factory tachometers

[J-Spec C10]

Which trucks came with factory tachs? I'm going yard hunting for one so knowing where to look saves a lot of time. Will I need to take anthing other than the gauge for the swap?

[78SilveradoSWB]

They were standard on Scottsdale and Silverado trim packaged Chevy models and Sierra Grande, Sierra Classic GMC models I believe but I may be wrong. Then again, it was an option for most models. Good hunting. Seen some on Ebay, but mostly as gauge packages vs. just the tach.

[Prerunner1982]

no factory tach on my 82 silverado...

[78SilveradoSWB]

Jon, you're right. I'm reading my brochure and it just says full instrumentation, meaning it doesn't have idiot lights. Tachometer is an option. Thanks fer steering me right

[Hooter]

It was an option. It's not in any particular model of truck. You will just have to look. I think a tachometer was only available till 1982

[Captkaos]

Originally posted by Hooter
It was an option. It's not in any particular model of truck. You will just have to look. I think a tachometer was only available till 1982

It was only availible for 1/2T's until 1981, it was availible as an option for others past that.

[J-Spec C10]

cool, I can't wait for another day off! I like touring the wreckin' yards, I dunno why, its just fun!

[75stepside]

hunting through salvage yards is like looking for burried treasure! ...just makes you all warm & mushy inside when you find it

[Hooter]

Originally posted by Captkaos


It was only availible for 1/2T's until 1981, it was availible as an option for others past that.

Thanks for clarifying that for me, I was always a bit confused on that subject

[78ls9silvrdo4x4]

if anybody finds one in good working cond please let me know , need one for the silv.

[Prerunner1982]

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1875484124

[bill_ont_canada]

Originally posted by J-Spec C10
cool, I can't wait for another day off! I like touring the wreckin' yards, I dunno why, its just fun!

Thats cos it's a guy thing Kyle...

There's nothing like looking through the Wreckers yard on a Saturday morning... With a fresh skiff of snow on the ground. and the smell of cutting torches and burning rubber wafting through the air, And then you see it... The piece you have been lookin for since last summer. Just like finding Gold.
It's an adventure every time I go.

[78SilveradoSWB]

Found this tachometer on Ebay:

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1876467100

[stomper]

Look in 2 1/2 ton trucks. They usually have them. I drove by an old '85 grain truck for sale the other day and it had one. Just gotta crawl up and look you know... I got a tach for my '86 that matches the other gauges in my dash. Got it on eBay for $125.

[1976K5CHALET]

As stated a factory tach was an option....you either forked out the cash or didn't. Two styles....73-late 77...manual oil psi gauge...makes a difference in the printed circuit board and the bucket....78 up went to an electric oil psi gauge...

The C60/70 series is an entirely different story....has a dual air guage set up for air brakes and the fuel gauge is located within the tach.....C/K series trucks are a drop in install....the dash harness was wired with a splice so you can interchange tach or no tach....which basically moved the fuel gauge around...C60/70 trucks are wired completely different.....and the buckets are different also....it can be installed....i bought a Helm 79 Medium duty wiring diagram for notes as an air guage for on board air would be sweet.

Azblazer

[KIILew]

Gauge package and tachometer applications are as follows for 1973 to 1987 light duty models only (excluding special editions in this discussion):

Standard instrumentation included speedometer/odometer, fuel guage, generator warning light, oil pressure warning light, engine temperature warning light. Standard on all years and models EXCEPT FOR 1973-1974 YE9 Cheyenne Super/Sierra Grande and 1975-1987 Silverado/Sierra Classic models.

Optional Z53 guage package replaced replaced the generator, oil pressure, and engine temp warning lights included with the standard instrumentation packages above with ammeter (1973-1975) or voltmeter (1976-1987), oil pressure, and engine temperature guages. This package was optional with all trim levels, except for the 1973-1974 YE9 Cheyenne Super/Sierra Grande and 1975-1987 Silverado/Sierra Classic models, where it was standard.

Optional U35 electric clock available on all 1973-1987 models but required purchase of Z53 guage package where not standard. Could not be ordered in conjuction with optional U16 tachometer.

Optional U16 tachometer available on all 1973-1981 models but required purchase of Z53 guage package where not standard. Could not be ordered in conjuction with optional U35 electric clock. ALSO: this tachometer option continued to be available on all 1982-1987 models, but ONLY AS A SPECIAL EQUIPMENT ORDER OPTION. (This fact is noted only in Data Books and NOT in brochures.)

