EA82 Timing belt failure

[Rust]

So I have broke 2 timing belts within the last month,  both on the drivers side.  I have checked the tension pulley and cog wheel, and everything spins freely.  I have also checked the cog/pulley surfaces to see if they have rough spots cutting into the belt.    The motor has around 110,000.

 

I'm stumped.........any ideas?

[jsyme]

How did they break? Were the teeth stripped off the inside of the belt?  Was there a sheer cut through the belt itself? Are the tensioners known good / replaced?  

I have an  230,000M EA82 and just swapped both belts after a similar failure. Works fine now.

[gjewers]

Did the first one last for very long?  I had a replacement break within 4-6 weeks of installing as well.  Was blamed on faulty belt.  Never had a similar problem but they have always broken prior to their designated replacement interval.  Could be an issue with aftermarket vs. factory parts also.  My plastic dist covers were not sealing very well either and belts were subject to dirt/grease/water etc. so that is a factor.  Got so I could change a belt in less than 4 hours on the side of the road.  Always kept a spare...

[idosubaru]

source of the belt that broke?

it was a brand new belt from the store?

 

pulley conditions?

[Rust]

I replaced both belts at 100,000.  with brand new belts.   Drivers side broke at 110,000.   Replaced drivers side with an older belt I had lying around (unknown age/ mileage) snapped within a few weeks. 

 

The teeth on both belts were not stripped, the belts just  snapped.

 

Passengers side is fine.

[idosubaru]

If you think the pulleys are good, I'd guess the first new belt was unlucky/cheap part, and the used belt was just used and deteriorated.

Rubber materials degrading over time is common depending on storate, age, type, etc.  easily seen with tires if you're around them enough in the right condition.

 

The only causative thing I can think of not mentioned is distributor/cam - if they're creating additional load.  But i'd expect those to fail/lock up (the cam/bearing surfaces) if they were the cause.

 

Pretty normal for drivers side to fail more often - more load/pulleys/bends.

 

What were the brand new belts - what brand, where were they bought?

The pulleys are absolutely not an issue? 

[Crazyeights]

Does the cam on that side feel ok when you rotate it? Perhaps the engine was run low on oil at some point and the cam is too tight to turn properly.

[Dee2]

I replaced both belts at 100,000.  with brand new belts.

 

Did you replace the tension and idler pulleys at the same time .  Chances are one of them is bad.

[Numbchux]

I just assume that EA82s like to eat timing belts. I had 3 or 4 of them that I put a lot of miles on, and I never went anywhere without spare belts, pullies, and the tools to do them.

[DaveT]

If everything is right, they should make it to at least 50K miles.

[Dj7291993]

My dad's had an oil pump strip 3 belts in a row. First one wasn't too suspicious, since it had been over 60k miles. The second one didn't make it 100 miles. Figured we just didn't get all the bits of the old belt out. I was driving it when the third one went, was losing oil pressure right before it went. Had to keep it above 3k to get the gauge off 0. That one didn't even make it 20 miles. Ours stripped, but it might be worth checking.

[88SubieSnack]

Hi there,

 

I just read in Chilton's repair manual that they recommend replacing a timing belt once it is removed from the engine. So I would say 'NO' to a used belt...And I agree with GrossGary 100%.

 

It would also be worth it to buy a complete timing belt component kit of a reputable brand. All pulleys included. I bought mine off of rock auto and so far about 30,000 miles. I just checked earlier today that my driver belt tension is finally loose and needs adjustment. And just like GrossGary said, the driver side has more load/pulleys/bends.

 

I hope this is helpful.

 

Kind regards.

[robm]

+1 on the oil pump.

 

Before replacing the belts, pull the oil pump and check that the bearing surface is good.  Might as well get new O-rings for it at the same time.

 

I had one seize and snap the belt.  The fact it was low on oil probably caused the oil pump damage.  Kind of like the heart, the first thing the oil pump lubricates is itself. 

[Rust]

Update:   So I inspected everything on the drivers side.  The gear on the oil pump is spinning ok.  I went back to my parts stash and replaced the tension pulley, the lower cog wheel, and found a belt with the official SUBARU stamp on it (non-aftermarket).   I know I should use new parts, but I'm cheap. 

 

So everything is buttoned back up and it is purring like a kitten again.

 

So I have several theories on why I keep snapping drivers side belts:

 

1.  running naked belts. (no plastic covers)  rusty pullys/gears cutting into the belt.

2.  running crappy aftermarket belts.

3.  The spring on the tensioner pulley rubbing on the edge of the belt.

 

I think in my situation I have a combination of all 3.  Hopefully this latest fix will get me through the winter.

