biglittledog Posted June 20, 2007 Share Posted June 20, 2007 Here is a pic of my "ruined" keyway. What's the best approach to this one? Possibly fixable with Loctite Quickmetal? Please let me know what you think if you've dealt with this... Thanks in advance! Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted June 20, 2007 Share Posted June 20, 2007 Hello and welcome! Your post title says it all. I think there are kits to deal with this problem. Others will know. I haven't had this issue...yet. Did you have the timing belt replaced somewhere recently? Often the crank pulley bolt doesn't get tightened enough and backs out and results in the hogged out keyway as in your pic. Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 21, 2007 Author Share Posted June 21, 2007 Here is another picture: Quote Link to comment Share on other sites More sharing options...
porcupine73 Posted June 21, 2007 Share Posted June 21, 2007 Wow...how long has the crank pulley been off this unit? It looks pretty rusty in there. Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 21, 2007 Author Share Posted June 21, 2007 The previous owner thrashed it and I bought it real cheap hoping to fix it. The guy also drilled out the harmonic balancer and installed two bolts in it that went directly into the timing gear and then put the crankshaft bolt on top of that. Can you tell me where to get info on any kit to fix this? I just took it off this afternoon. I think all the rust coloring is metal dust from the keyway that has oxidized over several years. It looks a lot worse in the second picture...the first pic is more accurate. Everything else around the timing gear looks fine, it's just out of the picture and you can't see it. Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 21, 2007 Author Share Posted June 21, 2007 Here's how NOT to fix the problem: PO had two bolts in here with the crankbolt unevenly on top. Pretty Frankenstein if you ask me and it actually made the problem much worse by having the crankbolt push down on two points only and made the balancer wobble all over the place. Quote Link to comment Share on other sites More sharing options...
xrturbo Posted June 21, 2007 Share Posted June 21, 2007 Holy crap!!! That is one of the worst ones I have seen!! A welder is how I would aproach that one. Either that or throw a motor in it. They must have run it for a while when it was coming apart. Quote Link to comment Share on other sites More sharing options...
eastwestboy Posted June 21, 2007 Share Posted June 21, 2007 When this happened to me, I made 3 hole in the pulley where the cogs are. I did it with a cutoff wheel on a dremel. I took my three leg hooked puller, put a round steel plate a bit bigger than the hole in the crank. On that, the puller could "stand" and pull/forced-pull the pully off the crank. I got a new key, with a fine small file I made the key-hole in the crank a bit deeper, with the right shape of course. I forced a small steel shim into the remaning gap between the outer side of the key and the new pulley. Oyeah, you need new pully, but not a new motor. It looked ugly, I was concerned, but I made 55000 km with it. Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 21, 2007 Author Share Posted June 21, 2007 ...It looked ugly, I was concerned, but I made 55000 km with it. That's pretty good. Did it finally fail again? I also found this because early Miatas have the same fecalsample engineering and the same problem: http://www.miata.net/garage/hsue/LoctiteCrank1.html Quote Link to comment Share on other sites More sharing options...
nipper Posted June 21, 2007 Share Posted June 21, 2007 That mawwork, but some of our engines have 4 cams and not two. One thing, when using super strong loctite, its extreemly important that the sites to see loctite be very clean. Also use a loctite primer, then it should work. Loctite has many levels of bonding agents, from its coming off with a screwdriver, all the way up to a nuclear bomb wont get it off. Be sure to replace any seals behind the cog before doing this. ALso read up on how to remove the loctite, then decide. nipper Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 21, 2007 Author Share Posted June 21, 2007 Thanks and I will double check on which Loctite to use. I don't have a DOHC engine so I'll be selfish and not worry about them now plus this is the crank pulley and timing gear so it shouldn't matter SOHC/DOHC. If you reference another link from the Miata fix, it gives a great description of what to do and it's written by an engineer who works for Loctite...can't get much better than that! Here is the second article: http://www.miata.net/garage/hsue/Softtop.htm An interesting quote from this: "Keyways of this type are normally used for the purpose of alignment. Assembly forces are usually transferred to other areas such as tapers - which from the photo's seem to be absent. This means that the force locking the assembly is the clamp load exerted by the bolt then holding the pulley against the shaft shoulder and any interference between the pulley and the shaft. Even a partial loss of this clampload (bolt stretch, thermal cycling, vibration) would lead to the entire load being transferred to the key - and subsequent key failure. It would seem that this design is only good engineering practice if a retaining compound is added during assembly. That's what I suspect originally shold have occurred and that's what I have proposed. The Loctite 242/243 or Quick Metal that you have added to the shaft cures to a tough thermoset polymer between the mating faces, keying into machining marks and micropores of the metal. This process turns the whole of the mating face area into a keyway (after alignment you could actually remove the key altogether and it would make no difference to the performance of the assembly). This assembly will dismantle with the standard puller. " Quote Link to comment Share on other sites More sharing options...
