Hard Shift from 1st to 2nd

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zmarty27

zmarty27

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Howdy, gang.

I took the Holley 1945 off for some much needed maintenance, and the thing is running like a champ. Only problem is, my slightly higher idle setting is causing it to shift hard from 1st to 2nd. Its gentle in relation to other "hard shifts," but it is certainly not normal for this occurrence. Is there a relationship between my Carb maintenance and my transmission. Crunching the numbers in my head and the only thing I can think of is lowering my idle setting.

Thanks for the help as always!

PSA: Running a '74 225 with the 1bbl (mentioned). Stock transmission and linkage. Only thing new are the gaskets and choke thermo.
 
zmarty27 said:
Howdy, gang.

I took the Holley 1945 off for some much needed maintenance, and the thing is running like a champ. Only problem is, my slightly higher idle setting is causing it to shift hard from 1st to 2nd. Its gentle in relation to other "hard shifts," but it is certainly not normal for this occurrence. Is there a relationship between my Carb maintenance and my transmission. Crunching the numbers in my head and the only thing I can think of is lowering my idle setting.

Thanks for the help as always!

PSA: Running a '74 225 with the 1bbl (mentioned). Stock transmission and linkage. Only thing new are the gaskets and choke thermo.
Click to expand...
It's all that new found power you've got now!
Actually, it's not your idle setting (you didn't say if you meant idle speed or idle mixture when you say "setting", but I digress)- because you're not at idle when it shifts from first to second. My guess is your kickdown linkage isn't properly adjusted after you removed and replaced the carburetor.
 
Professor Fate said:
It's all that new found power you've got now!
Actually, it's not your idle setting (you didn't say if you meant idle speed or idle mixture when you say "setting", but I digress)- because you're not at idle when it shifts from first to second. My guess is your kickdown linkage isn't properly adjusted after you removed and replaced the carburetor.
Click to expand...
I adjusted both speed and mixture. My apologies. Shade-tree mechanic in training, here. Lol
 
My point is that if it's shifting from first to second, it's under power and off the idle circuit and idle stop- that leaves the kickdown linkage as the only thing that could have changed before and after the R&R. Make sure it got reassembled correctly and adjusted properly.
And for what it's worth, make sure the fluid level in the trans is good- checked warm and in neutral (not Park) while running.
 
I'll add, to make sure the kick down linkage is installed correctly at the carb, and that it can move freely.
 
So far, I think I have everything mounted and in place as it should be. I will, though, check my transmission fluid.
 
There is no adjustment on those at the carburetor end. The pre-74's had a slide at the carb end of the rod and a simple pivot at the trans end, but that changed in 1974 when they went from the Holley 1920 to the 1945. The '74's and later have the adjustment slider at the trans end. So, unless you got under there and fooled with it, nothing should have changed. There is a procedure outlined in the FSM that explains how to properly adjust the throttle rod, and nowhere does it say to "make sure the rod is all the way back".

Have you raised the idle so much that it's taking off in gear without you touching the accelerator? A closed-throttle upshift on a Torqueflite is quite noticeable. Why don't you set the idle back to the factory spec? That is 750 rpm, in neutral, warmed up with the choke off. You can buy used, old-style diagnostic meters from ebay cheap that let you properly read the idle speed. Also keep in mind that trans fluid on a Torqueflite is checked in Neutral with engine warmed up. Pump does not operate in park, you won't get the correct reading. Good luck.
 
return spring rod to tranny still there

IMG_20191110_184215_LIn011.jpg


IMG_20191110_184305no4.jpg
 
I agree with professor fate, regardless of what you did, i'd adjust the throttle pressure (kickdown) linkage. You would want to shorten it to reduce the shift line pressure.
 
if its an automatic... "its the shift kit" if it is a manual "you have to push the clutch in between shifts..." ...:lol:
 
Re-adjust your kickdown.

Or leave the Holley off and bark seconds! Impressive with leaning tower of power!
 
Well, I’m back. After many a trial and error, I am admitting defeat. I’ve searched the forum over and I’ve yet to find a fully informational and properly depicted throttle cable in operating condition (for those of us on the elementary scale of all things mechanical). I understand it’s subjective to the car (or I would assume it is), but is there a thread on here that details what exactly to look for in terms of feel and pressure on the pedal and on the linkage itself? Trying to avoid a mechanic due to the money situation. Thank you all again for helping!
 
The "feel" you're looking for is in the seat of your pants so to speak. There is no factory value for the force to move the kickdown lever, i.e. pounds/sq. in., etc. if I understood you correctly Pm me with your email address, year of your car, and I can send pic of where to adjust the throtle pressure to control the 1-2 shift. It may be that in the end, you won't find an adjustment to suit you. If you don't find the feel your looking for by adjusting external linkage, you'd have to go inside the trans valve body to make adjustments and that is itself very subjective and cost prohibitive.
 
I haven't gotten a break to work on anything. I have, however, research a whole lot about the relationship between throttle and transmission. Stumbled upon this video in case anyone finds it helpful. Enjoy!


Start at 10:40 for /6 material.
 
If your linkage isn’t like the one depicted in the video, here’s an alternative from a ‘74 manual. Looks identical to mine. Here’s the adjustment instructions as well in case you need them. I’ll get to my ride this weekend when it isn’t raining. Until then…

5EBDF113-2A74-4029-8BA2-01E20F922B5D.jpeg


007F7BBC-DDE2-41D6-B02A-5E6D2947234B.jpeg
 
UPDATE: Adjustment to the shift lever was made yesterday. For the record, I wasn't expecting much out of deleting the slack from the spring, but let me tell you: the difference was extraordinary. I might do it every six months just to keep things in line. Definitely worth the time (took a total of five minutes and a little elbow grease).
 
Follow what zmarty said in post 16. That is correct for a 74. I just did this and followed the Factory Service Manuel
 
zmarty27 said:
UPDATE: Adjustment to the shift lever was made yesterday. For the record, I wasn't expecting much out of deleting the slack from the spring, but let me tell you: the difference was extraordinary. I might do it every six months just to keep things in line. Definitely worth the time (took a total of five minutes and a little elbow grease).
Click to expand...
If you held it all the back as I mentioned earlier, the spring should be compressed one would think. You must have just held it against the spring before or something. Either way I'm happy you got it figured out.
I was about to start with turning g the line pressure down a hair and ask what shift kit ,if any ,was in it.
 
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