Alternator tensioner pulley replacement for M1078

[DiverseThinker]

New to the group and this is my first post after purchasing my 1995 M1078 LMTV from a member on this site. I believe it has the 3116 engine. I had a catastrophic failure of the alternator tensioner pulleys when they came apart while the vehicle was being driven. Sounded like an explosion going off. The bracket of the tensioner is fine but I do need to replace the dual v-groove pulleys. My issue is I do not have the originals nor can I find a part number to reference in the TMs. I searched this sight, but either my search terms were not on point or this topic has not been discussed....I bet it was my search terms. Any one have the specs of the diameter of the pulleys, part numbers or have a reference to an aftermarket replacement?

 

[coachgeo]

from the yellow spread sheet. This sheet is linked to in the thread found pinned/stuck to the top of this FMTV forum

Vendor______________________________________________________________part # ______________________Vendor _______________part #

NAPA/DAYCO

38550

CAT

253-1864

 

[Ronmar]

from the yellow spread sheet. This sheet is linked to in the thread found pinned/stuck to the top of this FMTV forum

Vendor______________________________________________________________part # ______________________Vendor _______________part #

NAPA/DAYCO

38550

CAT

253-1864

When you search that P/N it shows a spring loaded tensioner for a serpentine belt, so that is not the correct part for a 3116…

 

[DiverseThinker]

Thanks coachgeo & Ronmar. I saw this spreadsheet but this part is for those engines that have a serpentine belt. I am looking for, I assume, the older version. Part number 5 in the attached diagram. It appears to be 2 v-groove pulleys. As mentioned, the bracket is OK. So all I really need is the pulleys, but I will take the full bracket to get the truck back on the road. The TM also calls this a "alternator belt take-up mount".

 

[coachgeo]

will check to get the spread sheet updated, thanks for input

 

[coachgeo]

Does this help

PULLEYS & BELTS

Diagram of OEM PULLEYS & BELTS. Contains 10 parts priced between $0.30 and $386.28. Fits C6500, C7500.

www.wholesalegmpartsonline.com

Ps- once you find the number do pass it on.... thanks

 

[coachgeo]

what about this one?

100-6267 | CAT 3116 Engine Pulley for Sale

CAT 3116 Engine Pulley, P/N 100-6267 for sale. Enjoy our hassle-free online checkout or call to speak to an expert.

www.vanderhaags.com

https://parts.cat.com/en/catcorp/100-6267 though in this one it calls it an Idler

 

[coachgeo]

in the TM's did you find the NSN number for it.... some of the NSN search websites will post additional part numbers you can use to track things further

 

[DiverseThinker]

what about this one?

100-6267 | CAT 3116 Engine Pulley for Sale

CAT 3116 Engine Pulley, P/N 100-6267 for sale. Enjoy our hassle-free online checkout or call to speak to an expert.

www.vanderhaags.com

https://parts.cat.com/en/catcorp/100-6267 though in this one it calls it an Idler

Coachgeo, You are a machine finding all these possibilities. This is the plate and Pulley for the water pump. The problem with many of these parts, on this site and others, is they do not have specifications. The only specific I know is the shaft diameter the pulleys need to slide on to is 1.375". I am assuming the diameter of the pulleys are about 3” in diameter but would love confirmation from someone.

 

[DiverseThinker]

in the TM's did you find the NSN number for it.... some of the NSN search websites will post additional part numbers you can use to track things further

Searching the TMs for “pulley” I only found references to procedures for repair, replace or maintenance. But I did not find any part numbers. It is possible the 11, or so, PDF files I have, and searched, are not all of the documents and there is another one with part numbers.

