Can someone explain what tightening the bands is? I had cars when I was younger that the trans slipped etc. Either from low oil or it was the bands needing tightening. What is it? Simple terms is fine. Does the trans need to be removed, opened up?
You're referring to brake bands. Automatic transmissions either use clutch-packs and/or brake bands to control the ring gears for each planetary gearset within the transmission. It's a band that has frictional material on the inside of it (like a brake pad) to clamp onto the ring gear to set a different gear ratio. The transmission definitely needs to be opened up to either adjust or replace those brake bands if there is slippage going on.
That's not necessarily the case depending on the transmission design (having to open up the trans). My autobox has its band adjustment on the outside of the transmission case. No disassembly required to adjust it.
@chucktobias
Oh, thanks for mentioning this.
Well, most of them require dropping the pan, just not all of them. 🙂
I have a ZF 4HP18 which has a single band with a quick-and-easy adjustment on the side of the case. Borg-Warner 3-speed automatics and the Ford FMX have an external rear band adjustment, but you have to drop the pan for front band adjustment. So it really depends on the design of the specific transmission.
I looked it up. Good explanation of what it is.
https://www.freeasestudyguides.com/transmission-brake-band.html
It's not something you do on modern cars. The bands adjust themselves. By the time the band wears out, the transmission is ready for rebuilt.
