Front end lower then Rear

[clarkedj]

Need an opinion on the height difference between front end and rear. The car is a 78 1800 that I just completed a front end rebuild on. New everything. In another post I am struggling with a rattling noise in the rear end and I have been under the car several times trying to figure this noise out. Today I was driving the car and parked it in a parking lot. As I was walking back to the car from across the lot I noticed that the front end is about 2 maybe 3 inches lower then the rear due to the rebuild. I have the new springs and shocks for the backend but have not installed yet as winter came upon us in Atlanta.

I know for all you northerners we don't really have winter in the south but it is colder then I want to spend in the garage on the floor. Good news is beer stays cold.

The question I have could the difference in height between front and rear be causing an angle differece in the drive shaft that could be causing a problem the rattling noise. I noticed last weekend that the angle that the drive shaft hit's the pumpkin seemed stressed. What I mean is rather then the drive shaft going straight in to the pumpkin the bracket holding the shaft is angled toward the garage floor. I had not noticed this before but it could have always been that way.

Thanks

Ed Clark
404-234-7366

[SLOSpider]

Most spiders sit high in the rear end. You probably got a exhaust/muffler loose or internal baffle bad. If it has a cat it may be bad. Have you tried banging on the pipes from under the car and see if you can hear the noise? Could also be in the rear brake pads, universal joint or internal rear end problem.

[Exit98]

Ed,

Also a common rattle point is the emergency brake cable where it passes under the tailpipe. Like SLO says, shake, push and pull along the entire exhaust system. Very common.

I modified the brake cable hanger which helped a little. When I replaced the two rubber hangers in the back which hold the muffler from the body I got a big improvement.

Check the easy stuff first.

[wikkid]

I'm thinking a lift difference between front and rear would not give you a sound, especially if that sound stays consistent through a ride. Reasoning being, that while accelerating, your front rises up; when braking, it plows. Does the sound change during those stance shifts?

[clarkedj]

Guys,

Thanks for the responses. Mark had mentioned the muffler and cat. I did check these with no rattling. I actually had the cat removed. In Georgia if it ain't there when the muffler is replaced no problem. Good thing I had a Sawsall and piece of expandable exhaust pipe. Ain't the south great.

Exit, I will check the e-brake to make sure.

Wik, The sound only occurs on acceleration or I should accurately say when I depress the gas pedal.

Slo, I suspect that it is either the universal joint or internal rear end. If it were the brakes I would think that the sound would be continuous as the car rolls. With my luck I suspect I have a pumpkin problem but I will check the U j before I pull the pumpkin.

Keep the ideas coming!

Thanks

Ed Clark
404-234-7366

[clarkedj]

I am going to take some pictures and post in my other string to make sure there is not something obvious that I am missing.

Thanks

Ed Clark
404-234-7366

[bobplyler]

Wheb my car was new, when someone sat in the passengers seat, it would rattle in the back under accelleration. I finally figured out that the exhaust pipe was hitting the differential. A couple of hammer blows fixed it.

[4uall]

I have heard of supports for the exhaust (see bottom left of photo springs and support) rattling while driving yet the exhaust is fine when checked

[RRoller123]

someone stole your cat....

[4uall]

Ahhh the great thing about owning a classic where I am is that there is no requirement for emission testing therefore no cat required (p.o. removed) MEOW

[rodman]

I have heard of supports for the exhaust (see bottom left of photo springs and support) rattling while driving yet the exhaust is fine when checked

Does not look good with the exhaust riding on the "Cable equalizer" for the hand brake...

[4uall]

Just looks that bad

[rodman]

Just looks that bad

I would think it will burn through it causing it to fail.

[clarkedj]

Guys ,

Thanks for the comments.

4U thanks for the pictures where the drive shaft meets the differential in your pictures is interesting. The back bracket holding the drive shaft on my car is more angled then yours. Mine points more to the ground. I think!

Good to live in the South with no emissions for classics. Too hell with global warming! oops! not PC. I think I am going to give the no Cat on my 1970 Deville convertible and see what happens.

Thanks

Ed Clark
404-234-7366

[giuliot60]

My new (stock) exhaust is very close to the panhard, that it will hit it during low revs when the car vibrates a lot. I may be due to the incorrect (hand made) down pipe on my exhaust. Hopefully that will correct itself when I replace with a stock style pipe.

The E brake cables all seem to do that Rodman. Mine is actually a good distance from my exhaust. But you could probably adapt a spacer to the bolts that connect the cable bracket to the body for more clearance.