98 1500 3.9L - 42RE or 46RE

[Tad Marko]

Howdy!

My mother's 98, 1500, short-bed, 2wd has the four-speed auto. Is this the 42RE or 46RE?

The internet seems vague on this.

I know there's little important difference, but I'm just curious about the details. Or is there an important difference?

Thanks!

 

[EvilSpirit]

Could have either trans. Easiest visual I.D. is that a 42 RE pan looks like a square with the corner clipped - 46RE has a bump out at the passenger front cover. You can go onto Rock Auto and pull up trans pans to see pics of both pans.

Differences? 46RE has a higher torque rating, being based off a 727 main body. The 42RE is based off the 904 main body and has a lower torque rating, but benefits from lower 1st/2nd gear ratios to help get the truck rolling better. The O/D units physically interchange, but have different direct/O.D. clutch counts in the O/D drum. Valve bodies are pretty much the same, but have different springs and orifice sizes to tailor shift qualities to application.

 

[Tad Marko]

I found a VIN decoder that has all the build specs for the truck. It indicates it's got a 3.21 rear-end (now to figure out what kind) and a 2.74 first gear ratio, which tells me 42RE. I'll crawl under this weekend and take a look at the pan.