Find top dead center after broken timing belt

Reply

  #1  
Old 01-27-02, 02:13 PM
Member
Thread Starter
Join Date: Apr 2001
Posts: 52
Replace timing belt after broken

Timing belt broke on '87 Nissan Pathfinder, v6. Went to gates.com and found out it is a valve bender. FYI, was not quite time to replace belt, but think had a cam-seal leak, caused crankshaft gear to eat off about half the teeth.

A friend (mechanic) told me to replace belt and turn over - possible that the valves are OK. Is this true? Or will I just do more damage.

Second, since the crankshaft turned but the cams didn't, how can I syncronize the cams and crankshaft? (find top dead center on Cyl. 1? - don't know how) My repair manual just shows how to do it with belt still intact - ie. with crankshaft and cams still in sync. I already have the pulley off with the timing marks on it. The belt I bought has the white marks on it - can I simply align those with the mark on each gear, or is there more to it. Seems to me I could be 180 degrees off this way or worse.

I am assuming that I will have to redo valves, but either way I need to know how to syncronize the crank and cam gears. Any help would be greatly appreciated. Thanks, Nick
 

Last edited by nbjmiller; 01-27-02 at 04:49 PM.
Sponsored Links
  #2  
Old 01-27-02, 04:44 PM
Member
Thread Starter
Join Date: Apr 2001
Posts: 52
OK, I put the new timing belt on by aligning the white marks, and turned it over a few times (didn't have water or other belts hooked up yet) to see if could hear valve damage. Sounded OK, but I have no way of knowing if everything is syncronized. I have looked/searched several forums and have found nothing on how to set top dead center once the belt has broken. I could really use some help. thanks, Nick
 
  #3  
Old 01-27-02, 04:54 PM
Joe_F
Visiting Guest
Posts: n/a
Should hit your parts store or library for a repair manual. It will give you the timing procedure in detail. A Chilton or Haynes is probably ok for this repair. Might want to spend the 25 bucks for the Alldata.com subscription. You'll get the OE style diagrams and information.

Likely you have bent valves on this one..
 
  #4  
Old 01-28-02, 08:53 PM
Member
Thread Starter
Join Date: Apr 2001
Posts: 52
Thanks, Joe. Subscribed to alldata.com - great info there. Aligned each gear with mark on engine (too dirty to see before), aligned white marks on belt with marks on gears. I knew whether it was top dead center on piston 1 because the rotor under distributor was pointing to #1 spark plug wire. Seems simple now. Too dark so haven't tried to start yet, will let you know if needs valve job.

Preesh...Nick
 
  #5  
Old 01-29-02, 05:14 AM
Joe_F
Visiting Guest
Posts: n/a
Ok, sure.

Good luck and let us know what you find.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes