'70 firewall grommet placement/cable routing

[Jim Ruggieri]

I'm trying to properly route the various cable and vacuum lines that run through the firewall. as simple as it seems I'm having difficulty finding the correct holes for the speedometer cable, tach and A/C vacuum line grommets.

Speedometer cable: The AIM clearly pictures it going through to the drivers side of the master cylinder above the wiring junction block. I have 'plug' in that location. If the cable doesnt go through as pictured in my link what does?

Tachometer: Should go in the same 4-hole grommet along with the oil pressure line and reverse wiring

A/C hoses: Big grommet with 3-hoses..it appears it goes through a touch to the passengers side of the distributor. Again, my car has plug in this location.

My car didnt come from the factory with A/C but was in the middle of being converted when I bought it. This may explain why there's a plug in the A/C grommet location but it doesnt explain why there's one in the speedo location.

I've provided links to 2 pictures, the first from the AIM with the suspect A/C grommet circled and the second from under the hood showing the mess I'm trying to correct.

Any and all help is appreciated,

Jim




AIM diagram
[IMG][/IMG]

[Chuck S.]

Re: '70 firewall grommet placement/cable routing

In 1970, the four speed transmission was made standard equipment for the first time, but the AIM continued to show the three speed transmission installation as if it were standard.

The four speed transmission uses a single speedometer cable (PN 6477901) rather than two cables, and it is routed differently to the passenger side of the tail housing rather than the driver side like the three speed. Proper routing for the four speed transmission is only shown in UPC M20...see Sheet A5.

I hope you didn't buy speedo cables for the three speed using the part numbers in UPC 12.

[Chuck S.]

Re: '70 firewall grommet placement/cable routing

In 1970, the four speed transmission was made standard equipment for the first time, but the AIM continued to show the three speed transmission installation as if it were standard.

The four speed transmission uses a single speedometer cable (PN 6477901) rather than two cables, and it is routed differently to the passenger side of the tail housing rather than the driver side like the three speed. Proper routing for the four speed transmission is only shown in UPC M20...see Sheet A5.

I hope you didn't buy speedo cables for the three speed using the part numbers in UPC 12.

[Jim Ruggieri]

Re: '70 firewall grommet placement/cable routing

Chuck,

Thanks for the prompt responce. I never bothered to look in options section of the AIM because its pictured in so many other areas of the AIM as well as various vendor catalogs. I did notice it attaches to the passengers side of the tailshaft and yes, I did buy the proper cable.

Thanks again,

Jim

[Jim Ruggieri]

Re: '70 firewall grommet placement/cable routing

Chuck,

Thanks for the prompt responce. I never bothered to look in options section of the AIM because its pictured in so many other areas of the AIM as well as various vendor catalogs. I did notice it attaches to the passengers side of the tailshaft and yes, I did buy the proper cable.

Thanks again,

Jim

[Chuck S.]

Re: '70 firewall grommet placement/cable routing

There is a hole in the side of the firewall projection that mounts the MC. The hole is about 9" from the top of the firewall where the MC mounts. That hole points toward the passenger side of the car, and there is a small clip just outside that opening. The speedo cable comes through a grommet in that hole and is retained by the small clip, and another small clip on the other side of the transmission tunnel. From there, the speedo cable turns down the passenger side of the transmission tunnel

As for the AC, see UPC60, Sheets E5 and E6. These sheets show the AC vacuum control tubing and wiring penetrations through the firewall. If I'm not mistaken, the AC grommets go into the two sides of the 45 deg angled cavity in the front top of the firewall.

[Chuck S.]

Re: '70 firewall grommet placement/cable routing

There is a hole in the side of the firewall projection that mounts the MC. The hole is about 9" from the top of the firewall where the MC mounts. That hole points toward the passenger side of the car, and there is a small clip just outside that opening. The speedo cable comes through a grommet in that hole and is retained by the small clip, and another small clip on the other side of the transmission tunnel. From there, the speedo cable turns down the passenger side of the transmission tunnel

As for the AC, see UPC60, Sheets E5 and E6. These sheets show the AC vacuum control tubing and wiring penetrations through the firewall. If I'm not mistaken, the AC grommets go into the two sides of the 45 deg angled cavity in the front top of the firewall.