How often to adjust bands?

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gumper

gumper

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I'm ashamed of this, but it's mostly because I didn't know. I've run my 727 for about 7 full race seasons and have never adjusted the bands. It's a mild auto shift street/strip build without a transbrake. Still seems to shift fine, but I'm sure it's way overdo for an adjustment. How often do you racers do this? I'm mad because I just had the pan off a few months ago for a fluid and filter change. What adjustment do you race car guys go with on the two bands? I know the factory specs are 72 in/lbs then back 2-2.5 turns, but some guys say that's too loose. I know it's going to be a nasty mother to get around the header for the outer adjuster. Any chance they're still OK and I don't have to touch them and still sleep at night??
 
Once before the season is sufficient.
 
If you have a blocked accumulator piston you can go quite a bit tighter that that.
Double wrap rear bands use a different spec than single wrap.

That give you something to do and think about instead of counting sheep? :D
 
...........904s use the double wrap rear band..........Depending on ur shift kit and clearances to start with will dictate ur front band adj..........I wouldn't go less than 2 turns out after the 72 in lb tork...........kim.......
 
I'm assuming it's standard 727 bands. How about the method of snugging the adjusters, then trying to turn the driveshaft until it starts to spin, then back out 1/2 a turn? I'm not sure I can even come close to getting a wrench into the outside adjuster let alone a torque wrench. Which one is low gear and which is 2-3?
 
gumper said:
I'm assuming it's standard 727 bands. How about the method of snugging the adjusters, then trying to turn the driveshaft until it starts to spin, then back out 1/2 a turn? I'm not sure I can even come close to getting a wrench into the outside adjuster let alone a torque wrench. Which one is low gear and which is 2-3?
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That method works fine for the rear band but I doubt it'll work on the front band because without the car running there is no oil to hydraulically engage the clutch packs to get an accurate feel on the front drum. I do something similar for the front band that works. Snug down the adjuster then with one hand start backing off the adjuster and using the other hand try to turn the front drum. When you get the adjuster backed off enough to allow you to turn the front drum without any drag your there. When you tighten up the lock nuts make sure the adjuster doesn't turn with it or you have to start over again

The rear band is the low/rev band and the front band is the second gear band (it really has nothing to do with 3rd gear as it only applies in 2nd)
 
Those servos have a lot of travel. If you are gonna adjust them every year, I myself would be tempted to adjust them on the loose side. Actually I have tried several different adjustments with no noticeable difference.(Streeter)
 
So I dove into it tonight, and can say with certainty that I never want to do it again. Getting to the adjuster on the outside with a torque wrench was a giant PITA. I managed to get it on though and go one tooth at a time until it clicked at 72 in/lbs. then I backed it off two turns and tightened it up. My socket wouldn't work on the inside adjustment, so I had to go with the method of tightening it until the driveshaft got stiff then back the adjuster 1/2 turn. I did feel the lever before the adjustment, and it had a good 5/8" of movement. Now it's more like 1/4". Like I said this is the first time I have adjusted the bands since I installed the trans in the mid 2000s.

There's also a lot more free play on the front band lever compared to the rear. I assume it's normal.
 
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AJ/FormS said:
1/4 between the lever and the plunger is how I have set an aweful lot of them
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I stick the tip of my index finger between them and tighten the adjuster till it hurts through my fingernail, and then lock it down.
Since I'm getting older and a little heavier than I used to be I should probably re measure that method one of these days. :D
 
TrailBeast said:
I stick the tip of my index finger between them and tighten the adjuster till it hurts through my fingernail, and then lock it down.
Since I'm getting older and a little heavier than I used to be I should probably re measure that method one of these days. :D
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Absolute precision!
Hopefully this helps with my sporadic consistency issue at the track. Ran 4 runs between 12.113 and 12.131 then threw a 12.21 out there when I had a .005 light and the other guy had a .070 package (which isn't great). I noticed my shift light came on twice before getting out of 1st gear, so there was a bit of a delay that could cause an issue maybe.
 
TrailBeast said:
I stick the tip of my index finger between them and tighten the adjuster till it hurts through my fingernail, and then lock it down.
Since I'm getting older and a little heavier than I used to be I should probably re measure that method one of these days. :D
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Yeah, it seems almost every thing gets a lil thicker as we age, or hangs a lil lower....
 
When you're ready to put it together, there shouldn't be any chance of drag, nor too much flap to pick up upon actuation hydraulically. Nice middle balance of both.
 
Darthomas said:
When you're ready to put it together, there shouldn't be any chance of drag, nor too much flap to pick up upon actuation hydraulically. Nice middle balance of both.
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I like the front band as tight as I can get it without any 1-2 overlap, but a non blocked accumulator can mask a slight overlap.
So we just say to go by the book specs to be safe. :D
 
gumper said:
I noticed my shift light came on twice before getting out of 1st gear, so there was a bit of a delay that could cause an issue maybe.
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A loose frond band can cause a little delay in the shift. Given your description it should be more consistent now. And yes there is a bit of difference in the play of the rear band adjuster compared to the front.
 
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