Ken

[ElGracho]

Speaking of the larger trucks (bigger than 1 ton...) they too had many variations. Not all of those trucks had the small air gage or small vacuum gage as previously mentioned so some of them are directly interchangeable with the CK10-30 factory Z53 style packages. If you find one of these, beware that there are also different speedo head designs so you may not be able to use your old speedo head to maintain your current mileage and the plastic gage 'bucket' and printed circuit for the tach insturment cluster is different that those that didn't have one so if you find a cluster, get the whole thing. KIILEW had an excellent description and to add to that keep in mind the oil pressure gage design went from mechanical to electrical 78.

One last point, there were dealer accessory tachs available (using a signal from the alternator) for DIESEL trucks at least in the 80's that combined the fuel gage and tach into one instrument that fit to the right of the speedo.

[crossy]

Well Kaos gave you the short version although he knows more:-) . i 've been called the guru of these things and this could get i nto a mighty lengthy discussion so i'll just post my old "WORD DOCUMENT' . I've learned all this the HARD WAY. Do not BUY JUST A TACH & FUEL GAUGE AS THE PC and CLUSTER HOUSING ARE TOTALLY DIFFERENT. this info may confuse you a bit but read it more than once. pay close attention to years mentioned as you are looking for the most sought after one. also note my EBAY findings. Most of all save it . DAVE

*,PLEASE READ ON FOR PROPER
APPLICATION. This is one of those items that is commonly mis-advertised as
73-87 when in fact there are several differences in each unit The first
thing to keep in mind is that GM did offer a Tach as an option after
1981 in light trucks,but they are rare as Hens teeth .I have found Canadian units that were supposedly from Mid 80's
trucks/blazers but the speedo is in KmH .It would be easy to install a U.S. MPH
speedo to it.There were 6 cyl. and 8 cyl. models available and a 6 cyl. one
is going to read high in a V-8 application. 95% are probably V-8's. Try to
know it works before you buy it. I have been TOLD that the 73-75 units are
NOT serviceable[I verified this now] and if they are bad, and keep in mind that ANY service will
probably set you back $125+ .I also found out Most of the tach repair places do'nt carry parts for these year tachs. The Light trucks were only offered with a
5,000 RPM tach but I have seen 4,000 RPM ones also. probably big diesel.
{when i say BIG ,I mean like a C-60/C-6000 series truck. The tach is easy to wire, but getting at least a short
piece of the factory pigtail to the back of it is nice to have, But not a
necessity. If you look close at the back of the tach it will tell you where
the wires go. many people don't know that there was a 'filter', that looks like a condenser, installed in many years of the factory wiring for radio interference reasons.It was mounted on the firewall behind the distributor. this is not a necessity .Speaking of distributors it does not matter if you have and old point ignition or HEI the tach still works.
MOST Tach dashes WITH a VOLT gauge are the common ones and will work in 78-84 for sure as pretty much a
"plug in and go" unit. It is possible to work on 1985 and 1986 models
depending on what you have still have in the way of the factory computer
[I.E.= if you have removed the factory feedback carb And ESC distributor,
Etc. and DON'T need feedback then it will be fine]. As far as pickups go it
will not work on an 87 and will not work on Blazers and Burbs from 1987 to
1991 because of feedback needed for the factory EFI computer(ECM). Again it can made,and at least one will be made by me to sell. The 1973
to 1975 models used an AMP gauge instead of the VOLT gauge and this can
cause major wiring problems (meltdown) if installed in later trucks equipped
for VOLT gauge or vice-versa. The 1976-77 used the volt gauge but had a
mechanical oil pressure gauge and creates a two year only dilemma of sorts.
If you find a 1976 or 77 unit with the VOLT gauge and the MECH. Oil pressure
then it can only be used in 76 and 77 models with a complete and KNOWING wiring change of the later model wiring connector.It is not just a simple matter of using the mechanical pressure gauge instead of the electric. If you are Brave and think you can rewire it to be compatible and use the mechanical oil pressure gauge then something to keep in mind here is
to get at least a little piece of the factory oil line and fitting that was
on the back of the gauge. I say this because the factory gauge has a unique
type of ferrule and fitting on the back of the gauge that is good to save
and reuse. I have made aftermarket lines/fittings work but have also had
them blow off the back and make one heck of a mess. The factory used a
steel oil pressure line and I prefer that to plastic or you can buy 1/8" copper. Keep in mind that
there were also several variations of needle colors and the type of
lettering/numbers on the gauges. Mixing and matching gauges can create a
weird looking unit. The big trucks ,like C-60's are easily identified by a
tiny fuel gauge UNDER the tach and anything from a clock,blank , air pressure
gauge ,or vacuum gauge CAN be where the small ,round ,lower left clock option goes in a pickup dash. Some big trucks only had 4,000
RPM tachs also[and you thought a 5,000 was too low]. LOL.. Big truck tach dashes can be made to work in a pickup ,but offer many of there own unique problems because of optional gauges that were available in them and the years of compatibility and options mentioned above DO NOT directly apply to them.
big things to get from all of this is , AMP or VOLT gauge could= FIRE, so Know it works! or BIG $$ to fix, 6Cyl. or 8 Cyl., 75% of sellers on Ebay Don't care about your concerns because I Email them all the time hoping they will correct their ad and they Don't. 25% are very grateful. ONLY 25%. YOUR WELCOME, DAVE

