VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 May have fixed two problems with one part

It was mid 50's here today, so I decided to take the 48 for a spin. This is the first time I've had her out since I put a new fuel pump in. I did about a 20 mile run with some interstate and some city driving. The new pump fixed the surging problem I had at interstate speed. I ran 60 - 65 for about 10 miles, and, all was good. Then It dawned on me when I got off the interstate - the car hadn't jumped out of 3rd gear at speed - not once. In the past, she's typically jumped herself out of 3rd a couple of times on a run like this. I'm keeping my fingers crossed on this one.

Regards:
Oldengineer

Happy to hear that. are you run a 216 with the original running gear?

Perhaps the stress on the driveline, from the bucking / surging was enough to pop tranny out of gear.

If it ain't broke, don't fix it.

Mario:
Yes, I'm running her original 216 and drivetrain. The only mod I've made is I did away with the vacuum shifter using a conversion kit. She's had a 3rd gear jumping problem since I bought her 3 years ago. I've replaced the side engine and transmission mounts, worked on getting the slop out of the shifter linkage, adjusted all the shift linkage, and changed the tranny lube to 85-140. The problem has gotten much better, but, never gone away completely. The engine is performing much better now, than, when I bought the car. I had to do some work on her valve gear, tune the engine, and replace the carb. After I put the new carb on her this Summer, she had a nasty surge at high speed - fuel pump just wasn't delivering enough gas. I installed a new fuel pump last week, and, today was my first chance to try her out.

Regards:
Oldengineer

Bob:

I'm inclined to agree with you. She was surging pretty good with the old pump at about 55 and up. With the way the linkage is set up on these cars, the engine bucking does move things around a bit.

Regards:
Oldengineer

OE,

I have given your car's slipping out of drive some thought. I just don't see how the fuel pump could have caused this problem or be the cure for it.

I'm saying that if the problem is in the transmission then the fuel pump is not going to fix it.

On the other hand, if the problem manifests itself owing to some external problem then enjoy the fix, whatever it was. Seems a twenty mile drive would have resulted in it slipping out of gear, if it had been doing it for some time.

The only time I had this problem was on the project 41 cabriolet back in 75 and it got worse and worse until I couldn't hold it in gear. That was in western PA on the way to Dunkirk up near Erie. Had to pull the transmission.

Good luck with it and keep your fingers crossed.

Charlie

The most prevalent problem with slipping out of third gear is wear or misalignment of the third gear and the input shaft where the gear meshes. If there is any taper between them the chucking back and forth (between power and no power to the gears) will work them apart. I have seen it numerous times. The only real fix is replace one or both parts. If the taper is not too bad and you pay attention to the position of the shift lever it might not get worse quickly. I have lived with the problem in my '28 Canopy Express by resting my leg on the shift lever to hold it in position particularly when going up or down a hill as that seems to be the time that inconsistent power is applied to the transmission input shaft.

O.E.,

If it were a tranny problem, gears and such, I would think the tranny would continue to hop out of gear, no matter what.

Being that the "hopping out of gear" stopped on this 20 mile trip, indicates to me, something other than the tranny has caused the tranny to now behave.

Charlie:
When I bought the car, the PO told me that the tranny had been rebuilt. Now, I'm not sure how good the rebuild job was. Looks to me like somebody used a lot of RTV on the ball on the tail end of the tranny. Anyway, it seems to me if the engine was flopping a bit around side to side under load as it cut in and out, that's got to move the shift levers some too. I know, when it was surging the way it was, the end of my gear shift lever would jump up and down about half an inch in 3rd gear. It stopped doing that on my trial run. The car used to do it really bad, the two mounts that go from the bellhousing to the chassis were completely missing when I got the car. The rear tranny mount was completely rotten. In its place is the new one you fixed me up with. That stopped a lot of the gear jumping, and, with all the mounts now in place, the car is a lot easier to get going from a dead stop. She used to hop like a frog unless I was really careful with the gas and clutch when I first got her.

Regards:
Oldengineer