Tach Dash Questions

[83burban]

Hey all,

I am purchasing a tach dash from a fellow board member here. B454rat (great guy to deal with if your and if your considering buying one from him - or anything else for that matter - I recommend it) but I have a couple questions.

Little info: This will be going into an 83 suburban, and the two clusters both have volt gauges and electric oil pressure gauges. I know that I will likely need to repin my connector, but here is the question:

Will a tach dash from a diesel truck work in a gas application? The dash I am hoping to get has the little fuel gauge at the bottom - leaving the bottom left space open for a vacuum gauge or similar addition that I will use. I just want to make sure the I don't plug a diesel tach into place and have it not work or wore fry.

Also, I plan on swapping my current speedometer into the new cluster - so the miles are accurate and a I can keep my cruise control - Since the new cluster likely isn't set up for cruise - is it as simple as cutting out the little box on the back of the housing to mount the cruise piece or is there other work necessary?

Thanks for the help,

Kurt

[BLE 'BURBAN]

Most likely not. But you can change out the face's of the gauges from the gauge motors like I did when I put a tach into my '90 burb with a factory electronic speedo.
Check out post #21 at the top of the second page of "MODDING MY CLUSTER" below in my sig.

[83burban]

Thanks Ble Burban... but I was under the impression that the tachs are the same, just that for diesel applications there was a special piece fitted to the harness that converted the signal.

Just want to double check - thanks

[DBLSPRT68]

Kurt, you bought a diesel big truck tach cluster? The diesel tach only goes to 4000 rpm, if you have a v8; you'll be maxed out most of the time........... If the cluster is from a 79 and up big truck, it will be a plug and play. No re-pinning will be needed. I installed one of these myself into my 83. It was from an 80's C40 or C60 big truck V8. Mine has the 5000 rpm redline. If you want to add a clock on the left empty hole, that's easy to do also. I've got an air guage from that old cluster I didn't use, because I wanted a clock. Here is some Tach info everyone should read, from the famous Crossy! http://www.73-87.com/7387garage/inte...achometers.htm This is the one in my 83

[83burban]

Thanks DBL...in a perfect world I would love to have your setup with a vac gauge instead of the clock. The cluster I am looking at has a 4000 RPM red-line - but my V* doesn't see north of 4000 ever anyways so it doesn't really matter to me what the red-line is.

My only question is will the diesel tach work in a gas application. I just don't want to plug it in and have it fry because the two tachs themselves are different

[DBLSPRT68]

I'm not completely sure on that. The only thing that comes to mind is; is the big truck diesel a 6 cylinder? or a V8? if it's a straight 6 and you hook the tach to a V8, it's going to read too high.....? Pretty sure on that? Any help out there fellas???????????????

[48cj2a]

I just found a tach repair site on the net that specializes in GM stuff so sent him some questions about this topic and will advise if I hear anything back.

Seach TACHMAN on the web.

[b454rat]

Originally Posted by DBLSPRT68

I'm not completely sure on that. The only thing that comes to mind is; is the big truck diesel a 6 cylinder? or a V8? if it's a straight 6 and you hook the tach to a V8, it's going to read too high.....? Pretty sure on that? Any help out there fellas???????????????

I know the 6 vs 8 cylinder tachs are different, but have no clue on the diesel. If it matters, the diesel was a V-8. Bout all I know is somehow they hook to the alternator. Need to find out how and what alternator, Cummins should be here in a couple weeks....

[95 S_Trucker]

Originally Posted by DBLSPRT68

I'm not completely sure on that. The only thing that comes to mind is; is the big truck diesel a 6 cylinder? or a V8? if it's a straight 6 and you hook the tach to a V8, it's going to read too high.....? Pretty sure on that? Any help out there fellas???????????????

there was only one tach made for the big trucks(i am assuming). i have a big tach cluster and it has a hole in the back of the tach, there are 2 pegs that could fit in the hole, a 6 cyl peg or an 8 cyl. i have the 8 cyl peg



and this is the cluster i pieced together, plug and play in my 85.



to get the correct mileage, you swap the entire speedo as well,

[b454rat]

That cluster is a diesel one, I have two of these sitting right next to me. So with that tach, you plugged it in and it worked as it should?? I have two other tach dashes, both are gas, neither have that plug on the back....

[83burban]

Thats awesome - thanks for all the help guys. It would appear that all the gauges are the same - minus the 6 versus 8 cylinder versions. I planned on swapping the speedo as well to keep the correct mileage.

[85gmcguy]

Originally Posted by 48cj2a

I just found a tach repair site on the net that specializes in GM stuff so sent him some questions about this topic and will advise if I hear anything back.

Seach TACHMAN on the web.

That's who repaired mine. He is super nice and usually has a good turnaround time. Sent me pics of my tach being calibrated with comparisons to the bench machine. I'd recommend him!

[Pop's C-10]

This guy on youtube running a 3rd gen F-body tach.

.20 second mark

YouTube - 5.3 - 4L60E LSX VORTEC LS1 ...

[48cj2a]

Originally Posted by 85gmcguy

That's who repaired mine. He is super nice and usually has a good turnaround time. Sent me pics of my tach being calibrated with comparisons to the bench machine. I'd recommend him!

What did you have done and what did it cost (how long ago too)?

[85gmcguy]

Originally Posted by 48cj2a

What did you have done and what did it cost (how long ago too)?

I sent it to him to have it repaired, but he found it wasn't broken (I found a wiring problem with the truck), so he called me with that news and asked if I'd like to have it calibrated. I did, and that was $50.00. That's probably been 2 years now. Call and talk to him , he'll probably give you an estimate over the phone.

[83burban]

85gmcguy - could you pm me his phone number. I would like to talk to him.

Thanks

Kurt

[BamaDave]

I am having problems with the one I have just put in. I was considering sending it to this guy but I see where where there might be a wiring problem. I hooked it up to a +12v ignition source. Is this right or should it have been to a -12v source?

[tcody]

Don't mean to hijack this thread, but I have been looking for the gauge cluster pictured above at the local truck parts yard and can not find one with a pod that has all the mounting tabs intact. If anyone has an extra one I would be grateful! It's for a 1989 GMC 7000 and has the air pressure gauge in the bottom left instead of the clock.
Thanks
Cody

[DBLSPRT68]

Originally Posted by tcody

Don't mean to hijack this thread, but I have been looking for the gauge cluster pictured above at the local truck parts yard and can not find one with a pod that has all the mounting tabs intact. If anyone has an extra one I would be grateful! It's for a 1989 GMC 7000 and has the air pressure gauge in the bottom left instead of the clock.
Thanks
Cody

Cody, welcome aboard here buddy! These come up here for sale once and a while. There is one on Ebay right now... http://cgi.ebay.com/ebaymotors/ws/eB...m=180718411183 You might not ever find a cluster with ALL the mounting tabs there, but you only need 2 or three. The bezel and the dash pad will hold it in place, not to mention being stuffed into the metal dash and a big wire bundle hooked to it . David

[my4by2]

Here's mine - started with the same gauge you have - sent it out to Redline Gauge Works & had them totally re-do it for me. All modern internals for my LS & re-silkscreened face to correct the diesel RPM range.

[b454rat]

You don't need to use a tach only housing, you can use a regular one non tach one. Just need to cut a small hole in the back for the tach wires to go thru. I did this to one of the trucks I had.

I still have two tach clusters left, haven't had any time to hit the yards and look for more. 2-3 can bring coupe extra bucks...