I had a 2002 3.7L with a 45RFE and it had the 2-prime (1.50:1 ratio). It did not have the 4-prime (0.69:1) ratio. Now I have a 2005 with both. I can kill the 4-prime (or 5th if you will) with one bit. Bingo it's a 45RFE.

Can you please describe (preferably with pictures) the substantial differences between these two transmissions?

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

Thanks for the fast response TJKJ, makes me feel a little better now that I know whats going on. So do you think its just the sensor causing all the shifting problems or could it be something more serious? Thanks man.

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.

No pics,sorry I don't have one at work,wouldn't have time to take pics anyways.The 545RFE has more parts internally,check out the parts #'s.

But one ?

Can you please describe(preferably with pictures) how the 45RFE and 545RFE are the same transmission?

If you have the time, I would encourage you to read TSB 18-025-01 (I found it most easily at the wjjeeps.com site). It detailed the availability of reflashing dakotas, grand cherokees with the 45RFE to a new TCM code allowing it to have the 5th gear / 2nd overdrive ratio thus making it the 5-45RFE.

Various cars have all sorts of part numbers so that's not a fair comparison to make. Due to the design of the 45rfe/545rfe with only planetaries and clutches, any multitude of gear ratios are available depending on how the clutches are applied. THis is also why the 45rfe in early KJ's was replaced with the cheaper 42rle in later models since the 2nd overdrive wasn't needed.

In the end, the two tranny's are the same with just a difference in TCM sw to allow the 2nd overdrive depending on application needs.

That TSB is for harsh upshift/down shifting of both the 45RFE and 545RFE.The 2 trans share some parts but you can not make one the other and the other one.The planetary gear sets are different to allow more/less speeds.The 45RFE does not have the correct planetary set for all 6 forward speeds.The Input/Reverse set is different but the 2 trans share the same reaction annulus/sun gear set.The valve bodies are also different to actually engage the 2nd overdrive that the 45RFE does not have or need.

The 45RFE and 545RFE share the same hardware. Only the software is different.
The 45RFE and 545RFE share the same hardware. Only the software is different.
The 45RFE and 545RFE share the same hardware. Only the software is different.

The 45RFE had to have 3 gearsets to meet Jeep Vehicle Development's uneducated goals.

1. 3.00:1 1st gear
2. 3:00:1 Reverse gear
3. 0.75:1 4th gear

Transmission engineering dutifully designed a transmission that met those criteria. The only way it could be done with those boundary conditions was to use 3 planetary gearsets rather than the usual 2 gearsets for a four speed. The side effect was you actually had a six speed, but two ratios (1.50:1 and 0.69:1) weren't useful.

What transmission engineering didn't do is say, "OK, you've forced us into a 3 gearset configuration. We could give you a six speed, and beat all of your criteria, except that 1st gear and Reverse wouldn't be exactly the same ratio." (they would, however, both be greater than 3:1) But this was the mid 1990's, no one had heard of a six speed transmission before, management was still getting used to overdrives and lockup torque converters!

So the 45RFE was launched with the WJ and gradually replaced all other Chrysler RWD transmissions... With two 'second' gear ratios, 1.67:1 for upshifts and 1.50:1 for kickdowns, and an unused 0.69:1 overdrive. Everyone thought of it as a 4 speed, because the ratios drove like it was a 4 speed...

Along came Mercedes. They said, "You need a 5 speed." (what they meant was, "You need to amortize our tooling for our old 5 speed while we prepare a 7 speed.")

Transmission engineering replied, "Look, we already have a 5 speed..." and activated the 0.69:1 ratio though a software change saving Chrysler the cost of having to adopt the Mercedes 5 speed.

Mercedes replied, "No, you REALLY need a 5 speed. Oh look! Here's one you can use, we don't need it anymore... (royalties for our superior design please.)"

Then Chrysler decided it needed a 6 speed to put behind the Cummins. Buying a medium duty transmission is expensive, designing a new one even more so. Mercedes would never let them spend that kind of money, Europeans don't want automatics in trucks, and they were already sellling the G56 manual to Chrysler to put behind the Cummins...

Transmission engineering to the rescue again. "Well, if we change these six parts, the (5)45RFE, which always was really a six speed all along will have six nicely spaced forward ratios. (and two Reverse gears but don't tell anyone) We'll slap a 12" torque converter in the front and call it done." That is how the 68RFE was born.

So to recap this story,
The 45RFE and 545RFE share the same hardware. Only the software is different.
The 45RFE and 545RFE share the same hardware. Only the software is different.
The 45RFE and 545RFE share the same hardware. Only the software is different.

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

Sorry, no pictures. You'll have to use your imagination.

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

Sorry,try again.Yes the software is different,though the only difference is the programming to activate the 2nd overdrive which the 45RFE has no parts for.

There is no need to 'try again.' Please continue on with your version of reality.

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

Replaced the sensor, disconnected batter-reset light, came back on. No GO. Sucks. into the shop tomorrow. Thanks guys.

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.

If replacing the sensor didn't help, the next thing to concentrate on is the wiring.

The two easiest things to check for are continuity (cut wire) and short to ground (abrasion of harness with bare conductor touching something).

Where to check...
sensor connector pin 1 (signal) is on the left looking at the harness connector with the lock on the top -> TCM pin 52 (should be markings on end of harness connector)
sensor connector pin 2 (ground) is on the right -> TCM pin 53

What to check...
Check both lines for continuity (<1.0 Ohm = good) or short to ground (>100 kOhm = good). For continuity check from the sensor connector to the TCM connector / for short to ground, check from either connector to the vehicle body.

