Hi all,

Recently had the timing belt on my DOHC skip some teeth. Was a brand new belt kit including tensioner. Was a Gates-brand. Well, I reset everything and about 500 miles later I believe it has skipped at least a single tooth, so I've parked it. I will purchase a brand new Subaru OEM belt and tensioner for it. My question centers around parts interchangeability. After perusing through opposed forces: http://opposedforces.com/parts/impreza/us_g11/type_28/engine/timing_belt_cover/ 

I've noticed that the '00-'07 WRX wagon has a 2.5L motor with timing covers that have timing belt guides for the cam sprockets as well as the crank. Any reason that these shouldn't work on the EJ25D? I'd like to add some additional security to the system. It seems to keep jumping off of the cams on the passenger side. Thoughts and advice will be appreciated. 

 

Greg

They will not work. Completely different cylinder heads. The WRX heads use a much larger OD for the cam seals. Look at them on the parts diagram and you will understand maybe. In any case the 25D doesn't need belt cover guides.  You should check to ensure the cams turn freely. A damaged/contaminated cam journal could lead to such problems and may end one day in a broken cam. 

The Gates stuff is junk. But you don't need to buy the parts from Subaru. Subaru doesn't actually make any of that stuff. Mitsuboshi, NTN, NSK, Koyo, Aisin, NPW. Stick to those brands. 

And honestly I would buy all new cam sprockets from Subaru. We are starting to see older plastic cam sprockets from the 90's just disintegrate without warning. This results in severe valve train damage. 

GD

 

Edited July 2, 20196 yr by GeneralDisorder

if you haven't, find the 'tooth count' for your engine on-line to triple check timing.

I second the Gates stuff as junk.  Had a water pump leak at 300 miles and the rest of the idlers were from China.  Like AISIN.  All OEM stuff.  Fits nice.

If buying online, and there's no mention of Manufacturer's name, DON'T BUY.

Thank you all for the input. I will only be purchasing a tensioner and belt. These cam gears appear to be in good shape. I picked them up from a subaru specialty shop in Boulder, CO when I bought my heads from them. They were refurbished.  Is there a setup process for the tensioner? I'd been told that I'm to remove the pin, then compress the piston, and replace the pin. . . all before installation. I had not utilized this technique when installing the gates tensioner. 

 

Take care,

 

Greg

Edited July 2, 20196 yr by suprunner

The gears are plastic and cannot be "refurbished" - whatever that means for a molded plastic gear. I'm telling you we have seen gears that look PERFECT completely disintegrate without warning. You have been warned. 

GD

13 minutes ago, GeneralDisorder said:

The gears are plastic and cannot be "refurbished" - whatever that means for a molded plastic gear. I'm telling you we have seen gears that look PERFECT completely disintegrate without warning. You have been warned. 

GD

Rick,

my English was poorly worded. The heads had been refurbished by the subaru shop. The cam gears were purchased alongside them. I can't attest to their actual ages, as I believe they were used inventory. Is there no visual inspection that can be done to see if there is the beginnings of failure? Or is it an all-or-nothing fail? 

 

Greg

I have seen seemingly perfect gears disintegrate without warning. Found all the pieces, put them together and there was no missing chunks, chips, or other damage to indicate a failure origin. We don't trust old plastic radiators.... why should the the plastic gear be any different? 

In the cases I have seen we found no evidence whatsoever of a cause other than aging plastic. The gear just flew apart, bent up the valves, and the car got towed. We replaced the valves, installed new gears, and sent them on their merry way. Much poorer of course. 

I don't trust them. Just my experience though. 

GD

@GeneralDisorder what’s the life “expectancy” of the plastic can gear? 

Mate they interchangeable with the older metal units? I only ask as I have a spare one I could use on my sister’s Gen3 that I’m about to do the HGs on. 

Cheers 

Bennie

8 hours ago, GeneralDisorder said:

I have seen seemingly perfect gears disintegrate without warning. Found all the pieces, put them together and there was no missing chunks, chips, or other damage to indicate a failure origin. We don't trust old plastic radiators.... why should the the plastic gear be any different? 

In the cases I have seen we found no evidence whatsoever of a cause other than aging plastic. The gear just flew apart, bent up the valves, and the car got towed. We replaced the valves, installed new gears, and sent them on their merry way. Much poorer of course. 

I don't trust them. Just my experience though. 

GD

 GD, does my 06 WRX have plastic cam gears? I don't recall anything odd about them from the belt service I did, but, didn't really pay attention either. Just trying not to screw-up the belt install.

13 hours ago, 1 Lucky Texan said:

 GD, does my 06 WRX have plastic cam gears? I don't recall anything odd about them from the belt service I did, but, didn't really pay attention either. Just trying not to screw-up the belt install.

You have plastic exhaust gears. Your intake gears are steel/aluminum avcs gears. 

gah - I guess I will replace the ex cam gears at the next belt service.

On 7/2/2019 at 10:15 PM, GeneralDisorder said:

I have seen seemingly perfect gears disintegrate without warning. Found all the pieces, put them together and there was no missing chunks, chips, or other damage to indicate a failure origin. We don't trust old plastic radiators.... why should the the plastic gear be any different? 

In the cases I have seen we found no evidence whatsoever of a cause other than aging plastic. The gear just flew apart, bent up the valves, and the car got towed. We replaced the valves, installed new gears, and sent them on their merry way. Much poorer of course. 

I don't trust them. Just my experience though. 

GD

Might this have caused a belt slip? I guess I'll be looking for new cam gears. Cheapest I've found are $80 a pop. 

Yes. And they are Subaru only. You would be best served with new ones. I doubt you will find cheaper than online dealers. That's the cost of proper maintenance. 

GD

And for the record, earlier phase1 EJ metal cam wheels don’t fit due to the shape of things from the head behind the wheel. 

Cheers 

Bennie

8 hours ago, el_freddo said:

And for the record, earlier phase1 EJ metal cam wheels don’t fit due to the shape of things from the head behind the wheel. 

Cheers 

Bennie

Not sure what you're on about. I've seen them used several times on later phase 1 heads. 

7 hours ago, 86BRATMAN said:

Not sure what you're on about. I've seen them used several times on later phase 1 heads. 

Yeah sorry I was talking replacing the plastic cam wheel on the phase two EJ.

This was in reply to my own post above asking whether the phase one RHS can wheel is interchangeable in the Gen3. It’s not, even though it’s got the key way and timing mark in the exact same location as the plastic phase two unit. 

Cheers 

Bennie