CUCV Technical Info

Here is information I have collected while working on my m1009, but this information can be used for m1008,m1028, m1028A, and any of the cucv series.

The CUCV (Commercial Utility Cargo Vehicle) was manufactured by General Motors for the U.S. government from 1984-1986. They were built from the heaviest duty parts of GM’s light commercial truck division.  The M1009 is a stripped down blazer that has been modified to reach a 3/4 ton load rating while all other CUCV series trucks are rated at 1 1/4 ton.

Known Problems:

Government Issued Manuals Regarding the CUCV:

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  1. TM 9-2320-289-10 — Operators Manual
  2. TM 9-2320-289-20 — CUCV Maintenance Manual
  3. TM 9-2320-289-34 — Intermediate Maintenance Manual
  4. TM 9-2815-237-34 — 6.2L Engine Maintenance
  5. TM 9-2320-289-20P — Parts Manual
  6. TM 9-2320-289-34P — Intermediate Parts Manual
  7. TB 11-5820-890-20-77 — Radio Install
  8. LO 9-2320-289-12 — Lube Order
  9. TB 43-0147 — Paint Specs

Miscellaneous Information:

  • Dot 5 silicone brake fluid (Level should be 1/4″ below top)
  • Power Steering fluid can either be dextron III transmission fluid or standard power steering fluid (Military used transmission fluid do not mix)

Batteries and Alternators

  • Group 31 or 6TLs (Original)
  • Any 800+ CCA batteries would work
  • Dual 100Amp Alternators wired in series for 24V
  • Passenger side alt MUST BE ISOLATED GROUND!


  • 6.2L Naturally Aspirated J Code Detroit Diesel V8 (Slightly higher output than early civilian C code engines)
    • Injector Pump
      • Stanadyne Roosa Master DB2 (Click for detailed information)
      • The estimated life is 100,000 miles. However, in a 25 year old vehicle, the seals are worn out.
      • If you are leaking fuel from the bell-housing cover, it is likely drain off from the IP through a hole in the rear of the engine compartment
      • The first seals to wear out are normally the throttle-shaft seals which are inexpensive but a time consuming job to replace in which the intake must be removed. Also the wearing of these seals normally corresponds with the wearing of the pump itself and it may be better to rebuild or replace the pump if it is original. Rebuilt pumps are usually in the $3-500 range plus a core charge if you don’t provide them with your old one. Getting your IP rebuilt is probably the best thing you can do for your vehicle.
    • Normal Coolant Operating Temperature: 180*F – 230*F
    • Normal Oil Operating Temperature: 180*F – 260*F
    • Oil Pressure: 40 – 50 psi (running), 10 psi (idle)
    • Governor Settings (Governed Speed)
      • Full Load: 3600 rpm
      • No Load: 4000 rpm
      • Idle Speed: 625 – 675 rpm
    • Compression Ratio: 21.5:1
    • Dry Weight: 650 lbs
  • Maintenance:
    • Fuel Filter (Fuel filter base is a common leak point)
      • NAPA# FIL3136
      • FRAM # P3940A
    • Oil
      • 8 Quart Capacity (including filter)
      • Filter is FRAM# PH5, NAPA# FIL1092, ACDELCO# PF1218CL, K&N# HP-3002
    • Thermostat
      • NAPA 381-190
      • Autozone 42995
      • Orielly 42995
    • Glow Plugs
    • Belts (Not for M1010)
      • Driver side alt Gates# 7575/Dayco# 15580/Goodyear# 15574
      • Passenger side alt Gates# 7483/Dayco# 15490/Goodyear# 15485
      • Power Steering Gates# 7448/Dayco# 15455/Goodyear# 15461
    • Air Filter
      • Any standard air filter designated for use in a diesel K5/K30 works
    • 27MT Starter Shimming
      • The 27MT starter needs to be shimmed to mesh properly with the ring gear. Even “no-shim” housings may need to be shimmed. Clearance should be measured per TM 9-2320-289-20. If the starter is removed, it is a good time to check the clearance between the pinion gear and the thrust collar per TM 9-2320-289-34.
      • Starter Shimming Guide


