VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Cranky Shift linkage - 48 Fleetmaster

My Fleetmaster won't go in 2 or 3rd gear with any consistency. It looks to me like the tang on the lower lever mechanism is supposed to stay in the slot on the upper lever mechanism - and - currently its not. I'm assuming if I re-adjust the levers so that the tang stays in the slot on the upper lever at both ends of its travel - it should solve my problem. I'm getting 1st and reverse a lot when I try to hit 2nd and 3rd. I looked at the old shop manuals on line and they're not real clear on how the two levers work together. Please clarify for me.

Regards:
Oldengineer

I have a 41 and have played with the adjustments on my 3 speed, but am not an expert. First, do you have vacuum assist on your car? Second, do you have a copy of the Chevy of the 40s parts catalog? It has great diagrams that help identify the names of parts. So calling a part a "tang" is not helpful. The parts catalog I mentioned is free to customers and annually gives current parts costs and lots of diagrams. How long have you had the car? Have you tried to adjust the linkage on the transmission? Have you purchased a manual for your car so you can easily follow the discussion on transmission repairs? Sometimes, the online manuals are confusing to use and follow? Are you familiar with driving a manual shift car of this age? Have you tried using different shifting techniques? I count to 10 after I push the clutch in before I shift to second from first gear. If I didn't sometimes my transmission grinds going into second gear. Please answer the above questions and I'm sure I and others will be glad to help. Good luck, Mike

Mike: I've had my 48 since last Summer. The shifter mechanism drove me crazy - about half the time it won't go in 2 or 3. I just took off the vacuum shifter mechanism - it was shot. I replaced it with one of the conversion kits, and, it still doesn't work correctly. I keep getting reverse in the 2nd position, and, 1st in the 3rd gear position. Yes, I'm quite adept at driving a car of this age - I used to have a 37 Dodge Coupe, and, have driven stick shift cars and trucks for close to 50 years. I have a shop manual for the car, but, it doesn't show how the 2 shift arms are supposed to interact. It looks to me like the tang that moves the lower shift rod is supposed to stay in the slot on the upper shifter mechanism and travel back and forth with it so that the tranny will hit the proper gear.

Regards:
Oldengineer

Hi, Still try to get a Chevy of the 40's catalog. Great picture of transmission linkage in it. I will take a picture of my linkage today and post it as well as post the diagrams in the parts catalog. I also do not have any vacuum assisted device on my car so hopefully we have the same set up. What I would recommend now is that you do not make any adjustments to your linkage from where things are connected on the steering column by the fire wall. Make all adjustments at the transmission by undoing the carter pins and rotating the linkage rods. If you do this before I post pictures then keep real close track of how many revolutions you change things!!! If things are working correctly I think you should be able to shift the car into all gears without the car being started? It may not shift as easily as if it were being driven but it should shift.

Before you removed the old vaccuum assist were you having the problem with the shifter not going into 2nd and third, but rather only wanting to go into 1st and reverse? Maybe your linkage on the steering column is the problem. Which is another story and we can discuss his latter? Good luck, Mike

Just another thought, What does it feel like when you disconnect both linkage rods at the transmission and then try to shift into all gears? Is the shift pattern a smooth distinct "H" with the feeling that 2nd and reverse are not in the same plain but rather well spaced a part, and the same with 1st and third? Mike

The picture of the whole steering column is not exactly what a 48 transmission looks like but very close My 41 manual under "Steering column assembly" talks about the proper linkage spacing on the steering mast. Which I think is a key starting place. If the linkage is not on the right place on the steering mast then all adjustments are not going to be standard. The manual then talks about adjusting the "shift control rod which is the linkage with the smallest shift rod. They call the adjustment finding the "neutral valve position."

Earlier I said to make all the rod adjustments from under the car because it is just too hard to work on the linkage on the steering mast because of the confined area it is in. I'm off to do physical theraphy so will be back later Mike

You took off the vacuum assist because it was "shot"..

What was shot and what "conversion kit" did you install?

Sounds like you have a mix of parts that may not be compatible with your car, as intended.

Mike:

Your information confirms my suspicion. My shift mechanism is out of adjustment because the tang that operates the smaller shift arm is not staying in the slot where it belongs. I'll adjust everything per the shop manual, and, that should cure my problem. Re: Your first picture - my mechanism looks slightly different - the actuating mechanism for the small shift rod on mine has a flat metal tang that fits in the slot instead of the round rod that yours has. Many thanks - you fixed me up with exactly what I needed.

Regards:
Oldengineer

Re: The vacuum cylinder - full of dirt (hose to filter had rotted off for who know's how long), Boot missing, seals gone - leaking vacuum around ram, screws missing. I just got the car last Summer, and, fought this thing missing/ refusing to shift, and jumping out of 3rd since then.

The conversion kit - scored a NOS kit off EBay that fit perfect & dimensions match those posted by others on forums. Original box indicated it was the conversion kit for 1941 - 48 Chevrolet. Rest of linkage appears to be original and matches pictures in parts books for my car. Having checked the shop manual, and, gotten some pictures of a correctly assembled setup, Mine apparently was taken apart by someone who didn't know how it was supposed to be put back together. I know now what needs to be adjusted, and, I'll have a crack at it this coming weekend.

Regards:
Oldengineer