47 pickup second gear pops out

[oldford2]

I am working on a 47 pickup. 3 speed on the floor. When you let off on the gas it pops out of second gear. What does the repair involve? I once saw one that the owner had a bungy cord from the dash to hold it in gear. Not interested in that "fix"

Also a second question. I would like to bleed the brake system. How do I detemine if it is DOT 3 or silicone
Thanks
John

[51504bat]

Mac Van Pelt will be the guy to answer this but IMHO the trans will need to come out and gone through to fix it properly.

[cadillac512]

Dot 3 will mix with water and look like milky water...silicone won't and will separate when you try to mix them.

[rotorwrench]

There are a number of wear locations that can cause a lot of gear movement when the thrust load reverses during engine braking. Gear bushing might be worn, the 2nd gear and mating cluster gear may have a lot of wear on the teeth. The counter shaft may have loose bearings or the thrust washer is shot. The synchro blocker ring may be worn out too. A person would just have to tear it down & have a look. The shifter detents in the tower should also be checked since they do aid in holding it in gear as long as everything else is good to go.

[oldford2]

Originally Posted by rotorwrench

There are a number of wear locations that can cause a lot of gear movement when the thrust load reverses during engine braking. Gear bushing might be worn, the 2nd gear and mating cluster gear may have a lot of wear on the teeth. The counter shaft may have loose bearings of the thrust washer is shot. The synchro blocker ring may be worn out too. A person would just have to tear it down & have a look. The shifter detents in the tower should also be checked since they do aid in holding it in gear as long as everything else is good to go.

Thanks for the response rotorwrench. Sounds the shifter dedents play a minor role. Can that be done on top or even worth checking?
John

[Floyd]

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The short answer is "it is worn out". Although everything mentioned above contributes to this condition, the main villain is the clearance for second gear has exceeded it .004 to .006 value on the mainshaft. It probably is now .012 or higher. And of course to get to this area the whole thing has to come completely apart. There are no shortcuts. Get MacVP book and have fun. When you do it correctly and completely, you will enjoy your efforts.

[Newc]

This soooo common and yes it is 'worn out'. I suffer with 2 cars that do this and the fix is a really good rebuild. DO NOT race with your old Ford transmissions, those days are past. Good gears are now GOLD. Newc

[Charlie ny]

My fix begins with rebushing 2nd gear and fitting the new bushing to the output shaft.
It does require a nice lathe and a top quality bronze bushing. I go for .0015 clearance and run the rebushed 2nd gear in at 1200 rpm. After that little exercise I do what I have to do to get .006 linear clearance between 2nd gear and it's thrust plates. On the later gear sets there is only the front thrust plate so that makes it just that much more fun. Gotta install new syncros........but be real cautious most available
are off spec....only reliable source is VanPelt or NOS Ford at swap meets....everybody
remember swap meets ?
Charlie ny

[slowforty]

I have a 40 that did that and replaced the transmission with a nice rebuilt one. There was much improvement, But once in awhile it would still jump out of gear. So i asked my friend who did the transmission about it. He said "Do you know what you were doing to make the transmission jump out of gear?" I said "Yes". He said 'WELL DONT DO THAT AGAIN AND IT WONT JUMP OUT OF GEAR." Along with some other choice words and phrases not suitable for general use.

[RalphM]

What’s a swap meet Charlie?
We never had those up here even before the country started falling apart.

[Talkwrench]

Jumps out of second hey ... Sounds normal to me..

[51woodie]

My '46 Coupe does that sometimes. I thought it was just something Henry's Engineers designed into the transmission, so you didn't have to put it into neutral when you pulled up to a stop sign or traffic light. Sorta the beginnings of an automatic transmission?

[tubman]

You could always do what the old stock car racers did. Bend a hook out of 3/8" steel rod and bolt it to the dash. If you position it correctly, there is enough give in the shift lever to put it in the hook after you hit second.

(Note : This will not work with column shift vehicles.)

[Floyd]

Rebuilding a trans that you own and have used has some great advantages. If it works except for the "worn out" part, then the gears are probably good to use again. Broken teeth and rounded off first gear would probably be noticeable to you already. The gears are the expensive part and can reuse them almost all the time. Also the bearings are probably pretty good or you would already know about that with noise. Since bearings are available and not expensive you should replace them anyway. However good used bearings seldom wear out and could be reused in a pinch (not recommended). This leaves the items that must be dealt with and that is the synchros ,the gear bushings , the clearance for second gear, mainshaft and the thrust washers for the cluster gear. These are all checkable and doable. It is math, not magic, measure, measure,measure. My point is you can redo your existing trans yourself (with the help of "the book" and the noted vendors. Redoing your current trans with known problems is way better than picking up one of those swap meet (swap meet defined above)cores for $75. Those cores at the swap meet are there for a reason and you will be replacing everything and many times the case itself. I have seen many where the bolts were the only reusable items. Also when you get it finished and up and running you will be surprised how difficult it is to pull it out of second gear manually with the clutch engaged and some load on the engine. Have fun

[frnkeore]

Whether it's a old Ford or a Muncie, the number one reason that they jump out of direct drive, is the input bearing and that also wears the pocket bearing, inside of the input shaft.