Finished up the Dana 60 last night and the owner came and picked it up.
Just finished drilling the 60-degree taper in the last hole to .200" depth. I got just a little bit of chatter in the bottom of the tapers but other than that I am quite pleased with how it turned out, as was the owner.
Removed from the mill vise, deburred and cleaned up before the owner arrived.
While I was awaiting the owner to pick up the steering link I thought I'd rack my Jeep and see if I could locate a slight rattle or vibration that we picked up last weekend on our Sunday drive.
I'm not sure if I mentioned this or not but after replacing the hydraulic motor mounts last week I thought it was smoother than before but also considered it just to be the placebo effect. During our drive last Saturday both on road and off, it was smooth as silk and just lumbered along like it usually does.
Our drive on Sunday went the same until we were coming back into Logan, UT and the skies opened up with a torrential downpour and even hail. As we drove out of the storm and into just a steady drizzle we decided to grab some dinner as it was getting to be early evening. Upon coming to a stoplight I could hear and almost feel a slight vibration. The wife couldn't hear it at first, I kicked it into Neutral and it went away then back into drive and it reappeared. My first thought was a heat shield on a catalytic converter because it had that same frequency sound but a different tone, if that makes any sense.
My next thought was that because I had to lift the engine I had both engine mounts removed and transmission mount loosened so maybe it didn't sit back down where it was originally and was contacting something. After a few more stops the wife could then hear it.
Upon arriving home I had the wife pull it into the shop while I popped the hood and poked around. I noticed that the new intake duct that I had installed a few weeks back had actually positioned the air filter quite close to the core support with the engine in drive and just torqued to the passenger side a bit. Upon kicking it back to Neutral the gap opened up to about an 1/8". So the next morning I went out to the shop and relocated my fog light relay so I could reposition the air filter giving me at least 3/8" on either side. We took the Jeep to breakfast and I didn't hear the noise any longer so I thought that must have been the issue.
I drove the Jeep to work Tuesday and didn't hear the noise so again, I thought the air filter was the issue. The wife and I ran to grab some dinner Tuesday night after a stressful day and sure enough as we were leaving the restaurant the noise returned. At this point I was baffled wondering what could be coming and going like that.
Last night I racked the Jeep and dug deeper into the issue, pulling the engine cover and looking back down behind the engine paying particular attention to the head to firewall clearance, A/C compressor to steering gearbox, passenger exhaust manifold to upper control arm mount and any known areas that I knew about when I installed the LS into the Jeep. None appeared to be any different than I remembered and all had adequate clearance. Moving rearward I thought I'd double check the catalytic converters, again, and upon using a gloved hand and tapping on the driver's side, the heat shield sounded intact and not loose or rattling.
I then moved to the passenger's side cat and tapping on it resulted in a rattle. It was a bit different than the high pitched and "tinny" sound I normally find with loose heat shields but about that same frequency. I started looking at the spot welds holding the shield to the cat and all looked good. Nothing appeared to be loose but that noise was definitely coming from the catalytic converter or shield. I stuck my head up as far as I could around the skid plate and could see something bouncing around when I tapped on the heat shield. I grabbed a small prybar and bent the lip of the heat shield down slightly to reveal the issue.
Here you can see the small rub mark outlined in yellow on the underside of the catalytic converter.
And here was the culprit. A freakin' rock had gotten between the heat shield and the body of the catalytic converter.
Holy ****, a small pebble nearly drove me near the breaking point.
Afterwards I took the Jeep on a road test to confirm that was in fact the noise and sure enough, quiet and smooth as can be.
I pulled it back into the shop to give it a wipe down with Final Inspection before putting it back into the house garage and when I climbed out of the Jeep I caught a "wiff" of coolant. I popped the hood and noticed I had cooland splattered on the intake duct as well as my coolant surge tank. WTF is going on???
Poked around and quickly noticed I had a small pinhole leak in the upper radiator hose.
So I put the Jeep back on the lift, let it cool and that's the job for tomorrow morning. Oh well, at least it's an easy fix being right at the top and my local NAPA is being good enough to warranty the hose for me so a little time and a gallon or two of coolant is all.
At least it happened at home rather than being in the back country off-road last weekend or while we are up in the Madison Valley of Montana in a week. Either of those scenarios would have been much worse. This is nothing.
