Rattling in Rear End

[clarkedj]

Guys,

I have a 78 Fiat 124 1800. I was about to tackle the rear end suspension as I just finished the fromt end about 3 months ago. I noticed a noise coming from the rear end like a rattling upon acceleration on the driver's side. At first I thought it was excessive noise coming through the floor since I sprang a fuel leak in the interior lines and ruined the carpet and all interior insulation. So ther isn't any noise barrier. I decided that I would drain the rear differential to see if there was a lack oil. It was down probably more then it should have been but I refilled with fresh oil and the rattling persisted. As I mentioned it only occurs on acceleration. I checked the u-joints but not really sure what the hell I am checking for. I know what a bad one looks like as I had to have my other sons replaced on his 4 runner. Any ideas would be helpful

Thanks
Ed Clark
404-234-7366

[So Cal Mark]

if it's only on acceleration, it could be in the exhaust. A loose baffle in the muffler or broken catalyst will rattle on acceleration

[clarkedj]

Mark,

Thanks for the response. I had not thought about that. I am going to try and record it for posting.

Thanks

Ed Clark
404-234-7366

[clarkedj]

Looks like the rattling in the rear end has actually become grinding at higher speeds upon acceleration. I took the car to my local mechanic ( he works on my wife and other sons cars, don't understand why they don't trust me ) he thought it sounded like a problem in the rear differential ( i.e. pumpkin). He asked when I drained the oil did metal pieces fall out ( i.e. parts of teeth). I said only shavings that had collected near the drain plug. He said there was a leak at the pinion seal as there was oil on the rubber bumper under the car above the driveshaft by the pumpkin. I wanted to get you guys opinions and thoughts on the problem.

Since I live in Georgia when I first bought the car I had Dave in Duluth replace the orginal differential with a used one he had in the shop. This has worked great for the last 5 years but wondering if I do have to replace should I use new.

Thanks

Ed Clark
404-234-7366

[rodman]

Looks like the rattling in the rear end has actually become grinding at higher speeds upon acceleration. I took the car to my local mechanic ( he works on my wife and other sons cars, don't understand why they don't trust me ) he thought it sounded like a problem in the rear differential ( i.e. pumpkin). He asked when I drained the oil did metal pieces fall out ( i.e. parts of teeth). I said only shavings that had collected near the drain plug. He said there was a leak at the pinion seal as there was oil on the rubber bumper under the car above the driveshaft by the pumpkin. I wanted to get you guys opinions and thoughts on the problem.

Since I live in Georgia when I first bought the car I had Dave in Duluth replace the orginal differential with a used one he had in the shop. This has worked great for the last 5 years but wondering if I do have to replace should I use new.

Thanks

Ed Clark
404-234-7366

Pull the cover off the differential look inside. Jack up the rear where both tires are off the ground look at the spider gears and ring and pinion see if you can see what it is doing.

[clarkedj]

Rodman,

I was under the car over the weekend, Thanks for your response BTW, I did not see a plate that I could remove from the back it looks pretty solid. Do I have to drop the pumpkin to see inside. I will take another look later this evening but the bolts were not obvious.

Thanks

Ed Clark
404-234-7366

[rodman]

Rodman,

I was under the car over the weekend, Thanks for your response BTW, I did not see a plate that I could remove from the back it looks pretty solid. Do I have to drop the pumpkin to see inside. I will take another look later this evening but the bolts were not obvious.

Thanks

Ed Clark
404-234-7366

Does your def look like this one in the rear???


IMG_20130128_175641 by fiatcs2000, on Flickr

[FiatMac]

Rodman,

I was under the car over the weekend, Thanks for your response BTW, I did not see a plate that I could remove from the back it looks pretty solid. Do I have to drop the pumpkin to see inside. I will take another look later this evening but the bolts were not obvious.

Thanks

Ed Clark
404-234-7366

The '78 probably does not have a removable back plate. The differential pulls from the front. The differential style changed in '79 to the style with the back plate. There may have been a few late '78 cars supplied with the later style as the Fiat factory sometimes had a tendency to install whatever was available in the overlap period between model years.

[clarkedj]

Guys,

Thanks for the responses. Mine does not look like the picture posted it has a solid back. So I guass that means I will have to pull the pumpkin? I am going to start an additional thread about the alignment between front of the car and rear. As this could be the basis of the problem.

Thanks

Ed Clark
404-234-7366