FAQ Thread for CUCV's

[CCATLETT1984]

DO NOT POST A QUESTION IN THIS THREAD,
....it WILL be deleted!!!!




So here it is, you guys asked for a FAQ thread. I am going to watch this one closely, so please keep all posts geared towards useful info. If you are posting referencing a past thread, please include the link to the thread. From time to time, I may clean up the thread, pointless posts will be removed, and I may edit posts to keep them on track.

Let's try to make this a good place for all of the solutions to questions that seem to come up every few months.

 

[CCATLETT1984]

Ignition & Door Keys are a "B" blank and the code is 73Y2.

 

[Michael]

RE: FAQ Thread for CUCV

Do not buy AC13G glow plugs. They are obsolete.



I prefer AC60G which is what GM recommends for all civilian 6.2 and 6.5 engines.

 

[Crash_AF]

RE: FAQ Thread for CUCV

OEM Tire Size for CUCVs is:
235/85-16 Load Range - E or 245/75-16 Load Range E for the pickup/ambulance
31x10.50-15 for the M1009

 

[Crash_AF]

RE: FAQ Thread for CUCV

Common maintenance items:
BELTS
All W/O AC
Goodyear "Gatorback" - 15485 fits the passenger side alternator on the 6.2
Gates - Driver's side Alt, 7575 Pass side Alt, 7483 Power Steering, 7448

HOSES
NAPA - Upper: NBH7995 Lower:NBH7996

GLOW PLUG RELAY
NAPA - ST85
Or
Ford Powerstroke relay
NAPA - ECHGPR110

Good discussion about the differences between the GPRs

http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=21485

CDR (PCV) Valve
GM - 25042462

NAPA CRB229143 is the incorrect valve...

This is a good discussion about the replacement valve.

http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=21492

 

[Michael]

RE: FAQ Thread for CUCV

CUCVs use metric bolts so you will need metric tools to work on them.

The main problems with CUCVs are charging issues and glow plug issues. The original glow plug relay was defective and should have been replaced before the truck left the service. If you have one that looks like the black one in second and third pictures, you should replace it. Most come out of the service with the silver one like in the 4th picture. Some of the dealers here have had them in the past. The first picture shows one I got at NAPA. I used ECH GPR109 for $28.49. It looks just like the ECH GPR110 but it is $85.49.

The ST85 looks like what the military went to and is $54.49 at NAPA online or 45.20 at the local store. It also shows one way to bypass the voltage dropping resister. Here is a link to some pictures I took when I replaced my last relay with a ST-85. The old one is what came with the truck from the military.

http://1plant4u.smugmug.com/gallery/7646020_poZhN#494046840_RAMog



The 109 and 110 relays will bolt up with the same holes as the original relay. They don't come with nuts on the posts and they aren't the same size as the original so you will need to get some while you are at the store.

 

[Michael]

RE: FAQ Thread for CUCV

I would rate this as the third most common problem, but probably the most expensive one if you don't know what to do when it happens.

CUCVs have an extra starter relay under the dash. It is known to either rust and not work making the truck not start or to stick in the on position letting the starter run until the wiring harness or the starter itself burns up and is permanently damaged. You should read the two links below and the links mentioned in them before you even put batteries in the truck. This is probably the most important thing to know and to think about so you will know what to do should it happen to you.

The relay is mounted to the plate that the big plug is mounted to under the edge of the dash next to the 4WD lever. It is the bigger silver relay next to two black relays. Its purpose is to switch the 12v single from the ignition switch to 24v to trigger the 24volt starter. It has four wires plugged into it, The red wire is 24 volt feed. Solid purple goes to the starter. Black is ground. Purple with white stripe is the ignition feed. You can unplug these and jump the red to the purple and start the truck in an emergency. There is a post further down with the part numbers.

 

[Crash_AF]

RE: FAQ Thread for CUCV

The wiring diagram for the CUCV glow plug system are incorrect. If you are replacing a missing Glow Plug Relay, the small orange wire goes to the glow plug side of the relay, not the resistor side as shown on the wiring diagram. If it is on the resistor side, the controller will light up the wait light, but will not activate the relay.

Later,
Joe

 

[maritimer]

RE: FAQ Thread for CUCV

if your expieriencing vibrations at low speeds try rotating your rear driveshaft 180* on the pinion. also if your in canada and looking for parts the GM Stealerships do not have acess to any parts information your best option is NAPA

 

[Michael]

RE: FAQ Thread for CUCV

How to decode your vin number:

1st digit = Nation of Origin
-- 1 = USA

2nd digit = company
-- G = General Motors

3rd digit = division
-- B = Chevrolet, incomplete example contract maintenance trucks
-- C = Chevy Truck
-- 8 = Multipurpose Vehicle All M1009's (blazers)

4th digit = GVWR/Brake System
-- E = 6001 - 7000 Hydraulic
-- F = 7001 - 8000
-- G = 8001 - 9000
-- H = 9001 - 10000

5th digit = Line Description & Chassis Type
-- C = 2 Wheel Drive 1981-86
-- K = 4 Wheel Drive 1981-86
-- D = military 4/4

6th digit = Series
-- 1 = 1/2 ton
-- 2 = 3/4 ton
-- 3 = 1 ton

7th digit = Body Type
-- 4 = 2 Door Cab
-- 8 = Blazer

8th digit = Engine Description
-- J = 6.2L V8 Diesel

9th digit = character is a check digit to verify VIN accuracy using a mathematical formula

10th digit = Model Year
-- B = 1981 F = 1985
-- C = 1982 G = 1986
-- D = 1983 H = 1987
-- E = 1984

11th digit = assembly plant
-- F = Flint

 

[AJMBLAZER]

RE: FAQ Thread for CUCV

CDR valves are important but unfortunately not supported in the aftermarket and GM wants an arm, a leg, and something else (or two) for them.

