Taking bets on what the problem is...

As you know I just a got a new wagon 2 days ago.  I drove about 300 miles home, ~100 miles yesterday, and about 30 in it today.   I barely got it home tonight.

Drive home from Tampa was fairly uneventful and she ran good.  Even got in a pack rolling low 90s for about 10 minutes then let them continue without me.   Most of the ride home on the interstate was around 80mph.  Once or twice I felt a little 'hiccup' while cruising.  Figured it was just a spark miss as it was only 1 and then only 3 times in about 5 hours of driving.

Yesterday was about 80% highway miles with no issues noted.

This morning.  A five mile run to the gym, no issue, 5 miles 2 hrs later I'm cruising steadily at 45mph and feel a single BONK. Sounded like the driveshaft let up and then slammed in again.   Wondered if it might be the torque convertor unlocking/locking or something....Stopped a few min later after a couple miles and checked the trans fluid and all looked good).  Was at my Mom's for 3 or 4 hours and then started driving home (about 13 miles or so).

I got about 4 miles down the road and got on the interstate.   I got up to about 70 and then it came back, but this time it was bonk bonk bonk....almost a chatter.   I took my foot of the gas and put it in neutral.  It didn't stop.   I got over onto the shoulder and got out to look.  I got a brief wiff of brake pad, but couldn't tell which one it was.

THought about calling for a tow but decided to see if going slower would help.  Pulled back out and stayed in the right lane doing 55.   It would do it like 4 or 5 times then stop for awhile.   Got off at the next exit about 3 miles down the road.  I was only about 2 miles to the house now and limped it down some side streets going 30 or less and it did keep doing it.  

I noticed hitting the brakes made it worse.   Got home and pulled in the driveway just as it was getting dark.   I don't feel real good (at a big fat lunch and it is not agreeing with my stomach right now) so I didn't jack it up and pull the wheel off.   Pretty sure it is the driver's front.  The suspension and steering seem fine and a visual with the wheel on the caliper looks to be in the right spot and not loose.

arm bushing, or ball joint, or maybe more than one.

With such low miles this wagon has done a LOT of sitting around. I'm sure it needs a thorough going over before hitting the road.

New tires on it so it could have a loose wheel.

94Woody wrote:

With such low miles this wagon has done a LOT of sitting around. I'm sure it needs a thorough going over before hitting the road.

New tires on it so it could have a loose wheel.

It most definitely will be gone through. After an event free ride home I got a false sense of security.

seized caliper,. heated rotor up,. melted grease in hub, outer bearing fried

broken belt in tire,. just guess's

Rev Bob

Universal joint.

Every new-to-me used car gets a thorough going through. I would check brakes or suspension.

I second the bearing issue from a stuck/overheated brake caliper. Had that happen before.

....waiting for the verdict!

Oh and Sprocket PLEASE change your profile pic. That hurts every time I see it.

-Mike

81X11 wrote:

Oh and Sprocket PLEASE change your profile pic.   That hurts every time I see it.

-Mike

I will change it when I can come to an agreement with the insurance company and get a check along with the destruction cert.

Until then seeing it motivates me.

So, tonight's update.

Last night it sounded like the driver's front. But I only had my window open so duh...
Anyway I rushed home from work and had 40 min before I had to get my daughter. Moved the car onto the driveway (out of parking again), and got the driver's front up and the wheel off.

Everything looked good and spun freely with no bearing noise. put wheel on and pulled top and bottom to check ball joints, seem ok and all fittings seem properly lubed. Pads look new and nothing out of the ordinary on the rotor. Hmm. Scooter underneath and quick check on ujoint bolts - nice and tight.

jacked up the pass side with same results. All look and felt good. Had to run to the high school and collect my daughter.

Got home and dropped the front of the car and jacked up the back. both wheels spin by hand with no dragging or bearing noises... Fire it up and put it in reverse with no gas.
Both wheels spin backwards at idle with no bad noises.

Put it in drive and the driver side spins (open 2.56) I hand spin the pass side and it sorta goes for a little but not really. Hit the brake and put in park. Stuff a coconut under the driver's rear wheel and put it back in gear with the desired result. Pass side spins again all quiet and nice....

Hmmmmph! It's just about dark now, sun already down so I drop it down and go for a spin around the block with no issues. I go all the way out of the neighborhood and get on Dixie Hwy as I have a 1.5 mile run with no light and usually light traffic. I run it up to about 45 or so and no issues. Get up to the big cross street and hit the brakes to turn into a parking lot to make a U-turn.

I think for a second I hear/feel something, but nah it seems okay. Make the return run back south and as no one is behind me I hard check the brakes at 45. It's fine. 1/4 mile later turn back into the 'hood and over the tracks and juice it a little so the ass wags going over the tracks (I'm easily amused), then make the quick right up the side street and BAM it happens (about 3.5 miles from pulling out of the house). I have all the windows down now so I can really hear well now.

