I have been trying to track down a clunk noise in my 96 Ford Bronco. I have replaced a right front axle shaft u-joint that i believed to be the cause of the noise but after replacing it, I discovered the noise is still there. The noise is mostly during acceleration and goes away when pushing in the clutch to shift. I also can't hear the noise after about 45 mph or so. I was investigating and found that my right rear break line has actually rubbed a hole in the rear shock. Could the bad shock be making that noise or would it be something else?
Check all of the front end bushings, transmission mounts and cross member bushings, shock absorber bushings and body mounts.
If all of this checks out then replace the shock absorber that is bad and also the other one, replace shocks in pairs. This is mandatory because it rubbed through.
If you still can't find the clunk then there is a service bulletin that was republished. It is listed below; it explains a clunk similar to yours. It is found on the Alldata information website.
1996 BRONCO, F SUPER DUTY, F-150-350 SERIES
NOISE - "CLUNK" - FROM STEERING COLUMN ON ACCELERATING AND BRAKING
This TSB article is being republished in its entirety to include 1996 model year vehicles and to include the latest level parts
A "clunk" noise heard/felt through the steering column when maneuvering in parking lots, driving in stop-and-go traffic, and driving over bumps may occur on some vehicles. This may be due to a "slip-stick" condition of the slider spring to the outer tube of the lower steering column
Replace the lower steering column shaft assembly with a revised Lower Steering Column Shaft (-38676-) assembly. For removal and installation procedure, refer to the appropriate year F-150/F-250 Service Manual
PART NUMBER PART NAME
F7TZ-3B676-AA Lower steering column Shaft 1996 vehicles.
F75Z-3B676-CA Lower steering column shaft 1997 vehicles.
Let us know if you need more assistance.
Is there a way to check on the condition of the slide spring in the lower steering column to make sure its working correctly before replacing the part? I removed my bad shock to see if that was causing the noise but it wasn't. I walked beside my bronco to listen for the noise and it sounded like the noise was coming from the middle of the vehicle. Could low or bad transmission fluid cause the noise by any chance? It has a 5 speed manual transmission.
You didn't mention you could hear the noise sitting still.
The way you now describe the problem points me in the direction of the transmission area.
When you push in the clutch you disengage the transmission from the engine. If the noise goes away with the clutch pushed in could mean two things, the transmission has an internal malfunction like idler gears, synchronizers, bearings and so on.
The second thing is that the throw out bearing could be going bad or some part of the clutch could be at fault. Parts for that would include throw out bearing, broken or weak clutch springs on the clutch plate, broken or weak fingers or springs on the pressure plate.
Checking the fluid would be the first thing to look into but it sounds like a clutch or transmission issue.
While underneath the Bronco today, I discovered that the nuts on the transmission mounts were loose. I noticed that there are slots where the studs come through and I'm guessing that is for alignment reasons. I tightened the nuts to see if that was the problem but the noise is still there. If the transmission isn't aligned right will it make this clunking sound or would I still need to be looking into a clutch/trans issue?
The transmission mount bolts being loose could cause a clunk on take off and stop conditions and also over big bumps, but probably not the noise you are hearing.
The best thing to do is to have some one put the truck on a lift and have them listen to the noise when the truck is in the air. It is easier to hear the noise and to locate it better.
It still may be a clutch or transmission issue.
Your local automotive professional can look at and give you a more definite diagnosis by hearing the noise as it happens.
What kind of cost am I looking at to have the clutch replaced by a mechanic?
You can look at about in the neighborhood of about 6.0 hours in labor plus parts. You would have to know the labor rate of your mechanic to calculate this.
The parts you could be looking at are the clutch plate, pressure plate, pilot bushing, clutch release bearing and clutch fork depending on condition, resurfacing the flywheel or flywheel replacement depending on the condition of the flywheel.
The parts list would be calculated depending on what you need.
Don't hold me to this but it could be in the ballpark of about 1500.00 dollars give or take a few bucks depending on the need for parts and or extra labor depending on what is actually found with the problem in question.
Would the clunk be more likely caused by a throwout bearing or on the clutch plate side? Or possibly the pilot bearing?
They are all suspected parts that could be making the noise and should not be ruled out.
A trained automotive mechanic can diagnosis the noise on the ground and in the air on a lift to determine where the noise is coming from.