Datsun Roadster Forum-311s.org

I'm hoping to get this sorted so that I can make it to Solvang.
Problem is the car is making a few mystery kinds of noises intermittently on each drive, lately. Noise #1 is a kind of rythmical mild scraping- like a tire rub, or a wheel lightly scraping. Noise #2 is more like a clunk, intermittently when braking or an acceleration- sounds like a battery thunk (except battery is secured) or a loose lower control arm ( bolts appear to be secure from the back and in looking thru wheel to bolts with the tabs in place)
Front wheel rotates smoothly when on jack stand, no unusual sound.
Rotors look good, brake cylinders are new as of 2 yrs ago. But brakes have felt slightly soft a few times, and I had one slight shudder. Fluid level is good and fluid is clean. Brake master does not appear to be leaking in front or rear. No leaks seen elsewhere.
Rear wheel rotates smoothly, no unsual sound.
Diff bolts are tight.
Tranny mount bolts tight . No problems shifting.
Torque rod intact, bushings intact.
Some movement on both wheels in 3 and 9 o'clock position- so worn tie rods?
All zerks have been lubed.
Shocks replaced a few years ago, shock mounts OK.
Engine has oil with good pressure, water temp is normal. No noises at idle. Engine sounds fine when running, good power. Any engine issues that could do this?

Any ideas on what to check?
Thanks in advance.

Linda

U joints or yokes on tranny and diff?
Dan

Linda, How about your front wheel bearings? Have you given them a look?

That was my thought, if the front bearings are loose you could get play, and the scraping could be the backing plate. Not sure on the clunk though - there I would check to make sure your caliper bolts are tight. Also check your front anti-sway bar mounts and tightness.

Loose rear brake shoe?

rear axle end play?

the backing plate comes to mind with the 1st noise - bent in by someone grabbing it to turn the steering .

brake bads often get worn/loose on the sides and cause a clunk esp. after sitting over the winter

Try your best narrowing down to front or rear problem and go from there.

Good ideas.
Caliper bolts were checked and they were tight.
Backing plate would scrape when wheel was rotated right? No noise when wheel was off the ground. Did not see anything bent but will re-examine. No noise when wheels rotated when jacked up.
Rear shoes are still pretty new, and the brakes had been adjusted within the last year, but will recheck that.
Rear axle end play, how much is there supposed to be? There is just a bit of push /pull with the wheel off and the rear on jackstands.
Front brake pads were done when the caliper cylinders were done a few years ago. They should still be good but I will check.
I am hoping it is something simple that has been overlooked
I don't know how thick the rotors are supposed to be, as well the brake drum in the rear I am not sure on the spec for that either.
Linda

If you can, find a long quiet downhill road. Coast down the road and see if you can duplicate the noises braking. Easier to hear and will eliminate the drivetrain. If you think it might be the brakes, try the hand brake only and see if there's a difference.
If you can find a quiet bumpy downhill, coast down it and see if you hear any suspension noise. Alot of suspension parts are tight with the wheel hanging, so check the front suspension with the jack under the lower control arm to get it at ride height.
Does it make any noise when you accellerate or release the throttle? That would lead me to trans mount, exhaust etc.
If you can't find the noise, have checked the important stuff, and it's just intermittant, ride to Solvang in a group. Most likely you'll be fine, and if not, you have help.

Clunk on braking (deceleration) and acceleration sounds exactly like a u-joint. Grab both sides of the joint and twist. If there's noticeable play in either the front or rear u-joint, replace them.

I had this same problem on my '56 Chevy. Drove me nuts until I figured it out. Very easy fix. If you do need to replace them, I always mark where the axle flange meets the differential and where the tube meets the transmission so, the axle bolts up the same way. I don't know if it matters.

Dan,
Did the ujoints already recently. And a good thing too, they were a mess.
http://www.311s.org/phpBB3/viewtopic.ph ... it=Ujoints" onclick="window.open(this.href);return false;

Linda

The backing plate may not rub without pressure on the wheel...esp if the wheel bearing are loose.

Brakes or backing plate for noise 1

Did you check your u-joint bolts......they come loose often.

Does it make noise when turning?

Phil

Guys, this noise analysis is all wrong.
I have recently been a passenger with Linda when she was driving her roadster and I can absolutely
confirm that the "mild scraping" and "clunk or thunk" noises are coming from Linda and not her roadster.!
As these are personal problems, Linda will have to resolve them herself.


Ted.

Ted, the next clunk you hear may be something upside your head....
Now back to our regularly scheduled trouble shooting....
Phil, I don't think there is a noise with turning.
Ujoint bolts at diff end are tight.
Will try to listen for scraping with a load on the wheels.

Linda