cv noise?

[whitebread]

need your help everyone, my 98 xlt is about to drive me crazy....

basics: 98 4.0 sohc 4x4, torsion front springs. this sat for the better part of 2 years when I picked it up, and don't know it's history, other than the trans was rebuilt a few hundred miles ago...

issue: I've put around 250 miles on it, and have had a couple noises coming from what sounds like the d/s front wheel, and I did a couple searches to lead me to eliminating one noise by chucking the wranglers that were on it. the other noise is almost like a grinding similar to metal-to-metal brake pads... I started by replacing the hub, and cleaning the rust and glaze on the rotors and pads with a dressing wheel, noise still there... today I replaced the pads entirely, noise still there... checked the front diff, and was pretty low on fluid, but not dry. Filled diff, noise still there.

the noise starts almost immediately after takeoff, and can't notice it after 45 mph. braking doesn't change the sound, and putting it in 4wd might change a little, (or could be my imagination). I can feel a tiny thumping from time to time in the floorboard, but can't say if that's just road feel or not...

I've never come across this kind of noise in a cv axle before, but am open to suggestions/opinions on what this could be, or if I'm on the right track.

Thanks in advance,
Darin

 

[J_C]

I'd inspect the CV boot, can't imagine it would be making that kind of noise unless all the grease is gone from a long term split in it.

Could it be the shield behind the rotor rubbing against it?

Thumping I'd sooner suspect sway bar end link or a ball joint. Sway bar more if it happens when changing direction, ball joint more if it happens as the vehicle suspension comes down after going up from hitting a bump or at the crest of an incline.

 

[whitebread]

cv boots are alright, swaybar links and bushings are good (new links 2 weeks ago) and ball joints seem fine (no play, travel seems smooth). checked backing plates for bends or other damage while doing brakes on both sides...

I can't seem to get it to duplicate the noise on the lift leading me to think towards the cv's. I can't seem to get a "click" out of them, so I hate to change them out unnecessarily.

 

[J_C]

Yeah nobody likes to swap a part if they're not sure. If it got to the point where that's what I was going to do, I'd grab a grease needle and see if shooting some grease in the boots did anything.

 

[whitebread]

I'm thinking more and more that it's the cv, or the carrier bearing in the center section, as I did hear some slight clicking when taking off...will dive back into it this weekend, as it's not a daily driver yet...

I am curious about something on this though, as I've never dealt with an "Auto" setting on the 4wd selector before. does the system transfer power to the front normally on take-off from a dead stop, then drop power once it's up and going, even if it's on dry pavement?

thanks for the responses so far!
Darin

 

[RandomNerd2000]

It works by all the ABS sensors, it detects slip in the rear wheels and engages the front wheels when slip is detected in the rear wheels, not a bad system IMO, I liked it.

 

[CDW6212R]

The axle CV's are very uncommon to go bad without showing signs, like a ripped boot, or loud noises(clicking etc). Skip those for now. I'd look very hard at the front drive shaft, the CV joint. That is very prone to go bad with higher mileage, plus it often can have symptoms which seem like they're forward, at the front axles, either side.

Lifting the truck up and running it in gear probably won't help, but others have had a little luck with that. I wouldn't do that until at least removing the front drive shaft.

My 98 Mercury developed a bad grinding noise a month after I bought it in 2003. It was like a bad bearing, right side, so I replaced both the right hub and CV axle. It wasn't that, and no boots were torn. It was my front drive shaft CV joint, which wasn't replaceable back then. I found it by removing the drive shaft.

 

[CDW6212R]

I'm thinking more and more that it's the cv, or the carrier bearing in the center section, as I did hear some slight clicking when taking off...will dive back into it this weekend, as it's not a daily driver yet...

I am curious about something on this though, as I've never dealt with an "Auto" setting on the 4wd selector before. does the system transfer power to the front normally on take-off from a dead stop, then drop power once it's up and going, even if it's on dry pavement?

thanks for the responses so far!
Darin

Yes Darin, it does "grab" the front drive shaft at any speed. It does sometimes make a slight noise in normal operation, but it's not a big deal unless you're a picky blah blah. Most people do not notice anything.

 

[whitebread]

Don, I'll give the driveshaft a try, thanks for the heads up on that. ordinarily I don't mind a little noise, but with the grinding sounds I'm getting, I don't want to be stranded on the road either. (plus the wife will drive this in bad weather, her pony car doesn't like the snow...) I'm an ex-mechanic, but have been out of it so long, that some of my diagnostic skill have sadly fallen by the wayside.

I'll let y'all know what I find this weekend, thanks again!
Darin

 

[J_C]

It works by all the ABS sensors, it detects slip in the rear wheels and engages the front wheels when slip is detected in the rear wheels, not a bad system IMO, I liked it.

I thought it used two driveshaft shaft sensors on the transfer case?

