There seems to be two band adjustments on these transmissions. One on the left side of the transmission (accessible through an oval plate) and the other on the right side (accessible from underneath). Can someone confirm the band on the left is for forward gears 1,2 & 3. And the right band is for reverse?

 

The front brake band is used only to select gear 2

The rear brake band is used for gears 1 and R

 

Andy - not to sound stupid, but is front the left side adjustment and rear the right side? Or visa versa?

 

The front brake band is the one on the left hand side of the car, near the selector lever, and is used when gear 2 is selected

The rear brake band is on the right hand side of the car and is used when Gear 1 or R are selected.

 

I take it that 3rd gear is not controlled by any band?

 

That's right. Here is a page from the transmission service manual describing how the gears are selected by the gearbox internals:

 

I have troubleshot a transmission shifting problem for a couple of years thinking it was the front brake band controlling the shift into 2nd. I still have the "juddering" problem on that shift once in a great while, but yesterday it happened shifting to 2nd, then again shifting to 3rd! Well, if there is no band for the 3rd shift, then it must be something else. So that lead me to start thinking outside the (transmission) box. And to the torque converter. Yes, this was suggested to me before, but I didn't know enough about automatic transmission technology to consider that option. I'm now beefing myself up on it. There's lots out there on the internet/YouTube to school off.

So... doing my due diligence before throwing myself into this - a few comments/questions: From the Forum I see there are two types of Flex Plates. And I don't know which one I have. But you on the Forum, back when I was troubleshooting the "bearing knock" problem suggested it was loose bolts/rivets on the Flex Plate. And since I replaced all the lower bearings and still have the "bearing knock" problem - you may be correct. So, I probably need to acquire a "solid" Flex Plate. Once the BW66 transmission is out, I don't plan on rebuilding anything on it. It shifts really well. Other than the Torque Converter, what else should I replace while I'm in there? I've already done the rear transmission seal, replaced the transmission rubber mounts, replaced the drive shaft center bearing.

 

Bill, At times when all my problems are gone, I think about the rod knock noise in your car. Does the noise change when you disconnect the spark plug closest to the firewall? Are all the bellhousing bolts tight? As I recollect there was a running change having something to do with the number of rivet's holding the ring gear to the connecting the torque converter plate. Opens up the possibility of the bolt condition holding the plate to the crank? Or the condition of the tangs connecting torque converter to pump. U-joints and trans mount alignment ailments are generally cause to a shudder while shifting.

Larry Louton

 

There is a front seal on the transmission. I remember replacing it as a precaution when I had the engine and transmission out on my 1980 XJ6.

 

Larry - The "knocking" very much diminished after replacing the mains and rod bearings. Still there a bit, but I'm not going to worry about it. I haven't done that spark plug test but feel it unnecessary as the "knock" is only detectable when at a drive through where I'm really close to a building and the sound ricochets off the building. Like at Dunkin Donuts. As for the rivets and bolts - when I had the cover plate off at the bottom front of the transmission, I think I checked them all and did not see anything that I thought was out of place or loose. Can you please elaborate about your statement of the misalignment and U-joints possibly causing the shuttering while shifting??

Fraser - yes, thank you. I would do that. I have recently replaced the seal where the shifting rod comes through the housing as that was leaking. So I know it's good. And I have in the somewhat recent past replaced the tail shaft seal, that was also leaking.

 

Hello Bill, OK, Let's talk about the Drive shaft alignment with a collapsed transmission mount. With the trans mount collapsed, The drive shaft is too low in the front, The u-joint in the front will bind causing a shudder.
If the center drive shaft mount is collapsed while shifting it will bend and whip like a bow, sounding like a shudder. Dry U-joints will sound like a shudder.

Larry Louton

 

Larry - I'm not saying you are wrong; I have to jack the car up to make observations. But... I installed new the rear transmission mount, installed new center bearing and aligned it best I could according to the manual. All this about a year ago. I think the shuddering problem was there before renewing these parts. But I don't remember.

 

Can anyone tell me when the switch from a Solid to a Riveted flex plate occured on a BW 66 for the Series III?

I have vibrations, only at low RPMs in all gears. Both in Drive and when individual gears are selected. It is most pronounced when 2nd gear is selected. Just adjusted the 2nd Gear left side band with no change. Getting ready to pull the front inspection plate on the bell housing to see if the torque converter bolts are loose.

The flex plate question is just for my knowledge base. No intention to drop the trans.

Vehicle has 58,000 on it, trans oil has been changed to Type F. Just got the car two years ago, so don't know if this condition existed with previous owner or is new or is normal.

I look forward to your responses.