*,PLEASE READ ON FOR PROPER
APPLICATION. This is one of those items that is commonly mis-advertised as
73-87 when in fact there are several differences in each unit The first
thing to keep in mind is that GM did offer a Tach as an option after
1981 in light trucks,but they are rare as Hens teeth .I have found Canadian units that were supposedly from Mid 80's
trucks/blazers but the speedo is in KmH .It would be easy to install a U.S. MPH
speedo to it.There were 6 cyl. and 8 cyl. models available and a 6 cyl. one
is going to read high in a V-8 application. 95% are probably V-8's. Try to
know it works before you buy it. I have been TOLD that the 73-75 units are
NOT serviceable[I verified this now] and if they are bad, and keep in mind that ANY service will
probably set you back $125+ .I also found out Most of the tach repair places do'nt carry parts for these year tachs. The Light trucks were only offered with a
5,000 RPM tach but I have seen 4,000 RPM ones also. probably big diesel.
{when i say BIG ,I mean like a C-60/C-6000 series truck. The tach is easy to wire, but getting at least a short
piece of the factory pigtail to the back of it is nice to have, But not a
necessity. If you look close at the back of the tach it will tell you where
the wires go. many people don't know that there was a 'filter', that looks like a condenser, installed in many years of the factory wiring for radio interference reasons.It was mounted on the firewall behind the distributor. this is not a necessity .Speaking of distributors it does not matter if you have and old point ignition or HEI the tach still works.
MOST Tach dashes WITH a VOLT gauge are the common ones and will work in 78-84 for sure as pretty much a
"plug in and go" unit. It is possible to work on 1985 and 1986 models
depending on what you have still have in the way of the factory computer
[I.E.= if you have removed the factory feedback carb And ESC distributor,
Etc. and DON'T need feedback then it will be fine]. As far as pickups go it
will not work on an 87 and will not work on Blazers and Burbs from 1987 to
1991 because of feedback needed for the factory EFI computer(ECM). Again it can made,and at least one will be made by me to sell. The 1973
to 1975 models used an AMP gauge instead of the VOLT gauge and this can
cause major wiring problems (meltdown) if installed in later trucks equipped
for VOLT gauge or vice-versa. The 1976-77 used the volt gauge but had a
mechanical oil pressure gauge and creates a two year only dilemma of sorts.
If you find a 1976 or 77 unit with the VOLT gauge and the MECH. Oil pressure
then it can only be used in 76 and 77 models with a complete and KNOWING wiring change of the later model wiring connector.It is not just a simple matter of using the mechanical pressure gauge instead of the electric. If you are Brave and think you can rewire it to be compatible and use the mechanical oil pressure gauge then something to keep in mind here is
to get at least a little piece of the factory oil line and fitting that was
on the back of the gauge. I say this because the factory gauge has a unique
type of ferrule and fitting on the back of the gauge that is good to save
and reuse. I have made aftermarket lines/fittings work but have also had
them blow off the back and make one heck of a mess. The factory used a
steel oil pressure line and I prefer that to plastic or you can buy 1/8" copper. Keep in mind that
there were also several variations of needle colors and the type of
lettering/numbers on the gauges. Mixing and matching gauges can create a
weird looking unit. The big trucks ,like C-60's are easily identified by a
tiny fuel gauge UNDER the tach and anything from a clock,blank , air pressure
gauge ,or vacuum gauge CAN be where the small ,round ,lower left clock option goes in a pickup dash. Some big trucks only had 4,000
RPM tachs also[and you thought a 5,000 was too low]. LOL.. Big truck tach dashes can be made to work in a pickup ,but offer many of there own unique problems because of optional gauges that were available in them and the years of compatibility and options mentioned above DO NOT directly apply to them.
big things to get from all of this is , AMP or VOLT gauge could= FIRE, so Know it works! or BIG $$ to fix, 6Cyl. or 8 Cyl., 75% of sellers on Ebay Don't care about your concerns because I Email them all the time hoping they will correct their ad and they Don't. 25% are very grateful. ONLY 25%. YOUR WELCOME, DAVE

