***** PLEASE DO NOT ASK QUESTIONS ABOUT YOUR TRUCK IN THIS THREAD.
***** PART NUMBERS ARE LISTED IN THE FREE PARTS MANUALS.
*****LOOKUP THE PART NUMBER, FIND THE CIVVY REPLACEMENT AND THEN POST YOUR FINDINGS
I thought that with more and more hmmwv's being distributed to the LEO/FD departments, a nice list of "things to check" should be compiled for the users to follow. These "things to check" by no means replaces the knowlegde gained from the technical manuals which are free to download here on SS (thanks SS for this).
Fan clutch system fails often and consists of several components: thermistor switch, tdm, solenoid, clutch and hoses. If it does not work, the fan clutch is locked on. This will consume what limited hp there is and it will drink a lot of diesel. Do not deep ford if system is not working correctly.
Flush coolant system, inside and out (between oil cooler and rad), they run hot and you will need all the cooling potential you can get. Water wetter helps. Replace all hoses, they can be the old orginal ones and they will burst.
Tear down all hubs and rebuild correctly per manual if you do not want the tire to pass you on the road and/or injuring someone.
Replace control box (under A-beam above left driver's knee) with either a yellow lable KDS box (with matching yellow label GPC) or a EESS control box. Most other boxes are junk and the one with a separate glow plug harness can burn the truck down at any time. Always disconnect batteries before changing/removing the control box or you can destroy the control box.
Keep batteries fully charged by adjusting generator to 28.8vdc. Low batteries cook control boxes. This generator is used on a lot of mv's so learning how to adjust it is important.
Replace glow plugs with the latest ones available. If you have swollen ones, obtain proper extraction tool to remove.
Clean ALL grounding connections and use star washers on grounds. Metal and aluminum are not friends. Install an engine ground harness. It connects the engine's left head (back end gound point) to the starter ground, the fire wall stud, the control box, and the generator ground.
Flush all oils from truck: geared hubs, engine, tranny, tcase and differentials. If tcase is overfilled and your tranny is low, you may have a bursted tcase cooling loop (google vampire disease hmmwv).
Geared hub drain plugs can be stuck at times. Weld a nut or allen wrench on them and then loosen.
Inspect all ball joints and do not over grease them. Boots will burst. If boot is torn, replace ball joint. Grease all propellors and steering link arm u-joints.
Steering linkage/componets are weak. If you grab the cross link and it wiggles up/down or back forth, then replace: pitman, idlers and all tie rod ends. Tie rod ends and pitman tend to rust in place. Put anti-sieze on all new threaded parts.
Inspect lower A-arms for cracks near cross member bolts. They can crack from abuse.
Check frame rails for rust through.
Install 3pt seat belts at all four seats.
Do not use the push button light switch in a hmmwv (another fire potential). Use the 3 lever unit only and carry a spare.
Do not lock brakes up while a tire is in the air or you can break a half shaft (less likely on the 12.1K units). Obtain correct spares. 3 different lengths per hmmwv.
Learn BTM technique for off roading...Brake/Throttle Modulation. It works.
Check all 7 bolts on each half shaft (6 at the brake rotor and 1 inside the hub). They can back out over time and destroy brakes. and/or half shaft. Use thread locking material and new METRIC lock washers or NORD LOCK washers at the brake end.
Drive tranny in H on pavement and HL or LL off road only when required. Failure to do so with damage your differentials and is hard on the tcase.
Replace headlights with LED ones. And/or look for hmmwv 24vdc light bar kits to use for off road and night vision operations. All tail lights and marker lights are prone to corrode so it is a good idea to clean the grounding connections at each light.
Wiper motors can quit working mostly from the connection between the windshield frame and the A-beam in the middle. Clean contactors by folding windshield down to expose contacts. Or remove the connectors and hard wire them. The older style motor is prone to failure so replace with new. While you are working on the wiper motor, replace the 4 plastic bushings inside the upper windshield frame (2 at wiper motor, one at each pivot).
Please read up on tire-rim combinations for safety reasons.
Keep truck 24vdc and use readily availble step down power supplies to power 12vdc equipment. Makes no sense to cut up a somewhat water resistant wire harness.
Oh and please be careful when deep fording a not necessarily ready for deep fording hmmwv. If you think it is just a higher snorkle and exhaust extension, you are in for several service surprises, including a possible replacement engine (or turn it in for another hmmwv!). Even at 30", several bad things can happen so please read up on this or it may fail you when you need it during a water crossing rescue.
Be safe!
Additional:
Parking brakes, 2 series.
1. Original on rear propellor infront of differential. Prone to sticking/rubbing and heating disk. Some fires caused by this. Lube slide assembly or upgrade to newer system. Replace cable if kinked.
