Confusion on 42rle and 45rle

[ZX2Fast]

I bought two Liberty's (both with selectable 4wd) to flip for tax season. One of them has transmission problems and while researching that, I found that they (gas engines) came with the 42RLE or 45RFE transmission and that they started the change over in April of 2003. The 2003 model year (build date 12/02) has a bent cross-member and a TCM on the passenger fender while the 2005 model year (build date 3/05 IIRC) has a straight cross-member and no TCM on the fender. Seems very odd too me. Too further my confusion, it seems this same designation (45RFE) was given to various transmissions both 2wd and 4wd and for different engines. This makes searching for a replacement... difficult.

Anyway, the 2003 has codes in the module, for some reason my scanner wouldn't give me the generic (Pxxxx) codes but gave me the specific codes.
0054 Gear ratio error in 4th
0053 Gear ratio error in 3rd
0036 Fault immediately after shift

It flare shift from 2nd to 3rd and doesn't seem to go into overdrive at all. It also falls out of 3rd and then just goes into full time 2nd gear limp mode. I just picked this up and haven't had time to look over it much because it is 5 degrees and tomorrow is -20, but any input on where to look would be appreciated but I fully expect that I need to replace the transmission. On that note, if anyone near Central Indiana has one for sale, I am in the market. I also am in the market for body parts on the 2005, pretty much everything on each corner needs replaced.

Edit: I noticed in my title I put "45rle" instead of "45rfe", I corrected this in the body of the post.

 

[04Liberty]

The 2003 with the TCM is your 45RFE. Your 05 by default has the crap 42RLE. All 45/545RFE transmissions both 2 and 4wd are interchangeable. The RFE was used from '99 through 2013 in most cases. The designation (45/545) is by programming. My Ram has one and is 2wd, you could take that trans, pull the tailshaft off, put your transfer case adapter on, put it in, bolt your transfer case on, do a quick learn and go. You can use pretty much any 45/545RFE. If memory serves there may have been a plug/solenoid plug change (I could be wrong) but the solenoid packs are forwards and backwards compatible. I would get it scanned properly to pull all the codes (both active and stored) to see what's going on in there. Are you positive on your numbers?

 

[JasonJ]

The 42RLE is just fine, if you keep it cool and full of clean fluid. 45RFE is better... but the 42 is OK.

 

[ltd02]

I had the 45RFE in my departed 02 and the 42RLE in my current 05. I don't really feel much of a difference shift wise. I have to say MY 42RLE has way more WTF moments. What do you expect from a Chrysler transmission?

 

[ZX2Fast]

The 2003 with the TCM is your 45RFE. Your 05 by default has the crap 42RLE. All 45/545RFE transmissions both 2 and 4wd are interchangeable. The RFE was used from '99 through 2013 in most cases. The designation (45/545) is by programming. My Ram has one and is 2wd, you could take that trans, pull the tailshaft off, put your transfer case adapter on, put it in, bolt your transfer case on, do a quick learn and go. You can use pretty much any 45/545RFE. If memory serves there may have been a plug/solenoid plug change (I could be wrong) but the solenoid packs are forwards and backwards compatible. I would get it scanned properly to pull all the codes (both active and stored) to see what's going on in there. Are you positive on your numbers?

I am positive on the numbers. My scanner is a knock-off, but I haven't gotten wrong codes from it, before. The numbers (and definitions) match the symptoms. If it were a Ford transmission, I would say it had a broken band and a leaking servo (for the flare shift), but I am not as familiar with Chrysler.

 

[04Liberty]

The 42RLE is just fine, if you keep it cool and full of clean fluid. 45RFE is better... but the 42 is OK.

Eh...42RLE is an adapted FWD transaxle. It wasn't great in that capacity either lol. Turning it sideways and converting it to a longitudinal 2wd/4wd trans is suspect at best lol. At least the RFE was designed for what it does. Plus if you throw 4.10's in the Jeep and still street/highway drive it, theoretically (it works for GC's and 02 Rams) you can swap TCM's and enable the 5th (2nd OD) gear.

 

[04Liberty]

I am positive on the numbers. My scanner is a knock-off, but I haven't gotten wrong codes from it, before. The numbers (and definitions) match the symptoms. If it were a Ford transmission, I would say it had a broken band and a leaking servo (for the flare shift), but I am not as familiar with Chrysler.

