2006 Jeep Commander 3.7 Timing guide problem

03-06-2019, 07:31 AM
I bought a decent commander for cheap, $700. The owner thought the head gasket blew but it is just the electric fan. I drove about 80 miles home and had a real bad noise. I have done heads on the 4.7 and I figured it was the timing chain. I checked the rockers and then decided to pull the front cover off.

The drivers side tensioner had failed and shattered the plastic guide. I replaced both tensioners and the drivers side guide. Timing was still good. I then screwed up bad.

I used the bolt in the crank shaft so I could turn the motor over by hand and check things out. I wrapped a rag aroung the shaft and tried to take the bolt out. The engine turned over backwards a little and the rag caught into gear.

The primary tensioner in the lower middle - near crank gear - cracked. The rag got eaten up into the gear a little and I just didnt see it in time. Its the one that looks like a crescent moon.

I looked it over and it seems that the plastic shouldnt go anywhere. I buttoned everything back up. Tonight I plan to finish putting the alternator, fan shroud and all that back together.

I am worried about it but I had already setup the front cover with RTV. I didnt want to have to scrape it all off and then pull the valve covers and chains back off. The primary tensioner cant be replaced without pulling the chains and gears off.

Was I stupid? probably. I dont know. It looks to me that the tensioner should be ok. I guess if its going to fail I will hear it and then do the job over with a full kit.

What do you think?

FYI its been almost single digits here so I was a little excited to just put it back together.

03-14-2019, 10:35 PM
Update - Timing ended up being off a tooth. I pulled the chains and did it proper. New tensioner. Set timing by zip ties and eye ball. Was not as bad as I remember the first time. It took me about 6 hours total and purs now.

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