I am restoring a 1947 V-8 1/2 ton truck with 4 speed. I would like to keep the truck as original as possible but all the info I read says the 4 speeds are hard to shift and should be replaced. When I got the truck from my dad it was not running and now I have it down to the frame. Should I be looking for another transmission? How hard are they to shift? What does double clutching mean? I read on another thread that the only transmission that will come close to bolting up is the heavy duty 3 speed with open drive. Will the heavy duty 3 speed bolt up without changing the driveshaft... I do not want to do any cutting on the crossmember!!! Thanks for any help...
4 speed truck transmission
- Thread starter Lenney
- Start date
Tinker
Well-known member
I don't have any issues up shifting. Down shifting is another deal. 1st gear is a stump-puller and I only use it to idle around while pulling into the garage. 4th is still 1/1 like 3rd on a 3-speed. Normally I start out in 2nd while driving around. I like it because it is different, you might not.
Double clutch. Push in clutch, take it out of gear, let clutch out, push clutch in, put into gear.
I believe the a 3sp closed drive will bolt up without any modifications. Not sure though.... sorry.
Double clutch. Push in clutch, take it out of gear, let clutch out, push clutch in, put into gear.
I believe the a 3sp closed drive will bolt up without any modifications. Not sure though.... sorry.
sturgis 39
BANNED
I think you want to adjust the engine speed when the transmission is in neutral. The usual rpm between gears is about 500. You want to adjust the engine rpm to the gear you are shifting to. If you are shifting down you want to increase the rpm by 500. If you are shifting up you want to lower the rpm by 500. You do not need a tach to do this. After you drive the truck for a while you will develop a feel.
COE Dan
Senior Member
I have a 4-spd in my stock COE. It took about 3 weeks of driving regularly to get the hang of it without grinding gears. Part of that was just finding the gears and getting the feel of the stick.
Tinker's post has the right description for double clutching. I don't use 1st either most of the time. Downshifting requires double-clutching but with an engine rev when you put the clutch back in while the trans is in neutral. If you listen to the engine, you can get the feel and downshifting isn't too hard. It's difficult to be quick with a double clutch but it can be done. After a bit, it has become second nature.
One thing to keep in mind is that the 4-spd has straight-cut gears. That makes the trans whine with significant volume at higher engine speeds. If you're looking for quiet operation, a 3-spd will be better - they should have spiral cut gears.
Since the engine is the same in all vehicles, the 3-speed will bolt in. The rear axle gear ratio may still be pretty short (i.e. high ratio, low gearing). Moving to the 3-spd will probably be similar to driving with 2-3-4 in a 4-spd. I don't know the ratios off-hand. The 4-spd may have a wider gear ratios between 2-3-4 than the 3 spd. I'm thinking that both trans' top gears will be 1:1 (3rd gear in the 3-spd; 4th gear in the 4-spd).
Mr Van Pelt who is on this site occasionally knows a thing or two about these transmissions...he would be a source of all the details on the two.
Hope this helps...
Tinker's post has the right description for double clutching. I don't use 1st either most of the time. Downshifting requires double-clutching but with an engine rev when you put the clutch back in while the trans is in neutral. If you listen to the engine, you can get the feel and downshifting isn't too hard. It's difficult to be quick with a double clutch but it can be done. After a bit, it has become second nature.
One thing to keep in mind is that the 4-spd has straight-cut gears. That makes the trans whine with significant volume at higher engine speeds. If you're looking for quiet operation, a 3-spd will be better - they should have spiral cut gears.
Since the engine is the same in all vehicles, the 3-speed will bolt in. The rear axle gear ratio may still be pretty short (i.e. high ratio, low gearing). Moving to the 3-spd will probably be similar to driving with 2-3-4 in a 4-spd. I don't know the ratios off-hand. The 4-spd may have a wider gear ratios between 2-3-4 than the 3 spd. I'm thinking that both trans' top gears will be 1:1 (3rd gear in the 3-spd; 4th gear in the 4-spd).
Mr Van Pelt who is on this site occasionally knows a thing or two about these transmissions...he would be a source of all the details on the two.
Hope this helps...
georgewarren
Senior Member
With time and practice you will be able to almost speed shift up and down by double clutching. Take your time and you won't even need the clutch. I drove a 63 Dodge Dart GT with a non working clutch from Camp Lejune, NC to Norfolk VA without a hitch. Good luck!
I had a '50 F-1 in which I changed out the 3-speed in favor of the "crash-o-matic" non-synchro 4 speed by choice.
It takes a little practice to learn to "double clutch" but once you become "intimate" with your truck, you will have no problem shifting. Shifting into low ("granny") will require coming nearly to a full stop.
You may (or may not) learn to love the characteristic old time "whine" these tansmissions have in all but high gear. LOL
It takes a little practice to learn to "double clutch" but once you become "intimate" with your truck, you will have no problem shifting. Shifting into low ("granny") will require coming nearly to a full stop.
You may (or may not) learn to love the characteristic old time "whine" these tansmissions have in all but high gear. LOL