Topic: 390 C6 Speedometer & heater cable routing

[Angela]

If anyone has a pic or other info concerning speedometer cable routing for the 390 C6 application, could you post it here? I've found lots of pics of 289 & 390 3 & 4-speed applications using simple google image searches, yet nothing on the C6 390 application. The Osborne body assembly manual specifies the 390 auto routing is different. I cannot figure out where the cable is clipped to the frame rail or floor pan, and even more embarrassing I'm not certain which hole in the firewall the speedo cable is supposed to pass through... is it the hole directly beneath that which the headlamp wire harness passes through?

Finally, there's a metal cable clamp attached to one of the mounting studs for the driver's side cowl vent. Are *both* the speedometer cable and heater control cables supposed to pass through that cable clamp, or just the speedo cable?

[J_Speegle]

Angela what year are we working on again ?

Sorry can't recall if its a 68 or a 67

[TLea]

There is a long U shaped clip that attaches to the stud in front of air vent. Neither heater cable nor speedo cable go in it. You said cables for heat so I assume you have a non ac car. Its a little hard to describe, the cable runs through the opening of the wiper motor support and up over the top of the speedo cable. On an AC car the vacuum lines are taped to heater cable and routed the same way.
Speedo cable, cant recall whether its above or below wiring but I think it will only fit one way (I'm pretty sure its above) There is a clip the frame rail that both the speedo cable and e brake cable run through and from there it goes into trans. There is another spring clip on the frame work that the transmission crossmember bolts to that it snaps in.
One thing I cant remember is whether or not the C 6 cable uses the spring clip on the fender apron by the proportioning valve or whether thats just for 4 spd cars?
Sorry I've only got 4 spd cars here at the moment. I would think the assembly manual would indicate whether there is one in that area for C 6

[Angela]

Whoa, um, what, say that again? Neither the heater control cables nor the speedometer cable routes through the cable clamp at the cowl vent? The assembly diagrams show both of these two cables routed through that clamp.... I just wasn't sure that was accurate. It seems like that clamp is affixed to the cowl vent for a reason, it must be there to hold something, right? Won't the heater control and/or speedo cables get caught in the wiper arm mechanism if not routed through this clip?

[Angela]

Jeff, it's a 67, 390 C6 SanJose.
I am now thoroughly confused as to how the speedometer cable and heater control cables are supposed to be routed.

Yes, it's a non-AC car. It does have smog / thermactor though.

[Angela]

I think the following image is of a C4 application, but perhaps someone may be able to comment as to whether or not the C6 routing is the same or similar?

A friend of mine found this picture for me, thus I have no information about it. The arrows indicate the speedo cable and the single large arrow indicates the clip attached to the cable. My original C6 cable has a clip still wrapped around it in approx the same location as shown here.

[Angela]

Also, someone indicated that neither the speedo or heater control cables are supposed to route through the clamp at the cowl vent. This confuses me and I'm looking for some additional feedback. Attached below is are two images from the electrical assembly manual, both of which show these cables passing through the previously mentioned clamp. Did the factory not actually route these cables as shown?

[J_Speegle]

First thanks for the confirmation as to plant and year. Keeps me from looking at allot of extra pictures that might not relate;)


 

...........Did the factory not actually route these cables as shown?

Believe those are two different clamps in the drawings in slightly different locations. I've never found the one shown in the picture with the speedo cable. What is the date on that page ?

As for routing don't thing I'm going to find any for under the dash and only recall the speedo cables going from the back of the gauge to the hole in the dash  (no clamp)

I think the following image is of a C4 application, but perhaps someone may be able to comment as to whether or not the C6 routing is the same or similar?

Its similar in places (under dash would be the same IMHO. Gauge pod and location are the same as well as they share the same exit into the engine compartment unlike some other years and models

Once the cable exits it shares a retaining clip attached to the drivers side frame with the E brake cable






After that it travels down the side of the trans on the drivers side to the transmission cross member where it attaches to a retaining clip then enters the trans at the tail shaft

[ruppstang]

Also, someone indicated that neither the speedo or heater control cables are supposed to route through the clamp at the cowl vent. This confuses me and I'm looking for some additional feedback. Attached below is are two images from the electrical assembly manual, both of which show these cables passing through the previously mentioned clamp. Did the factory not actually route these cables as shown?

It has been my experience that most automatic cars did not use the guide for the speedometer cable. I think it was used on manuals to keep the cable away from the clutch return spring.

[TLea]

Speedo cable outside passenger compartment is exact as Jeff picture shows. There is also a clip near distibution block but may be 4 spd only, cant remember. As far as cables hitting wiper linkage, they run substantially below it. Order of cables etc through firewall top to bottom,
wiper hoses
wiring harness
speeo cable
clutch linkage (if equipped)

[ruppstang]

Speedo cable outside passenger compartment is exact as Jeff picture shows. There is also a clip near distibution block but may be 4 spd only, cant remember. As far as cables hitting wiper linkage, they run substantially below it. Order of cables etc through firewall top to bottom,
wiper hoses
wiring harness
speeo cable
clutch linkage (if equipped)

The automatics also use the clip near the distribution block too.

[Angela]

Wow! Thanks a ton to Jeff for the pics and to those who added comments! Great help.

If I understand this correctly, there should be one "C" shaped clip with a bolt just outside the firewall, plus one more clip near the trans x-member. I'm in big trouble... I don't have this "C" shaped clip. Bang head here. Anyone have one and willing to sell it to me? 

As far as the clip inside the car, at the cowl vent, it sounds like you guys are telling me the automatics didn't route the cable through that clip. But what about the heater control cables as pictured above? Is that accurate or not? I routed my heater control cables through that clip because I thought that's what the osborne drawing indicated. That said, I'll admit the heater controls would work better if the cables did NOT route through that clip. I just figured they were supposed to be held in that ckip to keep them away from the wiper arm mechanism.

[ruppstang]

There is a J hook that hangs from the cowl for the main wire harness. If the heater cables lay in there fine if not I would not  worry about it. I have never had one tangle with a wiper arm. Now a AC duct that is a different story.

[J_Speegle]

Wow! Thanks a ton to Jeff for the pics and to those who added comments! Great help.

If I understand this correctly, there should be one "C" shaped clip with a bolt just outside the firewall, plus one more clip near the trans x-member. I'm in big trouble... I don't have this "C" shaped clip. Bang head here. Anyone have one and willing to sell it to me? 

Don't think its a "C" shaped clamp but rather a loop - more like a four sided rectangle if I recall correctly. Been a while since I had one off - if ever

Bunch of 67-68's in the Resto Mod shop currently will see if there is one there I can get a good clear picture of. Don't have one sitting around my garages in a box    It will help confirm the shape 

Marty agreed on the small S brake clip - both /all cars

[Angela]

Can anyone describe the bolt that holds the "loop" or "C" shaped clip show by the yellow arrow in Jeff's picture? The bolt that's holding the clip which holds both parking brake cable and speedo cables...

According to the chassis assembly manual this bolt is 40156-S2, and according to AMK that translates to a 5/16-18 hex head bolt without any integrated washer, 5/8" long, machine thread. However, when I look at the corresponding hole in the frame rail, I don't find any threads, which makes me think the correct bolt should be a cutting thread or tapping screw thread.

Can anyone help ID the correct bolt, machine or tapping thread?