the AW4 feel odd, and the spotty engagment of the lockup torque converter is idiosyncratic.

Cheers!

 

[Powerslave]

True.. Wish they had the aw4 like the xj's..

And those sensors are there to make sure a valve, solenoid, or clutch isnt bad. They stuck those in there to try and keep the ****** from killing itself but as you said, the sensors go bad sometimes..

Yeah, but the Input Output sensors? If the output sensor goes, you lose the speedometer, and the thing sticks in 2nd gear, and won't shift. That's stupid, because there is no MECHANICAL failure. The input sensor? Just an electronic failure, AND when any one of these two sensors fail, the solenoids do not PULSE (Bzzzzzzzzz-tick) anymore, they go HARD into gear when you put it in drive, and it slams right into second... It should go into a mode that allows you to manually shift, rather than limp and keep you under 40 in second as you limp to the repair shop. If they would have kept the RANGE sensor on the transmissions, this would be possible. I know after a certain year, they stopped putting the range sensors on... Even if the jeep has it, they should use it when a sensor goes...

I had a 2000 Chrysler Cirrus, LXi: THREE input sensor failures, two sets of tie-rod ends, one distributor (which has the coil built in), 98K when I traded that for the Vibe. I also had a 2000 Avenger ES, they have exact same power train, it had 145K miles when I traded it for the liberty, and not one problem with anything on the powertrain. I had to replace the upper control arms at 96k, because the camber kits were improperly installed, and the bushings got obliterated. No tie rod ends, no transmission ANYTHING... Why? Who knows, and I DROVE the Avenger! It even had a strut tower brace, lower front frame tie, and rear lower suspension tie. This thing would take bends at 90MPH that most people would not dare try. I drove the living hell out of it, and it never failed on me. I babied that freeking LXi, and look what I got...

 

[tjkj2002]

Yeah, but the Input Output sensors? If the output sensor goes, you lose the speedometer, and the thing sticks in 2nd gear, and won't shift. That's stupid, because there is no MECHANICAL failure. The input sensor? Just an electronic failure, AND when any one of these two sensors fail, the solenoids do not PULSE (Bzzzzzzzzz-tick) anymore, they go HARD into gear when you put it in drive, and it slams right into second... It should go into a mode that allows you to manually shift, rather than limp and keep you under 40 in second as you limp to the repair shop. If they would have kept the RANGE sensor on the transmissions, this would be possible. I know after a certain year, they stopped putting the range sensors on... Even if the jeep has it, they should use it when a sensor goes...

I had a 2000 Chrysler Cirrus, LXi: THREE input sensor failures, two sets of tie-rod ends, one distributor (which has the coil built in), 98K when I traded that for the Vibe. I also had a 2000 Avenger ES, they have exact same power train, it had 145K miles when I traded it for the liberty, and not one problem with anything on the powertrain. I had to replace the upper control arms at 96k, because the camber kits were improperly installed, and the bushings got obliterated. No tie rod ends, no transmission ANYTHING... Why? Who knows, and I DROVE the Avenger! It even had a strut tower brace, lower front frame tie, and rear lower suspension tie. This thing would take bends at 90MPH that most people would not dare try. I drove the living hell out of it, and it never failed on me. I babied that freeking LXi, and look what I got...

The speed sensors on the KJ,either trans,has not one thing to do with the speedo or ODO.The speedo is 100% controlled from a A/C signal generator(magnet and tone ring) in the rear diff until '06+ when ESP came out and they used to ABS sensors.

 

[Powerslave]

The speed sensors on the KJ,either trans,has not one thing to do with the speedo or ODO.The speedo is 100% controlled from a A/C signal generator(magnet and tone ring) in the rear diff until '06+ when ESP came out and they used to ABS sensors.

That's better...

I personally, never had ABS till this car. Company cars had them, but none of my POVs. The VIN on the Avenger I had, indicates ABS, but it did not have it. 2000 was the ONLY year ABS was an option on the ES model, go figure. There was no ABS pump, and I locked the tired up quite a bit. I know where the ABS pump was supposed to be, nothing... No MIL for ABS either.

 

[PanAmerican]

Here's one: 2003 KJ Renegade/77k & 42RLE...Zero issues Friday morning.

Sent it in to a friend's shop to change all the fluids. New trans filter, trans pan & Amsoil ATF. Disconnected the battery for 15 minutes to reset the TCM values.

Friday afternoon, it is absolutely fantastic and better everywhere w/one exception: When downshifting while on the brakes at about 15mph, I get a VERY hard downshift. Seems like it only happens at high vacuum conditions as it does not shift hard while downshifting at that speed while accelerating.

Any thoughts?

 

[RageOfFury]

Here's one: 2003 KJ Renegade/77k & 42RLE...Zero issues Friday morning.

Sent it in to a friend's shop to change all the fluids. New trans filter, trans pan & Amsoil ATF. Disconnected the battery for 15 minutes to reset the TCM values.

Friday afternoon, it is absolutely fantastic and better everywhere w/one exception: When downshifting while on the brakes at about 15mph, I get a VERY hard downshift. Seems like it only happens at high vacuum conditions as it does not shift hard while downshifting at that speed while accelerating.

Any thoughts?

Probably the Amsoil Universal ATF. ATF+4 is a must on these Chrysler trannies. They are extremely picky on the type of fluid. Use anything other than ATF+4 and you risk damaging the ******.

By the way, welcome(welcome)

 

[sleeve]

As ROF stated: The KJ (and all Chrysler's) need ATF+4 transmission fluid. Anything else and your transmission explodes in about 10K miles.

The KJ's are known for the clunky transmission. It's part of their personality.

 

[Ry' N Jen]

Over 100,000.0 miles and not one problem or noise from our KJ!

 

[LibertyTC]

Friction Modifiers ATF+4

changed all the fluids. New trans filter, trans pan & Amsoil ATF.
I get a VERY hard downshift. Seems like it only happens at high vacuum conditions as it does not shift hard while downshifting at that speed while accelerating.
Any thoughts?

ATF+4 (is synthetic) and has advanced friction modifiers. The Amsoil may not be fully compatible and could lack the complete friction modifiers.
Short of changing out the fluid and getting proper +4 fluid in there, you could add some additional friction modifier/Lubegard : I am pretty sure that would smooth out your shifts immediately. Your Amsoil will now perform like ATF+4.
Link: http://www.lubegard.com/~/C-113/LUBEGARD+Platinum+Universal+ATF+Protectant
After adding ensure you have correct level and reset thru battery again.

 

[ThunderbirdJunkie]

I personally, never had ABS till this car.

Thought you had a Jeep?

 

[PanAmerican]

Thanks for the help and the welcome, guys!

I'll be trying a few of the suggestions and will report back~