Road noise

M384X4 · Post by **M384X4** » Mon Mar 11, 2013 7:01 am

My M38 does have transmission second gear issues already. A have a new issue when driving at speed on the hardball, I hear a loud metallic sound almost like a bell. It is not a constant sound and seems to get bad after going fast on the road. Didn't hear it while running slow in 4x4. Sounds like its coming from under the driver not from the engine. The sound is like a metal object being thrown against another metal object that can almost sound like a bell. I thought it might be something in the emergency brake but all looks tight. Checked the drive shafts and they seem to be tight as well? Any ideas? Has no impact on moving or the engine.

Post by **wesk** » Mon Mar 11, 2013 9:20 am

Disconnect the rear drive shaft and spin the brake drum. Or remove the drum and check for broken or loose shoes and hardware.

timjuhl · Post by **timjuhl** » Mon Mar 11, 2013 8:03 pm

Check the "Bell Housing." Just kidding..... sorry but I couldn't resist.

Good luck!

Tim

M384X4 · Post by **M384X4** » Tue Mar 12, 2013 5:54 am

Nope...Dropped the drive shaft last night and removed the emergency brake drum, all looks in good order!! So it's not that...

skyjeep50 · Post by **skyjeep50** » Tue Mar 12, 2013 8:27 am

Something rolling around in the tool box?

Post by **wesk** » Tue Mar 12, 2013 9:18 am

The bolt and pin holes and pivots in UU, R, M, Z, AA, DD & JJ get worn and these parts clatter and ring the big round bell.

When I said spin the brake drum I meant with the rear drive shaft disconnected and then while it is spinning you grasp the handbrake lever rod and shake it up & down and sideways which will shake and rattle the loose actuating arm and linkage and shoes.

If this is too much bother then just remove the drum and shoes and drive it.

The fix for this problem is new parts. Many folks try bandaids like extra springs to maintain more tension between individual moving parts.

M384X4 · Post by **M384X4** » Tue Mar 12, 2013 9:59 am

M38, not the A1. Action is to violent for anything in the emergency brake. Guess I will check rear brake drums next.

Post by **wesk** » Tue Mar 12, 2013 12:24 pm

My bad on model jeep. I was under the impression you had narrowed down the location of the noise already to the lower center of the jeep. Can you let us know first about where the noise is centered.

M384X4 · Post by **M384X4** » Thu Mar 14, 2013 5:47 pm

Pretty sure it is the throw out bearing! after another test drive. Although the cable is very lose parked. I don't think tightening it will help? So what now?? The longer I drive it the worse it gets, but it is not constant. Maybe something to do with heat.

Post by **wesk** » Thu Mar 14, 2013 9:27 pm

Are you sure enough it is the throw-out bearing to separate the engine from the tranny? Or do you suspect the throw-out bearing? You can remove the center floor panels and the clutch inspection panel on the bell housing and drive it and listen to see if the bell clanging is truly coming from there.

M384X4 · Post by **M384X4** » Sat Mar 23, 2013 7:09 pm

Found the noise. Its the bearing shield on the rear transmission behind the drive shaft. I duck taped it and took it for a test drive, the noise was gone. Not sure what causes it or how to stop it?

Post by **wesk** » Sat Mar 23, 2013 7:56 pm

I assume you are referring to item D shield on Item C companion flange about 1 inch behind the brake drum? That shield was originally pressed on the companion flange. You will have to remove the companion flange and if it will not press on and fit tightly throw a few spot welds around it.

M384X4 · Post by **M384X4** » Sun Mar 24, 2013 11:26 am

no, its the shield on the rear axle at the end of the drive shaft protecting the bearings. Right behind the yoke. Never had the problem before, maybe there is an increase in vibration from the bad transmission? The shaft is in good order, tight. checking the fluid levels in the rear axle today. Guess I need to drop the shaft and pull those bearing....

Post by **wesk** » Sun Mar 24, 2013 8:19 pm

Same set-up. Item Q shield is pressed on item R yoke. Maybe it was hit by something you ran over?

To access both pinion bearings you'll have to pull the diff carrier. Why do you want to pull the bearings? Have you already determined they are bad?

M384X4 · Post by **M384X4** » Mon Mar 25, 2013 5:58 am

I'm going to put that yoke off to explore the cause of that noise. You're right I believe the bearing are fine, I checked the oil level is it ok.

I can turn the sheild by hand without turning the yoke, is that correct? or should the shield be fixed to the yoke? You say pressed which means to me fixed to turn only witht the yoke. Maybe the yoke nut just needs to be tightened?

Road noise

Road noise

Noise