First off, sorry if I am being redundant or kicking a dead horse or whatever you wanna call it. I know there are a lot of threads out there on the NP435 but I always like to personalize my question... So mine in my '72 F100 is having some problems. It grinds a bit going into first gear, which I know is unsycronized. That's not too big of deal seeing as that I don't use that gear much since it is so low. The problem is, that it seems almost impossible to get into second from neutral. Sometimes I try double clutching it and it works. Sometimes it will go in by itself just fine. But a lot of times it does not go in. It doesn't grind. It just won't go down. When it does that I have to start out in the unbearably slow first gear then quickly shift down into second.

Also, third gear is kinda hard to get to. That may just take some getting used to. I have read that it's in kind of a weird position. I haven't been in third to 4th much since I don't drive it much bc it's not licensed yet, but that seems the smoothest of all of them. The transmission just seems rough overall as well. It could be the cold since these winters here in Mo do get pretty cold. I have 80-90 gear oil if that means anything... Anyway, thanks in advance for the responses.

 

Shifting into first is best done when at a complete stop.

I think finding second is getting used to the idiosyncrasies of your specific transmission - it requires its own style. On my 73, it requires me to let go of the shift ball momentarily before shifting into third. My trans seems to need to 'reset' in neutral before doing anything else.

If the problem persists, then a rebuild might be in order. But first, put the trans in neutral and remove the top cover and inspect it for unusual wear patterns and the presence/wear of the pads on the shift forks.

 

By pads to you mean the plastic inserts on the end of the forks? I have had the cap off and I believe all of those are in place.

 

Almost sounds like the OPs clutch needs an adjustment. Like it's not quite releasing all the way.

On mine
1st goes in a smidge tight
2nd goes in easy
3rd I can't shift it into 3rd, I have to just think about shifting it and give it a light touch. There isn't much distance from where 1st is to where 3rd is to the right.
4th Goes in easy

My buddy who drives beefed up hot rods and drag cars drove it and was grinding everything. He said my synchros are probably bad. I told him that he was shifting way too fast.

I said when you push the clutch in, let the RPMs drop and listen for the engine to almost go silent and then shift. No grinding whatsoever.

 

Have you checked your lube level in the tranny? No tranny does well in a low/dry condition. It is a point often overlooked.

 

Alright, thanks. Maybe it just takes getting used to driving it. I have adjusted the clutch out but I can try more. And I'll check the oil level, but it should be fine bc I have changed it before and it has never appeared to be leaking.

 

Buddy of mine had similar problems it was clutch adjustment

 

Okay, thanks. I think I'll try adjusting the clutch out more.

 

This listed that the np435 trans uses 50wt. engine oil. Not The heavier wts, which makes it hard shifting through the gears.
Summer time you could get by with a 75-90wt.

Orich

 

Wow. All it took was a clutch adjustment haha. Thank you all for your replies!

 

How many of you all have actually tried running thick oil? Above freezing, the thick oil (I use 80w-90)makes them shift better, imo. The only time it gets a little stiff is when it gets below zero - which make them shift even better. I think the stiff oil helps out the synchronizers.

 

If I remember right, that's what I put in mine is 80w90. I was told not to use 50wt oil in it. Works fine for me so far.