What transmission do I have?

I have a 1990 Dakota 4x4, 4 speed automatic with push button overdrive. My planetary gears are shot and I've heard from many sources it is usually cheaper to replace the tranny than to have it rebuilt. I've been told it should be an "A500" transmission. The problem is that I've seen 42RE and 42RH in reference to this tranny. Please help or tell me where exactly on the tranny it would say what it is. Thanks in advance.

open the hood and look on the underside of it towards the front and look for a sticker with the factory specs.it should say it there so you will know for sure.its better than crawling underneath.

Yes, you have the A500/42rh. Same thing. You can also include the 46rh in your search though. It will bolt up and function just the same, but is stronger.

The 42re is the "electronic" version of the 42rh and started being used in '96. The change is it has an electronically controlled governor valve instead of the hydraulic governor valve on the previous transmissions. It can only be used on '96+ with the OBDII computer.

I always like posting this.....

I am looking to order a rebuilt one online and just want to make sure that I am ordering the right thing. The 46rh is stronger but will 100% be interchangeable with the stock 42rh? Sorry but I just want to make sure prior to ordering.

Yup, 100% interchangeable. It does have slightly different gear ratios though, as you can see in the poster that AP posted. First isn't as low on the 46 as it is on the 42, and first through third are closer ratios on the 46. Its up to you, I was just suggesting an alternative option that might last longer in the long run.

A change to a 46rh will require a matching torque converter, dust cover and engine to transmission braces.