johnj92131 Posted November 25, 2008 Share Posted November 25, 2008 Does anyone have info on putting a 45RFE or 545RFE transmission in the MJ?? Thanks Link to comment Share on other sites More sharing options...
Eagle Posted November 25, 2008 Share Posted November 25, 2008 Why? They are inferior in every way to the AW4. Why would you want to put one in an MJ? Heresy! Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 25, 2008 Share Posted November 25, 2008 I can possibly understand the 545RFE because it's a 5-speed w. a lower O/D ratio for the highway but that's about it. :cheers: Link to comment Share on other sites More sharing options...
Eagle Posted November 25, 2008 Share Posted November 25, 2008 The 545RFE is the transmission that was in my 1999 Grand Cherokee. Let me put this in perspective: I bought a 1988 Cherokee in January of 1988. Ten years later it had about 175,000 miles on it and I thought it ws getting tired, so I bought a 1999 Grand Cherokee in January of 1999 to replace the 1988 Cherokee. Chrysler bought back the '99 in October to keep me from filing a "lemon law" complaint. I still have the '88 Cherokee. It now has 290,000 miles on it. The 545RFE transmission was one of the major items of complaint I had with the Grand (along with the transfer case and the rear axle, and the front discs warping on a weekly basis). There's just not that much difference between a .75 final drive and a .67 final drive. Run one size larger tires and you've got the equivalent. That transmission is JUNK. (But ... it's from Chrysler, so saying it's junk is rather redundant). The AW4 is infinitely superior. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 25, 2008 Share Posted November 25, 2008 I agree Eagle, but if anything should explode in my AW4 (probably never will), I will look at 5-speed autos to replace it with, and it will not be a 545RFE for sure. The 5-speed would be good with the stroker. :D But of course the 4.0 blocks are limited for adapters, so the choice of trannys is limited too. The Aisin A350E or A650E 5-speeds would be my first choices, and one would ASSume they would have the reliability and durability of their older cousin AW4, but I haven't really researched it well yet. What really amazed me was the drivetrain loss of the typical autos. The AW4 averages 20% - 25%, but the 4 & 545RFEs are even worse, normally over 30%, according to the dyno boys at Hesco. Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 25, 2008 Share Posted November 25, 2008 There must be a difference in the older 545RFE & the newer style. I have the 45RFE in my '02 Ram Truck and it, as well as all of the 45 & 545RFE trannys, is tough as nails. It is a highly desired transmission that virtually never gives any trouble. The 45RFE can be turned into the 5 speed version with a computer flash if so desired, but I have never seen any need to do it to mine. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 25, 2008 Share Posted November 25, 2008 I don't know Taz, I've heard a lot of bad things about these trannys, mainly excess power loss, especially from Hesco. But then again, I've never had one, so I can't speak from personal experience. :D I know they are electronically controlled like the AW4, but with a separate computer (TCU like the AW4) or controlled by the PCM? I'm guessing by the PCM....... Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 25, 2008 Share Posted November 25, 2008 There is a seperate controller for the trans. I will never argue the fact that the AW4 is the wise choice in this situation, but the 45RFE & 545RFE are hailed by all the transmission techs that I have ever talked to. Every one of them say that they hardly ever work on one for more than just regular services. Mine has pulled a 5000lb trailer many miles over several states and has not given a minutes trouble with over 90K on it now. Next to the AW4...the 45RFE trannys are the best in the Chrysler line (in current production) from all my experience working at dealerships. Link to comment Share on other sites More sharing options...
aemsee Posted November 25, 2008 Share Posted November 25, 2008 I agree with the quality of the RFE series. There were some issues a while back, but they were assembly problems, not design flaws. What were the problems that you had Eagle? A lot of early issues were due to a lack of knowledge by the techs on how the trans and computer worked. As for the question about separate trans controller or PCM controlled. Both yes. Depends on year and application. JTEC engine controller used separate EATX controller, NGC uses same box, but separate processors inside for engine/trans function. NGC4 has combined engine/trans processor. Now, if you are looking to install a RFE, there is a trans only NGC box in a 2500 Ram with a Cummins, but it is a 6 spd (68RFE). Rated for 850 lb/ft of torque. Should handle anything you need in a MJ :D . Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 26, 2008 Share Posted November 26, 2008 Yeah...I forgot about the change to the NGC in 2003. Mine is a 2002... ;) Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 26, 2008 Share Posted November 26, 2008 A guy on NAXJA sent me the below; a goldmine of info regarding engine/tranny swaps into Jeeps. Good stuff! I had not seen this before. Not much on auto trannies though........ http://www.jeeps-offroad.com/showthread.php?t=4740 Link to comment Share on other sites More sharing options...
aemsee Posted November 26, 2008 Share Posted November 26, 2008 A tech I know did a 5.7 hemi/ 545rfe swap from a wrecked ram in to a TJ. If it'll work in a TJ, should work in a MJ! Link to comment Share on other sites More sharing options...
