Rear end troubles! Popping noise from rear of car.

jamesklyne · 07-09-2002

I have a 99 V6 mustang that I recently replaced the clutch on (with a "racing" clutch). Soon afterwards, I started hearing a popping noise from the rear of the car. The noise was most apparent during moderate-hard acceleration and during turns. Also, the rear tires drag around turn. I think that I blew the rear differential with the stronger clutch. Has anyone seen this problem before? Is it a cheap fix? I'm guessing it will run me $500-$600 for parts (self labor) but that's if I actually got the problem pegged.

Also, I put Ford Racing (authentic) 2000 Cobra R rims on my car and they scrape when I make a full turn on the wheel. Is there something that I have to replace/add to correct this? The tires are too wide, and I think they jacked up one of my tie rods.

Now this is irrelevant to my problem, but I am about to perform an engine swap on my car, and I wanted some suggestions on what I should swap in. I was thinking along the lines of a modular motor, but I am not sure which is better. OHV or OHC? 4.6 DOHC, 5.0 OHV, or 5.4 DOHC? If 5.4 should I go with the Lincoln Navigator motor, or a SHM motor, or are there other options? Need lots of help... mostly mental.

thanks,

jamesklyne

Vortex · 07-09-2002

The stock differentials can hold a good 300 horsepower without any problems? is your V6 pushing more than that? Even with a racing clutch, the engine would still be able to push thru it should it lock up. The clutch didnt break a differential. Check your U-joints and makes sure you dont have a lot of play in them. If your differential did go out, unless you are highly skilled in repairing them, i wouldnt attempt it due to proper spacings and such. If you get it done the replacement install kit runs about $80-$100 and if you need gears, they run from about $140-$200 depending on brands and distributor.
Not sure about the wheels, but if it were me, I'd go with the DOHC 4.6. While the 5.0 is a good engine, it would require too much in the way of swapping. computer, wireing harnesses and such, you would have to have a donor car. the cobra motor should go in with very little resistance. the 5.4 would be good for more horsepower, but again with the swapping issues, and also if you're going to use it as a daily driver, you dont need more cubic inches... you could build a 5.0 or 4.6 to be as fast as you want with the right mods and tuning, while still maintaining decent gas mileage...
These are just my thoughts and expressions. I'll provide help if i can with whatever you choose.

jamesklyne · 07-10-2002

Hey thanks, I'll look at the U-Joints, but Im not sure if that would cause the rear tires to drag around turns and make a popping noise, or am I mistaken?

Vortex · 07-10-2002

they can make a popping noise yes. and the dragging of tires, could be slack or binding of the u-joints that dont allow it to turn. Jack up the back and spin the tires back and forth... you should be able to feel something as far as friction.

jamesklyne · 09-02-2003

Sorry to bring this old tread up, but I never replied to what the problem turned out to be (in case someone else has this problem).

(This was quite a long time ago, like a year ago

)
I pulled the rearend cover off and noticed that the spider gears were totally stripped, BAD! Luckily I had gone to the junkyard a day before and pulled the rear out of an Aerostar. I just replaced the stripped spider gears with the Aerostar one's and TADA! Worked perfect.

-Jim

stang2_3 · 09-04-2003

If i were you, I would still have the thing checked out because I don't think the rear gears usually just strip like that by themselves. I just don't want you to have to replace that crap again real soon.

jamesklyne · 09-08-2003

It's been over a year and about 40,000 rough miles later and no problems. I looked at all the gears inside the rear diff and they all looked good to me.

Stangboy5666 · 10-06-2003

I really dought that you lost your rear end with a little popping noise. When I lost my rear end I shot spider gears down through the housing and chipped my ring and pinion gears to hell. The thing nearly jumped off the road. If you had lost your diff. you would hear a massive clunking not a popping. It would sound like Smurfs were taking sledge hammers to your axles. Also it would not stop when youwere taking it easy I dont think. It would keep it up all the time...