[Alfa-Al]

I performed timing chain tension check on 1986 Spider 2.0 Graduate; loosen bolt and pry out tensioner method. The bolt loosened readily and I got a little on the tensioner. Then the bolt did not tighten up. It looks like the head threads are stripped. Looks like pull the head and have it repaired. Any suggestions?

 

[spiderserie4]

that's bad luck
you could theoretically install a helicoil here with the head on of you get rid of a few things blocking your way, but that means taking the bolt out completely which is not a good idea as you might never get it back in as the little retaining collet into which the bolt screws into might not line up.

Its a bummer but it seems like head off - unless someone else can wade in with some miracle cure? Can a helicoil be done here with the head in situ, maybe just the cam cover off and the chain split so you can "feel" if the collet is in place and the bolt has found it?

By collet I mean the little buggar on the bottom right of this photo.

 

[Forzaguy]

My guess is you unscrewed the collett. It may still be in the tensioning mechanism.

 

[gigem75]

The ******* way would be to retap the hole with a size close and then have a machine shop cut the end of the new bolt down so it would fit the pad. or a timesert. I don't see any problem doing any of those while in the car. Just have plenty of rags on top of the lower chain and then wrap a rag around a smaller piece of hose and stuff that end in your shop vac and vacuum out the rouge metal. Flush with brake parts cleaner and vacuum again, then compressed air, then vacuum the rags out bringing along with them any metal missed. I've got to admit I've always had a fear of stripping those threads with that bolt. It will take a fair amount of torque but who knows who did what to it during it's lifetime. Goodluck!

 

[Giorgio68]

I agree with Forzaguy. Maybe accidentally you loosened the bolt more than necessary. You can still do it with the head on, no need to remove the head if the head is not stripped.
Use some grease to hold the wedge in place and a small mirror to see it how it lines up.......you need to do Mcgiver style work.
Goodluck!

Giorgio

 

[gigem75]

Getting the pad on there and lined up is easy, just use some grease and a mirror when it's lined up screw in the bolt. You should see a couple of threads when it's in correctly. If you see more then you have not stabbed the hole. With no pad the bolt will go down to the head of the bolt.

 

[spiderserie4]

but Alfa-Al says he cant tighten the bolt itself he is not saying he cannot secure the tensioner (by missing the collet).........doesn't that sound like stripped threads? even if the bolt was loosened too much and now did not line up/fit exactly back into the collet in the tensioner, you could still tighten the bolt...it would not turn round and round....it would hit something and tighten up (even if it was not doing the job it was designed to do) ...no?

 

[papajam]

I concur with SS4. Sounds like something is stripped. Easy enough to find out. Just remove the bolt and have a look at both the threads on the bolt and in the head. Engine not running, of course.

 

[Alfa-Al]

Thanks for the input. I will remove the radiator to get room and find out for sure. Its been a long time, but I installed the Sperry worked head in the '90's. Surely it had threads then; I'll see what I did over the years and what it has now. Yes, I had chain slap. Al

 

[Duke58]

Last time I looked at IAPs website they were selling new bolts:

Alfa Romeo Timing Chains

If it's stripped- the only way to properly repair it that I know of is to have an insert such as a helicoil or keensert installed.

Good luck.

 

[Forzaguy]

He also said he only loosened the bolt and it was secure when he originally backed the bolt off. Have never seen a bolt hole strip just sitting there with the bolt still in it. Unless, of course, he waaaay over torqued it when trying to reconnect with the collet.

 

[gigem75]

Yes he did, I proposed my ******* fix a couple of posts up from that. Not impossible at all to fix in the car. Like I said no telling what had been done to it before he got it. the fact it had slap leads me to belive that it'd been stripped for a long time and not entirely tight thus slowly pushing the tensioner gear back in all the while the bolt being nicely set in the pad.

 

[Forzaguy]

Another would be a blind nut on the inside surface. a tad of epoxy and the tension from the bolt would secure it.

 

[gigem75]

or devcon, that stuff is jb weld on steroids, actually now that I think about it you could fill the hole up with devcon and then drill and tap to the threads of the bolt. You really can machine that stuff. I'd wager you could get it tight enough to hold. Chase it with a tap first to get good clean metal for the devcon to stick to and then clean again and put in the devcon. That would be the real ******* fix

 

[spiderserie4]

I personally would not mess about with this tensioner bolt - you will always be dreaming of it working itself loose, the tensioner slapping about and the chain jumping a cog.........then you will REALLY have to take the head off (or what is left of it)

Try do it correctly, a helicoil (in the UK they have mobile guys who will do this for you, if you free up space for them to get in there to do it! A helicoil is not rocket science, but boy does it work. I would sooner take off the rad than the head, if you can get away with it.

As you have the cam cover off you will not have to worry about filings in the engine. Split the chain (engine timed correctly), take out the tensioner, stuff the hole with tissue paper and have a hoover at hand! (gives you the perfect opportunity to check the tensioner spring has not broken?.....cause of the chain slap?)

 

[gigem75]

I agree, that was my first choice several posts up, that or a time sert same result, good sleep. I would check mcmastercarr.com for metric helicoils if you can't find one locally, the tools for a time sert are pretty expensive. I'm putting my money on the slap being from the threads being stripped, probalby been that way a long time unless the slap appeared after he tightened the bolt.