727 band adjustment

thethee

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Quick question, my car is a '75 Imperial and the trans is a '66 727, do I just adjust to the specs in my '75 FSM or should I look for the '66 specs? Or would those just be the same..? My FSM says 2.5 turns for kickdown band and 2 turns for low-reverse band.
 
Speculation on my part, but I'd go with 66 specs. That trans doesn't know it's in a 75. :D

This is from my 70 FSM. With the TNT engine, the TFlite was specified as the "D32 Heavy Duty" box. That D32 might be the difference in kickdown backoff turns (2 TNT vs. 2.5 for your 1975 spec).
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what is the problem you are trying to fix? If it works fine then don’t mess with it. It won’t work any better.
1966 had a rigid band, 1976 had a floppy band from the factory. Who knows what it has now.
 
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what ismthe problem you,are trying to fix? If it works fine then don’t mess with it. It won’t work any better.
1966 had a rigid band, 1976 had a floppy band from the factory. Who knows what it has now.
Have the pan dropped to swap the rooster comb and it was suggested to me now would be a good time to also readjust the bands, just routine maintenance.
 
Speculation on my part, but I'd go with 66 specs. That trans doesn't know it's in a 75. :D

This is from my 70 FSM. With the TNT engine, the TFlite was specified as the "D32 Heavy Duty" box. That D32 might be the difference in kickdown backoff turns (2 TNT vs. 2.5 for your 1975 spec).
View attachment 486795
View attachment 486796
I'm going from memory here, but concerning the kickdown band adjustment, the applying levers have different ratios. 2.9, 3.8 and 5.0. The 5.0 was used in the Hemi cars (again IIRC) and maybe some other applications. It was the "hot setup" to use a 5.0 lever, but I think the 3.8 is now the weapon of choice. Most likely the 3.8 is a compromise in how fast it works v. how much force. But I'm no trans expert, although Jenner still looks like a dude to me, so there's that.
 
I'm going from memory here, but concerning the kickdown band adjustment, the applying levers have different ratios. 2.9, 3.8 and 5.0. The 5.0 was used in the Hemi cars (again IIRC) and maybe some other applications. It was the "hot setup" to use a 5.0 lever, but I think the 3.8 is now the weapon of choice. Most likely the 3.8 is a compromise in how fast it works v. how much force. But I'm no trans expert, although Jenner still looks like a dude to me, so there's that.

As I (barely) recall, when you got a quick-shift valve body or a full Jenner rebuild kit, there was a different lever or two in the kit. So yeah, levers. THAT would account for the backoff turn spec.
 
This is a good time to leave it alone then.

There is a 4.2 lever also. Don’t use the 5.0 lever if you don’t have a hemi trans internals, it will be disaster on the 2-3 shift. Yes it was the thing to do, but most people learned, and some the hard way. “Why did my car slow down”
 
This is a good time to leave it alone then.

There is a 4.2 lever also. Don’t use the 5.0 lever if you don’t have a hemi trans internals, it will be disaster on the 2-3 shift. Yes it was the thing to do, but most people learned, and some the hard way. “Why did my car slow down”
I agree about leaving it alone. That's usually my plan too. When you screw with things, they can come back to haunt you.

I do remember when I built the trans for my A12 back around 1982, I used a 5.0 lever (as that is what you did then) and I put 70K "drive it like you stole it" miles on it... and the present owner still has the same trans in the car, so I must have done something right. But yea, from what I've seen, the 5.0 lever isn't the way to go now.

The biggest issue back then was trying to get rid of the 2-3 overlap. A hard 2-3 meant too much overlap, which slowed you down. I would think the 3.8 lever probably helps get rid of some of that by applying the band faster. But again, I haven't done any of that work in many years. IIRC, Paul Forte was working with Chrysler on that overlap issue and they claimed 1-2 tenths were there in solving it.
 
This is a good time to leave it alone then.
I agree about leaving it alone. That's usually my plan too. When you screw with things, they can come back to haunt you.

In that case I will just leave the bands alone. Trans was working fine so yeah "if it ain't broke don't fix it". Apart from the part throttle downshift upgrade though.
 
Well, with a little finesse and attention to how the car reacts, I learned to do a manual 3-2 downshift on our '66 Newport 383 2bbl. All at part-thorttle for on-ramp/merging acceleration. Which also meant that WOT was not needed and after a little bit of practice, it was not noticeable, except to me. Then the 2-3 manual upshift once cruising speed was approximated. No disassembly required. Easier on the equipment, too!

