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rizzo
07-03-2004, 04:50 PM
I am a noob here but no where else. I have a 45RFE tranny in my 99 4.7. It has kerplunked! I want to put the 5-45rfe that replaced it from the 200 on up in there. Do I need the computer for it too? I am positive that it just bolts up...this is more or less a computer ?.

jwbronco
07-03-2004, 05:41 PM
They are the same transmission, the difference being a update in software for the PCM which gives you the second overdrive in the 99 and 00 models. I'm still waiting for someone to make some heavyduty parts for it. So what exactly failed in it? I have over 100k on my 99 now with the 45re tranny.

rizzo
07-03-2004, 06:08 PM
How sure are you? If I buy that bad boy tranny...I do NOT need a new computer? I just got a code P 0700 and my 4th gear is not working at all. It went out. This is my 4th tranny! I fawking hate dealing with this....

jwbronco
07-03-2004, 06:44 PM
I had a code 0700 on mine before and it was the output speed sensor, only cost me $14. Supposedly that is a common problem with them, the input speed sensor could be it too which is supposed to be the same sensor according to the dealer when I bought mine. I would try that first unless your sure its the tranny. When mine went bad it was all jacked up. I will try to verify the differences between the 545re and 45re and post it as soon as possible.

jwbronco
07-03-2004, 06:57 PM
Automatic transmission, new 545RFE five-speed with 4.7-liter engine provides a second overdrive ratio for increased highway fuel economy and reduced engine noise at highway speeds (Note: A Flash upgrade was introduced on September 15, 2000 which when performed on 1999 and 2000 models adds the new second overdrive ratio to upgrade those transmissions to 5-speeds)


direct quote from www.wjjeeps.com/newoptions.htm

As far as the TCM(transmission control module) you might have to change it to a the corresponding year but you can get them from a junkyard for less than $100. I would recommend you looking for a shop to make you a high performance upgrade and get a huge tranny cooler. So how did your last few trannys fail?


You might also want to talk to Wayne at APS because they have been working on some stuff for the Hemi powered 1/2 ton trucks. I've talked to him before and he's very knowledgable.

http://www.apsprecision.com

rizzo
07-03-2004, 08:23 PM
That is what I thought. I figured that if I had a 5-45rfe, I would nee dthe TCM and then I may need to get my ecu flashed. DAMN. I had Positive performance flash it last month for the Magnum Ported heads and the new throttle body. All was doing so well...
I will try the output speed sensor first (tomorrow) and see if that is the problem.

rizzo
07-03-2004, 08:24 PM
What kinda high performance upgrade are you talking about? I had my current tranny upgraded, but there is NOT too much to swap in internally. No one seems to make HD parts for them.

jwbronco
07-03-2004, 08:28 PM
I would recommend that you get both the input and output sensors and replace them for good measure, if that doesn't work you have two spares for later and its not like they cost much at all. Its only a 8mm bolt if I remember correctly and takes about a minute a piece to change. I'm really not sure if you would need to change your TCM but as far as your ECU goes I don't see why you'd need that reflashed.

SJX426
07-28-2007, 11:27 AM
If he has not done the flash upgrade, then he would only have a 45RFE and not the 545RFE. How do you do the RFE update? Do you need to go to the Stealership?

violatedppl
07-28-2007, 03:53 PM
holy old thread batman.

SJX426
08-01-2007, 11:16 PM
Yeah old but I just bought a WJ and would like to know how to do the upgrade!