Like an engineer of a steam train I undo my belt and hang my left arm out the window to get my head out there lol. It is most definitely in the rear and sounds like it is in the brake drum if I had to bet my lunch money.

It was now 7 and I have to cook dinner (in the oven now), so I parked it (did it only twice and then prodding it with the brakes did not happen again) and it will have to wait to Wed before I have time to pull the rear wheel as I teach tomorrow night........

If I was a betting man, thinking a shoe is loose and lurching around back there.

Quick check - look at the insides of the backing plates and see if both shoe retaining "nails" are in place on each end.

Best thing I ever do with drum brakes is spend the few bucks on a hardware kit and a few more bucks on new wheel cylinders and replace all that stuff.

And you know which shoe goes towards the front and which shoe goes toward the rear, correct?

My vote is OnStar module needs the software update OR your injector pump timing is off.
But I’ve been wrong before....

how are the u-joints ?

I just had the issue of the master cylinder leaking in the front circuit so the rear brakes were doing most of the stopping work. This would heat up the rear shoes, which would cause a bad vibration (almost like a flat). Brakes never went to the floor, never felt spongy.

If the shoes are old, they could be getting hot and separating from their backing and hanging up. Then that edge breaks off, turns to powder and all is well. Until the next piece anyway. It could be a cracked drum that expands with heat making the crack bigger and catching the edge of the shoe. I've never seen a cracked drum but I suppose it's possible with enough wear.

At least you've got it in the rear somewhere, so that's good. 50% of the car eliminated already!

Check for separated tread on the tires.

sherlock9c1 wrote:

Quick check - look at the insides of the backing plates and see if both shoe retaining "nails" are in place on each end.

Best thing I ever do with drum brakes is spend the few bucks on a hardware kit and a few more bucks on new wheel cylinders and replace all that stuff.  

And you know which shoe goes towards the front and which shoe goes toward the rear, correct?

Thought about this too. Was home for a minute at lunch and they feel seated from the back....Won't have time to pull the wheel until Wed eve though..

Isurf wrote:

how are the u-joints ?

up on stands the DS makes no noises. Of course no load, but they seem nice and tight.

Something in the axle ....

Look for missing upper A arm alignment shims. Explains the random BONKs, but not the brake pad smell.

Self adjust and spring were loose. Drum is okay. Tighten shoe and drive it for now. Will order new hard ware and shoes

Very cool! Thanks for letting us know! Glad you got it!

from the look of the drum the self adjuster arm was riding around on the face where the studs go through the drum as that part is all shiny. The spring is half worn away.

Had to be like that for awhile too as when I adjusted the shoes to make them snug I got 3 full turns out of the adjuster wheel! I know it's fine for now, my first vehicle had 4 drums and 3 of the adjusters were broken off.

I've had four of these wagons and rarely was able to keep the self adjusters working properly, even with new hardware, proper lube, all that jazz. Even tried swapping them side to side to get a better bite on the star wheel. No dice. I ended up just occasionally sticking the adjuster tool in through the slot and adjusting them a few clicks every so often.

The common practice of shifting into Reverse with your foot on the brake keeps the self-adjusters from "adjusting". The only way these little jewels will adjust is if the car is rolling in Reverse and the brake is applied from a fully released state.

Swapping the star wheels side-to-side will make the adjusters loosen the brake, as one side has a left-hand thread.

To be clear, I didn't swap the star wheels, I swapped the arm that engages them. In my case they were sliding over the star wheels rather than grabbing and turning them.

Trust me I tried exactly the brake technique you did. I'll keep that in mind next time I have a drum brake rear though!

I've never touched the rear brakes on my '96 wagon....but now want to get back there and check them out. Thanks for the motivation and glad you found the issue on yours!

I really REALLY like your new wagon. So Sharp!

The rear drums are used so much less with the proportioning valve (I think under 40% of braking to try to keep the rears from locking....and causing a fishtail) Over my wagons I think it's about 2.5 to one on front pad vs. drums replace.....

I probably won't ever spend the 7 bucks to get a new adjuster, just swap in my freshly rebuilt 9C1 rear with 4.10s....of course then I'm cutting holes in the floor and firewall, etc etc etc

I thought 9C1 rears were too wide. Wouldn't everything come out of the 9C1 and bolt up to the Roadmaster rear end (sans Disc brakes)? I'm vexed about the multiple width rear ends for B-bodies.

And yeah, I'm still betting that SwaggerWagon is right about that OnStar software update. Did you check that out yet?

Brandt51 wrote:

I thought 9C1 rears were too wide. Wouldn't everything come out of the 9C1 and bolt up to the Roadmaster rear end (sans Disc brakes)? I'm vexed about the multiple width rear ends for B-bodies.

And yeah, I'm still betting that SwaggerWagon is right about that OnStar software update. Did you check that out yet?

The wagon is the widest it gets. The 9C1 has the most narrow rear axle. Sprocket has the entire rear plus the disc brakes. He had to run a spacer to get the wheels sitting right.