[DaveT]

I don't know of any reason #1 has any effect.  I and quite a few others run them without the covers, for a lot longer.

[robm]

I only get about 40,000 miles out of belts without covers.  But 10,000 miles is too short. 

 

I would be leery of running a used belt, even if it says SUBARU on it.  If I were you, I would get another belt to keep handy, and carry the tools for a road-side replacement.

[montermahan]

After about 2,000 miles I had an after market (napa) belt pop in two. A subaru mechanic/friend said to tighten the belt a little tighter than the spring tensioner put it.  been going strong for 20,000 miles now.  It was on the distributor side,  he surmised the belt would jerk as cam went past TDC on the lobe and over the miles, it would give up.  I don't know.  

[DaveT]

The tensile spring isn't meant to set the tension. Tourque on the camshaft pulley is what sets the tension, when the timing belt marks are at the indicator on the flywheel / flex plate. (Not to be confused with the timing marks for degrees). Somewhere around 15 ft lbs iirc.

[RunsWithMoose]

hello, thought id share my experience in here. i own and work on mostly subarus in alaska, 

 

i have used belts on my car, almost always do. 258k miles on it had it from 142k . 3 belts from there to now and im hard on that car. 

reason i use used belts is i work on a lot of subarus . have a wall full of used belts.

 

distributor can break the belt. the bearing set in it can be bad and not show tell its hot. long drives or long idle periods. also seen them lock up in cold conditions. 10F or colder.

if the belt is not installed right, slap allowed will tear teeth off. so will dumping the clutch at a high rpm.

 

how to you drive your car? like a law abiding citizen or watch this an hold my beer? 

 

oil pumps can also creat a lot of drag although this is much rarer of a issue

 

also how are you installing that belt? use the single idler gear with the one 14mm bolt to get belt back on. if you slip it on with force you could be damaging a tooth and helping the ware right along.

and the no cover is a terrible idea. dabre bouncing around the bay could end up in the belt set. seen that many times

[robm]

The problem with covers, is the outer ones usually come off in pieces after the first TB change.  Kind of hard to put them back on.

 

I like to keep the centre cover. It protects a lot of the spinning bits, especially the ones lowest on the engine, and it goes on and comes off quite easily. 

 

The sump guard is an absolute necessity when running without covers. 

[ferp420]

With the timing belt cover removed the hardest part of changing the timing belts is removing the ac alternator and power steering belts the timing belts just slide on and off no big deal no tools needed the ease of timing belt replacement is part of what I love about the ea82

[Rust]

yes the AC pump is always in the way. I think I am going to fab up some alternative way to mount the alternator, and toss the AC pump.   I never use the AC, and it hasn't been charged in years. 

 

As far as the engine that started this thread, the belts are doing ok,  I had to put another distributor in.  Its chugging along ok.

 

I might  also fab up some belt covers that can be taken off/on with zip ties.  maybe cutting the center cover in half so it can be taken on/off without removing the crank pulley.  

 

Probably need a separate thread to debate running naked, or covered timing belts.    The factory did put them there for a reason, and the bare metal parts definitely get rusty without covers.

[Jakethewhite]

My timing belt recently broke while driving down the road. I was barely going 40mph. I pulled over and got a tow then changed the belt at home. When I went to drive it it was fine until I hit the freeway and it snapped again. Took it to the mechanic and he put another one on but told me the engine was ruined and prob would just keep snapping them unless I rebuilt the whole top end but he was not a Subaru mechanic and didn't know about non interference cars. I have a 87 Subaru gl 4x4. Is there any thing that you might think may be causing the timing belt to keep breaking?

[idosubaru]

It's Noninterference, your motor is fine (with 99%+ certainty)

 

What side is failing and how?

 

If the mechanic doesn't know Subarus or old ones then maybe he didn't install the belt correctly or inspect the pulleys properly.

 

* post a picture of where/how the belt failed, underside and topnside of it. Teeth, heat, sheared, delaminated and we can maybe tell what's going on?

 

1. What belts were installed - used, new, what brand and how old?

 

2. Maybe something is causing it like a bad idler pulley - the bearings seize all the time in those. If you have original bearings they're about as reliable now as a flat tire.

Edited July 16, 2017 by idosubaru

[DaveT]

When you replace a timing belt, the 3 idlers should be replaced also.

 

Also, folow the procedure for installing. Then turn the crank by hand a couple revolution s. Re check the tension. Run for 10 seconds or so. Re check the tension.

 

The reason I do this is that the belts walk into the position they want to run in during this. If you just put them on, tension and drive, they will settle in, but end up loose.