ok, I have something strange going on...
Driving down the road - not hitting the brakes... was hot today and van was warm for sure everywhere...

Anyways, it will randomly make a bang type sound and feels like the rear brakes are locking up, as it jerks.

It is not repetitive - happens randomly - at 40-45 but speed doesn't seem to matter as much -

would anything besides the rear brakes cause it to jerk like that from the rear or center and a sound? rear end? axle? what about the tranny? - I wouldn't think they make banging noises.

Does this like once ever 5 or 6 miles Wife said not on the Hwy at the faster speeds....

I haven't done the rears in 11 years, but didn't know if they can fail like this without hitting the brake petal

Thanks

 

I was going to suggest the e4wd system is locking up when it's not supposed to, causing the drivetrain to bind until it can skip a link on the Morse chain, but that option did not come out until 1990. My e4wd van did this when the front and rear tires wore unevenly, and the e4wd system was confused, and the lock up caused the binding when going slowly around turns, like in parking lots.

Otherwise, I would check the U joints, or the differential for broken parts.

 

Yes, it's just RWD only - so you are thinking Ujoints or rear diff and not anything witht he axle? just wondered if this was a common problem somehow with the RWD Aeros

Thanks

 

Have you pulled the drums off the rear brakes and taken a look? You could have a broken spring bouncing around in there.

 

I would put brakes as a root cause, far behind driveline issues.
Since a thorough inspection has you opening up the diff, I just now cleaned up the rear axle maintenance thread.
Because you are looking for broken things, strain all out bound oil, be ready with a magnet to drag thru the case.
Not covered in the thread...diff bearings.

 

The other parts that can wear out and make noise are the outboard axle bearings, but those make more constant noises. They will start from a dull moan and progress to grinding noises, but pretty steady. Of course, if they're really blown, they can make banging noises too, but you won't be moving very far.

 

I was going to start with the rear brakes I guess, since that is the easiest and cheapest... anyone know for sure if the 89 shorty used 9 or 10 inch drums? I know I can pull them off and measure, but I thought I'd just have them first ready to go

Any good tips on tools and hardware brands? - my main concern is pulling them, since I know they can be hard to get off, and I will need to turn the star nut on the back side of them though that slot... is there an easy tool for that?

Thanks

 

I've never had any trouble pulling the drums. The drum would have to be worn pretty bad to have to back off the adjuster. After 11 years, I doubt the automatic adjuster has been working for some time. The tool for that is called a brake spoon. It comes in about a dozen different shapes. Most people just use a common screw driver.
Brake drums are about fifty dollars each. It's a lot cheaper to have the old ones turned. Be sure to use a tubing wrench on the tubing nut.
Here's my biggest tip. Buy TWO cans of brake cleaner and only take the shoes and springs off one side and replace them before taking off the other side. It also helps if you take a picture before removal, but there's nothing like having the other side to figure out what goes where.

 

Someone once did a rear brake write-up, with pics.

 

link seems dead or taking forever to load?

Yes, I would only do one side at a time so I have the other as a reference. Anyone have any good tips for good brands? I might just have them turned yes...

Guess the only way to know if these are 9's or 10's is to pull them and measure them?

Thanks

 

Link worked - Thanks for the nice write up, RojoStar - I've done them myself YEARS ago - maybe did 4 Fronts to every rear job... but it's been a while - I recall them being stuck last time I did them... so will need to have a screwdriver ready for the back star nut access... hope that is not seized up.... if it is, any other tips to getting them off?

I guess Im gonna have to just pull them and see if they are 9s or 10s - It's just the XLT model not an EB or Sport, etc it did have the towing package from the factory (extra wiring, and tranny cooler) I don't tow with her anymore.... the Reese Class 3 that is on her has seen better days. if I tow more than 500 lbs, she might crumble lol

Would I need to replace brake lines if they still look ok, and aren't leaking?

Cheers

 

Old flex hoses can disintegrate from the inside out. This happened to me as I was bleeding an old brake system; slowly pumping the pedal to push old fluid out, suddenly the pedal turns rock solid, and no fluid coming out the bleeder screw. In humans, it would be called an aortic dissection; an inner layer of the hose split off and blocks fluid flow. It happens most often when you're pushing more fluid than normal, such as when bleeding the system. But it can happen in normal operation as well.

I would get one of the big names, Hayes, or Bendix. But even Ford's original parts will disintegrate with age, so it's important to check for these while you're periodically bleeding the system.

 

On my short list of suspects is momentary loss of spark and power, followed by fuel lighting off in the exhaust. iow's a backfire.

 

I'd be worried about a bad bearing. Perhaps on the rear wheels. A flat spot on one of the ***** could cause a wheel to lock-up and as long as both tires are on the ground both sides will lock.

A friend of mine had a 4 wheel drive Subaru that happened to intermittently and when it did, all 4 wheels locked up and put him in the median. They towed it back to the dealership and couldn't find anything wrong. He refused to accept the vehicle back and called the factory. They sent an expert tech out who tore into it and found the problem. Gave him a great deal on a new one to replace it and make up for the hell he had to go through making them find the problem which took several months and a lot of back and forth bickering.