makes grinding and popping sound

[gem1410]

• m998--I was driving my newly purchased 1986 m998 around my back yard--It has 26k miles --I was moving at aprox 10 mph in drive and the t case was in high----after going through a 1.5 foot deep depression with the drivers side front tire a very loud popping and grinding sound could be heard --the sound seemed to come from the right front but I am not sure-- the truck lost all forward speed --it felt like a shaft was torquing up and then quickly the joint would slip --I put the truck in reverse and had the same noise-----then went to low on the t case and the noise went away and the truck moved normally--put the t case back into h and it drove OK--only went 20 feet and parked it-----the noise was very loud and I could feel something slip and bang continuously as the truck tried to move forward----I did buy the truck as-is
  

 

[richark998]

You might have a bad CV (constant velocity) joint on one of the front half shafts, if that is where the noise is coming from. An easy check is to jack up the front end so the tires clear the ground, turn your steering almost to full lock on one side and try to rotate the tire. You should have it in 2wd, hopefully free. The wheel should rotate fairly easy without binding or locking up. When the wheels are straight ahead it may turn freely, but CV joints act like universal joints and can bind when they go bad. Thats why you need to turn the steering to one side to check them. The TM for replacement is TM 9-2320-280-20-2 Ch 6 Para 6-9.

 

[3cavtanker]

i thought that HMMWV's had full-time 4wd.......all the ones i drove, there was no 2wd setting

 

[3cavtanker]

Yes.....according to principles of operation in the -20 manual, vehicle is always in 4wd

 

[gem1410]

we are talking about 4x4 operation in High compared to High Lock----look at the lable next to the selector for the transfer case--HL-H-N-L-----see the inclosed link and see what the 20 manual says is the difference between HL and H and that is what we are talking about----have you every had this noise--this is the info I am looking for---Thanks George----------------------- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180591758767&ssPageName=ADME:L:OC:US:1123

 

[KsM715]

If it was a cv joint problem you should have it in both high and low range. You state it opperates fine in low range. I bet its in the t-case.

 

[gem1410]

I was going to look at it again yesterday but it was 27*---thought I would look at it today but its 17* in NJ------will get back with more info when it gets aroung 45*--thanks members --George

 

[nattieleather]

will get back with more info when it gets aroung 45*--thanks members --George

Ok we'll wait till June...

 

[gem1410]

Found it--Bad left front inside cv joint---I can see the brake disk moving and the shaft is not--when the humvee is in high range the power only goes to one wheel either in the back or front--the wheel with the least resistance gets the power--the wheel that is slipping gets the power--the broken shaft gets the power and the truck does not move--just like the Ford escort in snow--the power goes to the slipping tire--in hi lock the power goes to the front and rear differential and to the wheel with the greatest traction--same in low range------look at the video and notice the rotor moving and not the shaft--it made alot of noise--Anybody know where to get the cv joint or 1/2 shaft==thanks George--to watch video hit open and then allow--It is from me and safe to view--Richark998 was correct--thanks

 

[dburd72]

Axle

Try calling Mahwah Cadilliac Hummer ask for mike in parts 201-579-6500
By the way the M35a2 is great thanks again Doug B

 

[richark998]

I mentioned the CV joint first because that's the least expensive item to fix of everything that could have been bad. Well, one thing could have been cheaper. When I first got my HMMWV a couple of years ago I noticed a loud bang when I started to move forward. It would sometimes do that a couple of times but quit once I got up to highway speed. Oddly enough it always did it in my driveway which had a slight uphill grade. I finally found out that the tires were picking up large rocks from my unpaved limestone driveway and throwing them up under the rear fenders. VERY loud !

 

[gem1410]

I have that noise also--thanks

 

[dac9901]

Fellow Steel Soldier Members:

I need some guidance on how to track down this popping noise that occurs at speeds < 10 mph turning and going straight. When I let off the accelerator I can't hear the popping noise at < 10 mph, however with the slightest pressure on the gas pedal I hear this Popping noise when turning primarily and coming out of the turn. It sounds like it is coming from my drivers side rear tire. Before taking out the rear drivers half shaft for inspection (following TM 9-2320-280-20-2: section 6-9) IS THERE ANYTHING ELSE I SHOULD INSPECT?

I have an 88 M998 that was serviced at the Maine facility in 2006. I was hoping my Half Shaft was not bad but after reading this thread it sounds like the culprit. It just started after taking a casual trail ride in the mud. Any recommendations on where to order the Half Shaft if that is the culprit? Any part numbers to reference?

Thanks in advance.

 

[KaiserM109]

Maybe this is a dumb question, but are Humvees always in 4 wheel drive? What you described was what driving a 4x4 engages on a hard, dry surface sounds like.

 

[gem1410]

I replaced the front left 1/2 shaft--that did it---that was where the noise came from--the shaft looked good on exam but was bad--they are cheap--$125 on ebay

 

[Mike82ndABN]

sounds like the cv joint, there are two on each halfshaft, check your cv boots for tears, mud/water likely got in there while in that mud you were talking about, sometimes you cant see the tears unless you rotate the shaft just right so that the bellows separate.

 

[tage]

What's going on with your snorkel?! overkill?

 

[gem1410]

I take this humvee spear fishing-------that is pvc pipe from Lowes--tight fit--I was going to cut it down to 2 feet but just took it off---

 

[dac9901]

Thanks for the feedback. The NSN for the rear half-shafts is [h=2]2520-01-383-2387 per TM 9-2320-280-24P-1 for anyone needing it. I found one on eBay for $150. Thanks![/h]

 

[dac9901]

Update: replaced the rear half shaft and that resolved the popping and grinding noise. It was very easy to replace. This forum is so valuable! Thanks.