RAF2000 -- changing the timing belt, idlers, tensioner, etc.

Kolibri

FW and Gyros
Joined
Oct 17, 2014
Messages
1,636
Location
Wyoming
Aircraft
Cessna 152, 172, 172RG, 177, 206 -- Piper 180 -- RV-7A -- Calidus -- RAF2000 -- Sport Copter II and
Total Flight Time
1000+
RAF calls the service life of the EJ22 timing belt (and all its related mechanical parts) at 500 hours.
Given the questionable bearings in some of their idlers, R&Ring sooner is probably wise.
I'm right at 400 hours and will change them out this month.

A very helpful pictorial on the labor, which includes an interesting tip on employing the starter to loosen the crankshaft/alternator pulley bolt.

I have already Subaru's OEM timing belt and water pump, but am not eager to drop $500 for their idlers, roller, and tensioner.
(Do, however, replace all these parts with every belt.)

I was surprised to find that remaining package online for just $145.95 (including the belt).

Has anyone experience/opinion with Evergreen, GMB, and Mitsuboshi?
For my flight safety, cost is no object, but if these parts are equal to OEM, then why pay 3x more at the Subaru dealership?

Here is some review scuttlebutt so far:

Mitsuboshi timing belt -- very good
GMB tensioner pulley -- not highly recommended

Thanks, Kolibri

Evergreen TBK172AMH 90-97 1.8L 2.2L Subaru Impreza EJ18 EJ22 SOHC Timing Belt Kit

This item includes:
• 1 Mitsuboshi Timing Belt (211 teeth) (Mitsuboshi - OE Supplier for HONDA / SUBARU)
• 1 GMB Tensioner Roller
• 2 GMB Upper Idlers (left and right)
• 1 GMB Lower Idler (sprocket with bearing)
• 4 Camshaft Seals (32 x 45 x 8)
• 1 Front Crankshaft Seal (33 x 49 x 8)
• 1 Hydraulic Tensioner / Tenisoner Adjuster

Product Fitments:
1990-02/1997 SUBARU LEGACY 2.2L 2212CC H4 SOHC, (16 VALVE), ENG. CODE "EJ22"

81%2Bs2TnD6CL._SL1500_.jpg


 
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I bought a timing belt on line and it was just a tad small,ended up going to napa and buying my belt there,it cost more but was worth it.better quality and fit.

take a look at rock auto parts,go with a brand name,gates,dayco.


Best regards,
 
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shouldnt Mitsuboshi be spelled with a U instead of a O ?
 
Mitsubishi made in Japan, Mitsuboshi made in China.;)
 
Mitsuboshi (not a typo)

Mitsuboshi (not a typo)

Yeah, eddie, I'd wondered about that, too, but Mitsuboshi is a pretty big name in belts -- allegedly OE for Honda and Subaru.

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There are several factors which make sense to R&R of idlers, adjuster, tensioner pully, and water pump when installing a new timing belt:

1) you're already "there" after removing the crank bolt/pulley/cover

2) what seems a quiet, free-spinning part now can unexpectedly fail on you soon after, especially given RAF Canada's shoddiness in repacking idler bearings


Thought I'd let you guys know I had an engine failure today resulting in a forced landing, no damage to myself or the gyro. The engine has 330 hrs on it and is one of the RAF supplied engines. One of the engine timing chain idlers had overheated and lost its bearings. the other idler was replaced at 100hrs because it was leaking grease, should have replaced both but the other seemed ok. I inspected the timing chain at 300hr inspection and everything seemed ok. If you have an RAF supplied engine I would be seriously considering replacement of these bearings.

http://www.rotaryforum.com/forum/showthread.php?t=8198

I had grease all over my idler housing, finally looking at it thanks to Paul's righteous nagging. One flange on a pulley was bent down, as if whacked with a hammer. The tensioner, which should be full of silicone fluid was bone-dry. An engine stoppage waiting to happen. I would have an engine from RAF thoroughly inspected before I went airborne with it. Some have lasted as little as 30 hours before disintegrating. The water pump was also shot on mine and needed replacing. Sometimes "newly overhauled" means bead blasting and a can of silver spray paint.

http://www.rotaryforum.com/forum/showpost.php?p=108710&postcount=3

3) although the EJ22 is a non-interference engine (i.e., valves won't collide with piston if the timing belt breaks), an engine-out could occur over inconvenient or perilous terrain (5-10% of flight time in a rural gyro).

