Timing chain/tensioner changes? 22RE

[SteveH]

I once owned an '89 22RE 4Runner and the timing chain tensioner(s) failed at 172K. I now have a '94 22RE 4Runner, with 198K that has been pretty well maintained.

Did Toyota make any changes in the timing chain or tensioners between '89 and '94, or should I expect eventual failure here, too?

thanks - Steve

 

[snobdds]

The chain tensioner’s did not change between 89 and 94. In fact the chain tensioners are not the part that fails. The chain gets streched overtime and develops some slack in it. The role of the tensioner is to take up that slack, however there is only so much slack it can take up. Once the tensioner is maxed out, it starts rubbing against the driver side chain guide. The guide, being plastic from the factory, eventually fails. Then the chain will eat through the timing cover letting the oil and coolant mix...you know the rest.

If you have 198k on the motor and you have no idea if the timing chain has been replaced...replace it. Some get away with just removing the timing cover and loosing the oil pan to get enough clearance, but it's really not the correct way to change it. To do a timing chain right, the oil pan needs to be dropped and the head needs to be taken off. So this means a good seal is formed on the head gasket and the oil pan. Then you don't have to worry about anything for another 100k.

 

[bryan89]

as far as i can tell from the parts fische online, there have been no part number revisions to the tensioner or chain

 

[SteveH]

Thanks - excellent info. I appreciate understanding the failure mechanism, too. I'm aware of the fairly massive disassembly to correctly replace the timing chain. As my mechanic buddy said, many engines over 175K really ought to have a head gasket done anyway, so do it all at once.

 

[snobdds]

The 22re block will go to 300 - 350k before needing a rebuild if the chain and all that goes with it are done every 100k miles or so. So a 300,000 mile motor should have had 2 timing chains done it it's life, to give a good reference. However, most don't live in a perfect world.

The 22re is the best motor to work on, simple and the parts are stupid cheap. I like OEM parts, but go with what you like.