rear axles/diff? What would cause this sudden stopping?

[18screaminwheels]

First time this has happened to me, with any vehicle. Left my car sit for over 4 days...Get in it, start it, proceed to take off. I roll ahead about 3 feet and suddenly BOOM car jerks to a dead stop (engine doesn't stall). I Think WTF?!?!? back it up a bit, I get out, and look underneath around + wheels to make sure nothing is holding it up...I roll clear across a parking lot (probably at least 400 feet) i get up to about 10 MPH and BAM!!! car comes to a literal screeching halt.

Is my diff or axles automatically the culprit? Transmission fluid might be a hair low but its still in between the dots. I crawled under and looked at the diff...looks like it has been wet in the past, and may have a replacement cover. but cripes I've had the car for 6 months driving it nearly every day, and I usually take quick notice If I see spots on the pavement. Is it possible that sitting for 4 days allowed enough of the oil to drain off the gears (if it was low on oil already) to seriously eff it up? The car gets decent gas mileage, all things considered. And i noticed tonight it might possibly make a slight growl or rumble at very low speed, when initially taking off or coming to a stop, but i cant tell if that's my diff or transmission. But why would it drive fine all the way home for 10 miles after acting up like it did?

Why would it roll freely for hundreds of feet and then all of a sudden lock up? I thought these things got hot, rumbled, smoked, whined, and threw out all kinds of warning signs before they blew up? Any ideas???

[sly]

I bet something has come loose inside the diff and is binding the gears. It's either that or the trans. easiest way to check is to drop the drive shaft and manually turn the pinion gear. If it binds up on you at any point, it's the diff. Not sure how to test the trans end as that would require leaving the drive shaft yoke in to keep the seal.

[mcninetyone]

This happened to a friend of mine. He ignored a small leak in the diff and one day while getting on the expressway, the rear locked up tight. Snapped one axle and ruined the gears. One complete 97 CVPI rear end later he was back on the road and much wiser.

[1988 Grand Marquis Pat]

Just had my rear end rebuilt on my 88 MGM. There was a slight whine. Replaced ring and pinion,one axle and put in new bearings. Super quiet now


Motor City Patrick

[Louis]

Could be the diff, they can lock up like that with no warning. I believe that a car can still proceed in reverse but not forward.

When you say 'looks like it was wet in the past', it probably was leaking for awhile but is now dry. Pull the plug and check the diff fluid level.

[gadget73]

what year are we talking? the rear disc cars are sometimes known to have the parking brake shoes fall apart. Possible one could come apart and jam things up. removing the rear rotors would probably tell you something. If parts fall out, its a good sign that something ain't right.

[18screaminwheels]

what year are we talking? the rear disc cars are sometimes known to have the parking brake shoes fall apart. Possible one could come apart and jam things up. removing the rear rotors would probably tell you something. If parts fall out, its a good sign that something ain't right.

1997 LS with 15" rims, so am I pretty sure it doesn't have the upgraded suspension. 123,000 miles. It does have rear disc brakes though. I figured they didn't even bother with rear discs on these things as standard till after 2000. Kinda get the feeling it may have had the rear axle replaced already at some point.

[SVT98t]

The rear disk brakes were standard starting in 1992.
I'd definitely get the car in the air and disconnect the driveshaft to see if the problem is in fact the rear axle. All you need to remove the drive shaft is disconnect the four 12mm 12-point bolts and it will slide right out.
Remember to used Loctite when reinstalling the bolts!!


-ryan s.

[kodiak]

Also remember to mark the shaft and yoke to reassemble it back in the same position.

Sent from my VS980 4G using Tapatalk

[18screaminwheels]

Turns out it was the parking brake shoes falling apart and randomly seizing inside the hubs, simple fix once I got the rotors off

[SVT98t]

Glad to hear that it was an easy fix!


-ryan s.

[sly]

+1 we like easy fixes.

[gadget73]

Cool. Only thing that sucks about it, the axles have to come out to fix the parking brake. I expect you can get tie broken bits out without all that though if you don't use it. Its pretty nearly useless anyway in all honesty.