These should be replaced every 50k according to GM (correct me if I'm wrong) but the diesel gurus seem to agree that much more frequent intervals are better. However it seems like they aren't common in the aftermarket as a replacement part. Pretty much the GM/AC Delco route is the only one any of us could find in my CDR thread.

The correct GM part number for the military spec'd part is 25042462 with AC Delco calling the same part the CV871. The part listed for a 1986 Chevy K30 6.2L civilian truck is a 25042248 in the GM parts book and a CV870 according to AC Delco. GM and EVERYONE else list the military spec part as obsolete and it's a dead end. The civilian part could not be located at NAPA, Advanced Auto (Kragen/Schucks/Shumers), Auto Zone, CarQuest, and two local places here in Traverse City, MI. The only locations I personally could find them were my local GM dealers at $71 each and www.Rock-Auto.com for about $41 delivered.

I have a feeling these are becoming a rare part as the box I received is definitely old having the older AC label on it and the date code on the box being from 1997. Others have alluded to getting the part from different suppliers but I haven't tracked this down. I'd definitely consider mine NOS.

The civilian part bolts right to the CUCV's mount and the hoses hook right up to it. Mine had a slightly different angle on the pipe that curves out and away towards the front of the truck but it might just be a manufacturing deviation and didn't pose any sort of problem.

 

[AJMBLAZER]

RE: FAQ Thread for CUCV

One of the threads above references the NAPA GPR109 glow plug relay. This part is meant for pre-Powerstroke Ford diesels. It is $25 or so while the GPR110 which is very similar costs around $85. We're not sure what the difference is between the two but even the local NAPA couldn't tell me other than to say "$60 more". I used the 109 and so far, so good.

There are two small issues with using the NAPA Ford GPR109 relay, both of which are perfectly fixable.

1. The brackets on the stock relay are of a "north and south" orientation with one on the top and one on the bottom. The 109 has them in a sort of "north and west" orientation. All I did was put the north bracket in the stock hole and then drill a new hole below the stock lower hole to mount the west bracket with. I just couldn't turn it enough to use the stock lower hole without hitting the brake system stuff there to the right of it. Some people have reported they were able to get theirs to line up with the stock holes without trouble but I was unable to do that with mine. Might just be me.

2. The 109's larger studs use different threads than the stock relay's larger studs do. You will have to go out and find new nuts because of this. Minor but it is something to take care of before you're kneeling on the radiator shroud, stretched across the engine cussing.
The two smaller stock studs use the same thread as the 109's smaller studs so their nuts can be reused on the 109.
Note that this is for the original style relay these trucks came with from the factory. I do not know if the updated relay the military used was different.

 

[gt1009]

RE: FAQ Thread for CUCV

Autozone starter relay is part number AC40 and comes up as a blower motor relay but will work fine and only costs $6 as opposed to $20 or more anywhere else.

 

[Mike_Pop]

Starter relay part cross reference numbers

GM: 15591718

NAPA: AR135

Carquest: RY117

Autozone: AC40 (Has five pins but will work. This is also a Ford heater relay)

 

[M1075]

Here are the fuse box pictures and diagrams others have posted in the past.

 

[steelsoldiers]

If you would like to add an electric fuel pump to make fuel filter changes, water draining, priming after repairs, etc... easier, then you can use a 12v electric pump from a late 80's 6.2L civi truck. I wired it with an inline fuse to an ign. on circuit on the fuse block and used GM weather-pack connectors to make it look factory. I used it like that for 8 years without a problem. Just make sure to use an inline filter before the pump to catch any trash. Change it when you change your primary filter can. Also mount the pump on the frame close to the fuel tank so the fuel with keep the pump cool and it will also be less likely to suck air through a pinhole in the line. It's always easier to find a hole in your fuel line with a drip.

 

[maritimer]

What is the proper procedure to shift into 4H, from 4H-4L, 4L-4H, and back to 2WD. I am not sure I do it right, there is some grinding when I'm going between ranges. I looked in the Op man. and didnt find what I was looking for.

from 2hi to 4hi as long as the hubs are locked in you can shift at any speed, i recomend you do it while coasting no throttle. from 4hi to 4lo sto pthe vehicle shift to neutral then pull the lever into 4lo may take a bit of a jerk.

 

[Crash_AF]

From the HMMWV forum:

prob want to put this in the sticky in the hmmwv and Cucv threads but you can get them from about any parts store. I called Napa, Autozone, Advance, and orielly. they could all get it.

Dorman 904-101

it was $9.52

This is the kit that will get you all the little rubber flex lines that go on the injectors and the clamps that hold them on. Does not come with the caps for #7 and #8

Later,
Joe

 

[nf6x]

RE: Re: M1009 Key same as M1031?

Hey, I want in on this horse-beating rank-building stuff, too! Yeah, we all know that the blank is B and the blind code is 73Y2. I hear rumors that those details are in a FAQ somewhere... most likely in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying "Beware of The Leopard". But how about the cutting code: That's 313531! And the blank: Jet calls it a B49. Ilco uses yet another number; they call it S1098B! I could list the cut depths and spaces, but wouldn't it be better if I did that in a different post?

To use the key, insert it in the lock and then turn it either clockwise or counterclockwise, as required. That would be deasil or widdershins, respectively, in very old vehicles.

I can't let a chance to post a picture go by!

 

[Crash_AF]

The heater blower motor from NAPA is the heavy duty one. The blower motor part # from NAPA is 655-1076

Later,
Joe