4) the new parts are not all that expensive (and I'd trust a new bargain Evergreen kit over running RAF's older parts past 300 hours)

___
Evergreen sells several kits for the EJ22, depending on if you want their water pump and adjuster. All kits come with a Mitsuboshi belt, which seems to have a good rep (allegedly OE for Honda, although I'd install a Subaru dealer belt). Gates also sells kits.

Regarding an Evergreen adjuster, I'd probably buy a better part singly elsewhere for about $100 as I can't quite trust a $145 Evergreen kit (belt, 3 idlers, tensioner pulley) that even includes an adjuster.

A video I saw specifically caveated against the green sealed bearings in kits (sounds like Evergreen) for containing only single bearings (vs. the OEM top idler has a double bearing, see comparison photos below).

So, I'm not going with Evergreen, as I don't think the quality is there.

___
All three idlers (2 smooth, 1 toothed) have replaceable bearings. (The tensioner pulley apparently does not.) While I am installing new parts, some may wish to merely replace the bearings:


When replacing the idler bearings take a measurement of the position of the centre sleeve in relation to the pulley so that they can be re-assembled the same. They have no "foolproof" stops.

http://www.rotaryforum.com/forum/showpost.php?p=109895&postcount=9

6006-DWA ("DWA" means with C4 clearance) bearings
6005-DWA ("DWA" means with C4 clearance) bearings

(Note: most bearing houses will have only the tighter C3 clearances, which will often seize if used here. Go to Subaru dealership or RAF for the C4 clearance bearings.)

The old OEM bottom smooth idler had just a single bearing, but I understand that it's been superceded by a double bearing (as the upper smooth idler always had). The cheap kits have only single bearing idlers (note their "deep dish").

___
The toothed idler seems to have the worst failure rate in RAFs, and my Soob guy says the same. (30+ years in the biz. He even used to often sell low mileage EJ22s to some Florida RAFer named "Jan".)

He's dealt with Northeast Imported for years and has been pleased with their parts (especially their Six Star brand head gasket):


Northeast Imported Parts Inc. is an independent wholesale distributor of Subaru parts. Since our inception in 1979, our company has offered high quality Subaru parts at a competitive price. Our inventory offers choices of Genuine, OEM and alternative source parts.

We offer our own private Six Star label parts that identifies OEM parts.

http://www.neimportedparts.com/pdfs/9_29_Timing_Belts.pdf
http://www.neimportedparts.com/pdfs/Tensioners_and_Idlers.pdf

I've not yet priced Northeast Imported, but they seem the way to go.

Regards, Kolibri
 

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Sound like you have it under control Kolibri.

I always replace the pullys and water pump when the belt is replaced,just makes sense.




Best regards,
 
I had a idler come off & depart one day & another day had a idler cut through the plastic shroud & hanging on by the shin of its teeth so we used to replace the idlers & belts every 500 hours or so I think it was. The belts always looked like new but we replaced the lot anyway. We used Dayco kits here.
 
old parts out

old parts out

Am halfway done with this job, and it's going very well.

sliding the motor back for access to "that" bolt
I learned about this from the RAF Construction Manual disk 9. Quick and easy to do. Unbolt the two upper crossbars, then remove the stack of washers from the two longitudinal bolts in the front engine cradle (replacing the nuts with a couple of threads in). Pull from the prop hub, and the whole engine will slide back about 1.5", allowing enough room to get a 22mm socket on the crankshaft bolt.


removing "that" bolt
I've replaced timing belts before, but had trepidation about breaking free "that" bolt. I tried a trick learned elsewhere of positioning the wrench/breaker bar so that it won't move, and then bipping the starter. (photo below) I first removed the spark plugs, to reduce load on the starter.