2. Newer system replaces rear brake calipers with hmmwv/hummer specific manual actuation on side. This can be found as a complete kit on the internet. The main thing to remember with newer system is that the manual crank arm where the cable attaches to the caliper needs to be adjusted (via the parking brake lever) so that it rests at its stop (towards rear of vehicle). If not, your rear brakes will drag and warp rotors may result.
Front Brake Calipers:
Front brake caliper part numbers from OReilly Auto Parts. Both include pins. Both are remanufactured. Price at auto parts store is $21.99each plus core charge (A little cheaper at Autozone but higher core charge). Hummer H1 prices are over $250 each. These are identical parts from a 1982 AMC Eagle, same casting numbers, etc.
Right Front: AlCardone 18-4182
Left Front: AlCardone 18-4281
For the engine grounding harness as mentioned in thehummerguy's:
It is a 5 point harness:
point 1- left rear head ground terminal
point 2 label A - 25" TO DASH
point 3 label B - 33" TO GENERATOR GROUND
Point 4 label C - 35" TO CONTROL BOX MOUNTING BOLT
Point 5 label D - 73" TO STARTER GROUND
For those with 2.56 ratio differentials, these are the bearing numbers and seals for easy cross referencing if/when you maintain the hmmwv.
Carrier Outerbearing set LH & RH Gvt buys them in a set of cup & cone Timken LM603049 LM603012. Alternate GM 7451140.
Pinion bearing set large M802048 M802011, GM 7451155
Pinion bearing set small M88048 M88010, GM 7450984
Axle Stub Ball bearing Annular P207K, GM 9439608, 9439608, 9411324.
Output seal plain to flanges 6009472, 5579989, SKF 544401-22, CR0061
Thanks to Mark R for this.
This is from TheHummerguy. Follow it if you have electrical starting issues.
"Where are you buying your glow plugs? Who makes them?
i see post after post after post with this same issue, you guys really need to look up in the archives past issues because this one comes up every month....now, this starting system is not difficult, but you MUST and I repeat MUST start with known good parts. I for one use the Kascar non-swell glow plugs, while they are expensive, I have never had an issue after numerous trucks. The EESS box, I always use KDS yellow label with matching yellow banded Temp sender unit...this is not a glow plug controller as some folks call it, the TSU replaced the GPC as the GPC was a weak point and failed often.
the TSU just sends a signal based on engine temp that say either turn on the glow plugs for 6-8 seconds or don't, quite simple. NOW, if your EESS is a GREEN Label, NO TSU is Required, the glow plugs cycle every time at startup regardless of engine temp, I don't see many green label box but I have a few in my stock I use for trouble shooting.
today I am seeing alot of the new S3 EESS boxes on eBay, these are the latest generation of box, I now have all my trucks running this box and they work quite nicely, no more glow plug afterglow where the gen bounces up and down for 2 mins after cold start, you can tell this box by the extra maint port on the front for Diag.equipment to plug into. I have several of these new boxes, they are either Nartron or KDS, each come with there own TSU but I have found any of the KDS or Narton TSUs work, they are backward compatible, again, TSU, Not GPC glow plug controller.
there is the SSI box, I would never use one of these, never had any luck, also, make sure you don't have one of the early versions where the glow plug connector plugs direct into this box, so you would 3 plugs on this box, 2 for the body wiring harness and one for the separate glow plug harness...theses boxes are a no no, they had a habit of actully starting the truck on its own, several motor pools had hmmwv's burn to the ground.
So now you have a good box, good glow plugs, now go clean off every ground on the truck....dash, gen, all the lights, starter, engine, all the gauges etc...now make up a grounding harness, you can buy them from Kascar or make your own.
think of an octopus, where the head of the octopus is the start point, in this case the engine, on the left rear cylinder is the ground termination, starting from there, run a wire to each of theses locations:
1. Generator ground
2. One of the bolts that mounts the EESS box
3.to the stud on the firewall that feeds all the instrument gauges, you should have cleaned this ground so you know where it is. You have to take the inst cluster out to get to it.the stud passes through to the engine area near the fuel filter, one of the body harness grounds terminates there.
4. The starter ground
All 4 of these connections can be terminated into on large 2/0 solderless connector that has a 3/8 lug to bolt up to the engine head. Now everything you need to run is grounded.
I have had trucks that would do all of the issues you guys post about fixed with just this harness, I have eaten my fair share of boxes as well, bad boxes will eat glow plugs, but the Kascar plugs have a thermo limiter like the civ AC 60 G glop lug, you can't burn them up, Wellman is the Mfg I see that the goverment gets there hmmwv glows from, every DRMO engine I have ever received be it 6.2, 6.5 or Turbo diesel all have the Wellman 24v GP's installed.
hope this helps." Steve.
