Tranny question

CamperSpecialCruiser · Wed Sep 13, 2006 6:51 pm

I have a 1968 F-250 with the NP435 transmission that I recently bought. I've found that I have to stop completely when shifting into 1st gear. My father said that all the older trucks worked that way because they don't have "synchronized gears". What does this mean? What is the difference between synchronized and non-synchronized trannys? Thanks

flyboy2610 · Post by **flyboy2610** » Wed Sep 13, 2006 6:59 pm

A synchronizer is a device that is between two gears. It enables the two gears to run at the same spedd when being shifted so that they mesh smoothly. First gear on our trucks is not synchronized.
A non-synchronized tranny has no synchronizers. The speed of the gears during shifting must be equalized by the driver via a process known as 'double clutching', or if you know your tranny realy well you can 'float' the gears, which is shifting quickly at a precise time.

CamperSpecialCruiser · Wed Sep 13, 2006 7:30 pm

Thanks, that makes good enough sense to me.

spartman · Post by **spartman** » Thu Sep 14, 2006 10:24 am

If you want to learn how to double clutch effectivly drive a mack truck with a 5 speed tranny in it.

You will learn quick.

gonzalo medina · Post by **gonzalo medina** » Thu Sep 14, 2006 4:46 pm

Hey flyboy save what you just explained. PERFECT

flyboy2610 · Post by **flyboy2610** » Thu Sep 14, 2006 5:21 pm

Having been a trucker, I got good at double clutching and floating the gears.
I'll take a synchronizer.

Maxum96 · Post by **Maxum96** » Sun Sep 17, 2006 11:17 am

I never use 1st gear on my NP435. 2nd gear is like normal first gear. But then again my 390 is nice and torquey.

ToughOldFord · Post by **ToughOldFord** » Sun Sep 17, 2006 12:41 pm

Yep, you don't need to use 1st in the "granny low" transmissions with normal driving. These trannys would have been better labeled with a shift pattern of

L----2

1----3

Than the normal 4 speed pattern. That extra low gear confuses some people, ones that insist you just have to start out in first all the time.
1st in these trannys is only for pulling a serious load or pushing a Chevy, (like a rock), into a ditch.

flyboy2610 · Post by **flyboy2610** » Sun Sep 17, 2006 2:08 pm

ToughOldFord wrote: pushing a Chevy, (like a rock), into a ditch.

mljjones67 · Post by **mljjones67** » Sun Sep 17, 2006 3:35 pm

CamperSpecialCruiser · Sun Sep 17, 2006 4:18 pm

I'm currently driving a 1975 L-9000 with a 13 speed roadranger for my grandfathers building moving company. We also have a 1964 F-1000 with a 534v8 mated to a 12 speed so I do know a little about double-clutching.