front end clunk when backing up?

a77wing · #1 08-19-2005, 11:29 AM

i have a clunk coming from the drivetrain when i am turned to the left and backing up. it has done it a couple of times going foreward, but mostly back. it is not consistant either, seems to do it after the truck has sat for a couple of minutes. i have replaced the following: all ball joints, tie rods, idle arm, pitman arm. i took it to the mechanic today, he found i have a sloppy driver side half shaft. he wasn't sure if this could cause my clunk though. i have a new shaft ordered, be here tomorrow. the noise seems to be on the passenger side though. that shaft felt tight, and the wheel bearings seem good also. any thoughts? thanks!

BlazerLT · #2 08-19-2005, 01:06 PM

Have you greased the 10-11 fittings in the front end?

http://www.automotiveforums.com/vbul...d.php?t=344505

Also, check out this thread for a clunk fix I made up:

http://www.automotiveforums.com/vbul...d.php?t=302656

a77wing · #3 08-19-2005, 02:10 PM

i greased, and installed all the above parts. i kind of ruled out the hood, because the clunk only occurs when i initially move the truck about a foot or 2. i'll check the hood out, as it's an easy fix. any other ideas?

muzzy1maniac · #4 08-19-2005, 02:18 PM

Does it coincide with a quick dimming or flickering of the lights?

drdd · #5 08-19-2005, 03:30 PM

Keep us posted! I'm having the same problem. Mine is more of a loud click (sounds almost like the AC clutch coming on only much louder and from the passenger side).

Quote:

Originally Posted by a77wing

i greased, and installed all the above parts. i kind of ruled out the hood, because the clunk only occurs when i initially move the truck about a foot or 2. i'll check the hood out, as it's an easy fix. any other ideas?

Lt_Dusty · #6 08-20-2005, 08:52 AM

You might also check your anti sway bar end links. I had a clunk similar to you when backing up and turning. The top of the end link bushings were hitting the tie rod adjuster bolt and causing a clunk. It was fairly obvious since the adjuster bolt had worn a groove in the washer on the end link. I must admit these Blazers have more Clunks and pops than any other vehicle I have ever owned. I have eliminated them from suggestions on this forum, though. I still have a damn creek in the steering.

a77wing · #7 08-20-2005, 09:53 AM

i stopped at the dealer to get my washers, and the guys behind the counter pulled up some tsb's for me. one that really got my attention was for the torsion bar rubbing against the frame. i'll check that out as i'm replacing my idler arm again, and installing my new half shaft. this thing has got to get better....

BlazerLT · #8 08-20-2005, 07:10 PM

half shaft?

You mean inner tie rod end.

blazee · #9 08-20-2005, 07:30 PM

Quote:

Originally Posted by BlazerLT

half shaft?

You mean inner tie rod end.

Half shafts are what connect the front diff to the wheel. The are generically called CV joints, even though the CV joints are just a part of the half shaft. They are some times called the front axles, too.

blazee · #10 08-20-2005, 07:41 PM

The problem does sound like the torsion bars. You can climb under and take a look, it is pretty easy to see if the cross member is striking the frame, because there will be a clean spot or rub marks.

mrfixit64857 · #11 08-20-2005, 08:10 PM

if youve ever taken apart/rebuilt a CV joint/half shaft, you'd find the hub end looks like a Tibia/fibia/etc (end of a bone lol) with five (avg)hollows, five large ball bearings, a retaining ring with races and associated hardware and the axle SHAFT is attached into this ring.. usually when the joint goes out it's the disintegration of that retaining ring and its ball-bearing races, and the worse it gets, the more SLOP. In a turn, you hear a clunk... that's the combination of that slop trying to function at an ANGLE, and the sound is, understandably, different because the position is different. Replace that and I think your problem will disappear.

rlith · #12 08-21-2005, 10:11 AM

Also make note if it hapens while you're backing up... It could just as easily be your upper control arm bushings. Check them for dry rot/cracking on the edges. If present, that is most likely your problem.

rlith · #13 08-21-2005, 10:47 PM

Before going to the torsion bar mounts, do the control arm bushings...They are the more liekly culprit... Just a though is all.

a77wing · #14 08-21-2005, 10:52 PM

well, i've replaced the following front end components:tie rod ends, inner and outer, all ball joints, idler arm, pitman arm, and driver's side front axle.they were worn out and needed to be replaced, even if they didn't solve my clunk. the truck feels so tight now, just like new! i also installed the hood hinge washers, but my clunk is still present. tomorrow i'll be looking into the torsion bar mounts. i don't regret the work i've done so far, as i'm really pleased with the results. i think this truck was rode hard by the p.o., the bastard! only 80k on this thing. i'll post my results when i've figured it out. thanks for the help everyone!

blazee · #15 08-21-2005, 10:57 PM

The torsion bar mounts will cause a clunk when backing up and sometimes while going forward if turning. You will normally feel it in the floor, too. It only takes 5 seconde to climb under and see if it is striking the frame.

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