Loose passenger side timing belt after replacement

[errantalmond]

I recently did my front seals, timing belts, oil pump, idler, and tensioner (replacement).

Today I checked the belts (luckily i left the covers off), about 1000 miles down the road.

The passenger side belt is loose, so I loosened the tension and retensioned it, checking the timing - it hadn’t jumped any teeth. With the tensioner pushed fully upwards, it is still loose. It also looks worn compared to the driver side. I buttoned everything back up and looking at it when it runs, I see the passeneger side belt has about an inch of play on its longest side (crank to cam), while the driver side has only about a quarter inch of flapping. They’re not making any unusual sounds.

why?? 
please help

jon

[Step-a-toe]

fitting instructions say to give it all a few final rotations and recheck tensions, from memory. Did you do that ? Those belt tensioners bolts have a very low torque up on them, did you measure torque on initial and before you readjusted ?

[errantalmond]

I did - tension was good when I installed everything. Torque on tensioner bolts was tight because they have lock washers on them - I replaced them because that’s how it was when I took it apart. Torqued to ~11 ft lbs as per service manual.

[DaveT]

When  setting the tensioners -  Put the timing key on the corresponding cam pulley at the mark on the cover [top].   I made an adapter for my torque wrench to put the factory specified tension on the belt.  Make sure the tensioner moves down to the belt, then tighten the tensioner bolts,  while holding the torque on the cam.  The belts should not wiggle a lot on the slack side when all is set.   Another double check - do the tensioners have the springs on them?

 

[errantalmond]

1 hour ago, DaveT said:

When  setting the tensioners -  Put the timing key on the corresponding cam pulley at the mark on the cover [top].   I made an adapter for my torque wrench to put the factory specified tension on the belt.  Make sure the tensioner moves down to the belt, then tighten the tensioner bolts,  while holding the torque on the cam.  The belts should not wiggle a lot on the slack side when all is set.   Another double check - do the tensioners have the springs on them?

 

I reused the springs - they are still good. I did not torque the belt tension for lack of a square drive tool, but I did hold the cam sprocket with a tool while tensioning….

I’m not sure how you mean ‘make sure the tensioner moves down to the belt?’

when I put the belt on, it was ready touching the tensioner. With the tensioner bolts loosened, the spring pulls the tensioner almost looks the way up against the belt (nearly max tension)…

[idosubaru]

I put tension on the cam to pull the belt tight - and then button it all up while keeping the belt tight.

Maybe it’s routing or where I check it or apples to oranges but the passengers side seems like it’s usually looser than the drivers side. 

[Step-a-toe]

if you have a spare cam cog, you can make an adapter pretty easily. I used an old short bolt with 17mm nut/head and tightened it in the centre hole. I fitted 4 M6 bolts to each of the holes so if cam cog was mounted on a cam shaft , the stud part would face forward. I mate the two flat faces together, aligning studs and use a 17mm socket on a wrench to tension up the belts. Unfortunately standard torque wrenches do not work or should not be made to torque the other way to tighten up right hand threads. If you have a torque wrench that is meant to work both ways - all well and good - you can get correct tension on belts. No pic as I believe I have run out of photo credit in here, and, I pinch the cam wheel to weld to a lawn/ground coring tool I made of same diameter. I drive the corer with the 17mm end of my cross bar wheel brace . It was all I had at the time ha ha

[moosens]

Clamps help a tremendous amount to hold the tension as you release the spring tensioner. That way nothing shifts. 
 

Clamp the belt in place first so you don’t need three hands or more. Makes it much easier. 

[errantalmond]

After retensioning yesterday, the belts seem happy. I’m gonna keep an eye on it and do a more proper job of tensioning if it doesn’t stay put. 
and keep an extra pair in the trunk of course

thanks everyone

[subaru1988]

12 hours ago, Step-a-toe said:

if you have a spare cam cog, you can make an adapter pretty easily. 

You can also make one with a couple round, metal electrical box covers and an assortment of bolts and nuts. I did this by using my cam sprocket as a template for the holes. It worked pretty good. The FSM says the torque on the tensioner bolts should be 13-15 ft. lbs, FWIW.

Edited November 14, 2021 by subaru1988

[errantalmond]

Thanks. I read 10-12 in the maintenance section for the 88 gl, but 13 just felt better.

[idosubaru]

22 hours ago, errantalmond said:

 Torque on tensioner bolts was tight because they have lock washers on them -

These don’t have a washer under the bolts in stock form. (Or my memory is off or all the ones I’ve worked on were missing). This makes me wonder why those washers were added and if a previous owner was chasing an issue?

Is there any chance the bolt is not tightening enough?  I mean I see you’re posting torque values. You’re sure he’s reaching and keeping that value?  You’re sure the threads have never been stripped?  

These threads are prone to strip and with washers under the head there will be less thread engagement than normal. These don’t have a washer under the bolt head in stock form.  I’ve repaired a few of those threads with thread repair inserts or longer bolts and a tap. 

[DaveT]

The OEM bolts are flange head bolts.  No lock washers.  Never had one get loose.  Do not over torque them.

The springs are re usable, as long as they are in good condition.   

I should have wrote in my earlier post to push the tensioner in the direction the spring moves it.  But also, it should move freely.  Don't hold pressure while tightening it, it's just to make sure the spring moves it far enough kind of thing.