It worked for me,
CBODY67
 
Mine was open and off the car already so seemed like as good a time as any for it. Currently waiting on the parts, got a kit from Pat Blais.
 
I'm going from memory here, but concerning the kickdown band adjustment, the applying levers have different ratios. 2.9, 3.8 and 5.0. The 5.0 was used in the Hemi cars (again IIRC) and maybe some other applications. It was the "hot setup" to use a 5.0 lever, but I think the 3.8 is now the weapon of choice. Most likely the 3.8 is a compromise in how fast it works v. how much force. But I'm no trans expert, although Jenner still looks like a dude to me, so there's that.

This has me thinking a couple of things, for one, Is this the way Chrysler smoothed out shifting on the luxo cars? Similarly I have read that G.M. did this with Vacuum modulators, where the caddys and cars like my then 73 Toronado had a soft shift.

As it pertains to Chrysler, specifically mine, a 69 300 with bastardized linkage for a phenolic spacer.
The 1-2 shift is miserable with an rpm spike and slippage simulating an extra neutral. This trans has only a couple 1000 miles at most but I had the same issue before the rebuild. It seems like extending the rod gave improved results for a while but it really requires a little throttle to shift correctly. I'm wondering if a band adjustment would be in order. Or maybe a lever ratio change? I'm also swapping to a 3:23 as soon as I get off my but which I was hoping would have a side effect of curing this symptom. Until then I'm just driving if as I was 17. In which case it shifts perfect.
 
Extending the rod might raise line pressures a small bit, but the main issue, to me, is that they shifted too early in normal driving, which put any accel "on the converter", which would be softer and slower than if the kickdown rod has more pre-load on it. It also makes the vehicles feel "like dogs" with similar horsepower ratings of similar GM vehicles, by observation. I'm not sure of the original orientation for doing this by Chrysler, BUT in the later years of emissions rules, with emissions measured by "Grams/mile" rather than "PPM" (as originally done), the lower the rpms the lower the emissions from the tail pipe, it would seem. I have not looked, but suspect that adjustments on a C-body would be the same as a B-body vehicle with the same rear axle ratio.

In the middle 1980s, we traided for a current model year D-150 fancy Dodge pickup. Had the normal 318 4bbl V-8 and 3.21 rear axle ratio. Very similar to the same year Chevy 305 4bbl I was driving at work. So, being inquisitive, I asked the Used Car Manager for the keys to the Dodge and went out for a short drive. Right off the bat, it was doggy. If a new vehicle customer was comparing the two, the Dodge would be somewhat under-powered feeling, compared to the Chevy (with a comparable rear axle ratio). Then I tried shifting the trans manually and things changed! Getting it to a higher road speed in Low, then a bit higher than the factory shift point in "2", it felt much better and energetic. Just like I'd found in my own cars, years earlier. Same on a used Ramcharger a friend bought a few years later, too. Therefore, I suspected the early upshift orientation was something burried deep in Chrysler engineering rather than really what made the vehicles feel/drive better. Which might also related to their late-adoption of part-throttle downshifts, too?
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In earlier times, it was the mark of a luxury car that once you got the manual trans out of low gear, you could shift directly into "high gear" and drive the car all over town without shifting, except for stop signs and red lights. This was "luxury". Not unlike the 1970 and prior TFs which went into high gear and didn't come out until road speed dropped enough for a downshift or WOT happened. In the mean time, possibly millions of potential buyers came to drive "the new, hot-performing Chrysler products" and were disappointed in how they ran? Just knowing that the similar Ford or GM products "ran better". Not paying attention to the fact that the Chryslers usually had sharper throttle response due to the design of the TF torque converter. All these potential customers paid attention to was what happened, and kept happening, when they punched the throttle, by observation. Early upshifts didn't help the vehicles parform as they could.

In a lighter B-body, with possibly a different trans governor, things worked pretty well. So . . . . take the time to shave the trans governor weights (2bbl and 4bbl governors were different, as I recall, usually, especially on the 4bbl HP models) or put a bit more preload on the kickdown rod (like 2 more turns preload on the threaded rod or the .10" wide wire tie on the rest, at the bottom back of the slot in the rod) as I did.

The quicker/firmer shifts of the TF has always been liked and felt/heard, but when they happen too soon, the result is really noticed more than on a Ford or GM trans.

Just my observations,
CBODY67
 
Interesting. So if I understand correctly, by attaching a small ziptie at the back of slot on the kickdown rod you were able to move the shift points to a higher rpm to make the overall feel of the car better? Is there any downside to this?
 
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