 

[CDW6212R]

I thought it used two driveshaft shaft sensors on the transfer case?

I also gather it uses the ABS sensors to compare drive shaft speeds. The pre-98 models do have a speed sensor, so it may be used for the 4WD, for the rear speed. But I'm not positive of that, that should work fine also.

Darin, if you get the front drive shaft out and the CV joint feels bad, there is a rebuild kit now for about $85 from Dorman. It's not hard to install. Don't buy the other brand available, it's called Detroit Axle, that's a newer brand that's getting bad reviews.

 

[whitebread]

dropped the front driveshaft yesterday, still had noise.. tried to get the cv axles out without taking the entire spindle off, but failed...ended up frustrated and dropped the entire center section for further investigation this coming weekend... I felt a small amount of roughness in the movement on the driver's side inner joint, and passenger's side boot was torn, but moved around smoothly on both joints... ended up ordering both axle shafts, and a control arm for the d/s, because of slight play ( snowball effect started by "while I'm right here"...). got a buddy that knows diffs, and will be taking a peek in the case with me this weekend...

as of right now, "Harper" has been neutered and currently a 2wd, but the noise is gone!

 

[Dave98XLT]

If it is a tapping sound at low speed it might be a worn or loose upper shock bushing. Grab the top of the shock rod and shake it if it hits metal then it needs tightening or the bushing is shot.

 

[whitebread]

shocks and bushings are fine... sound was like a rubbing/scraping noise... will know more soon. this isn't a daily driver yet, so parts are coming in via snail mail...

 

[whitebread]

the saga continues....

pulled the front cover off, and pulled the carrier out to inspect the bearings,,,everything looks alright:no bluing/pitting/excess play on the carrier bearings or pinion bearings, no odd wear on the pinion ring gear either. there was some fine metal ( think fine sand ) but not enough to warrant any severe issues... I did forget to check the outer housing bearings, but since they don't need to be pressed in with shim variances (and are cheap enough ), I went ahead and ordered new bearings along with the housing seals. hope to have them in this week, and get everything put back together on the weekend. just glad this thing isn't my daily driver yet...

 

[CDW6212R]

the saga continues....

pulled the front cover off, and pulled the carrier out to inspect the bearings,,,everything looks alright:no bluing/pitting/excess play on the carrier bearings or pinion bearings, no odd wear on the pinion ring gear either. there was some fine metal ( think fine sand ) but not enough to warrant any severe issues... I did forget to check the outer housing bearings, but since they don't need to be pressed in with shim variances (and are cheap enough ), I went ahead and ordered new bearings along with the housing seals. hope to have them in this week, and get everything put back together on the weekend. just glad this thing isn't my daily driver yet...

Great, no bad news is good news. Order parts from Rock Auto when you need them soon but not really fast. Local stores can get most stuff in a day, but Rock Auto has many sources, it's usually 2 days or so for most parts.

I ordered a tough to get balancer for my 302, on Sunday, and it said it'd take an extra day. It came Tuesday late in the day, I almost started pulling my truck apart then to do the timing chain and WP, radiator etc, but it rained good the next three days.

 

[whitebread]

I did go through rock auto for all but 1 bearing (the 5707 on the d/s of the housing), and one of the stores I used to work at has it in stock. if I buy it online, I can get 20-25% off of it, and still pick it up at the store.

thanks for hanging in with me Don!
Darin

 

[whitebread]

no news to update as of yet. I replaced the outer bearings, cv axles, and upper d/s control arm/ ball joint, and just as I was putting the wheels on, I noticed that I wiped out the wheel bearings trying to seat the cv's and upper c/a's. got 2 new hubs waiting to go in, and waiting on 2 new rotors to come in...

hopefully have some good news saturday or sunday..

Darin

 

[whitebread]

final update on this, as I've gotten to the final step of the problem, and is now resolved...

after getting the new wheel bearings,new cv's, new upper d/s ball joint/control arm, new rotors, new outer bearings/seals installed, the noise was still there... I took a week to decide what to do: spend even more money on this pit, or sell it and cut my losses.... guess I'm a sucker for punishment, as I broke down and went to the junkyard and picked up another used center section, and installed it yesterday. no noise! I'm guessing that either the carrier bearings were indeed bad, or the pinion bearings were bad... I may keep it around and rebuild it at a later date, and possibly install a locker in it, time will tell...

Thanks to everyone who helped with ideas and suggestions, as I'll probably be asking for more for other problems (it was a $200 truck after all!)

on to the next headscratcher!
Darin

 

[CDW6212R]

Thanks for the update Darin, I'm glad you did figure it out. It's hard to diagnose a lot of the noises we read about on forums. The history of the vehicle helps the most. I expect you will know the condition of that truck better than us or the next person who works on it. Keep it running, it's still worth much more than you've spent on it.