Hey there guys, ever since I bought my truck, I've noticed that the trans only shifts up until 3rd gear. It does need some new oil and filter, but I don't know if the trans is a 3 or 4-speed one. There's a O/D switch on the dash, and since my dad had a '92 Ramcharger and it had 4 gears, I assume my truck has got the same. However, I don't get anything if I hit the O/D switch, and because of this, I went under the truck and found out that there are three connectors: one to the speedo thingy (I guess) another big one that is connected very close to the gearshift lever linkage and there is also a small connector with 2 female prongs that is disconnected and I couldn't find the recipient connector anywhere, so I'm thinking if any of the previous owners replaced the transmission for a 3-speed one, since the truck, once on 3rd gear doesn't feel like it needs another gear, yet my ears say that the engine is a little high on revs traveling at about 55 MPH, but I'm not quite sure about that because my dad sold the truck 1 year ago and I can't remember how the truck felt.

Anyway, more things that make me thing it's the 4-speed trans is that the speedo does not work, and my dad's truck used to stick to 3rd gear when the speedo sometimes stopped working, and after a shock or something, the speedo came back again and the 4th gear engaged right after that. Also, the gearshift sequence is pretty similar to that of my dad's truck: you take off, then the 2nd gear engaged and almost immediately (depending on how fast you're driving) the 3rd gear is shifted into.

I'm also thinking that this problem is due to the need of maintenance because the trans finds it hard to shift into drive or reverse when cold. If I accelerate a lot then shift to drive the gear engages normally, as well as the reverse.

I'm freaking confused on what it is, but I need to find out what transmission is it and if it is a 4-speed one, find out if it is possible to make the 4th gear engage, because the truck's computer is busted and I don't know if this has got anything to do with the trans problem.

You all may be thinking that I should take the truck to a trans shop, but first I would like to have an idea of what my problem is before a dishonest mechanic tries to pull some tricks to run with my money.

 

Since you have no idea what trans is in the truck or if it is stock or not. Your best bet is to copy down the 3 sets of numbers that you will find on the drivers side of the flange that the pan bolts to. Call the dealership with these numbers and they can ID the trans. The first number is the part number, the second is the build date, and the third is the serial number.

 

Thanks, SEAL, I figured I would ID the trans with the method you're telling me, however, I needed to know which numbers I had to look for.

Thanks for the great help you provide to everyone here.

 

Sounds like someone swapped in an A727 or A904. Your truck would have originally had the A518 or A500.

That little 2 prong plug is what engages the OD and lockup. If the computer does not work the OD and lockup will not work. PATC sells a kit that will allow those functions to be controlled without the computer.

The 500 series transmissions tend to be longer as they are the same as the 3-speed but have an OD unit attached. Look for a pressure test port located towards the front of the transmission extension. That can help determine what tranny.

The shape of the trans pan will help determine wether it is an A904/A500 or A727/A518.

What year is your truck? What engine? 4x4 or 2wd?

 

I'm assuming you have a 1990 from your tag and mine is a 91. I had a sticker located under the hood over the radiator on the RH side that had my options on it. It listed my trans on it and a lot of other good info to boot.

 

thanks guys, I haven't been able to keep up with this as I had a lot of things coming on... anyway, turned out that on june 15th, the dang transmission broke down. I had it rebuilt and the guy at the shop told me the model, which I can't remember, but he told me the truck was supposed to have the 4 speed electronic tranny, but they swapped it to the regular, non electronic 3-speed one. I remember the guy saying 3something3 or something like that, but I can fairly remember, I was so pissed off that day that I just told the guy to get the dang tranny fixed and that's it.