Bad clunking on stop? Is my transmission shot?

[mrshine]

After taking my 95 out a couple weeks ago it has developed a strange clunking sound as I brake and come to a stop. It keeps clunking once stopped, but chills out when I put it in Neutral (auto), and then picks back up when I shift back to Drive to get going again. It doesn't seem to be a problem once I accelerate. Every time I've put it into park to check under the hood it stops too. 

 

Is my transmission shot? I'm terrified this might be the death of the old girl!

 

Thanks in advance

[adamzan]

What happens if you put it in neutral, then brake and come to a stop? If it still happens I doubt it is the transmission. You could have a bad Universal joint, but that would clunk on take off as well.

[Slartibartfast]

I haven't heard of one doing that, and I'm not sure what would go wrong in the trans that would cause that noise with no other symptoms. Clunking with the truck completely stopped makes me think it's not U joints, suspension, or a bad engine or trans mount, and only clunking in park or neutral does suggest it's somewhere in the trans. Fluid level and condition look alright? Does it drive normally apart from the noise? Reverse still works? Does it sound any angrier while you're accelerating than it does when you're stopped in drive? Is it worse in one gear than another?

 

When you turn the ignition on, with the E-AT switch on "auto," does the light in that switch flash/flicker several times? That's how it codes for faults. IIRC it can only see electrical faults, so I'd be surprised if it had any idea what was going on, but it's worth checking on the off chance. If it is flashing, check the AT section of the FSM (get it here) for an explanation of how to read the code and what it means.

 

Has the engine or trans been out recently? Maybe a long shot, but I'm wondering if your torque converter bolts might be loose. I've heard of loose converter bolts making noises mistaken for engine knock.