hey guys, been a long time since i've last posted and even worked on the truck for that matter. lot of life changing events, marriage soon and new house.

anyways, i took the truck out for a test drive down a back road. its really the first time ive driven it since i got it 2 years ago. its a 1951 ford f1, 239 flathead v8, with a stock 3 speed on the tree transmission.

my problem is this; i'm driving down the road in first, clutch it for 2nd, and then to third. everything works great. i then downshift to second, and get ready to pull into my driveway while shifting into first to slow down, and i hear GRRRRR GRRRRRR GRRRRRR, as the gears slam and grind together as i try to shift it back into first. once i completely stop, it shifts into first fine. but not when going from 2nd to first.

is this normal for the truck to do that when shifting? i don't know enough about the transmission and can't find anything on the internet to explain what is going on. my only assumption is that the transmission considers first "low range" and wont shift back into it because of the gearing.

please help me understand what's going on.

thanks guys.

 

Down shifting not the easiest thing to do
non synchro trans you have to double clutch
matching speed of trans with engine speed

I dont like to down shift

Joe

 

I don't believe that 1st gear is synchronized in the 3 speed. As 48Atoy points out, you have to double clutch to match the gears.

 

You cannot downshift into first gear while moving. Unless you are loaded or on a long down hill, routinely downshifting isn't necessary for a stop. Downshift when cornering or for hill climbing as needed.

 

Your trans has no synchronizer into 1st or reverse gears. They didn't add a 1st gear synchro until the new 3.03 trans came out in 1963. You've been grinding away on the 1st gear teeth on your 1st/reverse slider gear AND the cluster gear. Hopefully you haven't removed too much expensive steel.

With these transmissions, you must be fully stopped before shifting into 1st gear (or reverse). That's fine when it's a stop sign or a nice red light. The problem was always when you were nearly stopped for a red light....which suddenly changed to green. Then the impatient driver behind you gets upset because you now have to stop in order to shift into first gear.

You have two choices at this moment if you want to get your vehicle moving pronto. Choice 1: shift into second gear and slip the clutch enough to get going again. Choice 2: learn to double clutch the trans right into 1st gear to get going.

Double clutching means a technique to quickly speed up 1st gear a bit, which will match its rotation speed to what it would be turning had it already been in gear at the vehicle's speed at that crucial moment. It takes practice to get it right, but if you do it well the trans will shift right into 1st gear....just like it was synchronized!

So....the car is rolling slowly to that red light and you've pushed the clutch pedal in anticipating a full stop. Now, shift into neutral....let clutch pedal out quickly and give the gas pedal a quick bump....push clutch back in and shift into first.

If you judged the quick bump in engine rpm's correctly, it goes right into first without a whisper. If you've sped up the engine too much, it will grind a bit.....not enough rpm's and it will grind a bit then too. You can also hesitate a bit longer before shifting if you think you oversped the engine. It's all a matter of timing and good foot work on the gas and clutch pedals.

Last but not least make sure your clutch is adjusted properly so you KNOW it is fully disengaged when pushed to the floor.

Practice in a parking lot....doesn't take long to get it down.

 

I've actually had newer cars (80's and 90's) do this same thing. I could never get them into first unless I was stopped or very close to it.

I would think, depending on the gearing of the rear end, starting back up from almost stopped would be fine in 2nd. Now, take this bit of advice knowing that I have only driven my frame and engine a couple hundred yards total.

 

With the column shifter especially, it's really, really hard to double clutch to 1st, I wouldn't even try. Like MacVP says, you're peeling off some expensive steel. Brake shoes are cheap.

 

i appreciate everyone's answers. although this isn't exactly what i wanted to hear, it at least lets me know nothing is seriously wrong with the tranny. luckily i am smart enough to know, grinding gears is baddddddddddd so i only did it a handful of times thinking it just wouldnt engage.

i will try double clutching. i never knew there was such a thing, and due to my environment where i live (there are a bunch of hills), i am thinking i will need first gear more than not. hopefully i can learn to do it without tearing apart the tranny.

thanks again!

 

Top speed in 1st (with stock gears?) is around 25 mph, at that speed in 2nd you should be able to pull up even a pretty steep hill. Flatheads make best torque around 2,000 - 2400 which in 2nd with normal tires is right around 25 - 30.

 

what a transmission looks like when you don't stop before putting in 1st gear

 

At least you have synchros in 2nd and 3rd. 1950 and back we have no synchros. Mac VP's description is good. Practice, practice, practice