42rfe or 42rle, what's the difference?

ShockT63 · **Posted:** Tue Feb 03, 2009 7:53 pm

I'm not well versed in transmissions, so I was wondering what the difference was between these two types of tranny's. I'm not sure what mine has. I guess I need to crawl under and find out.

tjkj2002 · **Posted:** Tue Feb 03, 2009 8:18 pm

Well one thing..................

There is no such thing as a 42RFE.

There is a 45RFE which is a much stronger transmission then the 42RLE.The 42RLE started it's life as the A604 which was 1st introduced in the early Dodge minivans.'02 and some early '03 KJ's got the 45RFE and then went to the 42RLE.

4---# of forward speeds
5 or 2---1-10 scale on how much torque the trans can handle,1 being the lowest
R---rear wheel drive
FE---Full Electronically controlled
LE---Limited Electronically controlled

jeepkj02 · **Posted:** Tue Feb 03, 2009 8:22 pm

Count the number of bolts on your transmission pan. The 45rfe has 13 bolts and the 42rle has 15 bolts.

ShockT63 · **Posted:** Tue Feb 03, 2009 8:47 pm

Thanks guys! Big help.

Fulltimer · **Posted:** Wed Feb 04, 2009 12:47 am

You could also call a dealer and ask for a build sheet. It has lots of goodies in it.

Terry

501 · **Posted:** Wed Feb 04, 2009 2:00 am

tjkj2002 wrote:

Well one thing..................

There is no such thing as a 42RFE.

There is a 45RFE which is a much stronger transmission then the 42RLE.The 42RLE started it's life as the A604 which was 1st introduced in the early Dodge minivans.'02 and some early '03 KJ's got the 45RFE and then went to the 42RLE.

4---# of forward speeds
5 or 2---1-10 scale on how much torque the trans can handle,1 being the lowest
R---rear wheel drive
FE---Full Electronically controlled
LE---Limited Electronically controlled

Well for once I fall on the good side of the fence, my build sheet says I have the 45RFE!

BennyMigs · **Posted:** Thu Feb 05, 2009 9:42 pm

Will a KJ with a 42 fit a 45?

tjkj2002 · **Posted:** Thu Feb 05, 2009 10:08 pm

BennyMigs wrote:

Will a KJ with a 42 fit a 45?

Yes but modification will be needed like the new crossmember,F/R driveshafts,and the biggest will be a new TCM and correct programming.

dieselenthusiast · **Posted:** Fri Feb 06, 2009 1:20 am

The 42RLE is still a good transmission. It may not be as strong as other transmissions, but it’s still a good transmission. If you plan to use your KJ for a fair amount of towing or plan to load down your KJ with armor, big tires, bumpers, and a winch, then you may want to think about upgrading to a heavy-duty TC and a Transgo correction shift kit. Also, if you have the 42RLE you may want to consider an aftermarket transmission cooler and/or add the 2002 KJ radiator.

BennyMigs · **Posted:** Fri Feb 06, 2009 8:41 am

I have an 03 with the stock tranny cooler is it the same as the 02? The problem I have had is the tranny take for ever to shift. I was that thats is common with the KJ. Will the shift kit help that? If not what will it do? Will the cross member off a KJ with the 45 fit. And one last thing is the the 45 part time or all time 4x4. Sorry if I hi-jacked the post.

BennyMigs · **Posted:** Fri Feb 06, 2009 9:19 am

O ya what about 545rle

ShockT63 · **Posted:** Tue Feb 10, 2009 7:34 pm

Thanks for the help guys. I discovered that I have a 45rfe!

calamaridog · **Posted:** Tue Mar 03, 2009 7:14 am

The 45RFE and the 545RFE transmissions are very good. These are stout transmissions used with V8 engines mostly. And of course, a lucky few early Liberty's and CRD models.

The 42RLE (A604 family) is a dog in comparison. Used with V6 engines only and plagued by problems throughout the design history.

Cost cutting measure to use the 42RLE in Jeeps. darn bean counters.

jeepkj02 · **Posted:** Tue Mar 03, 2009 9:46 am

BennyMigs wrote:

O ya what about 545rle

You probably mean 545RFE, which came in CRD KJs. Its the same as the 45RFE with an extra 5th gear.

42rfe or 42rle, what's the difference?

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