Vibration

[tdsiders]

Hello, I'm new to this site and am looking for advice. I recently bought my first CJ7 . It's an 84 model and I am planning on restoring it eventually. I want to drive it (play with it) for a little while before I start tearing it down. My problem is I'm not a mechanic so I'm gonna need help and hope I can find it here.a couple of days ago while driving it there was a loud vibration that started all at once and I could feel it but couldn't tell exactly where it was coming from. I was in two wheel mode. It wouldn't stop until I stopped and then I could take off again but by the time I shifted into 2nd or 3rd it would start again. After I got it home I crawled under and driveshaft, universal joints did not have any slop. It sounded and felt like gears but shifts smooth and it continues even with clutch in until coming to complete stop. This will be my first attempt at auto repair and rebuild. I wanted a jeep when I was 16 but didn't get one until last week and I'm 55 so I want to experience it all from chassis up. Thanks

 

[mriplaybass]

Welcome to the site!
Just because you can't feel any slop in the U joints doesn't mean that the joints are good. Sometimes you need to unbolt at least one end of the drive shaft to test the joints I assume you are running in 2WD, and the front hubs are disengaged, so let's start with the rear drive shaft. There are many things that can cause vibration, but let's start with the easiest one first. If the rear U joints are good, check the front wheel bearings, and the ball joints. Members on this site have a wealth of knowledge, and are great at diagnosing problems.

 

[Torxhead]

Sometimes you have to just keep after it to diagnose a problem. Like does it feel like it could be a suspension issue? stay with it and do more research.

 

[Lumpy Grits]

Need more info on the Jeep.
Has it been 'lifted'?
Could well be a drive-shaft angle issue.
LG

 

[tarry99]

Hello, I'm new to this site and am looking for advice. I recently bought my first CJ7 . It's an 84 model and I am planning on restoring it eventually. I want to drive it (play with it) for a little while before I start tearing it down. My problem is I'm not a mechanic so I'm gonna need help and hope I can find it here.a couple of days ago while driving it there was a loud vibration that started all at once and I could feel it but couldn't tell exactly where it was coming from. I was in two wheel mode. It wouldn't stop until I stopped and then I could take off again but by the time I shifted into 2nd or 3rd it would start again. After I got it home I crawled under and driveshaft, universal joints did not have any slop. It sounded and felt like gears but shifts smooth and it continues even with clutch in until coming to complete stop. This will be my first attempt at auto repair and rebuild. I wanted a jeep when I was 16 but didn't get one until last week and I'm 55 so I want to experience it all from chassis up. Thanks

The Drive shaft is a good place to start............along with motor & Transmission mounts , even suspension on lifted vehicles can have an effect on how smooth the vehicle goes down the road.......... but Tires / wheels can also be a rotational force that is more common to create vibrations especially if the tires are old, out of balance , over sized and have dissimilar wear patterns on the tire surface..........some times taking the fronts and moving them to the rear will help isolate the problem..........

 

[hdgapeach]

Are you feeling it in the steering wheel?

Stating that it continues while coasting with the clutch disengaging the remaining drive line makes me wonder about the "death wobble" scenario the old Ford trucks and VW Super Beetles are famous for. That'd be related to worn steering components.

Sometimes, pressing the brake pedal will stop the vibration (wobble). Just depends on how severe the wear is. There's gobbs of info available about "death wobble" found with a google search.

Worth a check anyhow. Vehicles as old as ours are bound to have something worn out up front if it all hasn't already been gone through.

 

[Hedgehog]

Take it out of 4WD........ or at least make sure it isn't engaged or partially engaged. That goes for the hubs too.

 

[Bent]

Vibrating after the clutch is pushed in sounds like a bad u joint or u joint miss alignment. Remove the rear drive shaft and drive it in 4h to see if the problem goes away. If you confirm that its the rear drive shaft, make sure that both yokes are aligned by laying it on a flat surface. it should balance on the flat area of the yokes around the u joint caps and not rock back and forth. If it rocks a little, it may be one or two splines off. Next change the u joints. If it continues, check the angles on the rear Transfer Case yoke and the pinion yoke. They should match. In other words, the Transfer Case should be pointing down as much as the pinion yoke is pointing up.
Miss alignment is more harmonic. U joint failure is vibration.
Buy a 12 point 1/4" socket for your 3/8 drive ratchet for the bolts on the u joint straps. Using a wrench will just make you angry.

 

[Neuner]

OP with one post again guys. Doesn't look like this one is coming back either.

 

[Hedgehog]

This is very frustrating. The inability to sign on and post multiple times has the potential to kill this board. I'd hate to see that happen.

 

[Neuner]

Yes, not that I ever really contribute anything but I've been on here less and less because of this. Been hanging out elsewhere more recently.

 

[Hedgehog]

Hmmm ... feels like you contribute to me...