I wish I wouldn't have started this but now I have to finish it because pieces are everywhere. Anyone else replaced speedo or tach before on these things? I took out the bolts which hold the steering column up, but can't pull the dash out because I can't get the speedo cable off the speedo. Seem like I could just get everything from the back if I could remove the top dash pad, but even with the screws out it feels like it is wedged in there. Any help removing top dash pad would be appreciated. Am I missing something. There are just the 6 screws just underneath the dash pad on the front that hold it i, there right? :banghead:

 

The A pillar trim must be removed as well, and there is a bracket (metal) coming out from the firewall just right of centre that the dash sits on and has 1 screw in it.

 

push in on the speedometer cable to take the tension off the retaining clip, move the clip and the cable should come out easily. Thats what I had to do on my 76.

 

Ok, thanks for heads up on the screw in the middle.

 

Ah, how often have those of us who have ventured into the dark crevices of the C3 asked ourselves that before pulling a little harder? You need an assembly manual for your year Vette. Not only will it show you the hidden screws, brackets, clips and other sundry expensive hardware before you break it, it will give you an idea of how each section of the car was put together, and will often give you a better idea of what order you need to remove things to get them apart. Working on stuff behind the dash is a perfect example of this, especially if you're messing with the gauges, wiring, or a/c stuff. Most of the big Corvette mail order places sell assembly manuals. Do yourself a favor and pay the extra 10 bucks or so for the index ... it's worth it's weight in gasoline. :)

 

Did this 3 weeks ago. What a pain in the a.. Make sure you replace all the light bulbs while you are in there. No sense in doing this job twice!

You need to get an AIM like the others guys are saying. Here is a rough order if it helps for now.
Remove steering column.
Remove header pad and side pillar posts.
Remove dash.
Undo odometer cable from bracket at bottom of dash pad under speedo. This is looped through the bracket supporting the steering volumn and severely limits movement of the speedo dash.
Unclip all wiring hangiong of the speedo dash.
Pull speedo dash slowly towards you and have a friend unhook the tacho and speedo from underneath the dash or above.

Good luck. Take your time. It is a pain in the butt but the results are worth it.



[Modified by stingry, 12:46 PM 4/16/2004]

 

The cables are actually held in by the retaining clips. Like it was said, relieve the tension and pindh them and they will come out.

Steve

 

To prevent damage to the steering column, make sure you loosen the two bolts on the flange where the column passes thru the firewall. Otherwise you put tremendous stress on the column with all that weight pivoting on the linkage.

Also, since the column only needs to come down an inch or so, do yourself a favor and re-install a longer bolt in support flange directly underneath the column and back it off until you have enough clearance. That way, you don't have to let the steering wheel sit on your seat/egg crate/whatever ... and it is still properly supported - yet down enough to allow for the removal of your instrument pad without stress.

Oh, yeah. And stock plenty of cool, malty beverages for frequent breaks.

:cheers:

 

Yes I am aware of the retaining clips, as when I pressed down on the one on the tach and pulled back on the cable it came right out. On the speedo I am doing the same thing but the cable won't come out. I guess I need to get the top dash pad out so I can back there with some leverage. What two bolts are you talking about at the firewall that hold the steering column. Are the heads to them inside or in the engine compartment side of the firewall?

 

Gage ......... Do your self a BIG favor and DO NOT try to remove the dash with the lower panels still installed. Use some WD or better Aero-Kroil to loosen your tach cable. There have been many posts on the forum describing how new dash panels have been broken in 2 trying to install them with a naked firewall. Just R&R'd mine, the clip holds it in. Rust might be binding yours, might try tapping on it. TIB[tiz a bitch]

 

Bolt heads on are on the inside. 3/8" heads I think. Two of them on either side of a (roughly) oblong-shaped flange where the column meets the firewall.

Just loosen them up a bit and you'll see the flange slide down if you already have pulled the vertical column bolts. That takes a bunch of stress off that end of the column. All the weight of the steering wheel and the upper column is otherwise cantelivered (sp?) off that lower flange.

But, I would also replace one of those vertical column bolts with something longer so you can support that upper column. As I said, you only need about 1 to 1.5 inches of drop. Supporting the upper column prevents any potential harm.

 

I just pulled my speedometer and tach out today, 1981. Pull the front bezel off the dash along with the lower piece below the steering column. Take the cross vent tube out (if you have it) and that will open up enough room to take the speedo cable out.

We have and electric tach so that was a no brainer and pulled the electrical plug. The speedo uses a spring clip to hold it in. Push on the clip with one hand and pull the cable with the other. Came right out.

Take both upper column bolts out and back out the two bolts at the firewall plate to lower the steering column. Once all the screws of the dash assy. are out, you can lower the column and pull the entire dash assy. out. Lift up the column and put the upper bolts back in to hold it in place.

Once you have it out, remove the clear bezel and then the screws holding the speedo head in. Push the speedo out from back to front. Ta, da! You did it.

A shortcut is to leave the dash in and then remove the clear bezel, screws for the speedo and push it out, back to front. I found it easier to pull the entire unit and this allows me to do some more cleaning back there. I also will have the speedo calibrated and replace the cable.

I don't know if this will help the older C3's, but that's how mine comes out. Time involved, 45min.

 

No, that won't work on older C3's. Everything has to be done from the back side of the dash. I just replaced my headlight switch, and it was truly a PITA. I think the entire car must have been built around the upper dash pad. I could do it again in less time, but my heart sure wouldn't be in it.



[Modified by 73ragtop, 5:01 PM 4/26/2004]

 

Finally got the new tach in and it all back together...I will pay someone to do it next time. Best $5 I spent was to buy some needle paint from Zip and repaint my needles and redline while I had the gauges out. It makes the gauges look brand new, I highly recommend it, even for the middle console gauges.

 

Congrats on the repair ........ I made 1 HUGE mistake when I did mine ......... I didn't test my tach prior to re install. Turns out it reads WAY to high (2000 reads 3000) so I've got to do it again. Just can't get my self motivated ... I guess it can wait till next year!

 

I am still debating whether or not to have my gauges rebuilt or go aftermarket but when I do finally do this job I plan on having a few extra sets of hands around for the job in case I need the help. I have been under my dash a few times.. that place is scarier than a ****!! :eek:

 

If there were room under there for a few extra sets of hands, you wouldn't have the problem in the first place. :)

Eddie