Hard shift to 2nd and 3rd

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J

jhdeval

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Let me start off with my level of knowledge in transmissions is nil. With that I have an issue and I am trying to figure out how and what I may need to do.

I have a 1965 Barracuda automatic. I believe it is a 904 torqueflite I could be wrong. When driving the car the shift from first to second is hard. I call it clunking. You can physically hear and feel it engage. I get the same thing into third. I called a local transmission shop and he suggested a vacuum modulator. I checked into that and it appears Chrysler did not use a vacuum but a mechanical kickdown.

Some background on what I have done and seen. First I changed the trans fluid and gasket. That did not help. While I was under there I noticed a box with what I believe to be one of the shift cables towards the "back", drive shaft side, of the transmission cover that had some silicon on it. It is near where the speedo cable goes.

So can anyone suggest what I can do or should I just have it adjusted by a professional? If a professional what kinda of cost might I expect.
 
sounds like someone has removed the accumulator spring,(this is a common trick for performance) or the accumulator piston is stuck. remove the valve body, check for missing spring 1-1/2"X 2-1/2".
Al
 
Does that mean I have nothing to worry about or should I make sure I get it back in there? I have noticed that once I hit third she rolls like a rocket. Smooth and plenty of power left to accelerate.
 
First off, stay far, far away from a transmission shop that thinks torqueflite transmissions have vacuum modulators, but do nothing only if you like replacing U joints all the time, because if it's shifting that hard, especially at part throttle, you'll begin to think of driveline maintenance as a weekly thing.

Space off the u joints you've eaten with an out of adjustment transmission long enough it sounds like birds chirping when you accellerate, and if you're lucky the rear one will grenade first causing you to replace not only the U joint, but possibly the rear yoke and probable bent and mangled driveshaft itself.

If you're lucky enough to have the front one go first, you'll get to experience the famous Pogo stick effect.
 
Sounds like someone has installed a shift improver kit in it. If you look at the linkage that hooks to the carb and runs down to the transmission you'll see an adjustable rod and socket where it connects at the carb. Shorten the linkage by screwing in the socket/rod assy. together and that'll lower the throttle pressure which in turn will soften the shift. Adjust it 1/2~1 turn at a time and test drive it each time until you get it where you like it. You'll notice that adjusting the throttle pressure rod shorter will also cause the shift points to be lowered and if you go too far you'll loose passing gear so you may just have to try and achieve a happy medium.

BTW: there is only 1 shift cable. It's the front one. The rear cable is the parking cable.
 
Thank you much fishy68 I will definetly give that a try and a hell of a lot cheaper than paying someone. I am finding a lot of "knowledable" mechanics screwing me.

I have one question and this is going to sound stupid but how will I know if I have lost my passing gear? What will it feel like?
 
Be very careful on just how much you lower that throttle pressure.
Too high will cause later and hard shifts.
Too low will cause low and soft to mushy shifts which will inturn cause a slip.
It's very easy to burn a transmission out with low throttle pressure,find that happy medium where you can still feel them yet they are comfortable shifts.
First shift point should be around the 15mph range and the second around 25mph with a correct throttle setting.
 
It might be easier and less frustration to just replace the valve body.
The shifts you are describing indicate that a stage 2 shift kit was installed and that means springs have been changed and the sepatator plate in the valve body has been drilled out.
If you just adjust the linkage after this has been done, you will never get it to work right.
A linkage adjustment will NEVER make it bang into gear unless fluid ports have been drilled.
Trust me on this one, as I have trans certifications up the you know what.
On my 904 I took the accumulator spring out and threw it away.
Drilled the 2nd gear band apply hole in the separator plate to 1/8 inch and adjusted my main line pressure to as high as it would go.
It now shifts nice and firm with a little tire chirp from first to second if I am on the gas more than the usual driving, and second to third is nice and quick but not hard.

Remember this,
The trans will NEVER bang into the next gear without drilled out oil flow ports or check balls removed to let the fluid travel to the clutches and bands faster and with more volume.

For second gear there is a chk ball that shift kits tell you to remove if you want a good hard shift, and some even instruct you to drill out one of the fluid track walls to get even more oil to the second gear band.
The point is that if your valve body has been modded, then you will never be able to adjust that out of it.
I think I have a pic of the ball they tell you to remove, so maybe you can at least tell by that if yours has been modded.

Here's a link to it with pics.
http://www.cuda-challenger.com/cc/index.php?topic=33093.0

If you see any of these mods in your valve body then it's been modded.
Especially note where the yellow ball is that they tell you to take out.
That is the second gear oil passage, and taking that ball out will make the trans bang into second.
 
I'm not going to get into a contest of "I know more than you do because I have papers that say I do" because it's childish but as I stated earlier it sounds like it has a shift improver kit installed, but even if a kit is installed, if the throttle pressure linkage is backed off just enough to lower the throttle pressure just enough to soften the shift (and I know from experience it can be done) but not so much as to lower it to where the shift is mushy or causes flare-up and goes right into 2nd and 3rd at under 15 mph at light throttle it'll be fine. Will it shift like a stock transmission? No... But if you don't mind a firm shift (but not teeth jarring) most likely all you have to do is carefully tweak the throttle pressure linkage a little at a time until it's where you want it. Generally all you have to back it off is 1 or 2 turns. I don't know where some guys get that once you install a shift improver kit it disables the throttle pressure adjustment (which affects shift firmness) but some seem to think it does.

BTW: Passing gear is when you put the pedal to the floor and it kicks down to 2nd gear (or 1st gear if your going slow enough) to give you quicker acceleration. The throttle pressure rod controls a valve in the valve body that works in conjunction with the governor and the more throttle pressure you give it the higher the shift points are and if you back it off too much the governor overrides the throttle pressure and won't let it drop back down a gear when you floor it.

The throttle pressure also directly affects the pressure to the clutch packs and front servo. By doing that the shift firmness can be altered. If a pressure regulator gauge is installed into the main line pressure port on the trans. (the one located between the servos) and you run the engine in drive and move the throttle pressure lever back and forth you can see the main pressure raise or lower. This is what affects shift firmness, and timing.
 
Take the valve body out, clean it and see what was done to it. Some things can be reversed to soften the shifts up.
 
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