eastwestboy Posted June 21, 2007 Share Posted June 21, 2007 No, it's still in place and I m still driving around with it. I don't like to think about taking off the pully again. The seal I ve put behind is still holding. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted June 22, 2007 Share Posted June 22, 2007 i read the miata description, and disagree on one point. replace the timing belt, seals and everything else that's original. you may not ever get to go into this engine again. (although, there probably is a way to release locktite.) when this happened to my 93 leg the shop said they could fix it, but that this was the last time anyone could. i don't know if that was an exageration, but we did the water pump, seals, belt , etc. i bought it with 98k miles, drove 55k miles and then made this repair. it ran great. my repair price was only slightly more than same work without a bad keyway, but if it got me another 60k miles, it was worth it. i wrecked the car the following year (20k later), but it was running great. i sold it to the insurance company for 2500$ in 2000 with 173k on the clock. edit: before the failure, it did have the crank pulley wobble mentioned in the miata write up. ( i was not smart enough to know it was a problem, what a dummy.) i also noticed this on my 95 leg a couple of years later, and imediately had it repaired. keep an eye on the crank for wobble. has any one seen this problem on 2.5 liter engines?? Quote Link to comment Share on other sites More sharing options...
uniberp Posted June 22, 2007 Share Posted June 22, 2007 The area to the left (counterclockwise) fromteh key is the worn area, correct? Seems to me the best fix in this case woudl be to grind the worn area square and fit a stepped one piece key , with part of it flush with the surface of the crank, OR making a second key that fit along side. My main worry would be that the crank woudl be rounded off or indented on the engine end, or if there is a taper, that the taper was rounded. That would prevent a solid or purhaps square purchase of the pulley to the shaft. I read that Loctite fix, and the time it took to make the crank-locking tool could have been better spent on hand filing the keyway. But in the worst case scenario, I guess I would just clean it up, squirt on the glue, and hope for the best. Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 22, 2007 Author Share Posted June 22, 2007 i read the miata description, and disagree on one point. replace the timing belt, seals and everything else that's original. you may not ever get to go into this engine again. (although, there probably is a way to release locktite.) when this happened to my 93 leg the shop said they could fix it, but that this was the last time anyone could. i don't know if that was an exageration, but we did the water pump, seals, belt , etc... I agree with you and I spent a long time yesterday talking with the guys at our local Subaru-only repair shop here (tons of Soobys here in Colorado and this is the biggest independent Subaru shop in the USA plus they are actually nice). They have a used and new parts dept and we were comparing my parts with some replacements. I have meticulously cleaned the shaft and reassembled the parts with a new timing belt, perfect used timing gear, new key, and new bolt torqued to 125 ft/lbs with loctite 243. I used the 660 locktite on the shaft and key and locked the timing gear to the shaft with it also. The timing gear should never have to come off again for the life of this engine (168k already). I used the 243 on the crankbolt and the pulley as I may remove it sometime in the future. Interestingly, none of the pulleys they had were any better than mine so they suggested locking the timing gear on pretty permanently like I have now done, and then checking the crankshaft itself for wobble from bearing wear. They agreed this repair should hold if the crank is straight. They also said when the pulley wobbles, the face contacting the timing gear wears until it's not flat. This makes things even worse. They said almost every used pulley they see has some problem so we thought buying a new one was a good idea if everything starts and runs okay. If this works I'll probably go to the later style pulley with the big rubber block in the center. I need to let the Loctite cure for a day before I start her up. I have some more pictures of crazy stuff the PO did including jumping the timing belt 3 teeth to account for the worn shaft! No wonder the car wouldn't run right! I'll post the pics tonight... Quote Link to comment Share on other sites More sharing options...
biglittledog Posted June 22, 2007 Author Share Posted June 22, 2007 The area to the left (counterclockwise) fromteh key is the worn area, correct? Seems to me the best fix in this case would be to grind the worn area square and fit a stepped one piece key , with part of it flush with the surface of the crank, OR making a second key that fit along side... But in the worst case scenario, I guess I would just clean it up, squirt on the glue, and hope for the best. Yes, that is the worn area. Also there is no taper on these cranks unlike later Miatas. I think the guy is right in saying the key is never meant to carry a load. It is only there to maintain alignment primarily during assembly. Maybe not the best engineering on SOA's part and really no room for error in fit of all parts and torque value for the crankbolt. The crankshaft could've been longer and the pulley had twice the contact area with the shaft and we all probably wouldn't be worrying about this. The new timing gear has no slop whatsoever on the crankshaft and I should never have to take it off. It's fit with Loctite 660 and should be permanent. The pulley is the bugbear for this engine... A design with no room for error plus a BIG error in the torque value for the crankbolt in all the manuals equals lots of messed up 2.2L cars... Quote Link to comment Share on other sites More sharing options...
MeJay Posted February 14, 2015 Share Posted February 14, 2015 posting so I can find this later as this is my son's car's problem too. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted February 14, 2015 Share Posted February 14, 2015 (edited) we have learned a lot since 07 regarding this fix. the locktite is not needed, nor the key for that matter. it just aligns everything until the bolt torque takes over. the cause is improper bolt torque. Edited February 14, 2015 by johnceggleston Quote Link to comment Share on other sites More sharing options...
MeJay Posted February 15, 2015 Share Posted February 15, 2015 Hi again John.....I'll do a search but is there a specific post or thread I should look for? Quote Link to comment Share on other sites More sharing options...
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