81 Marquis back end shake around corners - Ford Forums

K_TOWN_FORD · 04-24-2005, 18:37

I have 1981 marquis thats has a almost a slight knocking/shaking/binding sound coming from the back of the car only when you go around corners, more so right corners. I've kinda been trying a few things under different conditions to see if I can pin point it somewhere.
> When you let the car sit overnight and go in the morning its not even there.
> worse when you done a few hard corners then go slow around corners.
>worse after you have spun the tires
> worse when you have passengers in the car.

The car does have a posi rear end and a rear sway bar. The car had previously towed a 27 foot 7000 pound trailer. That was 10 years ago and since has had a 351 crate motor put in and a aamco transmission put in, both have 35000 miles the car never pulled the trailer with the new motor and tranny?

Just wondering if any of you guys could steer me in the rigth direction and possibly tell me were I should tell my mechanic to look at because im so puzzled at this point. A friend told me that it might be out of rear end fluid?.

Another thing because it has a posi rear-end should it have speacial fluid in it compared to a non-possi rear-end.

BlueSteel · 04-24-2005, 21:27

If it towed a heavy trailer for some time check the rear shocks, also rear end lube won't be a bad idea, just some 90 weight oil will do the trick, the other thing is, since your going to play with the rear pig, take the check plate off and see if the ring and pinion gears are okay, they get warn to the point they howl at high speeds and clatter on corners. Also make sure you have the right tires, 205/75/R15 - 225/55/R16 rear, 205/75/R15 - 215/65/R16 front.

K_TOWN_FORD · 04-25-2005, 12:38

Hey Thanks for the suggestions. The car has heavy duty springs and shocks in the back will make sure there good I assume they are, it looks like someone kicked the car in the ass and it stayed up 5 inches. I'm going to take a look at the rear end for sure. As for tires the it has on front and back 215/70/R14 I thought that was really weird for a car of this size its funny because it has the Mercury 14 inch hubcaps I wonder if they came with this size tire and rim from the factory.

BlueSteel · 04-25-2005, 14:52

They did come with 14s, see if the tag is still on the passenger rear door inner rocker, it should tell what you should use. If not there I'll post the info.