easy 904 band adjustment Q

-
Rapid Robert

Rapid Robert

Well-Known Member
Joined
Aug 6, 2006
Messages
1,921
Reaction score
471
Location
Lincoln Nebraska
67 up 904. will be pulling the VB & wondering what I should adj the inside band to while I am in there, (snug & how many turn out?). shifts normally up thru the gears then mashed in third gear (if that info helps).thank you for your time. RR
 
There's a specification for torque values on those bands (in-lbs). Refer to the FSM to determine those values. 65'
 
While you are in there get a 4.2 lever and adjust to "67" 273 Commando specs. You will also need a small inch pound torque wrench and a square socket. Up the pressure also. If the trans is older, you can also add part throttle downshift from A & A transmission.
 
I can get a 4.2 lever & was going to back off the allen bolt on the side that I had read about (they said leave several threads, just enough so it stays engaged). I have the t wrench/socket & I will see of I can find the commando specs (I will google it). If no luck where should I search next? Much appreciated. RR
 
a guy posted that he loosened both nuts/shanks then tightened one till the driveshaft can just be turned with one hand then loosen it another 1/2 turn then locking it down then the same way with the other band except you turn the driveshaft the other way. I may have missed repeating something here but that is the jist of it. I am going to try this. RR
 
Rapid Robert said:
a guy posted that he loosened both nuts/shanks then tightened one till the driveshaft can just be turned with one hand then loosen it another 1/2 turn then locking it down then the same way with the other band except you turn the driveshaft the other way. I may have missed repeating something here but that is the jist of it. I am going to try this. RR
Click to expand...
Then why did u ask for help if u already have your mind made up? We could tell u not to do it that way but hey we’ll let u find out for yourself.
 
i'm assuming this is for your roundy-round car? if that's the case i would eschew any "factory" spec adjustment and instead seek more application specific information.

some of the goals are the same-- you want the band to hold tight, but in that type of racing kick down and part throttle driveability are not exactly a concern. so likely you'll want more lever for better apply and more pressure. basically, i'd think that you would want zero slip or overlap between shifts.

i know this is sacrilege, but a lot of the chevy guys run autos in the bull ring so maybe look into how they set up their stuff and apply some of the same ideas to what you're trying to accomplish.

i'm not particularly knowledgeable with this specific goal in mind, so i'm sure that somebody will be along shortly to tell me that i'm full of **** and tell you how to do it the right way.
 
An oldie but a goody:
fishy68 said:
torque both to 72 In/lbs then the front band gets backed off 2 to 2-1/2 turns. If you can verify which front servo lever the trans has you can make the adjustment more precise. The ratio of the lever is stamped into it. It will be anywhere from 2.9 to 4.2 The 2.9 thru 4.0 gets backed off 2-1/2 turns and the 4.2 gets backed off 2-1/4 turns. If you can't verify the ratio of the lever just back it off 2-1/2 turns.

The rear band is also dependent on the type. It will either be a single wrap band identified by being one solid wrapped or a double wrap band identified by being slit in 3 parts around the circumference so the inner part can move independently from the outer parts. Most stock trans. had the single wrap band.

If it's a double wrap band back it off 3-1/2 turns. If it's a standard single wrap band back it off 2-1/2 turns.
Click to expand...
I can't add any more than that- it pretty well covers it all.
 
You must log in or register to reply here.
-

Back
Top