GP7 grounding spring

[bossman]

Hello again. Please, tell me where the grounding spring goes on GP7's. I've heard so many different stories, I thought I'd ask the experts. Between the motor and frame or between the truck and frame? Thanks, Bossman

[rtraincollector]

according to my Greenburg's 1945 - 1969 Repair and operating manual it shows it between the power truck and the frame. 

[cwburfle]

The debate goes on. After looking at the issue carefully, I believe that the spring goes between the motor and the frame.

Early Budd cars did not have the spring at all.
The Geep power truck has a couple of nodes on the top of the truck (same as the Budd) for the chassis to ride on. Adding a spring on that side obviates those nodes.
Look at your Geep from the side. Without the spring between the truck and body, it looks level (more or less). Add the spring, and the motor end is a bit high.

Look at the action of the spring as the truck rocks underneath the chassis with the truck in contact. Seems correct.

I have disassembled Geeps and Budd cars that came from their original owners. The springs were on the motor side, with matching wear marks. No wear marks on the truck side.

Some will point to a drawing in the Lionel service manual that seems to show the spring on the truck side. True, but the service manual does contain errors.

Then there is the question, which way does the hump go? (hump up, towards the motor)

[sir james I]

I always assemble them between the motor and frame.

[rtraincollector]

I was going to say I have done it both ways and it worked fine. When I did it on top of frame it seemed to work better with the hump going up towards the motor. When done on the bottom of the frame I did the hump towards the truck.

[cwburfle]

One more arguement for the spring to be on the motor side:

When the spring is on the truck side, there is nothing on the motor side to help the truck rock over uneven track.
When the spring is on the motor side, the truck rides on those nodes I mentioned in my earlier post, and can easily rock.

[rtraincollector]

cwburfle

One more arguement for the spring to be on the motor side:

When the spring is on the truck side, there is nothing on the motor side to help the truck rock over uneven track.
When the spring is on the motor side, the truck rides on those nodes I mentioned in my earlier post, and can easily rock.

 

I think I have mine that way now. it works both ways but I think it works better the way your saying,