Knocking / Clunking in reverse

[deziner75]

2003 Sport 4.0L - 90k miles. Drives great, no issues EXCEPT....

terrible klunking/knocking sound in reverse that increases in speed/frequency the faster the vehicle moves in reverse. I'm not sure if it quite matches the tire rotation rpm. I've greased the zerk fittings that I could find (6 I believe). What else should I check for and where else should I look? I'm not ready to bring it into the dealer yet to be told its the reverse gear or something transmission related, but maybe having a service tech give it a listen would be the best thing?

I've searched a good amount, but nothing I've found quite seems to fit the bill here....

ETA: Oh, and awesome forum. I'm a new T4R owner and have dug through the site, already implementing some mods and $-saving ideas.

 

[TechWrench]

2003 Sport 4.0L - 90k miles. Drives great, no issues EXCEPT....

terrible klunking/knocking sound in reverse that increases in speed/frequency the faster the vehicle moves in reverse. I'm not sure if it quite matches the tire rotation rpm. I've greased the zerk fittings that I could find (6 I believe). What else should I check for and where else should I look? I'm not ready to bring it into the dealer yet to be told its the reverse gear or something transmission related, but maybe having a service tech give it a listen would be the best thing?

I've searched a good amount, but nothing I've found quite seems to fit the bill here....

ETA: Oh, and awesome forum. I'm a new T4R owner and have dug through the site, already implementing some mods and $-saving ideas.

I think you are going to have to get the vehicle up on a lift, or jack stands, and physically check the u-joints in each drive shaft for play. But, a more likely cause could be the parking brakes inside the rear brake disks. It is a common issue, especially on early 4th gens, that one or more of the brake shoe retaining pins comes loose from the backing plate allowing the shoes to move out of place and cause problems. To check them out, you will need to remove both rear brake disks to see them.