727 doesn't shift into second gear like it should

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duster360 said:
To be honest with you I forgot to look. The transmission is a '70 model. And it is still behind the 340 it came from the factory with. If that might help with a guess at the ratio. I had 2 1/2 turns stuck in my head and that is what I ended up doing. I could probably go back and tighten up the front band a 1/4 turn if the ratio calls for it but I don't think it would make a difference as far as the 1-2 shift. Next time I take the pan off I will be a little more aware of what I am doing and check the ratio to be sure I have the exact adjustment. But even going from the 1 turn out to the 2 1/2 turns out still made no difference.
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1970 727's that came behind 340's generally had the 4.2 kd lever so your close on the adjustment. It should actually have been backed off 2-1/4 turns rather than 2-1/2 but if anything having it backed off more should have helped the situation if I'm understanding you right and it's shift overlap. There is one other thing that causes 1-2 shift overlap and it's the cushion spring inside the rear servo. When you manually shift it the rear servo basically has 2 springs that need to come off before it's fully released. With a shift kit installed 2nd gear hits so fast the rear servo doesn't have time to fully release before the front band is applied. There is a fairly simple mod to do to overcome it which involed removing the inner spring and shimming it solid. It's main function is to make the 1-2 shift softer to please the older generation that doesn't like a harsh shift so eliminating it for performance is not big deal. But here's the catch. All 1971 and earlier HP 727's I've been into had a spacer where that spring is so basically the mod was done from the factory. But who's to say the rear servo wasn't switched out with a standard servo sometime in it's 42 year life. The only way to know for sure is drop the pan and check so see if it has a spring or shim in the servo. You might want to ask your rebuilder if he did any mods (drilled anything, added any check balls he thought might have been missing, etc...) or swapped the rear servo while rebuilding it since you said the 1-2 shift was fine before.
 
.................340 trannys have a 3.2 ratio arm.......2 1/4 turns is right 4 it, 2 1/2 wont hurt anything......there are 4 ways to help/cure ur 1-2 shift problem........vb change.......as u dont know what is done in there....back off low band to 3 turns.....pull out the rear servo and shim it or replace it with mr. randys rear billet servo....pull out front servo and make sure there is both the big and little springs in it.......if the spring is out of the accumulator put 1 in under the acc, not between the vb and case.....kim.....
 
If I dropped the pan could I just push on the servo to see if it feels springy or solid. Or would the spring be too stiff to push in?
 
Best I remember there is no spring in the front servo. It will slide up and down in the hole. But it was ran like this before the rebuild. I have a couple spare 727's so parts are no problem. Just have to make sure what will and won't interchange because the other 2 are later models.
 
duster360 said:
If I dropped the pan could I just push on the servo to see if it feels springy or solid. Or would the spring be too stiff to push in?
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It's too stiff to tell.

duster360 said:
Best I remember there is no spring in the front servo. It will slide up and down in the hole. But it was ran like this before the rebuild. I have a couple spare 727's so parts are no problem. Just have to make sure what will and won't interchange because the other 2 are later models.
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No spring at all? Just slides up and down in the hole? That's a major problem. It needs something in there if for no other reason to make it release all the way so the front band doesn't drag. I use 2 springs to make sure it doesn't apply too fast and releases quicker.
 
I have to work on my truck tomorrow but maybe saturday I can drop the valvebody and check the servos and open the valvebody up and see if maybe he put a checkball in the wrong place. I will get B&M to send me the instructions again ( I deleted them somehow ) and go over the valvebody real good.
 
.............Ask ur rebuilder if he did any modifications, or corrected anything he thought was suspect........something had to of happended while it was apart...he may have a couple of springs in the vb mixed up.............kim.......
 
oldkimmer said:
.............Ask ur rebuilder id he did any modifications, or corrected anything he thought was suspect........something had to of happended while it was apart...he may have a couple of springs in the vb mixed up.............kim.......
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That could be very well be possible. I would like to fix this on my own if possible. I have decided that I will be building my own trannys from now on. I now have a DVD, books and of course you FABO members. I have some knowledge of them but not really the diagnosis stuff. But thanks to you fellas I am now learning. So don't give up on me. Any ideas you fellas can come up with I can look in my book and get an image of what you are describing and go to work.
 
fishy68 said:
It's too stiff to tell.



No spring at all? Just slides up and down in the hole? That's a major problem. It needs something in there if for no other reason to make it release all the way so the front band doesn't drag. I use 2 springs to make sure it doesn't apply too fast and releases quicker.
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Sorry fishy68, I got confused, I was thinking about the accumulator.
 
If its a performance trans with the shift kit. While your in there block the accumilator. Thats what Fishy68 had me do and ive researched it seems like a common mod with these. Need a peice of metal round can be hollow. 2 7/5- 2 15/16 long about 1/2 inch in diameter.
 
Ok, I drove the car again tonight. Tried the first to second gear shift again several times to just to make sure I am feeling everything right. It is not as bad to bog manually shifting to second gear as it was before the band adjustment. My son doesn't know much about cars but he even said something before I did. Before the car would just almost feel like I was pushing the brake pedal and now it has some drag but not to where the car will fall on its nose so to speak. I can wind it up close to 4 grand and shift with some hesitation but not bad.
Going to throw this short story in also.
My oldest son ( 17 ) was with me when we pulled onto a side street to do another test. He was grinning ear to ear when I hit the gas and that little 340 had both back tires ( 245-60's ) spinning and the car floating sideways as the shift light came on at 6 grand. I don't think he or I will ever forget that moment.
But when I hit second I really didn't feel the hesitation and I let off the gas.
 