  • Turbo-Hydramatic 400 (Th400)
    • CUCVs should have a factory deep sump pan and a bolt on cast aluminum torque converter cover
    • Dextron III Oil
      • 4 Quart capacity
      • Replace filter ever 2 years or 24,000 miles
        • NAPA#  ATP14558,
        • FRAM#  FT1020A (w/gasket)
    • If running oversize tires or towing an external cooler is HIGHLY recommended in addition to the water to oil cooler in the radiator

Transfer Case:

  •  NP208 aluminum chain driven transfer case (M1009/M1008/M1028/M1010)
  •  NP205 cast iron gear driven transfer case with PTO abilities (M1031)
  • Dextron III fluid
    • 5 quart capacity
    • Level should be 1/4″ below filler plug


  • M1009
    • 10 bolt axles front and rear with 3.08 gears and a Gov-Loc in the rear (Not Dana 60 front and 14 bolt rear like some believe)
  • All other CUCV’s
    • Dana 60 front
      • Front Capacity 4.5 Quarts
    • 14 Bolt FF rear with Detroit locker and 4.56 gears (some have a true-track locker in the front as well, but it is rare)
      • Rear Capacity 5.4 Quarts
      • M1028 needs GM additive

Lights/Blackout Lights

  • The right toggle switch moves power to the service lights, horn, dash, etc (up position) or to the blackout lights (down position). Pull it out and flip it up or down.
  • The left switch turns on the blackout drive light. Flip it up or down; it will return to center position.
  • If your lights suddenly don’t work, check the right toggle switch.


There are multiple options to get a tach installed in a CUCV the simplest being a digital tiny tach ( the fuel injection lines on the CUCV are 1/4″ OD. The CUCV alternators also have a tach output on the alternators so that can be used for certain tachometers as well.

CUCV Fuse Box:

Fuse Panel

Some information on this page from

120 Responses to “CUCV Technical Info”

  1. Erik says:

    Can you tell me where the volt meter hooks up at? And how it hooks up? The wiring location where it supports to come out and then hook up?

  2. Wayne says:

    regarding v belts new belts are metric width approximately 7/16 in
    These trucks pulleys are designed for 1/2″
    Makes a big difference.

  3. orlando says:

    has anyone installed the gear vendors od set on cucv? ony in 2wd of course but seems like a good way for highway improvement?

  4. KP86CUCV says:

    Regarding belts for the ’86 M1009, the part number for the various belts all have different outside dimensions.

    Driver side alt:
    Gates #7575 is 58.07″
    Dayco #15580 is 58.57″
    Goodyear #15574 is 57.57″

    Passenger side alt:
    Same, three brands have different outside circumference.

    Are these differences in measurement negligible? I read somewhere else, can’t find source, that folks had issues with certain belts. Any help would be appreciated and thank you!

  5. Mark C gross says:

    I have a m1008 cucv and I was wondering if they come factory with a block heater?? Being a military version i would think they would but I’m not sure….been looking around the block but havnt seen any. Thanks

  6. Chris says:

    I have installed three different wiper/washer motor combinations. The issue is with the washer motor which works when first installed and after that will slowly move the cylinder when energized but not the full stroke and will not pump fluid. All lines have been thoroughly cleaned and inspected. It is a M1008 1984.

  7. terwixonse says:

    Help. I am looking for guide

  8. Anthony says:

    My 85 gen 1 light comes on after I turn the truck off. I’m having to disconnect the ground on the batteries or they will drain

  9. auto tech says:

    We are looking for a fire wall wiring plug, interior fuse box and harness and underhood harness.

    Anyone out there with a junk yard unit? need the harness, or possibly pieces.

    our phone is on the web site dolsontire dot com

  10. robert says:

    I have a problem with lights , brake lights , turn signals , emergency flashers nothing works and need help

  11. Pete says:

    Is there a differential conversion kit to increase highway speed on a m 1028A1?

  12. Steve says:

    Hey fellow M1000 series owners.
    I have a 86 M1009 recently the window washer stopped working. I checked all hose making sure they weren’t clogged, took off reservoir & cleaned no issues in previous listed, so I purchased a new wiper motor/pump, but still not working. was wondering if anyone else has run into this issue? Thanks

    • anon says:

      Yep. Wipers failed to “park” and only had one speed. Squirt didn’t. I got a remanufactured wipermotor and pump (single unit). Everything worked for about two weeks before the squirt pump failed again. Had the wiring tested and my mechanic says it’s the pump. He recommnded putting in an aftermarket electric pump.

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