No bands in the RFE lol

This is what you posted:
0054 Gear ratio error in 4th
0053 Gear ratio error in 3rd
0036 Fault immediately after shift

But that actual numbers assigned to those differ
0054 = P0054 HO2S Heater Resistance Bank1 Sens2
0053 = P0053 HO2S Heater Resistance Bank1 Sens1
0036 = P0036 1/2 02 Sens Heater Relay Malfunction

However the text you have listed correspond to
Gear ratio error in 4th = P0734
Gear ratio error in 3rd = P0733
Fault immediately after shift = p1790

That's why I asked. Normally in Rams P0734 & P0735 (for 4th & 5th gears) are the kiss of death because 9.9 times out of 10 the OD clutches are shot. Considering your symptoms this may be the case here as well. Luckily it's quite easy to find a replacement, then you just have to pay for a quick learn (or if you know someone with a DRBIII) to reset the CVI values in the TCM. If you were here I could lol, but IN is a bit far lol.

 

[ZX2Fast]

Well that is why I said, "if it were a Ford".

The codes it gave me were manufacturer exclusive, not the OBDII generic codes. Sometimes this scanner won't read the generics (not sure why) but will read manufacturer specific, which is what it did in this case.

I picked up a transmission today from a junkyard (they even pulled it already) with 89,000 miles for $200, no core! Even has a 90 day warranty. So when the weather gets better, it will be getting installed. It is possible my scanner might do a relearn, if not, I can't imagine the dealer would want too much too do it.

 

[04Liberty]

Well that is why I said, "if it were a Ford".

The codes it gave me were manufacturer exclusive, not the OBDII generic codes. Sometimes this scanner won't read the generics (not sure why) but will read manufacturer specific, which is what it did in this case.

I picked up a transmission today from a junkyard (they even pulled it already) with 89,000 miles for $200, no core! Even has a 90 day warranty. So when the weather gets better, it will be getting installed. It is possible my scanner might do a relearn, if not, I can't imagine the dealer would want too much too do it.

Nice. Highly unlikely (but possible) that your scanner has that capability. Quick learn process involves starting the engine, put it in gear, then the computer runs the trans through every gear engagement to set the CVI values, then back to park. At a dealer it'll cost an hour's labor, any more than that and they're trying to screw you. I'd see if any of the trans shops in the area have the capability. Remember to install the flat filter seal properly (meaning make sure the old one is out first) and use ATF+4.

 

[ZX2Fast]

So I picked up the transmission (from a salvage yard) and did some disassembly towards removing the current bad transmission when I noticed the one I got from the salvage yard isn't the same. The sticker has "RFE" on it and "858" above that. My current transmission (the bad one) has a different main electrical connector and the cooler lines connect on the driver side whereas the one I got from the salvage yard has the cooler lines on the passenger side. Did they give me a 45RFE from a Cherokee or something like that? I am not that familiar with Chrysler. My vehicle has the transmission computer on the passenger fender and the curved cross-member so it should be the 45RFE.

 

[ZX2Fast]

The more I look at it, the more I think the one in my vehicle is a 42RLE. I can tell the transmission has been out before (broken cross-member bolts, broken plastic clips, etc.) and I wonder if someone installed a 42RLE. Not sure how they pulled it off, the wire harness is all plugged in at the TCM, not sure how too tell if the PCM is original though it seems that would be a pain too swap since the transponder would have too be programmed. Just my luck too get the oddball vehicle. Wondering now if I can just get a 45RFE harness and put the correct transmission in it. The one in my vehicle has 992-AA on it, which from the pictures I can find means it is indeed the 42RLE.

 

[LibertyTC]

The Trans pan... 42RLE has 13 Bolts 45RFE has 15 Bolts

 

[ZX2Fast]

It has 13 bolts. But, since it has the curved cross-member and the TCM on the fender, isn't it supposed too be a 45RFE?

 

[jeeper03]

It has 13 bolts. But, since it has the curved cross-member and the TCM on the fender, isn't it supposed too be a 45RFE?

Some of the earlier 42rle transmissions had the TCM on the fender as well. Mine does and I’ve seen a few others that way too. That is not a good direct way to tell which ****** you have. Counting the pan bolts is better.

 

[LibertyTC]

Here is a quick Jeep decoder where you type in the VIN # & it will show the trans type.
link: https://www.youcanic.com/guide/jeep-vin-decoder
After decoding, scroll down and look below where it states:
Additional information on the vehicle:
Does it state 45RFE?

 

[ZX2Fast]

When I was trying too figure out what transmission it had (in the snow), I used a thread here. No mention of some of them getting the TCM, curved cross-member, and still being a 42. That VIN decoder would have been much more useful in that thread. The decoder says it has the 42 in it, thank you so much!