OK, first off I,ve got a 1984 CJ7 with the 258 6, TF999 auto trans, 4.10 gears with the Dana 30 frt and the Amc model 20 rear with an ARB locker and 35 BFG,s. It all started on a trail I,ve been developing for a few a few years now. It,s all rock in what,s called the Canadian Shield which is granite rock with lots of swamp and lakes. This trail pretty much requires 35,s a locker and reasonably low gears and it still bites quite a few rigs. We were pushing a new section trying to turn it into a loop trail that will prob take about 8 hours or more to run when finished. After several hours we decided to head back to camp and I was in the lead and driving thru a tight forested section where we had pushed some small [1 to 2 inch] trees over when one of them hit the frt diff and was deflected back where it went thru the flex a lite housing and took out one of the two electric fans and then put a small hole in the rad. I was about 3 hours out at a crawl but made it back in one hour. Every 15 to 20 minutes the temp gauge would rise to 210 and we would add about a half a gallon water and keep going. Also the power steering pump belt would twist off prob from the antifreeze on it. Well we made it back to camp and headed to the trailhead where there was a car trailer I could use. In the last 100 yards the belt came off again and put a small hole in the trans line under the rad. It was leaking but not real fast. Anyway once home everything was fixed and I even took it to work a few days later. That night after it sat outside the garage for a few hours I started it up to put it away and when I put it in drive or reverse it made a really loud clunking noise. I went around the block a couple of times to see if I could pin it down and it kept making the clunking noise, almost like there was some slack in the driveline. When I had put it back together I did make one change, There were a set of urethane engine mounts on the bench, they are about 1/2 inch thicker than the stock pieces and I did overfill the auto trans a little. Other than that, nothing changed. Anyone got got any thoughts?

The clunks you describe prolly come from SLACK in the driveline system... starting with a broken engine-tranny mount.. a partly clogged tranny filter... U-joints.. and finally the ring & pinion might be making the noise..
You just have to shake it out yourself..
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Exactly which mounts did you change? <img src="/forums/images/graemlins/confused.gif" alt="" /> Perhaps your transmission and/or transfer case is hitting the body at some point because of the new mounts. <img src="/forums/images/graemlins/cheers.gif" alt="" />

I changed the 2 engine mounts, got a couple of urethane mounts on ebay awhile back. Thanks for the input, I,ll look further into it, when I find the cause I,ll post it up.

In that case I'd check #1 on BJ's list first, the trans/Tcase mount. Good luck! <img src="/forums/images/graemlins/cheers.gif" alt="" />

It took awhile, but I swapped out the transfer case and it fixed it. The inside of the case looks good but I suspect a problem in the tailhousing.

we are happy you got her repaired.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

Just in time for snow. I woke up this morning and there is a couple of inches of snow on the ground.

Snow, eh? Where are you?

Thanks for the update. I hope you enjoy snow! I'd like to see it here again, it snows here about once per decade! Last time in 97! We're about due. <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" />