 

[Ronmar]

You are looking for the 24P manual. That has all the system exploded views and individual part numbers. You can get it up in the tech manual section Unfortunately that part does not appear to readily cross to an off the shelf part. The P/N for the pulley is 12420812 if you google that you will get suppliers of NSN based parts, if you take the cage code you can determine who actually made the part and you may be able to find a comparable that way…

Good Luck

 

[coachgeo]

US Army Sale | Bekleidung - Ausrüstung - Fahrzeugteile

Hier finden Sie original US ARMY Ausrüstung und Fahrzeugersatzteile.

us-army-sale.de

but there are folk (easier to find on facebook though) that sell parts off non running trucks etc. They are in here too... just not as active

 

[DiverseThinker]

You are looking for the 24P manual. That has all the system exploded views and individual part numbers. You can get it up in the tech manual section Unfortunately that part does not appear to readily cross to an off the shelf part. The P/N for the pulley is 12420812 if you google that you will get suppliers of NSN based parts, if you take the cage code you can determine who actually made the part and you may be able to find a comparable that way…

Good Luck

Thank you Ronmar for directing me to this. I did submit a Request for Quote for purchasing two of them. I suspect, they will either ignore this or charge way too much for them.

 

[DiverseThinker]

If my plans to purchase new pulleys do not work out, the next step would be to try to find an after market replacement. If I can find one, I will let everyone know the manufacturer and model number. If this does not work out, then I will simply purchase pulleys that have a different shaft diameter and have a new shaft welded to the current bracket. I do hope that I can find existing after market pulleys.

 

[DiverseThinker]

US Army Sale | Bekleidung - Ausrüstung - Fahrzeugteile

Hier finden Sie original US ARMY Ausrüstung und Fahrzeugersatzteile.

us-army-sale.de

but there are folk (easier to find on facebook though) that sell parts off non running trucks etc. They are in here too... just not as active

Thanks again Coachgeo, I did not see that your post was a link to someone selling the part. I will attempt to purchase this and have them ship it to me.

 

[Ronmar]

Yea too bad yours self destructed. I suspect if you knocked out the freeze plug on the end you would find 2 snap rings and a off the shelf roller bearing that could be pressed out and replaced… I have rebuilt several idlers over the years it is really easy to do…

 

[Ohiobenz]

New to the group and this is my first post after purchasing my 1995 M1078 LMTV from a member on this site. I believe it has the 3116 engine. I had a catastrophic failure of the alternator tensioner pulleys when they came apart while the vehicle was being driven. Sounded like an explosion going off. The bracket of the tensioner is fine but I do need to replace the dual v-groove pulleys. My issue is I do not have the originals nor can I find a part number to reference in the TMs. I searched this sight, but either my search terms were not on point or this topic has not been discussed....I bet it was my search terms. Any one have the specs of the diameter of the pulleys, part numbers or have a reference to an aftermarket replacement?

I've got a like new one if you're still looking.

 

[BERZERKER888]

New to the group and this is my first post after purchasing my 1995 M1078 LMTV from a member on this site. I believe it has the 3116 engine. I had a catastrophic failure of the alternator tensioner pulleys when they came apart while the vehicle was being driven. Sounded like an explosion going off. The bracket of the tensioner is fine but I do need to replace the dual v-groove pulleys. My issue is I do not have the originals nor can I find a part number to reference in the TMs. I searched this sight, but either my search terms were not on point or this topic has not been discussed....I bet it was my search terms. Any one have the specs of the diameter of the pulleys, part numbers or have a reference to an aftermarket replacement?

these are your friends.. especially -10, -3 and 24P

M1078 TM's

Listed below are a number of the TM's for the M1078 trucks. To save them to your computer, right click, select "save as" m1078_TM 9-2320-365-10.pdf TM 9-2320-365-10 for the M1078 series trucks. m1078_TM 9-2320-365-20-1.pdf TM 9-2320-365-20-1 for the M1078 series trucks. m1078_TM...

www.steelsoldiers.com

 

[coachgeo]

these are your friends.. especially -10, -3 and 24P

M1078 TM's

Listed below are a number of the TM's for the M1078 trucks. To save them to your computer, right click, select "save as" m1078_TM 9-2320-365-10.pdf TM 9-2320-365-10 for the M1078 series trucks. m1078_TM 9-2320-365-20-1.pdf TM 9-2320-365-20-1 for the M1078 series trucks. m1078_TM...

www.steelsoldiers.com

there is pictures and part numbers from the TM in this thread already

 

[coachgeo]

there is pictures and part numbers from the TM in this thread already

btw- ton of searching done off those numbers. Only one available is overseas....... until @Ohiobenz stepped up. Not sure @DiverseThinker has seen that yet though