Welcome to the North American Subaru Impreza Owners Club Monday December 11, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Subaru Conversions

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 05-26-2005, 05:30 PM   #1
Scooby Newbie
Member#: 60758
Join Date: Apr 2004
87 Vanagon Syncro

Question 2.5 sohc timing parts interchange?

I'm thoroughly confused. I've been getting input on this over at the subaruvanagon yahoogroups list, but they've pointed me here for the experts to weigh in.

Two shortish questions up front, very long story with details below for people who want all that:

question 1: Do SOHC 2.5 imprezas (say 2002) have different timing parts than similar year legacys and outbacks? I know the timing belt is different. The impreza is supposed to be: 13028AA181 and the outback/legacy is supposed to be 130281121b. Apparently the legacy belt is longer. Why? Are idlers different? Are cam or crank gears different? Does anyone have the ability to run a cross reference and tell me what the heck part numbers (idlers waterpump and cam and crank gears for legacy and impreza) go together?

question 2: Does the 44/40.5 teeth count mentioned in the factory manual and endwrench articles apply to all 2.5 sohc motors. Is there a different count for legacy/outback 2.5 sohc motors? I have one confirmed count of 47/43.5 on a legacy motor.

Here's the long story:

I have what I was told was an 02 impreza motor (longblock from junkyard in 03 with supposedly 20k) that I installed in my Vanagon Syncro Westy. It's been running great for about 10kmiles until the lower toothed idler exploded down in california (I live in Seattle). Luckily it was caught before the belt fell off the cog (which was hanging from the bolt w/o any bearings left. Close one!). A used toothed idler was sourced, belt removed and reinstalled on the road and I was on my way back home (800 mile drive).

On returning home I decided to replace everything (belt, idlers, water pump, tensioner) because I'm now thinking the car was hit in front, causing the idler to fail (motor didn't have timing covers or belt -- shop put those on when I purchased it...hmmmm.).

I lined up all the marks (factory belt and motor) before removing the old and everything seemed fine. Just for kicks and because I'm the paranoid sort, I did a tooth count. Uh, oh, all the factory manuals say I should have 44 and 40.5 teeth. I came up with 47 and 43.5. Like I said, all the lines and marks are lined up correctly. The motor runs fine as currently timed.

So, I check the belt part number.

It comes up as a legacy/outback belt (130281121b). The parts guy I checked with says the 121b belt is definetely longer than the impreza belt I thought should be on there.

What's the deal? Is this really a legacy motor or some kind of "blended" motor? What is the difference between the two? Why the bigger belt on the Legacy? Cam or crank gear size? Idlers different?

I'm going to replace the belt and idlers anyway, so I might as well get the correct ones (that match the cam and crank gears if they are different). I don't even mind buying new cam and crank gears if needed (only ~$20 each)

If it does turn out that I have a legacy motor, is that going to make a difference to my ecu and wiring (which for sure is from an 02 2.5 impreza 5spd -- wiring/intake/ecu came from different place than longblock).

I've always had a little hesitation/miss running through 4500 at WOT but have never been too worried about it (this is a vanagon -- even a poorly running sube is light years ahead of the stock motor). WHen the idler exploded I thought, ah-ha, that dying was the cause of the of the miss, but now I'm wondering if the belt/motor or other mismatch is the cause. (FYI, I didn't rev past 4500 on the way home because the belt had a small hole in it and I didn't want to test it our the used idler any more than necessary so I don't know if the miss is still there).

Right now, I'm frozen. Even though engine is running and I was able to line up all the marks exactly, I'm afraid to pull the belt (and then gears so I can check/compare parts) until I know the answer to the tooth and parts interchange question.

Thanks for listening. I'm all ears for any and all suggestions!

Tim in Seattle
* Registered users of the site do not see these ads.
Dogstar is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-27-2005, 05:57 PM   #2
Scooby Specialist
Member#: 41626
Join Date: Aug 2003
Chapter/Region: NWIC
Location: Mt Vernon, WA
SPB We make people
quit teh internet


I did not read your entire thread but the service manual for the sohc engine gives the incorrect notch count for the timing belt. As you stated the manual says like 44 and 40.5 and 47/43.7 is what you got.....I think I counted 47 and 44 not a big difference.........either way though I commented on this to my local dealer as to possibly make a feed back report but I doubt anything was done....but to make a long story short I put my timing belt in my rs to those 47/44 specs and it has ran fine with no problems for probably 10k miles or more until it was pulled it for a swap, so I would not be afraid to run it if I was you......plus if you attempt to get it at 44/40.5 its not possible.
agterlik is offline   Reply With Quote
Old 05-31-2005, 09:15 PM   #3
Scooby Newbie
Member#: 60758
Join Date: Apr 2004
87 Vanagon Syncro


Originally Posted by agterlik
.but to make a long story short I put my timing belt in my rs to those 47/44 specs and it has ran fine with no problems for probably 10k miles or more until it was pulled it for a swap, so I would not be afraid to run it if I was you......plus if you attempt to get it at 44/40.5 its not possible.
That's really helpful. Thanks. I'm probably too hopeful that you may know the part number of the belt you used, but hey, I guy can dream.

I talked to the head tech in Tacoma and he was clueless about the tooth count issue -- for a legitimate reason, I suppose. ("we use factory belts with marks. I haven't counted teeth in years!"

That's what I get for being paranoid and counting teeth. I'll report back when I get this thing back together.
Dogstar is offline   Reply With Quote
Old 06-21-2005, 12:35 AM   #4
Scooby Newbie
Member#: 73675
Join Date: Nov 2004
Location: Columbus OH
2004 WRX
WR Blue


I was too worried about that, i have a 99 SOHC 2.5L, and I used the marks I layed on the belt when I took it off to replace a head gasket. Well, I put the belt on, with those lines lined up and guess what!! My timing is completely off ... I have no idea what to do at this point...
chrismindless is offline   Reply With Quote
Old 06-21-2005, 06:55 PM   #5
Matt Monson
Scooby Guru
Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
99 2.5RS, '85 911
'73 914 and 2012 BRZ


If you were lined on your marks, my first guess is that your crank gear wasn't at 12 o'clock when you put the belt on. This would mess everything up even with the heads on mark...
Matt Monson is offline   Reply With Quote

Thread Tools
Display Modes

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
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Phase 2 2.2 vs. 2.5 SOHC timing cover eppoh Normally Aspirated Powertrain 3 03-19-2010 01:25 AM
2.5 SOHC Timing w/o belt marks dimunation Normally Aspirated Powertrain 6 12-23-2006 02:16 PM
2002 2.5 SOHC timing belt replacement carguy4 Service & Maintenance 9 12-19-2005 03:50 PM
2.5 SOHC Timing Belt Replacement Parts serendipity Service & Maintenance 9 09-24-2005 02:08 PM
2.5 sohc timing teeth count? (impreza vs. legacy) Dogstar Normally Aspirated Powertrain 1 05-28-2005 06:59 AM

All times are GMT -4. The time now is 11:50 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.