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firewall diagram? haystack style grommets?

Posted: Fri Feb 18, 2022 4:39 pm
by johnscf
I have been posting recently and getting some help with some rubber pieces I inherited from a PO. I am in the process of putting my 68 2000 back together. While I had it off the road to be painted I went ahead and pulled the dash. I took a lot of pictures when I pulled it off but apparently not enough. I have two questions, 1) is there a place on the site with a diagram of the firewall showing what cables/hoses/wires go through which holes. I’m fairly certain I’ve got my heater hoses in the right place but I’m not sure about some of the others.2) I’ve used Dean’s site to identify most of the grommets but the haystack style ones that are for the speedometer cable and the tach cable I can’t figure out how to get them over the fittings on the ends. Do the fittings have to be removed? It looks like the pieces that screw in to the backs of the gauges are factory crimped. Is there some trick to this or am I just overlooking something? Be forewarned I’ll probably have more stupid questions as I go forward reassembling everything. I apologize in advance.

Re: firewall diagram? haystack style grommets?

Posted: Fri Feb 18, 2022 6:29 pm
by DAC21
I'm not familiar with the term Haystack Grommet. Is this picture what you are referring to?
2372.1.jpg

Re: firewall diagram? haystack style grommets?

Posted: Fri Feb 18, 2022 9:27 pm
by devo
From Curtis. Its for a 66-67. Maybe close enough to the 68?

http://www.kendo-usa.org/datsun/firewall_66_67.pdf

Re: firewall diagram? haystack style grommets?

Posted: Fri Feb 18, 2022 9:55 pm
by johnscf
DAC21 wrote: Fri Feb 18, 2022 6:29 pm I'm not familiar with the term Haystack Grommet. Is this picture what you are referring to?

2372.1.jpg
yes

Re: firewall diagram? haystack style grommets?

Posted: Fri Feb 18, 2022 10:37 pm
by Curtis
I have this diagram for high windshield but it is subject to error. I never got the rest of the info.

http://kendo-usa.org/datsun/firewall_68.pdf

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 11:43 am
by johnscf
Curtis wrote: Fri Feb 18, 2022 10:37 pm I have this diagram for high windshield but it is subject to error. I never got the rest of the info.

http://kendo-usa.org/datsun/firewall_68.pdf
Thanks Curtis, this is helpful. Still trying to figure out how to get these grommets over the speedometer cable the tach cable and the oil pressure line

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 11:51 am
by Steve_69
Curtis, You are the man! Nice sketch. I disassembled everything on my 68 firewall at the beginning of this week and did a video of it so that I could refer to it during reassembly. The video is much too large to post, but maybe I can help fill in some of the missing parts of your diagram. I will try to do that and re-post it when I am done.

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 11:54 am
by dynaguy
I sliced, along the seam of the grommet, with a sharp, single edged razor blade. Was then able to place it over the cable. Then super glued it back together, put the seam at the bottom, hardly noticeable. FWIW Pat p.s. be sure to clean off any oil on the razor blade prior to cutting or the super glue will not adhere. Rubbing alcohol works well for this.

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 3:12 pm
by Curtis
Steve_69 wrote: Sat Feb 19, 2022 11:51 am Curtis, You are the man! Nice sketch. I disassembled everything on my 68 firewall at the beginning of this week and did a video of it so that I could refer to it during reassembly. The video is much too large to post, but maybe I can help fill in some of the missing parts of your diagram. I will try to do that and re-post it when I am done.
Thanks. I forgot I had done this.

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 3:23 pm
by DAC21
dynaguy wrote: Sat Feb 19, 2022 11:54 am I sliced, along the seam of the grommet, with a sharp, single edged razor blade. Was then able to place it over the cable. Then super glued it back together, put the seam at the bottom, hardly noticeable. FWIW Pat p.s. be sure to clean off any oil on the razor blade prior to cutting or the super glue will not adhere. Rubbing alcohol works well for this.
I'm glad to hear someone has successfully done what I was thinking of doing. Choke and throttle I'm good with disconnecting them (already disconnected) and sliding the new grommets on, but the electrical harness passthrough wiring "not gonna do it" I have never had much luck with super glue, wondering if there is a rubber type cement that would work well?

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 4:47 pm
by Curtis
Since I do so many grommets for the firewall I bought a grommet tool. By hand takes some work but I've done lots of them. Usually I get the one plug through and then bend the other one backwards.

https://www.aircraftspruce.com/catalog/ ... ckkey=4582

Re: firewall diagram? haystack style grommets?

Posted: Sat Feb 19, 2022 7:13 pm
by Steve_69
To follow up on Curtis' 68 diagram.
1. The circle just to the left of center is the heater control valve and mounting bracket.
2. The circle at the top, just to the right of center is the other heater hose.
3. The two small holes on left and right middle are the heater box mounting bolts.
4. The two holes you have listed as speaker mounts, I am not sure that is what they are. Under the glovebox, there is a sheet metal bracket attached to the cardboard on the fire wall, there is a thin metal bracket mounted on these holes. The bracket has one hole east and west. I do not know what mounted to this bracket as whatever was, was missing on this car and one leg is bent. It does not look like it mounted a speaker.
5 Everything else looks correct.
I hope this helps.

Re: firewall diagram? haystack style grommets?

Posted: Wed Mar 23, 2022 4:13 pm
by SOUPY
Maybe too late to help johnscf, but here is a hack I used, also I used this for rebuilding the master cylinder. You know, if you only buy a seal kit and you need to get the inner seals on the piston, not a fun job! Buy a sacrificial plastic automatic transmission funnel that tapers down to the smallest diameter you can find, cut the end off high enough that the big end will just slightly go over the speedo or tach nut. Apply lots of silicone spray to grommet and slide over the small end and hold large end over nut and bingo! Done! Unless you put on in wrong direction! Here is a picture of funnel I cut for the MC seals.

Re: firewall diagram? haystack style grommets?

Posted: Fri Mar 25, 2022 8:36 pm
by Solex68
Clever. This idea will come in handy!