I need to add some more fluid to my 4 speed manual trans and i was wondering what is a good kind to use and maybe if u guys know how much i might need.

 

Valvoline, Penzoil, Havoline, a good name brand will work fine, look for ones that help fight varnish and buildup, and dont forget if it is a newer trans they use Dextron 2\Mercon fluid.

 

What year is your truck? It probably calls for gear oil (abt. 80wt.).
I switched my 91 4 spd over to royal purple (trans and diff). Made a significant difference in how smoothly it shifted and it runs a little quieter now.

I do have to throw out the disclaimer that I did this a few months after I bought the truck and it could likely have been the first time either of those fluids had been changed, so non-synth might have made just as much of a difference...but I like to pretend the extra money I spent was worth it

 

If you have the heavy duty 4 speed it takes the gear oil, the newer standard duty trannies call for dextron/mercron fluids. The heavy duty 4 speed is a T-19 tranny.

 

thanks
Ill check to see if the trans is a t 19
Its an 1987 f150 and is geared really low

 

It takes the Mercon II auto trans fluid. Don't let the "Automatic Transmission" notation fool you. There has been many a discussion on this subject.

 

The only tranny that take the gear oil is the T-19, all others use the mercron ATF. The T-19 is a older design heavy duty transmission with a granny gear first gear. This tranny is used for heavy hauling and does not have a overdrive.

 

i almost 100% sure mine is the t 19
my first gear like 5mph