Thanks for clearing that up...that's what I get for assuming a corporation would think logically
| LOST JEEPS http://www.lostjeeps.com/forum/phpBB3/ |
|
| 45RFE -> 545RFE flash? http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=24862 |
Page 1 of 2 |
| Author: | warp_foo [ Sat Sep 29, 2007 8:46 pm ] |
| Post subject: | 45RFE -> 545RFE flash? |
Good evening folks, I have searched around the various forums, google, and even a few Dodge forums, but I haven't found an explicit answer to this question: Can the 45RFE transmission in a 2002 Liberty Sport 4x4 be flashed to 545RFE spec? If so, will the dealers do it? Are there aftermarket options? The data I have thus far is that there is a flash for the 2000-2001 GC to enable the 5th gear OD, but no mention of the Liberty. I would expect that, for on-highway use, the flash (if available) wouldn't hurt anything and might help get a bit more out of a tank of gas. Yes, I know it's a heavy truck and I know it's primary goal is not ultimate fuel efficiency. Still, I do commute with my Liberty and if a minor upgrade can make a positive change with no downside that I can see, why not do it? Has anyone any info on whether this is doable, or have any of you hacker types have flashed with the GC firmware successfully? My apologies if this has been asked a few dozen times, but my searching turned up no results related to the Liberty 45RFE. Thanks. m |
|
| Author: | tjkj2002 [ Sat Sep 29, 2007 10:20 pm ] |
| Post subject: | Re: 45RFE -> 545RFE flash? |
warp_foo wrote: Good evening folks, Not possibe,the 545RFE is really a 6-speed auto(still two 2nd gears with one a downshift only,and 2 OD ratios),the 45RFE is really a 5-speed auto(two 2nd gears with1 a downshift ony and 1 OD ratio).The flash for the Grands(if they have the 45RFE) only will unlock the second 2nd gear for the normal upshift and downshift.
I have searched around the various forums, google, and even a few Dodge forums, but I haven't found an explicit answer to this question: Can the 45RFE transmission in a 2002 Liberty Sport 4x4 be flashed to 545RFE spec? If so, will the dealers do it? Are there aftermarket options? The data I have thus far is that there is a flash for the 2000-2001 GC to enable the 5th gear OD, but no mention of the Liberty. I would expect that, for on-highway use, the flash (if available) wouldn't hurt anything and might help get a bit more out of a tank of gas. Yes, I know it's a heavy truck and I know it's primary goal is not ultimate fuel efficiency. Still, I do commute with my Liberty and if a minor upgrade can make a positive change with no downside that I can see, why not do it? Has anyone any info on whether this is doable, or have any of you hacker types have flashed with the GC firmware successfully? My apologies if this has been asked a few dozen times, but my searching turned up no results related to the Liberty 45RFE. Thanks. m |
|
| Author: | Guest [ Sat Sep 29, 2007 10:28 pm ] |
| Post subject: | |
From everything I've read, the 545RFE and the 45RFE are internally identical. there's a guy that swapped a Hemi into his '00 Dakota and used the 03 Hemi's ECM with his 45RFE's TCM and it gave him an extra forward gear. Aren't there 8 forward and 3 reverse potential ratios for both the 45 and 545? |
|
| Author: | warp_foo [ Sat Sep 29, 2007 10:53 pm ] |
| Post subject: | |
tjkj and Thunderbird, thanks for the response. This link: http://www.jeepiki.com/wiki/index.php/45RFE/545RFE ...and others I have found indicate that the two transmissions are, in fact, the same hardware. And this GC forum discussion has additional info: http://www.jeepsunlimited.com/forums/sh ... p?t=733991 And here is a Dodge Dakota forum posting with information regarding the GC Service Bulletin which references 'enabling' the 5th OD gear. http://www.dodgedakotas.com/boards/gen/23574.html Of course, none of the above is rock-solid evidence that the 45RFE can have the 5th OD enabled for every 45RFE built... m |
|
| Author: | Jeepjeepster [ Sun Sep 30, 2007 12:23 am ] |
| Post subject: | |
Ive also read about getting the flash done on the grands. Seems like any dealer can do it if they want/know what their doing. Ive always read that the 45rfe and the 545rfe are the same also. |
|
| Author: | Guest [ Sun Sep 30, 2007 12:28 am ] |
| Post subject: | |
I'd kill for another overdrive. Did they change the TCM from the '99-01 and the 02-3 45RFE? Maybe it was just on the first couple years of the 45RFE, and the newer TCM can't take the same flash? |
|
| Author: | tjkj2002 [ Sun Sep 30, 2007 8:54 am ] |
| Post subject: | |
Just looked in the part manuals,some parts are different in the 45RFE and 545RFE.The input carriers are different which will give different ratios between the two,although the rear planentary gear packs are the same other parts are not.Oh this was comparing the 45RFE from a '02 KJ and a 545RFE from a '06 KJ CRD. |
|
| Author: | KY Liberty [ Sun Sep 30, 2007 2:01 pm ] |
| Post subject: | |
I've asked B&G, APS, and my transmission mechanic and they all have told me that the two transmissions are very close, but they are different and it won't work. I wanted it while I'm running 4.10 gears and 29.5" diameter tires so I'd have the second overdrive with the .67:1 ratio instead of just the .75:1 that I have now. Would probably gain me a couple mpg at interstate speeds, but the cost of swapping the transmission could never justify it. Now that I'm going to 31.1" tires, the .75:1 should put me at just about the right rpm on the interstate so I'm not worried about it anymore. Plus, if it puts the rpms too low, I would think it might switch constantly between the overdrive gears, and back to 3rd through hills. |
|
| Author: | Guest [ Sun Sep 30, 2007 2:56 pm ] |
| Post subject: | |
tjkj2002 wrote: Just looked in the part manuals,some parts are different in the 45RFE and 545RFE.The input carriers are different which will give different ratios between the two,although the rear planentary gear packs are the same other parts are not.Oh this was comparing the 45RFE from a '02 KJ and a 545RFE from a '06 KJ CRD.