Worked . . . like . . . a . . . charm! One bip, and it was free. In fact, I had the bolt and pulley out in less time than it took to remove the center cover. (I don't know if such would have saved Gary-in-Oregon's bacon years ago; sounds like his mechanic overtorqued it.)

If you don't want to try that, use crankshaft pulley wrench 499977000 to remove the crankshaft pulley bolt.
Or:


Go to your nearest good hardware or plumbing supply and ask to see a plumbers strap wrench.
It has a heavy duty handle with a heavy duty canvas strap. This will hold that pulley
Just make sure the strap is at least 18-20" long. Enough to encircle the pulley.

or:

I put the end of a socket wrench handle in one of the holes for the lower engine sprocket to stop the crankshaft from moving while I broke the bolt loose. There are two holes in the steady bearing plate that line up with the six holes for the lower engine sprocket.

I used a 1/2" drive socket wrench with a cheater pipe to loosen the nut.


____
Visually, all the parts seemed fine, confirming my impression (of the belt, at least) from all the 25 hour side covers inspections. However, once the belt was removed, spinning the idlers was educational:

comments on my EJ22 parts after 399 hours (with Subaru part #s):

tensioner pulley (13069AA037) -- spun freely without any noise, probably reuseable (although I didn't).

adjuster (13068AA051)-- Although I'm not going to reuse it, "just for fun" I compressed it with an 8" C-clamp and held the piston in place with a rivet stem. Taaaaake your tiiiime in compression else you can blow out the seal. (Anything less than a few minutes, and you're rushing it.) These don't go bad often, and I probably could have left it in.

upper smooth idler (13073AA142) -- spun freely without any noise, probably reuseable (although I didn't). Double bearing.

lower smooth idler (13073AA142) -- was tight, but sounded like a (good) skateboard. It was also a double bearing part, but many are not. Be sure yours is.

sprocket idler (13085AA080) -- the noisiest of them all, probably would not have lasted until RAF's 500 hour replacement schedule. This is the most notoriously failed idler in the EJ22 (on ground and in the air). I highly recommend that you inspect your with belt off.

water pump -- although not noisy in operation, once removed it was skateboardish in sound; very glad to replace it now. (btw, its housing was drilled/tapped for a 90° brass elbow for a vacuum hose to the intake manifold. Is that universal in RAFs? Must I mod my new water pump for this?)​

Here is a stellar opportunity, while you're "there", to not only replace the water pump, but coolant (use the orange DexCool for aluminum engines).

_____
Am waiting on the new parts which I ordered at wholesale (all above OEM, for just $300 -- less than half of dealer). btw, Mitsuboshi is confirmed OE timing belt for many Jap cars, including Subaru.

I've some tips/photos on the belt installation which I'll post next week.

Regards, Kolibri
 

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The small hose probably goes to the crossover water manifold between the heads its a

bypass for the thermostat,the auto heater hoses were/are the bypass for the thermostat

until it opens however if the heater hoses are shut off then the water can't recirculate

causing a major problem.the water pumps usually don't get loud,they just start leaking.

Also while I had my covers off I cut them where I can remove them without removing the

crakshaft pulley.Good info about the double bearing on the idler pulley.



Best regards,
 
What can happen is that the pulley part can depart from the bearing, not sure why that happens but it did to me twice. Possibility the pulley wasn't as tight a fit on the bearing at time of manufacture !The bearings didnt give hardly any drama.
 
eddie, thanks for the info about the hose to the crossover water manifold. In the new water pump I'll need to drill a 29/64" hole and tap to 1/2" pipe, according to the RAF Construction video. They recommend Red Loctiting the elbow.

Also while I had my
cover off I cut them where I can remove them without removing the crakshaft pulley.​


A good tip, and I've heard of others doing so. How did you seal the newly split cover? Create its own flange?

____
Chopper Reid, those were some really wayward pulleys! Perhaps that's a strike against installing new bearings in old pulleys? (Not that I know if you'd done so.)

