Hi all im quite sure i have the np435 4spd tranny in my 76 f100 4x4. First question is what are the recomended shift speed and at what rpms? Also i finally was able to go put around in it for the first time and 3rd gear( counting 1 2 3 4) not L123. Growls ag least thats what it sounds like . I dont hear or feal any clanking or clatering it just growls a little any ideas on that? And lastly if its is something how deathly bad is it? ( cuz its 100 miles to my shop) and can a novice repair it in driveway? Thank u all very much

 

Shift speeds depends on gear ratio and load for starters I'd say 10 to 15 25 to 30 35 to 40 thats if your starting out in 1st or granny gear.If you are hearing a growling noise I would say you got a bad input or output bearing in your trans .The output can be changed with trans in truck but you have to have special tools to do so front one you have to pull trans.Usually the higher the gear your in the louder the bearings growl also when your down on the throttle the growl is louder

 

Ok thank thats what i was worried about would it be pk to drive it to my shop for now ? I would b able to getvit fixed there because they would have the special tool. I read one post where a guy drove with that " growl" for quite some time before anything went bad

 

As long as it's just whining & not clunking/crunching, you should be OK........it's probably been like that for at least a good few thousand miles.
There are the input & output bearings that get noisy; & also the countershaft bearings, & needle rollers on the mainshaft.

It is full of oil, isn't it?

 

Im goin to check the oil today lol it was a little late yesterday to check . The fill port is that odd square head bolt on the passenger side right? Next to the pto cover ?

 

Yes..... the top one, roughly level with the top of the PTO cover.