help with a noise from the back of the car.

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Swan Song

Swan Song

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Guys i just got the car yesterday and it seemed fine but today I am freaking out thinking I got burned or something. Please help me.:pale:

I am getting a noise coming from the back of the car when i drive it. I suspect it to be in the rear end or drive train somewhere. After slowing to make a turn, the car has a loud rhythmic thump back there and kind of rolls funny in the first gear and early into the second gear before smoothing out.


What should i be on the lookout for? what would cause that and how is it corrected?

sorry I forgot to tell you about the car. duh!
1976 Dart Swinger Special
AT
360 4bbl

Not sure what else you may need.


Thanks in advance for any help.

Moderators feel free to move this if I am in the wrong forum. thanks
 
Does this happen in both a straight line and corner? Tight clutches is a sure grip can be grabby around a corner if the friction modifier additive isn't used. Also, broken spider gears in the differential can make all kinds of funky noises. Have you been doing one wheel burnouts or spinning off gravel onto pavement? Also could be a tailpipe banging on so something or a loose rear u joint.
 
Maybe you've got a spool or the rear gears have been welded....:scratch:
 
Sounds to me like spider gears. What is the 5th digit of the VIN? Should be a C or G. That will give us some idea of which rear end you should have in the car...
 
Vin# : LH23G6G143670



L = Dodge Dart

H = High Price (’73-‘76) Swinger Special

23 = 2 Door Hard Top

G = 318 V8 Engine

6 = 1976

G = Manufactured in St Louis, Missouri

143670 = Production Number



Fender Sticker Options



Line 1

M21 M26 M33 N37 R21 K5K

Line 2

KY4 U B41 G51 J52 L31

Line 3

KY4 E2Y3 000 B24 13906

Line 4

344 D32 A998 LH23 G6G 143670


I can remember test driving with the guy and it did not do this at all and even the ride home was smooth... I dropped it off for tinting and it started after that.... (ferris bueller flashbacks of joyriding filling my mind.)

It does it after turning for sure... I suspect a broken transmission mount but am not able to check till friday as I am out of town this week.
 
Start with the simple....belts shifted in a tire etc....
 
d55dave said:
Does this happen in both a straight line and corner? Tight clutches is a sure grip can be grabby around a corner if the friction modifier additive isn't used. Also, broken spider gears in the differential can make all kinds of funky noises. Have you been doing one wheel burnouts or spinning off gravel onto pavement? Also could be a tailpipe banging on so something or a loose rear u joint.
Click to expand...

^^^x2
Also check emergency brake cable...clips missing and half-arse rig job can give you rhythmic thumping. Don't know about the "kinda rolls funny in 1st". I had a real well respected mopar mechanic 25 yrs ago look at my 8 3/4 rear end to find a "thumping" noise that was bothersome. Couldn't find anything wrong. Years later it was the exhaust hanger slightly loose allowing the improperly rigged emergency brake cable to create quite a symphony! Cheap fix. Hope yours is too. Let us know what you find!
 
I always say do a visual, jack it up and turn the wheels by hand in neutral etc. check the U joints. if you want to run through the gears with the rear up do that while watching underneath. You can idle it in all gears, I wouldn't rev too much. Keep in mind that you are not under load, this is just a visual you may see something loose or bent etc. Look at the spring bushings, shock bushings, check anywhere that there may be play or loose and missing parts. You would see if a tire has a shift belt or bent rim etc. It is a PITA and a lift may be better for this. If anything, you will "get a feel" of any play in the rear, also you will know if it is a Sure Grip or "One legger" Like stated before start simple, make sure tire pressures are set, check wheel lug torque, if it is a spool or tight clutch setup tire pressures may effect it. It is always good to make sure the lug nuts are tight, Check the differential oil level, and if you are ambitious the transmission oil level and make sure you have a pinion snubber installed while you are under there. I know work right? when it is over you will know what you have or at least get the basics covered . I know you just got the car, but don't get yourself too upset until after you look at it and maybe find the noise. It may be a simple fix
 
According to the VIN you have a 7 1/4" rear end (G 318). They don't last too long behind a 360. Pull the cover on the rear end and check for bits of metal and chunks of teeth. How do the spider gears look? If you are lucky all you will find is shiny gear oil. I had a '77 Roadrunner (318/ 7 1/4") that started making the sounds you are describing. Listened to it for a couple of weeks until I heard a loud bang while pulling out of a gas station and the car quit moving. The bang was the gear carrier breaking into pieces after a big chunk of spider gear worked its way in between the ring gear and the pinion...
 