72ScampTramp said:
If its a performance trans with the shift kit. While your in there block the accumilator. Thats what Fishy68 had me do and ive researched it seems like a common mod with these. Need a peice of metal round can be hollow. 2 7/5- 2 15/16 long about 1/2 inch in diameter.
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I will definitly keep that in mind when I go back in the trans. Which may be tomorrow.
 
green1 said:
John Cope sells an excellent book for $20.
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Just looked at the Cope racing website and the 727 handbook he has on sale for $15 is the one I have. It is a very good book. The other book that refers to 904 and 727 I dont have.
 
If I were you I would take it out or take it to the builder and let him do the work. You paid for the work and you should have a good working trans.
 
72ScampTramp said:
If I were you I would take it out or take it to the builder and let him do the work. You paid for the work and you should have a good working trans.
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Yep, my trans sequels the tires on the 1--2 shift. sequels them loud shifting at 6,500. You take off nicely and then around 45 mph light the tires up in 2nd by banging it in to 2nd gear :D
 
Well, the fact that he didn't even adjust the front band even close to where it should be was enough for me. He supposedly is a good trans guy. He even builds late model stuff. I want to learn this stuff and what better way than to dig in this thing myself. Then I won't have anyone to blame but myself.
 
duster360 said:
Well, the fact that he didn't even adjust the front band even close to where it should be was enough for me. He supposedly is a good trans guy. He even builds late model stuff. I want to learn this stuff and what better way than to dig in this thing myself. Then I won't have anyone to blame but myself.
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just cause he knows this late model stuff good doesn't mean he knows the old 60's tricks of the trade.
 
You also have an unknown vb. It affects the bands, servos, etc. One ball wrong place, or wrong size....

I would buy a new kit for vb, start over, to eliminate that unknown .

Buddy just had one done by Turbo A, Paul said the front was 2 turns, to wear in; check it for 2 1/2 after 500 miles. And I seem to remember that it was a 4... . strut

Lay on your back, get tf in your eyes, juke that parking rod out; not so bad as to have to pull the trans.
 
green1 said:
You also have an unknown vb. It affects the bands, servos, etc. One ball wrong place, or wrong size....

I would buy a new kit for vb, start over, to eliminate that unknown .

Buddy just had one done by Turbo A, Paul said the front was 2 turns, to wear in; check it for 2 1/2 after 500 miles. And I seem to remember that it was a 4... . strut

Lay on your back, get tf in your eyes, juke that parking rod out; not so bad as to have to pull the trans.
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Thats the plan. I had B&M email me the instructions to the kit that I installed in this valvebody 20 years ago. I will be pulling it tomorrow and going through it. It is was their basic kit with no major mods.
I still remember buying the kit at the local parts store for $15 right off the shelf. Now I would have to order it and it is $30.
I figure between these instructions and my 727 handbook it will be no problem. I am also going to check on the accumulator mod trampscamp mentioned.
 
duster360 said:
Sorry fishy68, I got confused, I was thinking about the accumulator.
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no problem. If there is no spring at all in the accumulator you need to make a blocker rod like scamptramp said because with nothing to hold the accumulator piston stationary it'll slam back and forth and eventually break.

duster360 said:
Ok, I drove the car again tonight. Tried the first to second gear shift again several times to just to make sure I am feeling everything right. It is not as bad to bog manually shifting to second gear as it was before the band adjustment. My son doesn't know much about cars but he even said something before I did. Before the car would just almost feel like I was pushing the brake pedal and now it has some drag but not to where the car will fall on its nose so to speak. I can wind it up close to 4 grand and shift with some hesitation but not bad.
Going to throw this short story in also.
My oldest son ( 17 ) was with me when we pulled onto a side street to do another test. He was grinning ear to ear when I hit the gas and that little 340 had both back tires ( 245-60's ) spinning and the car floating sideways as the shift light came on at 6 grand. I don't think he or I will ever forget that moment.
But when I hit second I really didn't feel the hesitation and I let off the gas.
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That's great you made progress but any, and I mean any overlap is very bad on a trans. The first time I ran into a trans. with an overlap problem was about 20 yrs. ago and it was due in part to a shift kit that wasn't designed properly. It was in a truck I used for work and I had to drive it for a couple months before I could find time to pull the valve body back out and fix the problem. I only put about 3000 miles on it and even in that little time it had quite a bit of friction material in the pan. Overlap is a trans. killer.

BTW: is this the same B&M shift kit you've had in it all along? Nevermind. I was typing when you posted that it is the same kit.
 
Acc modification good, I have never had a tranny shift as good as Turbo A; I may be local to them, but love it.
 
no problem. If there is no spring at all in the accumulator you need to make a blocker rod like scamptramp said because with nothing to hold the accumulator piston stationary it'll slam back and forth and eventually break.



I was reading over the instructions tonight for a refresher before I go back into it. The instructions say to take out the accumulator spring and thats it. No mention to block it with a rod or anything. Guess that is why I just took the spring out 20 years ago. I will make up a rod to put back in it. Scamptramp mentioned the rod length, but what about the diameter, maybe something around 3/8"?
 
green1 said:
Acc modification good, I have never had a tranny shift as good as Turbo A; I may be local to them, but love it.
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A turbo action kit (badged under Mopar Perf.) is the one that caused the bad overlap problem on my truck. But their tech support was real good and helped me figure it out.
 
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