sychronization of gears

[stevenelle]

Just replaced 3 speed column shift with 4 speed floor shift on B2B. There is a small tolerable bit of grind when going from 3rd to 4th. However when downshifting from 4th to 3rd there is much major grinding. Is this trans suppoed to synchronize for downshifting? I may not have perfected my double clutching technique, but even that does not seem to help a lot. Is there a fix for this, or should I get used to it?

[52B3B108]

I have the four speed transmission. When you're downshifting you need to make sure you're getting the rpm's back up high enough to shift. Of course you always run into a situation where you've had to slow down and you're going too slow for the gear you're in and too fast for the gear you need to downshift to. You'll just have to take it to a big parking lot somewhere out of the way and practice. It's alway worse downshifting going uphill.

[Reg Evans]

I think 51 was the first year for the syncro 4 speed. You can tell if your trans is syncro by looking at the drain plug. If it comes straight out of the trans parallel with the ground it is syncro. If the plug angles down it's not.

[Guest Nile Limbaugh]

There is a trick called 'heel and toe' which involves both braking and feeding gas at the same time with the right foot. The art comes from the sportcar world of road racing and allows the driver to rev the engine in order to match gearbox rpm's while braking for a corner. If the position of the pedals in your truck (I've never driven one) allows this process it makes downshifting a breeze once mastered. In my high school days my buddy and I could even downshift into first at any speed below 30 without grinding anything; but it takes practice. We were probably lucky that we didn't scatter the box while learning!!

[Mario Loya B1B]

My 49 1/2 ton requires the double clutch technique which I have only half perfected (I can upshift but not downshift w/o grinding). What is the best way to upgrade to a synchro transmission. Is it as simple as just making a post '51 transmission swap. If so how easy are these to come buy?

[Reg Evans]

My guess would be that the synchro would slide right in and bolt right up to a 4 speed crash box bell housing but that's a definite maybe. Ebay or a cheap parts truck might yeild one.

[Guest jtw3749c]

I had a 4 gear in my 53. I also had to double clutch. It just a matter of practice. Drive it often enough and it becomes second nature. Double clutching basically aloows the gears to line up for the shift. No grind. Gathering parts for mine to go back stock and it will get the 4 gear back in it. Love the Granny gear.

Try learning to shift up or down without the clutch. Now that's a trick. I use it still today on all my stick trans.

[Robert Thornton]

steve what all did you have to chang out to put 4 speed in your truck . i was told that the bellhousing needs to be changed, any thing else. i have another 3 speed out of a 53 but i'm still not sure if my linkege is not my trouble i have to take both hands on shifter one next to colum the other on the knobe and pull hard to get back to 1 st or rev shifts good other than that. also netural is at one o'clock not at 3 like it should be thanks robert

[Young Ed]

The driveshafts are different lengths between 3 and 4 spds. Also your problem sounds like it probably is linkage. The 1 and R rod needs to be adjusted.

[Guest DS 49 Dodge]

Hi Steve - To downshift, while in neutral between gears, double clutch while giving the gas a few revs to get the rpms up. With a little practice you can downshift very cleanly.