Regards, Kolibri
 
I didnt seal or make new flanges,just cut it in halve at the crank shaft, the cover is just to

keep fingers and other foreign ogjects away from the belt,the cover bolts will hold it in

place just fine. I suppose a flange could be made if wanted to! I have heard of all kinds of

stuff getting to the belt and stopping the engine when the belt came off.



Best regards,
 
The RAF used rod ends to support the motor disconnect front of motor use a motor bike strap let it roll back and now use air tools. I have a soob on my dom .have not done any thing to engine in five years at the end of bensen days last year slight coolant leak .Rock auto sells a dacco kit the only timing belt I use .The only belt for the drive is gates. My dom is old school carbed not bad mouthing my eng butt the 2.0 ENG EFI WOW .Two of those in my gang.Keven and Bill both have a great flying gyro
 
Your absolutely right Dave its OK to save where you can,but you always get what you pay

for,cheap just doesnt work when your butt is on the line. Subaru makes a great aircraft

engine it the installation that usually is the problem





Best regards,
 
its OK to save where you can,but you always get what you pay for,cheap just doesnt work when your butt is on the line.
Yes, I totally agree. Just to reiterate, all my parts are Subaru OE, wholesaled by a national distributor (hence the bargain price).

I did not order the Evergreen kit, and would not recommend it.

If you're considering a used RAF, take off the two side timing covers, and you'll be able to see if the idlers are single or double bearing. Use one of the small mirrors on a telescoping handle with a flashlight to peer behind the center cover.

Regards, Kolibri
 
Good reminder there, thanks Dave. I already replaced the (original) horribly spliced fuel pump ground wires with new ones I made of heavier gauge and heat-shrinked contact ends.

____
I've now a box of new Subaru OE parts. The water pump is getting drilled/tapped for that elbow. Glad to have this behind me. The work went well; will post any helpful tips soon.

Regards, Kolibri
 
job all done!

job all done!

The only snag I had was discovering stripped threads in the block for the tensioner pulley (an M10x1.25 bolt, at 26-32 ft/lbs). Somebody before me had overtorqued it, probably trying to eliminate the (intended) .015" of of pulley clearance from the eccentric standoff. Time to summon the Gods of Helicoil. There was very little extra room to drill out the hole (I don't have air tools there, thus the 90° drill chuck with a long 13/32" bit), but it worked. The "trick" to doing a helicoil right is to drill straight, tap cleanly, and then remove all shavings.

Save the two smooth idlers for installation last, after you've installed the belt and lined it up from crank to both cam sprockets. It's easy to bolt them in, slightly pushing the belt.

Do consult the Subaru engine chapter in your RAF Manual for all the torque values.

After all the idlers are on, and the adjuster piston is released from its holding pin, you must back and forth slightly turn the prop to remove the belt slack. (Failure to do this can risk shredding belt teeth at first startup.) After a bit of back-and-forth, spin the prop in proper direction a few turns. Confirm that your belt marks are all still lined up. This all went very smoothly, and I didn't find it the hassle that others have on Subaru sites.

Last moderate issue is how to anchor the crank while torquing the pulley bolt to ~70 ft/lbs. This was easy (see photo), although I'd recommend putting some old fuel hose around the socket extensions to protect the rear plate holes.

She fired right up, and seemed even smoother than before. Idling in chocks, I checked for leaks, and seeing none I took her up for 0.7 hours. No issues at all, and I watched the coolant temp gauge like a hawk. Landed, and confirmed no leaks. Very happy to have this job in my rearview mirror, and I think I caught it just in time. (It's been on mind for months, and I urge the brethren not to procrastinate on it. It's easy enough to at least push the motor back, remove the crank bolt, pully, and the two smooth idlers to at least test spin everything for noise.)

I hope this has been helpful, and encourages RAF owners to perform the service. It's really not all that onerous, and you can relax for up to 500 hours afterward with all those new Subaru OE parts.

Regards, Kolibri
 

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