BLHTAZ Posted November 26, 2008 Share Posted November 26, 2008 A tech I know did a 5.7 hemi/ 545rfe swap from a wrecked ram in to a TJ. If it'll work in a TJ, should work in a MJ! Yep...I know a guy that did it with a 4.7L / 45RFE in a TJ down here :thumbsup: Link to comment Share on other sites More sharing options...
johnj92131 Posted November 26, 2008 Author Share Posted November 26, 2008 Why am I looking for info on the 45RFE/545RFE? I was looking to see what was out there for an Automatic transmission with a lower first gear and a higher overdrive ratio. I found this link: http://www.vibratesoftware.com/html_hel ... .htm#5spat It seems to suggest there is a version of the 545RFE with a .50 overdrive instead of the .67 overdrive. If true, that would have a 3.00 first gear compared to the 2.80 first gear of the AW4 and an overdrive of .50 compared to the AW4's .75 overdrive. That would let you run a 4.56 final drive and still go down the freeway at a very reasonable engine rpm. But it would likely be cheaper to just buy another truck. Link to comment Share on other sites More sharing options...
aemsee Posted November 26, 2008 Share Posted November 26, 2008 The 545 has a 1st gear of 3.00, OD 5th of .67. The 68rfe has a first gear of 3.23, OD 6th of .62 (rev is 4.44 :eek: ). Nothing approaching .50 for OD Link to comment Share on other sites More sharing options...
johnj92131 Posted November 28, 2008 Author Share Posted November 28, 2008 Aemsee, Yes I thought the .50 gear might be a misprint. But I also noticed that the chart said 2003 - 2008 for the .67 5th gear. Still wondered if the .50 final gear might be an added "feature" for the 2009 year. Does anyone know? Link to comment Share on other sites More sharing options...
aemsee Posted November 28, 2008 Share Posted November 28, 2008 Aemsee, Yes I thought the .50 gear might be a misprint. But I also noticed that the chart said 2003 - 2008 for the .67 5th gear. Still wondered if the .50 final gear might be an added "feature" for the 2009 year. Does anyone know? I checked the 09 specs and no .50. They would have to change the number of teeth on the planetary sets for the ratio to change. You'll just have to go with taller tires :D Link to comment Share on other sites More sharing options...
cocco78 Posted November 28, 2008 Share Posted November 28, 2008 I'd also tend to agree these were good transmisions. I had a 99 grand with the 4.7L and this was a great combo. I towed with it and probably did some stuff with it that it wasn't meant to do, great trans IMHO. If I ever thought about getting rid of the 4.0L i'd probably do a 4.7L/auto swap. I hauled my wrangler from the up of mi round trip to tellico and it never skipped a beat. Even towing through the mountains, no problems... It did have the factory tow package with the trans and power steering coolers... But we also have a dakota with the 4.7L in it and the trans feels alot different, it seemed to struggle towing a 2 place alum snowmobile trailer. I know the dakota is only a 4 speed auto, and the Jeep was flashed to be a 5 speed. Maybe the updated flash was a better program for the trans? Link to comment Share on other sites More sharing options...
Sir Sam Posted November 29, 2008 Share Posted November 29, 2008 I have the 545RFE in my CRD and I gotta say I feel its a pretty stout trans. Link to comment Share on other sites More sharing options...
aemsee Posted November 29, 2008 Share Posted November 29, 2008 What kind of CRD do you have? Link to comment Share on other sites More sharing options...
Sir Sam Posted November 30, 2008 Share Posted November 30, 2008 What kind of CRD do you have? The KJ kind. Link to comment Share on other sites More sharing options...
aemsee Posted November 30, 2008 Share Posted November 30, 2008 I would love to put that drivetrain in my MJ. Link to comment Share on other sites More sharing options...
Sir Sam Posted November 30, 2008 Share Posted November 30, 2008 I would love to put that drivetrain in my MJ. viewtopic.php?f=7&t=10092 Link to comment Share on other sites More sharing options...
dunl Posted April 25, 2009 Share Posted April 25, 2009 I know this is an old thread, but I have some useful info to add. These 45RFE trannys are very good, we have one in our Liberty. Quite stout, no real issues.....except the following: http://forum.calgaryjeep.com/index.php?topic=11469.0 About $180 to fix and it now drives like a dream. When you pull away from the start line with it floored, the tach rides right up to the red before dropping into 2nd, then does the same thing again before hitting third. Almso 240,000km on our KJ, and this transmission is acting like it is new. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now