timing belt slips off tensioner B230 engine

Thread Tools
 
Search this Thread
 
  #1  
Old 10-26-2008 | 10:52 AM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default timing belt slips off tensioner B230 engine

Hi Everybody,

1987 740 turbo, B230FT engine.

I've changed a few timing belts in my time, but this is a first.

After changing all front oil seals, I put a new tensioner (INA) on and slipped on and aligned new timing belt to the pulley wheels. Once I released the pin to let the tensioner take up slack, I rotated the crankshaft 1 whole revolution (CW) and the belt was starting to slip off the tensioner roller. If I go 2 revolutions of the crankshaft, the timing belt is barely hanging on the roller. Yes, the hanging pin of the tensioner is pushed into the background hole in the front of the engine.

I had torqued overhead camshaft bolt to 37 ft-lbs but had not yet torqued intermediate camshaft to that spec. Is not torquing intermediate camshaft bolt to that spec part of the problem because it's not properly aligned with the overhead camshaft?

Any ideas? Thanks.

 
  #2  
Old 10-27-2008 | 02:59 AM
dgm76513's Avatar
Joined: Nov 2007
Posts: 58
Likes: 0
From:
Default RE: timing belt slips off tensioner B230 engine

Make sure the harmonic balancer/crank pulley are lined up properly, they're keyed but I've seen the pin get smashed and whatnot. Also make sure those stay plates are in place on your crank pulley for the timing belt.

My timing belt slipped off when my harmonic balancer flew off while driving. It was a mess.
 
  #3  
Old 10-27-2008 | 05:45 AM
jsinton's Avatar
Junior Member
Joined: Oct 2008
Posts: 22
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Did you remember to put back the alignment keepers for the timing belt on the main crank gear? I forgot to put that back one time, and the same thing was happening.
[align=left] [/align]
 
  #4  
Old 10-27-2008 | 08:12 AM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

Like stated already make sure the washers/spacers on the crank are set correctly.
 
  #5  
Old 10-27-2008 | 08:46 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Thanks, guys. Yes, I have the back crankshaft shim (which doesn't lock to crankshaft); pulley boss (or gear), which is keyed to the crankshaft; front crankshaft shim, which is keyed to the pulley boss; and the crankshaft gear/harmonic balancer, which is keyed to the pulley boss.

I suppose I had better doublecheck that there is no burr or something like that on the crankshaft that is hanging up the front shim. Still, the alignment of the intermediate camshaft over the crankshaft looks dead on.

But, I will check.
 
  #6  
Old 10-27-2008 | 08:58 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Oh, I forgot. Playing around with all this, I still haven't torqued down the crankshaft bolt yet. Could this be the problem?
 
  #7  
Old 10-27-2008 | 09:15 PM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

It is possible it is causing it.
Also may sound like a stupid question but did you possibly swap the intermediate shaft pulley and the cam one?
 
  #8  
Old 10-27-2008 | 09:30 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Tech, nope. They're put on correctly. I labeled overhead with an "O" and intermediate with an "i," respectively, when I took them off.I also did remember to put the washer behind the overhead cam gear. There was no washer for the intermediate.
 
  #9  
Old 10-27-2008 | 09:38 PM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

OK are you sure the washer was behind the cam gear?
Some had them but alot didn't have the washers. But the washer would fit unless it is supossed to be there it would have to have the hole to slide over the pin to fit. If you look from the side of the car does any of the pulleys look out of line?
 
  #10  
Old 10-27-2008 | 09:58 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

The washer has a slot to fit over the cam key. Yes, it was behind the gear because I took photos almost every step of the way. What I did discover, looking back at some of the photos, was that the cylindrical hole (on left) of the tensioner guide rod was out a bit rather than being pushed all the way in over the protruding guide post on front of engine. Maybe I just have to adjust this so as to tilt the roller.
 
  #11  
Old 10-27-2008 | 10:01 PM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

Try that and see if it helps.
 
  #12  
Old 10-28-2008 | 08:56 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Tech, update.

1) pulled crankshaft pulley, shims, and pulley boss and made sure everything was pushed up tight on crankshaft.
2) torqued crankshaft bolt to 100 ft-lbs. Better, but belt still slips.
3) Seems that overhead camshaft pulley could be pushed forward 1/8 - 1/4", since the belt slips off about that much after several revolutions of the crankshaft. Strange. There was no problem with the old belt and tensioner roller for the current overhead camshaft. The original keyed washer is in back of the overhead camshaft pulley-its original position.
4) May put in old tensioner roller tomorrow and see if that helps.

This is really strange! Am I missing something?

Thanks.
 
  #13  
Old 10-28-2008 | 09:02 PM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

Maybe try removing the washer behind the cam gear and see if that fixes it.
 
  #14  
Old 10-28-2008 | 09:15 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

I would have thought I needed another washer in there from the angles. But, you might be right. Will try that tomorrow.

Thanks!
 
  #15  
Old 10-29-2008 | 07:43 AM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

Let us know how it goes.
Like I said earlier alot of the cars don't even have the washer from the factory.
 
  #16  
Old 10-29-2008 | 07:32 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Tech,

Removed the 2-mm washer; didn't help. The belt still slips off.

I may have to put another washer in there, or perhaps the cam gears are old and the teeth are rounded.

Also, I'm using a Conti-tech belt. I heard they have a good reputation.

What do you think? Should I get new cam gears?
 
  #17  
Old 10-30-2008 | 08:07 AM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

Heck of a time for me to remember and ask this.
But also make sure the belt is the proper one. The Later model cars have round teeth belts. The older cars have the square teeth belt.
Make sure you have the correct belt.
 
  #18  
Old 10-30-2008 | 06:31 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Tech,

Finally figured it out. The new INA tensioner roller has a flat back hanging plate (against front of engine). The old INA tensioner roller has a small angle bend in that plate, enough to ensure that belt does not slip off.


 
  #19  
Old 10-31-2008 | 07:22 AM
tech's Avatar
Administrator
Joined: Sep 2004
Posts: 36,349
Likes: 40
From: Orlando, Florida
Default RE: timing belt slips off tensioner B230 engine

OK glad that you figured it out.
 
  #20  
Old 10-31-2008 | 04:46 PM
fredbyte's Avatar
Thread Starter
|
Senior Member
Joined: Oct 2007
Posts: 369
Likes: 0
Default RE: timing belt slips off tensioner B230 engine

Oops, the saga continues. A professional mechanic said the back of the hanging plate on the tensioner is supposed to be flat. "Something is out of alignment," he said.

He will be coming over to look at it. I'll keep you all informed.
 


Quick Reply: timing belt slips off tensioner B230 engine



All times are GMT -5. The time now is 04:23 AM.