Also visually inspect both connectors for damage. Be careful probing inside the female terminal with too large a pin - they are easily damaged.
if the continuity or short to ground fails then you need to inspect the harness between the TCM and sensor.

If none of that works, then it's time to try a shop.

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

well thanks for the info man! I have been real busy at work and my girl has been driving the CRD and I don't have time to check it out. I took it to a shop last night and they called this morning saying that their Snapon scanner that was updated two weeks ago could not get any further then I did. So I took it to a second shop that said 'I can read any cars computer', nope both said I hate to say this but time to go to the dealer. The one shop recommended a wiring shop which I stopped it and talked to, and they sent me to a third trans shop that they have been dealing with for over 30 years. The guy at the 3rd shop says he likes these kind of problems and has fun trying to figure them out. He also said that he has more equipment then just the simple snap on solist and that he would Not send me to the Dealer.

He is going to look at it in the morning, and he is not just going to plug into the OBDII and say, Go to the Dealer.

I Hope i know something in the morning.

Thanks for all the help, I might still need some more. .

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.

How come you know this stuff about the (5)45RFE?

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L.O.S.T forever!
Silver 2002 Skoda Fabia TDI, 235,000km
Former car: Jeep KJ 2003 CRD

DIESEL - saving millions of liters of petrol every day!

deleted.

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Manure green 2005 CRD sport4x4, GDE Hot tune, Cat Gut, OE skids, Draw tight hitch, Duramax lift pump, 160K on multiple varieties of fuel, XM radio, Escort live with Redline, fog light mod, GPS, Icom IC7000 all band radio call sign KC9QPF, Grabber AT2s on Soft 8s, FIA grill blanket.

painemann-

i suggest dropping the pan... mind acted similarly and there was metal, chunks, in my pan.... i have a post on here about it.

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Trevor

'05 Limited CRD Inferno Red Pearl Coat
Home made provent installed @ 35443, SEGR installed @ 35466, Fumoto valve @ 37500, trans and transfer case skid, In tank pump installed @ 43500, Suncoast TC & Transgo Shift Kit @ 44730, EGT, Boost, Trans temp gauges, Samco hoses, Rebuilt Trans w/ HD454RFE kit @ 56K, Inmotion Stage 2 @ 56K

danoid's a Chrysler transmission engineer, which doesn't seem to get him much respect on transmission issues.

actually on tj's original point - the parts numbers are different - he was correct - if you look at the parts diagrams - there are a lot of significant components with different part numbers - however the new part numbers - bolt up to the old part numbers - so I'm not sure how much of a change - the change was, although a couple of oil passages here or there wouldn't be obvious on a parts diagram.

(however as to not having parts for the 2nd overdrive? - the gear clusters appear to be the same - in fact the diagrams appear identical)

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2005 CRD
stuff
Skeptic quod gratis asseritur, gratis negatur

Well, the third trans shop was a lot of help. The first two shops I went to just used their Snap On solus scanner and for some reason could not get anywhere with it so they just said 'I hate to send someone to the dealer, but I just can't help you with this one'. The guy at the last shop took a day or so of checking wiring and hooking trying a few different scanners/computers. He gave me a call and said 'Hey good news is its working, its shifting fine, the bad news is I don't know what I did to fix it'...
He said one of his computers pulled a code from the engine the was a mass air flow fault but its not doing it anymore and he couldn't find out how that would be related to the code that was pulled from the trans (P0715). So it has around 65miles on it now with no problems.
The guy at the shop said he didn't want to charge me because he did not even know what he did and said just come get it and if it works then great and if it does it again bring it back and we will continue to figure it out.

I wish I knew what it was so i could just fix and not have to worry about it happening again.

Wish me luck,
Thanks to everyone that tired to help me with this. I hope I'm not back on here in a week starting all over!!!!

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.

Snap-On tools software doesn't support the CRD. That's why they couldn't communicate with it.

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2005 sport crd-SOLD No regrets

Sounds to me like the dreaded 'intermittent wiring condition.' I have one that hits my MAP sensor about once a year and another (that I caused) that takes out the MAF on very large bumps. I wiggle the wires on the MAP and re-plug the MAF as needed to turn off the check engine light.

Somewhere there is probably a circuit open (connector with a spread female terminal / pushed out connector / bad crimp between wire and terminal / split wire) or a circuit short (wire with abraded insulation grounding out or connecting to another circuit).

They are a devil to find and sometimes they truly do 'go away.'

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2005 CRD Limited Flame Red w/ Renegade rock rails & light bar, AirLift 1000. 225/75R16 MT/R's on cheap black steel wheels, dual MOPAR subwoofers, Ipod kit & seat covers, Samco hoses - totaled and gone. 2008 WK Laredo 3.0L diesel - AirLift 1000, wife won't let me mess with it much. 2013 JK Sahara on order.

Well, I don't really want it to happen again, but I do want to know where the problem is. I'm just the kind of person that likes to know now (so I can fix it now) rather then later and have it happen when I don't want to deal with it (like deer hunting up north in the cold/snow).

I'll look around and see if I can find a bad connector. But if all else fails maybe I can take a trip up to Lake Orion, ?? ha.

Thanks for the info Daniod, I'll look around the MAP and MAF for a bad connection, but I just hope its not in some stupid place that I'll never think to look.

Hey why do you think it tripped the P0715 ? This is weird.

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-05 Dark Khaki Limited CRD. GDE ECO tune. In-tank lift pump, Transgo doo doo kit, B&M trans cooler, replaced trans solenoid pack and filters, Newer Michelin tires, Timing belt with all related parts replaced at 110,000miles.