Okay okay, so I have another post about beefing up my trans some may have seen, I was standing in the NAPA store tonight and this guy comes up and starts talking about the truck etc, he says how he is a tech for dodge and owns many of their vehicles.. He tells me that I may be better off grabbing a 42rh and beefing it up.. He says its a direct bolt, direct fit behind my 5.2 magnum (originally has a 46rh) and will be better once beefed up... He says the 42rh has taller 1st gear and a little better gearing throughout.. Ultimately I could have a nice 42rh with 94k on it out of my old jeep I know works amazingly.. If I can just beef that up I would love to.. I know all my b&m parts also work on that trans too.. So anyone know if there is truth here? Will it be plug an play??

 

from the 01 service manual. your tech is correct on the gearing. i don't know about size, strength, etc.

GEAR RATIOS The 42RE gear ratios are:
1st . 2.74:1
2nd . 1.54:1
3rd . 1.00:1
4th . 0.69:1
Rev. . 2.21:1

GEAR RATIOS The 46RE gear ratios are:
1st . 2.45:1
2nd . 1.45:1
3rd . 1.00:1
4th . 0.69:1

 

Yeah see I think ultimately I'd be happier with the 42rh! Can anyone confirm the fitment questions here?!

 

That would actually be a lower first gear in the 42RH. What motor is in the jeep and are you sure its a 42RH as I think jeep went to the electronically controlled trannies earlier than the rams?

The Chrsyler Designation for trannies is 4 for four speeds, the next number is the torque handling capacity a 2 or a 6 in this case followed by an R (not sure what this means) then an H for hydraulically controlled or an E for electronically controlled.

Following this designation a 42RH is weaker than the 46RH. I think the key words are "beef up the 42RH". I doubt a 42RH will stand up in a fullsize very long as the 46RH barely does. I think the 42RH is based on the A-904 so the case and rotating mass is smaller.

Make sure the 42RH is the same length as the 46RH and make sure your t-case will bolt up the the tranny.

You can get different gear ratios in your 46RH by swapping planitaries.

What B&M parts do you have? Their shifts kits have a poor reputation in the shops around here.

 

Hmmm, the jeep has a 4.0 an yes I'm positive it is a 42RH in there.. I have the B&M heavy duty transpak for torqueflite part #10227

Also that does make sense about the transfer however I'm also looking at my service manual an it is saying that the 42 has taller gears, so with heavy duty parts a performance torque converter and the transpak.. An a swap of my rears gearing would make for a better drivetrian in thought.. I've been doing some looking around and found guys with 5.2 2wd dakotas running 42rh's

 

The bellhousing on that 42RH maybe different then the Magnum series of engines. The 42RH is very common in anything with the 3.9L V6 and dakota V8 applications.

As far as strength goes a new torque converter and shift kit will help (still not recommending the shift kit, a transgo with internal tranny mods has been recommended to me by tranny shops) it will not make up for the weakness. The 42RH has weaker and smaller planitaries, smaller and fewer clutch plates in the clutches. Those are the main things you need to "beef up".

 

I'd contact PATC and ask them about it, it's not a bad Idea if it can be built for it.

 

The Chrsyler Designation for trannies is 4 for four speeds, the next number is the torque handling capacity a 2 or a 6 in this case followed by an R (not sure what this means) then an H for hydraulically controlled or an E for electronically controlled.


R= rear wheel drive