*,PLEASE READ ON FOR PROPER
APPLICATION. This is one of those items that is commonly mis-advertised as
73-87 when in fact there are several differences in each unit The first
thing to keep in mind is that GM did offer a Tach as an option after
1981 in light trucks,but they are rare as Hens teeth .I have found Canadian units that were supposedly from Mid 80's
trucks/blazers but the speedo is in KmH .It would be easy to install a U.S. MPH
speedo to it.There were 6 cyl. and 8 cyl. models available and a 6 cyl. one
is going to read high in a V-8 application. 95% are probably V-8's. Try to
know it works before you buy it. I have been TOLD that the 73-75 units are
NOT serviceable[I verified this now] and if they are bad, and keep in mind that ANY service will
probably set you back $125+ .I also found out Most of the tach repair places do'nt carry parts for these year tachs. The Light trucks were only offered with a
5,000 RPM tach but I have seen 4,000 RPM ones also. probably big diesel.
{when i say BIG ,I mean like a C-60/C-6000 series truck. The tach is easy to wire, but getting at least a short
piece of the factory pigtail to the back of it is nice to have, But not a
necessity. If you look close at the back of the tach it will tell you where
the wires go. many people don't know that there was a 'filter', that looks like a condenser, installed in many years of the factory wiring for radio interference reasons.It was mounted on the firewall behind the distributor. this is not a necessity .Speaking of distributors it does not matter if you have and old point ignition or HEI the tach still works.
MOST Tach dashes WITH a VOLT gauge are the common ones and will work in 78-84 for sure as pretty much a
"plug in and go" unit. It is possible to work on 1985 and 1986 models
depending on what you have still have in the way of the factory computer
[I.E.= if you have removed the factory feedback carb And ESC distributor,
Etc. and DON'T need feedback then it will be fine]. As far as pickups go it
will not work on an 87 and will not work on Blazers and Burbs from 1987 to
1991 because of feedback needed for the factory EFI computer(ECM). Again it can made,and at least one will be made by me to sell. The 1973
to 1975 models used an AMP gauge instead of the VOLT gauge and this can
cause major wiring problems (meltdown) if installed in later trucks equipped
for VOLT gauge or vice-versa. The 1976-77 used the volt gauge but had a
mechanical oil pressure gauge and creates a two year only dilemma of sorts.
If you find a 1976 or 77 unit with the VOLT gauge and the MECH. Oil pressure
then it can only be used in 76 and 77 models with a complete and KNOWING wiring change of the later model wiring connector.It is not just a simple matter of using the mechanical pressure gauge instead of the electric. If you are Brave and think you can rewire it to be compatible and use the mechanical oil pressure gauge then something to keep in mind here is
to get at least a little piece of the factory oil line and fitting that was
on the back of the gauge. I say this because the factory gauge has a unique
type of ferrule and fitting on the back of the gauge that is good to save
and reuse. I have made aftermarket lines/fittings work but have also had
them blow off the back and make one heck of a mess. The factory used a
steel oil pressure line and I prefer that to plastic or you can buy 1/8" copper. Keep in mind that
there were also several variations of needle colors and the type of
lettering/numbers on the gauges. Mixing and matching gauges can create a
weird looking unit. The big trucks ,like C-60's are easily identified by a
tiny fuel gauge UNDER the tach and anything from a clock,blank , air pressure
gauge ,or vacuum gauge CAN be where the small ,round ,lower left clock option goes in a pickup dash. Some big trucks only had 4,000
RPM tachs also[and you thought a 5,000 was too low]. LOL.. Big truck tach dashes can be made to work in a pickup ,but offer many of there own unique problems because of optional gauges that were available in them and the years of compatibility and options mentioned above DO NOT directly apply to them.
big things to get from all of this is , AMP or VOLT gauge could= FIRE, so Know it works! or BIG $$ to fix, 6Cyl. or 8 Cyl., 75% of sellers on Ebay Don't care about your concerns because I Email them all the time hoping they will correct their ad and they Don't. 25% are very grateful. ONLY 25%. YOUR WELCOME, DAVE

[Captkaos]

Originally posted by crossy
Well Kaos gave you the short version although he knows more:-)

I will 100% DENY that! Dave is THE man when it comes to Tach clusters. Compared to him, I know nothing. Besides, I couldn't find his document that he saved.

