I have changed the fluid twice and only have 44k on the truck. Running Redline MTL(4.5 qts) and shifts better then the stock fluid and a lot better then the Amsoil MTF.

I do not like the 3rd to 4th gear shift. It does not grind but it just doesn't feel smooth going in. Its weird though, because when you are in traffic and you shift out of third at say 1700-1900 RPM, it feels notchy going in. However when you are rodding or revving higher(like 2500 or so) in third it goes in very smooth. I've only done a couple of 1/4 mile runs, but it feels great when shifting fast. But, if you go slow and drive like a grandma, shifting at 1700-1900 it feels notchy. But you almost have to do this in traffic.

When it is cold I double clutch into 4th and 5th. After it warms up those gears feel better.

So, lately, I have been double clutching into 4th in traffic.

I would think its a synchro, but you can downshift into 4th smoothly everytime. And with the double clutch its smooth and shifting quickly its smooth.

Anyone else have this same issue?

 

No issues going into 4th here. With enough revs I can hit 4th w/o using the clutch

 

Dido

The 6sp is notchy anyways, and I think it shifts better with out the clutch too. and mine shifts way better with a heavy load on it