Timing Gear Cover - Chapter 1

Submitted by bill on

Timing gear cover mystery

July 30, 2019

When I first bought the 40 and replaced all the cooling system, I had noticed a lot of PO red RTV stuff around the timing gear cover. Later I traced a lot of the oil on the garage floor coming from the timing cover area when the engine was hot. I assumed some sort of misguided repair had taken place in the past. Finally pulling (out with the radiator again) everything to try and figure out what's going on with the leak, and a number of issues showed up.


engine plate



timing cover engine

Closer inspection showed a few bangs on the pulley and and a few stripped bolts (smaller, in the block plate) in that RTV mess on the cover's bolt pattern, shorter on where it should be longer and so on. Most of the oil leak seemed to be right on the bottom where the 2 larger bolts go through the brazed plate on the cover and things meet the oil pan front. I've now pulled the timing cover and sure enough there was no stock gasket on the cover (just the red RTV) and the main round seal used is labeled "National Spain" and does not look right, does not seem deep enough - not like Toyota anyway.


cover seal

The strange thing is some wear on the seal housing area in the timing cover and some odd wear on the pulley shaft where it looks like it hit and rubbed the housing at some point. Also the oil slinger has wear around it's ID and was sort of locked up next to the gear and a pain to pull off the shaft. The inside gear area looks clean and I'm trying to determine if whoever had the cover off went any deeper - seems to be the proper paper gasket behind the plate on the block. And there's no metal chips from all the wear I can see - inside the cover area/gears seem very clean.


oil slinger wear

So what could have happened, could the crank pulley have come loose at some point? The crank shaft seems really clean. Can't figure out what would grind away on the oil slinger that way? Note the marks on the gear. There are even rotational grind marks in the bottom of the seal seat. Maybe the front seal started to leak and someone pulled everything and then reassembled incorrectly and then pulled it apart again when the noise started - it must have made noise? Maybe they tightened the cover out of alignment and banged the pulley back on rubbing against the housing? Even though some of that red stuff looks like it may be behind the plate (between plate/block) I don't think the plate was off - will try to take a closer look. Again, the pulley has a good ding or two, but that could just be from these guys messing with it.


seal wear

Timing Gear Chapter 2