Are the 45RFE and the 545RFE really the same?

[Hockeygoon]

So you basically repeated what I said but added gear ratios lol...?

Yes.

 

[tommudd]

Thanks to all for the preceding discussion on 545RFE's. Always wondered if conversion was worth it, but when it leads to lugging of the engine, that kills the idea for me. Lugging an engine is not good and will end up costing far more than any savings in fuel cost. Good information!

Thats it , can't see why some thinks its such a great idea.

 

[04Liberty]

Thanks to all for the preceding discussion on 545RFE's. Always wondered if conversion was worth it, but when it leads to lugging of the engine, that kills the idea for me. Lugging an engine is not good and will end up costing far more than any savings in fuel cost. Good information!

Thats it , can't see why some thinks its such a great idea.

Only really a good idea on a KJ if yu have 4.10's and do a lot of highway driving, though the 545 was put in 2500's with 3.73's...

 

[chris03kj]

I actually did the swap and have noticed 2 more mpg on city/highway driving and 4-5 more when on the full highway. I haven't noticed any "lugging" and don't really know what I would even look for in it. I can actually still accelerate in the 5th gear, but if I go to pass someone and have to step on the pedal it just downshifts, and it is worth it for me as I have to drive to Florida from Chicago and back a few times a year

 

[JeepJeepster]

The 42re has a 0.69 4th and it lugs the heck out of my 04. Basically anytime I'm not on level ground with NO headwind, shes lugging... And shaking...

 

[twowings]

A real shade tree tech :happy175: hard at work.

He sure spent a lot of money on them fancy jackstands...all the rednecks around here use good ol' concrete blocks...or an old rim...:ROFLJest:

 

[windman]

they are same transmission. you can flash 545 into 45 control module. i had done this to our 2000make WJ. it gives you ability to cruise 200-300 rpm lower. But makes it shift to overdrive later than usual. as far as i remember it was shifting to highest gears around 82 km/h instead of 74 km/h. If you cant reach that speed it stays on a higher gear which i did not like after flashing the software with starscan terminal . 4 gears are better for all around driving. 5th overdrive ratio is only good for highway driving.