SeanPritchard

Ok, hopefully someone has experienced this before. I have now changed the Timing belt on my 91 Toy 4runner (V6) twice. Both times the belt has jumped time due to the tensioner coming loose. The Chilton manual recommends tightening the bolt, attaching the spring, then releasing the bolt to allow the spring to gain tension. The first time I had an immediate knocking followed by the belt popping off quickly. The second time I tightened the bolt enough to hold in place but the pulley was still movable. This time it lasted considerably longer (15 minutes) but wound up the same way. I am trying find out the correct process I must complete in order to get this thing back up and running. Should the tensioner bolt be tighter even though it doesn't appear to allow any movement? Obviously I am getting tired of making the same mistake and any help would be greatly appreciated.

callmej75

Make sure you put the spring back on the tensioner with the bolt loose. then let the spring put tension on the belt and tighten the bolt.

SeanPritchard

Thanks for the quick reply, how tight should the bolt be in your estimation? I am worried about making it too tight but it is clear I haven't been tightening it enough up until this point. Is there a too tight?

callmej75

No prob....FSM says 25ft lbs. I would watch "strong arming" it because once you break a bolt it only spirals downhill before wrenches start flying Once you have the belt lined up and all marks match up, it should be pretty hard to get that spring latched that holds the idler firmly against the belt. That alone should be enough tension.

SeanPritchard

The spring should be enough tension? The spring has been attached the whole time and its still jumping. I am just baffled as to why this keeps happening. I expect the bolt should be firmly tightened, like you would a typical bolt. Not cranked on but definitely solid, is that right?

callmej75

Yeh that sounds about right. Not sure why its jumping off...hopefully someone can jump in and offer some more advice. Sorry thats all I got..

SeanPritchard

Thanks very much for your input, I really appreciate it

eric-the-red

A little blue Loctite on the bolts might help, and is it possible that the spring is stretched and no longer has enough tension.

SeanPritchard

Thanks Eric, thats what we were thinking too. It seems odd that a spring wouldn't just come with a new tensioner considering the constant strain it is under. I am about to start pulling it apart again (third time in four days, ugh) and this time I am using a torque wrench just to be safe. I think I am leaving the bolt too loose and it is working itself out as the motor vibrates

SeanPritchard

And I found this picture on someone elses thread, this looks exactly like my setup. The bolt in question is the tensioner bolt

callmej75

When I had my timing belt on and tried pulling that spring with a pair of pliers, it must have slipped 7-8 times before I got it latched. Under alot of tension! You might want to replace the spring or for right now try to pry the tensioner over, not REALLY tight, but tight enough for tension purposes and tighten the bolt at the same time you are prying on it. Should get you going instead of waiting on a new spring.

SeanPritchard

Thanks j75, I got it going this morning and managed to drive around all afternoon. I think this nightmare may be over. Thank you very much for all the help, I desperately needed a second opinion

callmej75

no problem! glad ya got it going...