Replacing the gear selection switch in an 812 Cord

[alsancle]

So last spring I drove my dad's 812 Cord to get a new top.   The one on the car was done in 1966 and it was starting really look the part.   The car was restored in the mid 60s by my dad,  drove from Boston to Auburn twice for the reunion and one a first in class on one of those trips.   The odometer shows 6700 miles (setback at restoration) and 6500 of those happened before 1975.    The car has probably gone 20 miles in the last 20 years.   Never a good thing. 

 

The drive was about 12 miles through 2 towns in February.  It was nice day,  about 40 degrees.   Cool for the top down,  but no chance of the car over heating!     First issue I noticed was no fourth gear.   Not really that big a deal, an 812 Cord will go 45/50 mph in 3rd no problem.     Car was in the shop for couple of months and then in April we went to get it.  Jonathan Chase did the top and it looks great!   Hop in the car to drive home and first issue is no reverse.  Crap.   We push car out of the garage, and then find the next issue. No first gear.   OK,  no reverse,  first or fourth.  I have second and third.  I start thinking about calling a rollback and doing the trip in my mind.   Well,  my garage is about 1/2 to my dad's from where we were and it was mostly level the whole way with a few stop lights but on level ground.    I'm thinking I can make and I did without burning the clutch up.

 

There is a full thread on the ACD forum on the selection switch.    Also,  Jim O'Brien the cord tech has written a multi part article for the club newsletter on debugging and fixing Cord transmission issues.

 

https://www.acdclub.org/forum/cord-810-812-acd-forums/9011-gear-selector-switch-wiring

 

So this is now April 2020 and the Cord is in my garage and my truck is out in the driveway.   No bid deal with summer coming and I figure we will get the thing fixed for summer...

[alsancle]

People are intimated by the Cord 810/812  transmission and shift mechanism.   Like a lot of things,  it is not so complicated after put in 100 hours of studying it.   😄

 

The Cord being front wheel drive has an electro-pneumatic gear shift mechanism operated by a small shift mechanism on the steering shaft.

 

I attached a picture of the dash in a sedan,  but the open cars are the same.   The shifter is actually a "preselector" where you preselect the gear you want to go in and when you push in the clutch it closes the circuit which closes contacts on the "interlock switch" located on the transmission.    The thing on the left with the wires attached in the picture below is the interlock.

Edited February 2, 2021 by alsancle (see edit history)

[alsancle]

Before you can actually look at the interlock switch you have to remove the bumper and the transmission cover.   I assume if Cord had made it in to 1938 they would have designed an access cover.  That would have been a good idea.

 

With the cover off and someone in the car you can observe the shift arm moving as the interlock fires the solenoids for the two vacuum assemblies.  There is one on top and one on the side. 

 

The chart down in the left corner of the schematic shows which gear you are in by where the lever is.  

[alsancle]

I'll have to continue later when I'm done snowblowing and shoveling.  We got 12-16 last night in the People's Republic.

 

So,  last April when I tucked the Cord in to my spot in the garage I was thinking no problem leaving the truck outside for the summer.    Of course,  most posters on here new what was going to happen.  Instead of jumping in my clean warm truck this morning,  I had to go out the back door which led to the first problem.  Then out back to my truck which led to the second problem.