Education needed on BW Overdrive

[sjaakslinger]

I'm trying to learn everything about my newly acquired 47 Coupe. It has a 50s (?) overdrive installed by a previous owner.

 

I read some stuff about the overdrive. I included a picture of a passage from a manual. Can anyone enlighten me on this clutch thing? Is there a situation with the overdrive enabled, where you don't have to clutch??

 

I also read about the booklet by Randy Rundle. I'm in Europe, so I don't have easy access, I might order it on a trip to the US.

 

Edited Monday at 08:00 AM by sjaakslinger
Missing pictures

[kencombs]

With the overdrive cable in the OD position, but speed less that the governor setting, the drive shaft will not turn the trans output shaft when coasting.   So clutchless shifting is possible.

Edited Monday at 01:30 AM by kencombs

[sjaakslinger]

7 hours ago, kencombs said:

With the overdrive cable in the OD position, but speed less that the governor setting, the drive shaft will not turn the trans output shaft when coasting.   So clutchless shifting is possible.

Ah, thanks!

[P15-D24]

Downloads section has quite a bit of reference info on overdrives. 

[Loren]

If you are in Europe you might be familiar with the old SAAB freewheeling.

The B-W R10-G1 has a sprag clutch which works just like the SAAB freewheel, in fact if you took one apart you'd see the familiar rollers.

As in the SAAB you can let off the gas and down shift. You can up shift by allowing the engine rpm to drop below a certain threshold.

Remember that any speed above 27 mph, when you take your foot off the gas the transmission will try to shift into Overdrive.

One thing to remember as with the SAAB you can not park the car in gear and expect it to hold it from rolling.

You have to lock the Overdrive in direct drive and set the parking brake. Some folks carry wheel chocks, which is the smart way to go.

The old MoPar parking brakes are usually not in the best of shape and they will fail at a most inopportune time. 

[sjaakslinger]

Thanks for all the info. I can't really test the overdrive yet, the car isn't registered yet, so I can't take it on the road. All parts seem to be there and hooked up though. Even the kickdown at the carb. Although the switch can hardly be activate, the gas pedal travel is limited by the carpet.🙄 I have to fix that.

 

The overdrive cable at the overdrive unit seems to be wrongly mounted I think. It's impossible to make that 90 degrees turn on the lever. I think the cable bracket should go on the lower bolt of the solenoid (?). 

[Sniper]

13 hours ago, Loren said:

The old MoPar parking brakes are usually not in the best of shape and they will fail at a most inopportune time.

That is the truth. I came home from work once and my 51 was half in the road half in my driveway and I don't have a steep driveway at all.

 

6 hours ago, sjaakslinger said:

so I can't take it on the road.

Well technically you can't get caught. LOL

[Booger]

PB not to be trusted. keep small 2x4 in trunk

[Young Ed]

Or just remember to pull it out of OD... I personally don't use my OD around town just when I'm hitting the highway or freeway 

[Loren]

Yes those old parking brakes are suspect!

They hold real good when you leave they on!  ( After a couple of blocks )

On a dark foggy night in San Diego, my 49 started to slow down on a flat road. I gave it full throttle and it did a sudden nose dive.

I restarted it and let out the clutch and the engine died again without so much as a wiggle of the car.

As I sat there looking at the dashboard trying to figure out what was going on, tendrils of smoke drifted up between me and the dashboard!

I opened the car door and leaned down to look under the car and there was a bright orange glow on the ground.

Once I released the hand brake I was able to proceed on my way like nothing happened.

 

I knew a guy who washed his old Plymouth for a date, then went in to shower. When he came out the car was gone!

He heard a commotion down the street and saw his car upside down in the middle of the intersection.

In those days a 1949-54 Plymouth was a "Transportation Car" and you could buy a good one for $150. ( 1964 )

By Monday he was driving a 1953 and it was nicer than his late lamented 1950.

 

Those days are long gone so be real careful with your "Survivor Car".

[sjaakslinger]

Sound like a design flaw.🫣

 

Luckily The Netherlands is as flat as a pancake....

[kencombs]

The only Mopars I have experience with that had trans-mounted park brakes were the later internal-expanding drum and shoe on Powerflite and Torqueflite  units. They were excellent!   Would lock the rear wheels at 36-40MPH with a strong pull on the handle.   The only  weakness was the lack of a locking or limited slip differential.   One wheel on ice made it totally ineffective.

 

 

Edited yesterday at 04:56 AM by kencombs

[martybose]

You will always need to use the clutch when shifting the three speed.  If it is set up properly you never need to use the clutch to go into or out of overdrive.

 

Marty

[kencombs]

21 hours ago, Young Ed said:

Or just remember to pull it out of OD... I personally don't use my OD around town just when I'm hitting the highway or freeway 

Or, park with trans in reverse.   If it's properly assembled OD is locked out when in reverse.