What about the 545 in an 03 Hemi Ram? I'd imagine some parts would be different in the CRD because of the torque curve being so drastically different and it'd need different ratios |
|
| Author: | tjkj2002 [ Sun Sep 30, 2007 5:07 pm ] |
| Post subject: | |
ThunderbirdJunkie wrote: tjkj2002 wrote: Just looked in the part manuals,some parts are different in the 45RFE and 545RFE.The input carriers are different which will give different ratios between the two,although the rear planentary gear packs are the same other parts are not.Oh this was comparing the 45RFE from a '02 KJ and a 545RFE from a '06 KJ CRD. What about the 545 in an 03 Hemi Ram? I'd imagine some parts would be different in the CRD because of the torque curve being so drastically different and it'd need different ratios |
|
| Author: | Guest [ Sun Sep 30, 2007 5:16 pm ] |
| Post subject: | |
Thanks for clearing that up...that's what I get for assuming a corporation would think logically
|
|
| Author: | tjkoen01 [ Tue Oct 02, 2007 2:16 pm ] |
| Post subject: | |
ThunderbirdJunkie wrote: Thanks for clearing that up...that's what I get for assuming a corporation would think logically
don't sell the former DC corp short....the TSB says it can be done on a GC....you would have to find the right person to talk to at the dealership. i think most would be reluctant to flash a computer with a program for a different one, but i think it could be done. The worst that could happen would be your TCM would be toast, right? anybody have an extra one laying around?? |
|
| Author: | tjkoen01 [ Wed Oct 03, 2007 6:38 am ] |
| Post subject: | |
i wonder if we can steal a TCM from a GC with a 4.7 and the correct year and pop that in the Libby? I think the GC i got my evic from was an '01 with a 4.7, i'll have to see if they still have it. |
|
| Author: | jg45 [ Wed Dec 24, 2008 12:17 am ] |
| Post subject: | |
tjkoen01 wrote: i wonder if we can steal a TCM from a GC with a 4.7 and the correct year and pop that in the Libby? I think the GC i got my evic from was an '01 with a 4.7, i'll have to see if they still have it.
Yes you can. I did it last night and now have a second overdrive. I really like the way it shifts now. I get the shift to 5th just below 50 mph and it holds down to about 43. I used the TCM from an '03 Grand Cherokee with the 4.7/5-45RFE combo. The service manual said that the pressures where the same for the GC 5-45RFE and the Liberty 45RFE. The HEMI 5-45RFE has higher line pressures. The transmission service manual also indicates that the extra gear is activated by applying the 2C clutch instead of the 4C clutch in combination with the OD clutch. I'll have to do some additional driving to see if there is any boost in mileage. |
|
| Author: | XR [ Wed Dec 24, 2008 11:02 am ] |
| Post subject: | |
Looking forward to the next report on that one.BTW what did the TCM cost you? |
|
| Author: | jg45 [ Wed Dec 24, 2008 11:09 am ] |
| Post subject: | |
Found it on http://car-parts.com and it was $65 shipped. |
|
| Author: | XR [ Wed Dec 24, 2008 11:49 am ] |
| Post subject: | |
Was it plug-n-play?Found one close by. |
|
| Author: | jg45 [ Wed Dec 24, 2008 12:05 pm ] |
| Post subject: | |
Yes it was. These are the steps I took: Disconnect the positive battery cable. The TCM is mounted to a bracket on the right side inner fender. It bolts to the bracket from the backside, so I had to remove the bracket. Disconnect the cable from the TCM before unbolting the bracket. Swap the TCMs on the bracket and reinstall. Reconnect the cable to the TCM. Next, with the battery cable still removed, I turned the key to start and held it for 12 seconds. I repeated this step. This is to clear the learned adaptive shifting and reset the PCM as well. Now i reconnected the positive cable and started the KJ. I let it sit at idle (not touching the accelerator at all) until it reached operating temperature. Shut it down and started it again, this time shifting into each gear. Shut it down again, restarted and took it for a test drive. Drove around city streets taking it easy at first so that the TCM and PCM could learn the basics and then took it on the highway. Now I drive it like normal. |
|
| Author: | KY Liberty [ Wed Dec 24, 2008 2:11 pm ] |
| Post subject: | |
Wow, everyone told me this absolutely wouldn't work. Glad you didn't listen. So, what is the RPM change at highway speeds with the extra overdrive? I would really be interested in this now that my gas milage is terrible with the lift and heavy tires. A couple hundred less RPM at highway speed should make a lot of difference for me with the 4.10 gears. I'm quite familiar with replacing the PCM and getting it to relearn, so a TCM swap would be rather easy. I have the Transgo reprogramming kit in mine, but that shouldn't matter since it is the same one for the 45RFE and 545RFE. |
|
| Author: | jg45 [ Wed Dec 24, 2008 3:20 pm ] |
| Post subject: | |
It's about 200 RPM. |
|
| Page 1 of 2 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|