Oil Filter Numbers
Ac pf35
champion lab ph1218
fram hp4
fram ph13
fram ph5
mobil1m1302
motorcraftfl12
purol30040
purol34631
purol35132
wix51060
wix51061
***** PART NUMBERS ARE LISTED IN THE FREE PARTS MANUALS.
*****LOOKUP THE PART NUMBER, FIND THE CIVVY REPLACEMENT AND THEN POST YOUR FINDINGS
I thought that with more and more hmmwv's being distributed to the LEO/FD departments, a nice list of "things to check" should be compiled for the users to follow. These "things to check" by no means replaces the knowlegde gained from the technical manuals which are free to download here on SS (thanks SS for this).
Fan clutch system fails often and consists of several components: thermistor switch, tdm, solenoid, clutch and hoses. If it does not work, the fan clutch is locked on. This will consume what limited hp there is and it will drink a lot of diesel. Do not deep ford if system is not working correctly.
Flush coolant system, inside and out (between oil cooler and rad), they run hot and you will need all the cooling potential you can get. Water wetter helps. Replace all hoses, they can be the old orginal ones and they will burst.
Tear down all hubs and rebuild correctly per manual if you do not want the tire to pass you on the road and/or injuring someone.
Replace control box (under A-beam above left driver's knee) with either a yellow lable KDS box (with matching yellow label GPC) or a EESS control box. Most other boxes are junk and the one with a separate glow plug harness can burn the truck down at any time. Always disconnect batteries before changing/removing the control box or you can destroy the control box.
Keep batteries fully charged by adjusting generator to 28.8vdc. Low batteries cook control boxes. This generator is used on a lot of mv's so learning how to adjust it is important.
Replace glow plugs with the latest ones available. If you have swollen ones, obtain proper extraction tool to remove.
Clean ALL grounding connections and use star washers on grounds. Metal and aluminum are not friends. Install an engine ground harness. It connects the engine's left head (back end gound point) to the starter ground, the fire wall stud, the control box, and the generator ground.
Flush all oils from truck: geared hubs, engine, tranny, tcase and differentials. If tcase is overfilled and your tranny is low, you may have a bursted tcase cooling loop (google vampire disease hmmwv).
Geared hub drain plugs can be stuck at times. Weld a nut or allen wrench on them and then loosen.
Inspect all ball joints and do not over grease them. Boots will burst. If boot is torn, replace ball joint. Grease all propellors and steering link arm u-joints.
Steering linkage/componets are weak. If you grab the cross link and it wiggles up/down or back forth, then replace: pitman, idlers and all tie rod ends. Tie rod ends and pitman tend to rust in place. Put anti-sieze on all new threaded parts.
Inspect lower A-arms for cracks near cross member bolts. They can crack from abuse.
Check frame rails for rust through.
Install 3pt seat belts at all four seats.
Do not use the push button light switch in a hmmwv (another fire potential). Use the 3 lever unit only and carry a spare.
Do not lock brakes up while a tire is in the air or you can break a half shaft (less likely on the 12.1K units). Obtain correct spares. 3 different lengths per hmmwv.
Learn BTM technique for off roading...Brake/Throttle Modulation. It works.
Check all 7 bolts on each half shaft (6 at the brake rotor and 1 inside the hub). They can back out over time and destroy brakes. and/or half shaft. Use thread locking material and new METRIC lock washers or NORD LOCK washers at the brake end.
Drive tranny in H on pavement and HL or LL off road only when required. Failure to do so with damage your differentials and is hard on the tcase.
Replace headlights with LED ones. And/or look for hmmwv 24vdc light bar kits to use for off road and night vision operations. All tail lights and marker lights are prone to corrode so it is a good idea to clean the grounding connections at each light.
Wiper motors can quit working mostly from the connection between the windshield frame and the A-beam in the middle. Clean contactors by folding windshield down to expose contacts. Or remove the connectors and hard wire them. The older style motor is prone to failure so replace with new. While you are working on the wiper motor, replace the 4 plastic bushings inside the upper windshield frame (2 at wiper motor, one at each pivot).
Please read up on tire-rim combinations for safety reasons.
Keep truck 24vdc and use readily availble step down power supplies to power 12vdc equipment. Makes no sense to cut up a somewhat water resistant wire harness.
Oh and please be careful when deep fording a not necessarily ready for deep fording hmmwv. If you think it is just a higher snorkle and exhaust extension, you are in for several service surprises, including a possible replacement engine (or turn it in for another hmmwv!). Even at 30", several bad things can happen so please read up on this or it may fail you when you need it during a water crossing rescue.
Be safe!
Additional:
Parking brakes, 2 series.
1. Original on rear propellor infront of differential. Prone to sticking/rubbing and heating disk. Some fires caused by this. Lube slide assembly or upgrade to newer system. Replace cable if kinked.
