Urambo Tauro

INTRODUCTION:

I completed this repair on my 172,000-mile 5.0 about a month ago, and just wanted to share a collection of things I noticed that may provide a good heads-up for anyone doing this in the near future. This is not a walkthrough of the process, but a supplement of notes that you won't find in a repair manual.

The only failure at the time was the water pump, but after hearing of timing cover gasket and harmonic damper/balancer failures after twenty years of service, it seemed wise to do it all at once. Also, with the timing cover off, this was a good opportunity to change the timing chain before putting it all back together.

A few weeks prior to this, I had flushed my cooling system during a thermostat job. I also changed the oil and used some degreaser on the engine bay, which definitely made the impending work more pleasant.


DISASSEMBLY:

After removing the electric fan and recovery tank for access, I decided to clean the tank for better readability. After draining it, I poured in some hot water, dishsoap and a handful of small metal pieces (bolts, nuts, small chains). I then shook the tank vigorously to clean the inside. After removing the metal bits, I rinsed the tank thoroughly and cleaned the outside as well. It doesn't look like new, but it's definitely better than it was.

I used a sheet of cardboard to protect the radiator fins for the rest of the job. Before removing the crankshaft bolt to release the harmonic damper/balancer, I placed the (manual) transmission in 5th gear and made sure the parking brake was set. This held the crankshaft steady for me to loosen the crank bolt.

Sure enough, the rubber piece in the damper was beginning to crack and tiny chunks had fallen out, though it wasn't bad enough to disrupt anything yet. No matter; I was changing it anyway.

I used penetrating oil on all timing cover and water pump bolts, but it would not seep far enough to lubricate every bolt's threads. I took my time and carefully worked each bolt. The ones that gave me the most trouble were the water pump bolts on the outer ends. No matter how much I backed them out, the bolts never loosened up to be able to turn by hand. As I wrenched on them, they reached a point where I thought the threads had stripped, as they were still hard to turn, but were no longer moving away from the engine.

But there was enough of a gap to get a prybar behind the timing cover, and I was able to pry it away while continuing to turn the bolts out. They still never loosened up, and held on to the last second. Once the timing cover was off, I saw a bunch of crud in the timing cover's (non-threaded) bolt-holes. It had the consistency of soft wood, and I cleaned it out with a drill. I used thread chasers to clean all threads in the cover and the block to facilitate reassembly. I also cleaned the bolts themselves.

The timing chain felt loose. I found about half an inch of deflection, which is right on the edge of OK-spec. The new one I had ready for install was TIGHT.


REASSEMBLY:

My new Fel-Pro timing cover gasket kit came with new corner pieces for the bottom where it meets the oil pan, but the existing oil pan gasket was steel-cored, and cutting the corners out of it was going to be a problem. So I cleaned it up well and applied a generous amount of RTV on both sides prior to bolting the timing cover back on. I am pleased to report no leaks.

I had trouble installing the new front seal in the timing cover, so I left the seal in the freezer overnight to shrink it a bit. The next day, I went to tap it into the timing cover, which I suddenly realized I should have brought indoors. I had left it in the cold garage, negating some of the benefit from freezing the seal. But I managed to tap it in without damage, and continue my reassembly.

Another mistake: I should have dry-fit the timing cover gasket before installation. Instead, I just smeared RTV on it and put it in. The ugly result was extra bits of gasket hanging out that could have been trimmed off first.

The new Harmonic damper/balancer had runs of paint making the timing marks hard to read, so I wire-wheeled the paint off of that area and re-painted it. Once dry, I used a silver Sharpie to highlight 10° BTDC.

Refilling the cooling system took a long time. I had done it several times before, but having the timing cover off allowed the block to drain more thoroughly than before. I finally managed to get all of the air out and prevent an overheat condition.

americanfisher93

Good write up

88 orangepeel notch

Great job, well written. Those tips will really help the next guy/gal down the road.