59 C1 FI Tach Cable Grommet

[John F.]

Can someone explain to me how this huge 3 inch long rubber grommet is supposed to fit properly in the firewall for a 59 FI car? The hole in the FW is 2 3/4 inches wide. If I squeeze the 2 inch think by 3 inch long grommet it doesn't even take up the entire width of the hole. Secondly, immediately behind the hole is the firewall insulation board (repo from CC) with this small hole and it sure isn't fitting through that without tearing it. Below are some pics.

[John F.]

Re: 59 C1 FI Tach Cable Grommet

Nobody knows the answer to this?

[Bruce B.]

Re: 59 C1 FI Tach Cable Grommet

John,
I can't seem to find anyone selling the grommet for the 59 tach cable hole, so I'm curious where you got yours and is it really correct?
Concerning the firewall insulation, it is very possible the hole was put in the wrong location.
Bruce B

[John F.]

Re: 59 C1 FI Tach Cable Grommet

Bruce- I got mine from Corvette Central and I'm sure it's probably not correct. My firewall insulation hole is in the right spot, it's just that the hole is way to small for the rubber grommet on the cable to fit into.

http://www.parts123.com/parts123/yb.dll?Parta~ShowPicTxt~Z5Z5Z50000050e~Z5Z5Z5AADFI~Z5Z5Z52

Paragon look to have the same one.

https://www.paragoncorvette.com/p-350173-tachometer-cable-w-tang-drive.aspx

Was the original grommet oval/egg shaped like the hole? I'd be curious to see any pictures of original ones out there.

[Bruce B.]

Re: 59 C1 FI Tach Cable Grommet

John,

I searched in Nolands Adams book (Resto & Tech vol 1) and found the following;

Page 292,the grommet you pictured from CC is for a fuel injected car, 1959 only. It was replaced by a plain round 1 hole grommet in 1958. Also note that the round hole it goes through is behind the tach drive FI distributor.

Pages 248 and 262 both show a small round grommet with part number which is used with a tach drive generator for the drive cable. The hole is above the heater fresh air hose roughly.

So, unless your car has a FI engine the CC part is wrong.

As far as the large hole you have in the firewall, that is a mystery to me, but I am no expert on 59 cars.

The only oval shaped grommet I am aware of is used for where the hood release cables go through the upper firewall, but they are less then 1" by 3/8" in size.

Hope this helps.

[Jerry C.]

Re: 59 C1 FI Tach Cable Grommet

This grommet goes in almost sideways. If you check how the cable goes in the distributor it is the only way it will fit.

[Bruce B.]

Re: 59 C1 FI Tach Cable Grommet

John,

In addition if the 59 FI car had a solid lifter engine it would use a 1110914 distributor which had a tach drive and therefore would use the CC short tach drive cable with the big round firewall grommet.

If it was a low HP hydraulic cam engine it would have used a 1110915 distributor which did not have a tach drive. Therefore the tach was driven by the generator using actual cable speed to drive the tach.

[Bruce B.]

Re: 59 C1 FI Tach Cable Grommet

This grommet goes in almost sideways. If you check how the cable goes in the distributor it is the only way it will fit.

Jerry,
The round tubular shaped grommet goes in through the round hole behind the distributor.

[John F.]

Re: 59 C1 FI Tach Cable Grommet

Bruce- Thanks! I did look at those pages. it's a 914 with a 59 RPO 579 hi lift (FI car). the hole is 2.75 inches wide. the grommet is 2 inches in diameter. they wouldn't try to fill the 3/4 inches with .07 oz of sealer would they? i'll try to put it in at angle and see if that helps. I'm trying to get everything set before I drop the body on the frame.

[Bruce B.]

Re: 59 C1 FI Tach Cable Grommet

John,

Glad I could help. I also learned a lot.

I have a 57 FI car which I finished a few years ago and I drive the wheels off it. My FI runs great and is a ball to drive.

Where are you in Ohio, it has been so wet in Middletown (45042) I haven't even put insurance on ther car yet. Hopefully soon.

Good luck with your 59.

Bruce B

[John F.]

Re: 59 C1 FI Tach Cable Grommet

East of Cleveland about 30 mins. it will stop raining one of these days. enjoy the summer!

[Lou C.]

Re: 59 C1 FI Tach Cable Grommet

Photo of grommet installed.

[John F.]

Re: 59 C1 FI Tach Cable Grommet

AWESOME!!!! thank you very much.

[John F.]

Re: 59 C1 FI Tach Cable Grommet

Hi Lou- Any chance you can send me a pic of the inside? Curious how your firewall insulation fits and if the grommet comes through the cardboard insulation. The repop garbage out there is a terrible fit.

[Lou C.]

Re: 59 C1 FI Tach Cable Grommet

5861FItachgrom.jpgDoes this help?