LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

100K rumbles
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=3&t=32888		 Page 1 of 1
Author:  phxtoad [ Thu May 29, 2008 7:49 pm ]
Post subject:  100K rumbles
Looking for blind feedback on a rumble I'm experiencing before I get it checked out:

The silver piglet has 100K on her now, and I've experienced just about every front end issue aside from killing the front diff. Blown CV's. shafts, carrier bearings, hub/bearings, control arms, ball joints, etc.

First, I have brand new front CV/halfshafts, and a new Frankenlift installed (I figure I'm keeping her till she dies so it was time). I have Al's arms, and all new upper and lower Moogs. The rumble I'm describing occured before they were installed. I also just had a 100K tune-up/inspection by my old trusted mechanic and he found no anomolies (but I didn't have him look into this - I forgot).

2WD hard acceleration turning right (typical right turn entering traffic). (Edit - it does it straight ahead too) I feel a knocking from up front. Feels a little like the CV's, but it's a far deeper and bigger feeling. Otherwise things are smooth as burlap (she hasn't been silky for years).

4WD low, again hard acceleration but straight ahead (while on pavement for demonstration). The ship shudders and the knocking is loud and crazy. No me gusta.

I'm not an wiz at all when it comes to internal mechanics. My guesses are:

1. Engine mounts? Looked at the engine while in drive/reverse and on the brakes. You can see the engine torque over in each direction about the same amount. I have no reference to what should be a normal movement though. I experience no vibes, etc. in normal driving though, high or low speed.

2. Worn teeth on the front gears? Since everything spins even in 2WD, I figure this was possible.

3. Shot carrier bearings at the front diff housing? I had this before and it was evident at highway speeds. I'm not getting this now.

4. Prop shaft? Again it spins in 2WD. I've traced an annoying rattle to the prop shaft, but seems unlikely as the culprit. I'm going to pull it though, to see if I still feel it rumble in 2WD.

No issues with the tranny or transfer case to speak of.

Any thoughts?

Thanks,

Todd
Author:  phxtoad [ Wed Jul 16, 2008 4:51 pm ]
Post subject:  Help!
No replies last time - maybe this time...

Well I had a new custom prop shaft installed and that solved #4.

I still have the same rumbles though. :( I think knocking is a better term to describe them. Anyway now I occasionally feel and hear it on engine start. This has me leaning more towards engine mounts. Would you agree?

Now that I'm used to it, the knocking occurs even while coasting through a right hand turn - completely off the gas. It doesn't do it on left hand turns at all. Nearly any straight ahead acceleration other than a crawl from a stop causes it as mentioned before. Also, I feel it when I go over a bumps while accelerating from a stop.

The suspension feels tight - I just had everything re-torqued. So I'm still convinced it's drivetrain related.

Any thoughts???

Thanks,

Todd
Author:  Bill.Barg [ Wed Jul 16, 2008 5:03 pm ]
Post subject: 
Todd,

It seems like the 4 low makes the knocking worse. This might be a big clue. Is the distribution of torque from the transfer case different in 4h vs 4 lo, I wonder? Is the very low speed of 4 low making the knocking sound from, say the transfer case, more noticable.

The right hand turn under no load means the left wheel is turning faster than the right, so it is the one spinning the front diff gears. Maybe this is another clue.

Difficult mystery !
Author:  BeepBeepJeepJeep [ Wed Jul 16, 2008 8:54 pm ]
Post subject: 
How often do you do 4LO testing on pavement? That may be your problem :lol:
Author:  sleeve84028 [ Thu Jul 17, 2008 8:50 am ]
Post subject: 
Do you have any side to side play in the half shafts?
Author:  phxtoad [ Thu Jul 17, 2008 12:06 pm ]
Post subject: 
Beepbeep, it was humorous: I was in the lot and put it in 4lo to test things. Sure enough I forgot where I was for a second and started to turn. After quickly stopping I smacked my self in the head and got out of 4 wheel drive. Even that slightest of a turn and I could feel things getting 'grindy' Don't try this at home kids!

Sleeve, I'll check for play - but I think I'm going to pull both CV/half shafts, then drive it to see if that generates some clues.
Author:  Jeep Dawg [ Thu Jul 17, 2008 9:59 pm ]
Post subject: 
phxtoad wrote:
Beepbeep, it was humorous: I was in the lot and put it in 4lo to test things. Sure enough I forgot where I was for a second and started to turn. After quickly stopping I smacked my self in the head and got out of 4 wheel drive. Even that slightest of a turn and I could feel things getting 'grindy' Don't try this at home kids!

Sleeve, I'll check for play - but I think I'm going to pull both CV/half shafts, then drive it to see if that generates some clues.


Let us know what happends when you pull your half shafts.
I have reolaced front DS, rear DS both cv's and rear diff's. every thing was ok but now I am getting something like you are saying.
Author:  phxtoad [ Thu Jul 24, 2008 2:13 pm ]
Post subject:  Update
Update: Well in the end it turned out to just be a busted transmission mount. I had it replaced, so it's now nice and smooth and time to 'wheel. Yippee! :D
Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/