Is it possible that when it was at the tinting shop someone set the parking brake and it is now partially stuck? Just something else to check.
 
Pull rear cover, EZ visual. Then rotate the raised tires and see if you see anything rolling around in there. If you chipped a gear tooth, you could drive right through it and not notice it at higher rear end speeds. I broke a 7.25, not fun. broke just about everything in there. pinion, gear, spiders, bam!
 
Sounds suspiciously like a broken spider gear. As has been stated pull the diff cover and look for chunks. Could have been the last owner doing one last burnout or someone in the tinting shop....or you if you "got on it" after you bought the car. The small rear ends are not strong and will break easily if abused, even behind slants and 318's.
 
Thanks all... The fella who sold it to me is helping me look at it. I really don't think he's guilty of anything... Matter of fact he's the one who suggested the tranny mount as a possible issue. its just hard rubber or plastic and God only knows how old it is. The tint place most is the likely culprit, but good luck getting them to admit that. I dont think its going to be that bad after talking with everyone, and even if it is, I still love this car.

I will let you all know what we find. I got a friend who owns a lift and I need him to help me with a couple of small issues anyway.

Thanks for everything guys
 
BTW... I am trying to decode the fender stamps... anybody got a complete list? I keep finding a couple of them that are missed everywhere I look. if you can help, thanks.

Vin# : LH23G6G143670



L = Dodge Dart

H = High Price (’73-‘76) Swinger Special

23 = 2 Door Hard Top

G = 318 V8 Engine

6 = 1976

G = Manufactured in St Louis, Missouri

143670 = Production Number



Fender Sticker Options



Line 1

M21 M26 M33 N37 R21 K5K

Line 2

KY4 U B41 G51 J52 L31

Line 3

KY4 E2Y3 000 B24 13906

Line 4

344 D32 A998 LH23 G6G 143670

Back from tinting!!!
20141004_184127.jpg
 
grumpuscreature said:
According to the VIN you have a 7 1/4" rear end (G 31:cool:. They don't last too long behind a 360. Pull the cover on the rear end and check for bits of metal and chunks of teeth. How do the spider gears look? If you are lucky all you will find is shiny gear oil. I had a '77 Roadrunner (318/ 7 1/4") that started making the sounds you are describing. Listened to it for a couple of weeks until I heard a loud bang while pulling out of a gas station and the car quit moving. The bang was the gear carrier breaking into pieces after a big chunk of spider gear worked its way in between the ring gear and the pinion...
Click to expand...


Swan Song said:
G - vin and fender are above
Click to expand...

The rear end is identified on the fender tag not the VIN. The VIN tells the original engine size. With these cars being nearly 40 years old there is no telling what might have been changed over the years. If it is a Mopar rear end and you have 9 bolts on the rear end cover than it is a 7 1/4, 10 bolts would be an 8 1/4 and no bolts would mean it has been upgraded to an 8 3/4.
 
Oklacarcollecto said:
The rear end is identified on the fender tag not the VIN. The VIN tells the original engine size. With these cars being nearly 40 years old there is no telling what might have been changed over the years. If it is a Mopar rear end and you have 9 bolts on the rear end cover than it is a 7 1/4, 10 bolts would be an 8 1/4 and no bolts would mean it has been upgraded to an 8 3/4.
Click to expand...

Very helpful! Thanks so much.

Well I got back home last nite and jacked it up.
The transmission did not feel loose, nor the drive shaft or U joints.
I knew the rear brakes were redone and in need of adjustment so we did the back up and pump method.

Thinking they could cause the symptom.

Afterward, we drove around the block taking it very easy...... Nothing
So we drove around the development at noral pace....... nothing
Finally, we took it out for a small drive making sure to gow all the way up to 60mph and back down...... nothing

Btw, nothing in reverse either.

I couldn't recreate my trouble....
Did the adjusting the brake fix the problem?
 
In the lower right corner of everybody's posts are some buttons, one of which is the "thanks" button. Click on the button and it will show up as a thank you on their status.

Good news on the car, hope that was all it took!
 
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