Noise

Hello,

As I mentioned in my introduction, I recently got myself into the Jeep world, buying a “restored” CJ2a 1948.

So, here’s my first miracle. The car produces a weird noise in certain situations. Shifting from 2nd to 3rd at around 30ish mph it starts to vibrate (you feel it wenn you sit on the passenger side with your feet on the floor board). It’s over when you get closer to 40mph. I checked for all kind of loose parts (brake lines, muffler …) but couldn’t find anything.

It seems also to be much stronger when the gears are not in mesh (not pulling nor pushing). It sounds like a really load vibration sound coming more from the rear … but it’s difficult to locate.in particular since there is no sound at all at low speeds.

Any ideas? I know, “weird noise” questions are always difficult to tackle, but it’s maybe a common thing and easy to locate

Thanks

Klaus

Check the "clocking" of your driveshafts. I went through this. My u-joints all lined up so I dismissed that. I was wrong. The "ears" that hold the u-joints on either side of the slider in your shaft must be the same or in plane or it will vibrate and drive you nuts.

Easy to check. If they are 90 degrees from one another, the slide the shaft apart and line them up.

May not be your problem, but it's one thing to check, Oilly

Green Disease, Jeeps, Old Iron!

Oilly,

Just checked both shafts. Both, rear and front drive shafts the two U-ends are definitely not positioned at 90 decrease …. Should they be?

If yes, is there an easy fix to that? Sorry, probably a stupid question but I’m more a motorcycle guy …

Thanks

Klaus

. The man from Kansas beat me..

Edited by muley - 20 June 2022 at 9:19am

Joined Jan-8 2015
I never met a mule I didn't like!
OD Mule 01-52 M38
Big Red 19fiddy CJ3A salad

The u-joint in either end of the driveshafts could be a cause for vibration at certain speeds. A worn u-joint or one that is binding will do that. A check for looseness or binding is best done with the driveshaft out of the jeep. The u-joint should move smoothly in the yoke with no catch. Do not make the common mistake of over tightening the u-bolts that hold the u-joint in the axle yokes or the front transfer case yoke. This can distort the u-joint bearing cap and caused binding. Use new lock washers under the u-bolt nuts and let them to the work of securing the nut without over tightening the nut.

46 CJ-2A #64462 "Ol' Red" (bought April 1969)(second owner)(12 V, 11" brakes, M-38 frame, MD Juan tub)

U.S. Coast Guard Chief Petty Officer(ret.)
U.S. Army Vietnam veteran and damned proud of it.

BavWilly wrote:

Alright … that could be the issue. They are not aligned like on the phone. How can I correct this?

… and no, no Canadian pop group member Smile

OK, many of their songs sound like the beatles. People thought they were but under a different name. I was just curious.

Jim
CJ-2A - 81299

The driveshaft slip yoke will have to be removed from the other end (spline end) and reinstalled with the correct phasing. It can be done with half of the driveshaft still in the jeep. The slip yoke and u-joint needs to be removed by carefully removing the dust cap on the end of the slip yoke. On older style slip yokes, usually there are small tabs that bend over the end of the slip yoke that need to be straightened. On newer style drivehafts, the cap unscrews from the body of the slip yoke. If it is the rear driveshaft that needs rephasing, it is probably easier to remove the u-bolts at the rear axle yoke and remove the dust cap, rather than disconnect the end at the transfer case. Regardless of how you remove one end, the dust cap is disconnected from the slip yoke and the slip yoke just slides off the driveshaft spline. Align the driveshaft in correct phase and slide the slip yoke back onto the spline. Re-install the dust cap. Check both front and rear shafts for correct alignment and roadtest. It wouldn't hurt to give each grease zerk on the u-joints a shot of grease and also the zerk on the slip yoke. Hopefully that will correct your vibration.

46 CJ-2A #64462 "Ol' Red" (bought April 1969)(second owner)(12 V, 11" brakes, M-38 frame, MD Juan tub)

U.S. Coast Guard Chief Petty Officer(ret.)
U.S. Army Vietnam veteran and damned proud of it.

Looks like Kansas types faster than I do Smile

If you can't get there in a Jeep you don't need to be there!

Thanks guys. You’re amazing

I will open the U-bolts on both (front and rear) shafts and align the ends. Will report back after the road test.

Later

Klaus