[J-Spec C10]

Yikes! that was more in depth than I expected. So I'll just go and find a couple and then compare them to the article. Anythng I can't use I'll just sell on the parts board.

[1976K5CHALET]

Crossy....very impressive display of GM lore!!!! Now go to Ebay and buy that CUCV cd manual.....more interesting ideas and such....i'm gonna run some of the numbers at my local gm dealer tomorrow for the hell of it....

Azblazer

[crossy]

the CUCV's are a whole different breed. They do not sell well other than areas where guys do serious off roading. the lazy utilitarian type people , like me, that i deal with have no use for a stripped down ,smokey diesel ,camo paint, rough riding ,blah blah blah. ;-).
I just so happens though that i saved a some useful ID info on those Miliatry trucks and have a link to a site dedicated to them.

COPIED INFO*************
What do you need to know about them? I can pretty much tell you everything. (almost) Another better site is www.steelsoldiers.com <http://www.steelsoldiers.com>
Heres some info to start with:
Configurations:
M1008: Tactical Cargo, 1¼ ton
M1008A1: Tactical Cargo, 1¼ ton
M1009: Tactical Utility, ¾ ton
M1010: Tactical Ambulance, 1¼ ton
M1028: Tactical Shelter Carrier, 1¼ ton
M1028A1: Tactical Shelter Carrier w/ PTO, 1¼ ton
M1031: Tactical Chassis, 1¼ ton
Length:
M1008/A1, M1028/A1: 220.7 inches
M1009: 191.8 inches
M1010: 227.7 inches
M1031: 212.9 inches
Width:
M1009: 79.6 inches
All Other Models: 81.2 inches
Weight (curb):
M1009/M1031: 5200 lbs
M1008/A1, M1028/A1: 5900 lbs
M1010: 7400 lbs
Height:
M1009, M1008/A1, M1031: 76 inches ave.
M1010: 101.6 inches
M1028/A1: 107.1 inches
Engine: V8, 6.2L (379ci) displacement, fuel injected diesel, liquid cooled, compression ignition, nope, no turbo (I will slap on a Banks™)
Horsepower: 135 at 3,600 RPM
Transmission:TH400, 3 speed, automatic
Transfer case: NP208, 2 speed, locking, chain driven, all models except M1028A1 and M1031 which have the NP205 gear-driven t-case
Axles: All models have Corp. 14-bolt rear and Dana 60 front except M1009 which has Corp. 10-bolts front and rear
Differentials: All models have the Detroit No-Spin except the M1009 which has the Gov-Loc
Electrical system: 12/24 volt, negative ground, 100 amps (200 amps M1010 ambulance)
Heating/Cooling: hot-water heat all models, AC only in M1010 ambulance
Brakes: Hydraulic, front discs, rear drums
Fuel type: Diesel
Fuel capacity:
M1009: 27 gal
All The Rest: 20 gal

------------------
Steve S.
86 K30 4x4 6.2L Diesel "Steel Soldier"
<http://members.aol.com/_ht_a/txstruck/myhomepage/>

[navybear70]

Originally posted by ElGracho
One last point, there were dealer accessory tachs available (using a signal from the alternator) for DIESEL trucks at least in the 80's that combined the fuel gage and tach into one instrument that fit to the right of the speedo.

I ran across a factory tach cluster at the local salvage yard today! I think the truck was a Sierra. It has the little fuel gauge under the tach and some other gauge where the clock or fuel would go. Possibly a vacuum or pressure gauge. The guy wants $75 for the entire cluster. Is it worth trying?

[75stepside]

Originally posted by crossy
I have been TOLD that the 73-75 units are
NOT serviceable[I verified this now] and if they are bad, and keep in mind that ANY service will
probably set you back $125+ .I also found out Most of the tach repair places do'nt carry parts for these year tachs.

i have a tach cluster that i bought for my project... any idea of where i can get it serviced... the tach works, but is a little delayed... i know that yearone services tachs, but they want $250 to do it... also, how do i tell what year the tach is... ???

[crossy]

if you email me at home , all4trux@snip.net . I'll try to pinpoint a year for you. As far as the tach repairs I think I went to a Yahoo search hand put in "automotive tach* repairs" i emailed everyone that came up. I copied and pasted a general question about repairs after i tild them what it was . something like .

Hello, I found you company in a genral internet search for tach repairs . I have a blah blah from a blah blah that reads a little slow . appx XXX RPM at XXXXrpm . I was wondering if you think you might be able to fix it and what your minimum charge is .



I got back many repies. DAVE