Bouncy clunk rub clunk rub rub rub...... Looking for a thread on fixing a noisy cab latch / air suspension

[Reworked LMTV]

Looking for a thread on fixing a noisy cab latch / air suspension. Tried to search for it.

Clunk rub clunk rub rub rub...... Yeah

Latch has been rebuilt.

Thank you

 

[BKubu]

Any chance it has something to do with the air bags? My truck made a noise like that before I replaced the air bags. I initially thought it was the cab latch. In my case, it wasn't.

 

[Keith Knight]

Are you running original cab suspension?
If so you replaced the air bags. While doing that the small shock absorber inside has polyurethane bushings that rot out causing lots of noise. 8 years ago when I replaced my air bags I couldn’t find new bushings or shocks so I machined new bushings out of rubber.

 

[Ronmar]

Yep could be shock absorber bushings, the ones on mine I disassembled, the shocks were fine, the bushings had disintegrated, and of course the airbags looked like a cat scratching post…

if it is squeaking, look to the hooks from the cab that hook over the pins on the arch. Lube them to quiet them up…

 

[GeneralDisorder]

All some of the reasons the Army deleted that stupid system. It doesn't help ride quality enough to even bother with. Too bad it's more work to delete it than to fix it.

Shock bushings are shot. They always are. Rest of the noises are adjustments and lube.

 

[Ronmar]

Actually deleting it would be quite easy. Some say 4” box or round tube cut to length and welded in place of the shock assemblies… way easier than building my own system:O

 

[GeneralDisorder]

Actually deleting it would be quite easy. Some say 4” box or round tube cut to length and welded in place of the shock assemblies… way easier than building my own system:O

Nice. Yeah do that. Get air ride seats if you must have the truck feel like a water bed. No one will argue that these trucks NEED seats.

They don't need the cab air ride. The A1R rides essentially the same. It's tough to notice a difference once you delete the coil springs and put some decent seats in them, They deleted the air ride cab and installed "suspension" seats which are just *not* a steel slab under some foam. Helps a little - about as much as the actual air ride funny enough.

 

[Ronmar]

But I did design my own works great!

 

[canadacountry]

@GeneralDisorder I know you weren't talking about that but in a book I have about trucking humour (real stories nevertheless) he talked about the old tractors that didn't have airbag suspension so you had to practically hang off the steering wheel itself every time you hit a bump. "nothing like hitting the ceiling then your spine slam back into whatever they called a seat! no wonder many drivers ended up short and chubby from this." he more or less moaned about

I'm sure someone in the military would have the same thing to say about this! (ignoring these crazy young soldiers who drive their willy jeeps' recklessly fast far off the road tho..)

 

[Reworked LMTV]

Any chance it has something to do with the air bags? My truck made a noise like that before I replaced the air bags. I initially thought it was the cab latch. In my case, it wasn't.

Replaced the bags. Guess I need to replace the rubber bushings.

 

[GeneralDisorder]

Replaced the bags. Guess I need to replace the rubber bushings.

The bags have the bushings inside them...... those must have been used or old stock eh?

 

[GeneralDisorder]

@GeneralDisorder I know you weren't talking about that but in a book I have about trucking humour (real stories nevertheless) he talked about the old tractors that didn't have airbag suspension so you had to practically hang off the steering wheel itself every time you hit a bump. "nothing like hitting the ceiling then your spine slam back into whatever they called a seat! no wonder many drivers ended up short and chubby from this." he more or less moaned about

I'm sure someone in the military would have the same thing to say about this! (ignoring these crazy young soldiers who drive their willy jeeps' recklessly fast far off the road tho..)

Tractors - especially old one's - don't tend to have "suspension" in the normal sense. They tend to have the axles bolted directly to the engine and the drive wheels just sticking out of the transmission and not an actual frame. The suspension is literally the tires. Thus "removing" the engine or transmission effectively means you are splitting the whole machine in half. They also don't have much weight on their own in terms of the body and frame (there's not one of either really), so they don't have any mass and the drivers seat accelerates up and down in a rapid and violent way......

Mostly it's just tires full of beet juice connected directly to your (solid steel) seat.

FMTV suspension is a LONG, LONG way from being an old tractor.

 

[Reworked LMTV]

The bags have the bushings inside them...... those must have been used or old stock eh?

New from Factory.

 

[GeneralDisorder]

New from Factory.

That's not a rave review.

Delete the system. Delete the problems.

 

[Ronmar]

Yea, too much unobtanium in the system anyway…