1991F150guy

Well I have looked into prices of transmissions and started to think maybe attempting to make mine usable might be worth it. What I have is a 1991 f150, 5.8, automatic. I'm having two problems, the first is that when try to go from a stop my truck is VERY slow I can't hear it slipping,(I've driven a few cars with slippy transmissions) it feels like my truck is starting off in overdrive rather than first because like I said it doesn't sound like it's slipping but it's really slow and after it shifts it accelerates better. My second problem is that unless it's in neutral or park the RPM's won't go past 2,100 ish. Some times if I keep my foot in it it will go up to 2,600 ish but that bothers me because I know that the motor can rev past that. I'm wondering what could cause this. I have no clue if this could make a difference but my transfer case it a little screwy and won't go into 4low, could this make a difference?? Well those are my problems. Any advice or help at all would be great! I really want to get this figured out before spring because that's when it will become my daily driver. Thanks in advance!!!

Rusty but trusty

I always like to start with a fluid/filter change. Easiest thing to try.

1991F150guy

Ok thanks. I'll try to get that done this week. Is there a way to do it myself? Or do I need to find a shop?

Rusty but trusty

Yea, you make a big mess on your garage floor!!! Haha, it's really not hard to do at all, just time consuming and messy. Pick up a cheap manual from auto zone (Haynes). It will have it all spelled out. Here is a short version: take out half of the pan bolts, loosen the other half, let pan drop down and drain, go have a couple beers, remove pan, inspect pan for metal (metal is a very bad sign), clean pan, pull old filter off, push new filter on, place new gasket on pan, install pan and torque bolts (do not over tighten bolts!), then fill trans to proper level, run/drive it, inspect for leaks, check fluid level again.

1991F150guy

Alright. Doesn't seem that hard. Next question, what is the best transmission fluid to use?

Brandon587

Also know, a little bit of metal is actually ok and normal, small fine flakes on the magnet. It should feel soft if you run your hands on it.

Rusty but trusty

Thanks for clarifying, you are correct, tiny particles or metallic fuzz is normal. If the magnet is wearing an Afro then you have a problem. To OP Check your owners manual or have the parts store look up the OEM fluid for ya. I've done trans fluid/filter changes on GM's but haven't had to do it on my Fords yet.

Brandon587

Lol I just didn't want him to freak out when he saw some when he changes the fluid