• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

M923A2 horrible loud noise coming from the differential or transfer case - 5-Ton

doghead

4 Star General /Moderator
Staff member
Super Moderator
Steel Soldiers Supporter
26,247
1,168
113
Location
NY
Are your differentials full of oil?

Drain them and look for parts/particles.

An IR temp gun is good for finding hot spots. You can compare all the same areas on both axles.

Are any of your universal joints hot? Have they been serviced recently?

You can pull the rear drive shafts from back to front and remove the axle shafts, to disengage each differential, to isolate which one it is coming from.
 

rchalmers3

Half a mile from the Broad River
Steel Soldiers Supporter
1,925
30
48
Location
Irmo, South Carolina
Are you able to produce the noise in any other gear than 5th? At any other speeds?

Does the sound seem like it may be from the transmission?

Rick
 

madcroc1

New member
85
0
0
Location
deerfield beach, FL
Ok, Thanks for advice. I'll do it tomorrow. I just got the truck about a month ago and changed the Oil and Tranny fluid. I didn't really look at the differential oil yet. I put my hand on the axles and they didn't seem too hot. I couldn't find a dip stick for the transfer case but will check with the TM now..
It really seemed odd that since it is intermittent that it could be in the differential.
The noise doesnt sound like gears grinding but more like something is slipping...
 

Suprman

Well-known member
Supporting Vendor
6,845
660
113
Location
Stratford/Connecticut
It's hard to tell where the noise is coming from when you are in the cab at highway speed. Could it be the fan kicking in and the fan clutch is bad.
 

Stevepala

Member
57
0
6
Location
Connecticut
Get a medical stethoscope and take off the end that the doctor presses to your chest when listening to your heart. Now get a long piece of steel brake line the you can attach to the hose end of the stetoscope. This will act as a long distance listening devise so you pin point the noise location. Now jack up the rears on wood blocks so the tires are off the ground. Put someone in the truck you trust and run it up to speed and listen with the stethoscope. Be very careful. I have done this before, it works like a charm.
 

madcroc1

New member
85
0
0
Location
deerfield beach, FL
The noise seems to come and go in any gear. I'm dont think it in the transmission. it is extreeamly loud. It sounds kinda like what a failed fan clutch would sound like but louder and its under the truck not under the hood..
 

madcroc1

New member
85
0
0
Location
deerfield beach, FL
both of your what? both of your trucks ? This noise is so loud it certainly is not normal. But again it is intermittent which is odd. I'm thinking it might be in one of the differentials. I just searched the TM and there is no Differential Maintenance procedure in the manual
 

madcroc1

New member
85
0
0
Location
deerfield beach, FL
It come and stays for a while. Usually the rest of the day. When I park the truck for the night, usually the next day there is no noise until I drive it a bunch of miles and then it come again. It seems to last for about 5-10 miles and then slowly goes away.. Today the sound engaged and stopped a few times over about only 1 mile. It sounds like if you were fishing with a big game reel and imagine hitting a huge fish that takes the line out really fast (no clicking) just a fast mild grinding sound but really loud.
 

Suprman

Well-known member
Supporting Vendor
6,845
660
113
Location
Stratford/Connecticut
There are probably a lot of noises that are present but you just can't hear them over engine noise with the nhc250 but that you can hear with the 6cta
 

two.fiveM35

Active member
1,234
11
38
Location
Victoria , Texas
Great thread. My M923a1 does the same thing, I just changed the oil in the transfer case and it was black. But didn't fix the noise. I have also greased all the drive shafts, still no change. Mine is intermittent and seems to be related to bumps in the road. The noise starts instantly and stops instantly, kind of like a compressor kicking on and off,it has no pattern. Also maybe thought it was the fan clutch, but I could never get it to come on with the hood up. My truck was a 2010 Red River rebuild with only a few hundred miles since rebuild.
 

doghead

4 Star General /Moderator
Staff member
Super Moderator
Steel Soldiers Supporter
26,247
1,168
113
Location
NY
Why not put the bolts in to manually lock the fan on, and see if it stops making the noise?

Are you guys wearing hearing protection?
 
Top