2. Newer system replaces rear brake calipers with hmmwv/hummer specific manual actuation on side. This can be found as a complete kit on the internet. The main thing to remember with newer system is that the manual crank arm where the cable attaches to the caliper needs to be adjusted (via the parking brake lever) so that it rests at its stop (towards rear of vehicle). If not, your rear brakes will drag and warp rotors may result.
Front Brake Calipers:
Front brake caliper part numbers from OReilly Auto Parts. Both include pins. Both are remanufactured. Price at auto parts store is $21.99each plus core charge (A little cheaper at Autozone but higher core charge). Hummer H1 prices are over $250 each. These are identical parts from a 1982 AMC Eagle, same casting numbers, etc.
Right Front: AlCardone 18-4182
Left Front: AlCardone 18-4281
For the engine grounding harness as mentioned in thehummerguy's:
It is a 5 point harness:
point 1- left rear head ground terminal
point 2 label A - 25" TO DASH
point 3 label B - 33" TO GENERATOR GROUND
Point 4 label C - 35" TO CONTROL BOX MOUNTING BOLT
Point 5 label D - 73" TO STARTER GROUND
For those with 2.56 ratio differentials, these are the bearing numbers and seals for easy cross referencing if/when you maintain the hmmwv.
Carrier Outerbearing set LH & RH Gvt buys them in a set of cup & cone Timken LM603049 LM603012. Alternate GM 7451140.
Pinion bearing set large M802048 M802011, GM 7451155
Pinion bearing set small M88048 M88010, GM 7450984
Axle Stub Ball bearing Annular P207K, GM 9439608, 9439608, 9411324.
Output seal plain to flanges 6009472, 5579989, SKF 544401-22, CR0061
Thanks to Mark R for this.
This is from TheHummerguy. Follow it if you have electrical starting issues.
"Where are you buying your glow plugs? Who makes them?
i see post after post after post with this same issue, you guys really need to look up in the archives past issues because this one comes up every month....now, this starting system is not difficult, but you MUST and I repeat MUST start with known good parts. I for one use the Kascar non-swell glow plugs, while they are expensive, I have never had an issue after numerous trucks. The EESS box, I always use KDS yellow label with matching yellow banded Temp sender unit...this is not a glow plug controller as some folks call it, the TSU replaced the GPC as the GPC was a weak point and failed often.
the TSU just sends a signal based on engine temp that say either turn on the glow plugs for 6-8 seconds or don't, quite simple. NOW, if your EESS is a GREEN Label, NO TSU is Required, the glow plugs cycle every time at startup regardless of engine temp, I don't see many green label box but I have a few in my stock I use for trouble shooting.
today I am seeing alot of the new S3 EESS boxes on eBay, these are the latest generation of box, I now have all my trucks running this box and they work quite nicely, no more glow plug afterglow where the gen bounces up and down for 2 mins after cold start, you can tell this box by the extra maint port on the front for Diag.equipment to plug into. I have several of these new boxes, they are either Nartron or KDS, each come with there own TSU but I have found any of the KDS or Narton TSUs work, they are backward compatible, again, TSU, Not GPC glow plug controller.
there is the SSI box, I would never use one of these, never had any luck, also, make sure you don't have one of the early versions where the glow plug connector plugs direct into this box, so you would 3 plugs on this box, 2 for the body wiring harness and one for the separate glow plug harness...theses boxes are a no no, they had a habit of actully starting the truck on its own, several motor pools had hmmwv's burn to the ground.
So now you have a good box, good glow plugs, now go clean off every ground on the truck....dash, gen, all the lights, starter, engine, all the gauges etc...now make up a grounding harness, you can buy them from Kascar or make your own.
think of an octopus, where the head of the octopus is the start point, in this case the engine, on the left rear cylinder is the ground termination, starting from there, run a wire to each of theses locations:
1. Generator ground
2. One of the bolts that mounts the EESS box
3.to the stud on the firewall that feeds all the instrument gauges, you should have cleaned this ground so you know where it is. You have to take the inst cluster out to get to it.the stud passes through to the engine area near the fuel filter, one of the body harness grounds terminates there.
4. The starter ground
All 4 of these connections can be terminated into on large 2/0 solderless connector that has a 3/8 lug to bolt up to the engine head. Now everything you need to run is grounded.
I have had trucks that would do all of the issues you guys post about fixed with just this harness, I have eaten my fair share of boxes as well, bad boxes will eat glow plugs, but the Kascar plugs have a thermo limiter like the civ AC 60 G glop lug, you can't burn them up, Wellman is the Mfg I see that the goverment gets there hmmwv glows from, every DRMO engine I have ever received be it 6.2, 6.5 or Turbo diesel all have the Wellman 24v GP's installed.
hope this helps." Steve.
Oil Filter Numbers
Ac pf35
champion lab ph1218
fram hp4
fram ph13
fram ph5
mobil1m1302
motorcraftfl12
purol30040
purol34631
purol35132
wix51060
wix51061
Last edited by a moderator:
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