Car in reverse = odd clunking every few yards

[KINGPIN33]

Hi All, been awhile since I last posted on here.

I'm having some problems when I put the car in reverse.

It's an automatic and I've recently changed the rear discs/removed dust covers and changed out the leaking differential shaft seals on both sides.

Problem:
When the car is in motion and I reverse in any direction, I feel a clunk/hard vibration every few yards. It feels like there's some resistance in the differential or brakes. I raised the rear of the car and each of the rear wheels turn freely without any resistance.
When the car is in motion and I reverse in a straight path, there's no clunk/vibration or feel of resistance...

I'm puzzled and am not sure where to look first. Any pointers would be appreciated. Thanks

Thanks.

 

[Moy]

It sounds like your differential. Could be your spider gears. It sounds (from your post) like the way a welded differential sounds/shakes the car when in reverse.

You said that you replaced the diff seals, I recommend removing the fill plug and stick your finger in and check to make sure that there is an adequate amount of fluid in the diff housing. Also make sure you used the correct type of LSD fluid.

 

[adampecush]

how close does your exhaust come to the output flanges of the differential?