Another Gen III Timing Belt Interval Question

[2to4wheels]

Quick question. looking at a Gen 3 that had it's timing belt changed at 65K miles. When is it due again? 150k? Why is it that the manual recommends at 60k and 90k?

 

[normal_dave]

My 3.5L recommends every 60K. Looks to be the same for the 3.8L (although I read somewhere later intervals on the 3.8L could go to 105K?)

Gates belts says the same: page 41-42 in the document below.
http://www.gates.com/~/media/Files/Gates/Automotive/Catalogs/Automotive/TimingBeltReplacementGuide.pdf

 

[plh]

3.8l replacement interval is 60K according to the FSM.

 

[montypower]

It varies for the 3.8L. Believe CA spec is 60k. Everywhere else is 90k. Manual has both listed. It should be fine for 90k with SOHC motor. However, I wouldn't run the belt longer than 8years or so. And your motor will be destroyed if it breaks, so sometimes sooner is better.