74 Cj 5 Shakes Right Front When Brakes Applied Hard

Springs are tight, motor mount on right side is new, transmission mounts are new, new brakes, transmission does whirr and is something I am rebuilding down the road, this feels and sounds like the transfer case is shaking when brakes are stomped, at a real loss for what this could be, raise front wheels and there is no wheel play to speak of, I’m a strong guy but could it be that I can’t simulate the wheel play enough just by raising and shaking it, thinking ball joints perhaps,? Won’t do this in reverse! Any ideas appreciated.

 

Loose u-bolts?

 

Have you tried it with the clutch in and also with clutch out to see if there is any difference? Clutch in should idle the load on the drivetrain.

 

"When brakes applied?" Sounds like a clue. I'd start there.

Drum, or rotor, warped?

 

New front rotors

I will try that

 

I will check those too

 

Brake fluid leaking onto drums (or any grease, oil, etc) can cause quite a violent chatter or brake lockup. You'd think it would cause the opposite but it makes the brakes very sticky. Had a leaking rear seal on a drum brake equipped rear axle that would lock up that wheel with the slightest touch of the brakes.

 

Is it pulling to the right?

Or just feel a shaking somewhere in the right? And do you just feel a shaking, or do you hear a rattle/vibration?

 

Steering wheel stays pretty stable, you can see the shake, like the transfer case is moving, it’s a shake, rattle, no pull, everything seems solid underneath

It’s also noisy

I have a little 8 second clip that you can hear the chatter really well if I could send it to anyone who thinks they can tell what it is? New drums in front by the way, no leaks

 

I am just throwing this out here
would the front slip joint possibly frozen/stuck

 

Is the front drive engaged? (Driveshaft spinning?)

If so, is it coming in contact with the engine, or anything else? That would certainly make a racket and shake the t-case.

Hard braking will compress the front suspension and make the driveshaft come really close to the engine, or other parts. If mounts are worn, if it has unplanned fab, or wrong parts were used, it's a definite possibility.

 

New front drive shaft, 4x4 not engaged

 

I just checked driveshaft and bell housing for signs of contact, nothing there, great suggestion though

 

Just to be clear, the driveshaft is not spinning? If the hubs are locked, or it has flanges rather than hubs, the driveshaft will spin even if not engaged.

 

Has locking hubs that aren’t locked, it free spins, I checked, could the front axle bearings be so worn that that causes the shaking/chatter, I guess to rule out an out of round drum I could swap the fronts left to right and vise versa, see if the problem becomes a left side chatter?

 

They are new drums but you never know?

 

Jack one corner, spin the wheel. Listen for bearing noise.

As it's spinning have someone slowly and lightly apply the brake. You'll be able to tell if it's bad if it grabs in one spot.

Does the noise happen 1 or 2 times per tire revolution, or many more?

 

I was going to suggest that if all else failed. Swap sides)

 

Ok, seems like more than once per rotation, that’s why I tend to think it’s not brake related, to me it feels like the brakes are already locked and it just chatters, I will raise vehicle and go from there