Rolling thumping sound

[msmoorenburg]

I want your thoughts. The jeep has developed a intermittent rolling thumping sound 10mph or less after its warm . It will thump going straight or in a turn. Here is a key thing when light brakes are applied it goes away. The thumping feels/sounds like right front.

Here is the status of the front end

1. New brake pads
2. Turned rotors (200 miles or less)
3. New u-joints & axles (upgraded to bigger u-joints 1st attempt to fix this problem)
4. The hub bearings are tight (still tight when turning them)
5. Hub adapters and rim lug nuts are tight
6. no visible ball joint wear
7. trackbar is tight
8. front diff flush of the regear looked great
9. no obvious pulling while breaking
10. no front driveshaft

I am leaning to replace the front calipers maybe rotors too


Pics of the front diff flush

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-17227-1360594777569_zps5cfdc2e8.jpg

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-8244-1360594702990_zps47cdae5d.jpg

[Mudderoy]

Did you jack the front up and wiggle the tire to check the wheel bearings?

[msmoorenburg]

Did you jack the front up and wiggle the tire to check the wheel bearings?

yup all ball joints and the hub bearing are nice and tight

[4.3LXJ]

Matt, generally if I get a soft thump instead of a harsh one I start looking at associated things that center around soft things like rubber. Wish I could be there to hear it.

[msmoorenburg]

Matt, generally if I get a soft thump instead of a harsh one I start looking at associated things that center around soft things like rubber. Wish I could be there to hear it.

It comes in harsh, after brakes are applied then released it starts off soft. I originally thought it was a u-joint binding up. But now with it going straight i'm questioning the floating pins in the brake calipers (getting misaligned and binging/releasing) I would go after hub bearings (same feeling as if a race went and the ball is popping) but they are relativity low mileage 7~10k just a guess. This issue did popup after rotors were turned (warped from sitting since 06) I turned the rotors myself and know they were turned correctly.

[4.3LXJ]

Rotate the tires just for giggles?

[msmoorenburg]

Rotate the tires just for giggles?

almost did that. I have maybe 800 miles on them and this problem is intermittent. I drove 80 miles Saturday 50/50 city/highway and it only hit me 2 times

[4.3LXJ]

I hear ya on that. But I would do that anyway. I have had so many tires do weird things to me

[msmoorenburg]

I hear ya on that. But I would do that anyway. I have had so many tires do weird things to me

will do can't hurt a thing trying

[cantab27]

go the brake lead matt.....if goes away when ya brake start there......

[msmoorenburg]

From Direct-Hit


With OEM Direct diagrams, components, TSBs, and R&R procedures

Number: 81724
Vehicle Application:
1998 Cherokee 4.0
Customer Concern:
When the brakes are applied, there is a grinding noise heard. The brakes were worn and the rotors were scored. Installed new Bendix rotors and Bendix brake pads. This took care of the grinding noise. The vehicle came back 2 days later with a thumping noise in the L/F wheel. Inspected the brake pads and rotors and the brake calipers seem to be free and working properly. The noise will go away with light pressure applied to the brake pedal.
Average Reported Mileage:
88125
Tests/Procedures:
Road test to verify the complaint. Check the brake rotor runout.
Tech Tips:
Check/inspect the spindle for rust build up on the rotor mounting surface.
Author:
Brainard Janicki
Potential Causes
With OEM Direct diagrams, components, TSBs, and R&R procedures
Brake Rotors
Confirmed Fix Summary
With OEM Direct diagrams, components, TSBs, and R&R procedures
Confirmed Fix
1 - Brake Rotors
Confirmed Fix Details
Tech Reported Fix Details
Confirmed Fix
Frank Radeshak
March 30, 2005
1998 Jeep Cherokee, 4.0L, Vin S, Eng Cfg L6 *
Brake Rotors
88,125 miles Brake Rotors
- Confirmed Fix - Exact Vehicle Match
- Confirmed Fix - Similar Vehicle Match * - Indicates a Similar Vehicle - Not an exact match to the vehicle selected

[msmoorenburg]

So for a little update. Since its been cold and raining here I didn't fool with the issue just drove the Jeep. So Monday and Tuesday no issues just blow and go :P no thumping. So today I decided why not drive into work (48miles). So after 30 mins of 70+ driving I was curious if it would come back. First light nada 2nd light nada. I'm thinking sweet, then the parking garage bam thump thump thump small brake pressure GONE. So now I confirmed it is the passenger side (thanks to the concrete walls and the echoing) So I'm gonna do some parts changing this weekend.

Parts i'll replace
1. both calipers (under warranty or i have some under)
2. pads (under warranty only a month old)
3. replace both rotors

Hopefully this will cure my thump-er :banghead::banghead:

[LizardRunner]

Sounds like you have the cure there Matt. I had that problem with the green lizard and did a complete rebuild of the Calipers and the issue went away. It may have been the rusty cups that I pulled and replaced with slightly larger ones after honing the bore.

[4.3LXJ]

We shall see. The mystery just goes on .... for now

[msmoorenburg]

So today da Bear and I reworked the front brakes here what was replaced

1. 2 rotors
2. new pads
3. 2 reman calipers
4. tire rotation


I did have to do some welding on the knuckle. The brake pads had wore a grove into knuckle. Both sides top and bottom

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-24599-1361155285160_zps4bd50c39.jpg

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-25474-1361155469710_zpsa3d10d23.jpg

The fix

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-43210-1361155331586_zps14678c13.jpg

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-16815-1361155320428_zpsd69e9503.jpg

The end product

http://i1135.photobucket.com/albums/m639/sellitx/photobucket-16690-1361155272829_zpsc7b0aa26.jpg

Let's hope this cures the rabbit :patriot:

[XJ Wheeler]

Nice job on fixing those grooves, i need to do mine too. They're a substantially worse than that. Hope that takes care of the issue.

[msmoorenburg]

Well so far 100 miles under the brake job and no thumping :D

[XJ Wheeler]

Well so far 100 miles under the brake job and no thumping :D

Awesome, about time you just get to enjoy that thing without having to take it apart every weekend.

[Brasscatz]

Awesome, about time you just get to enjoy that thing without having to take it apart every weekend.

Tell that to Patrick!! :mock:

[msmoorenburg]

So I'm gonna say new rotors/pads/calipers have resolved my issue. My gut feeling is it was a hanging caliper since my brake peddle is now a little softer that it use to be.