Rebuilding cam synchronizer

[joeasheville]

Well, after replacing my third cam synchronizer in the Vulcan in the 1997 Taurus, I'm beginning to wonder if these things can be rebuilt. From what I understand they have been rebuilt by places like NAPA and Cardone, but I'm interested in doing it myself. Each time I've got the genuine Motorcraft unit at $150 a pop. That cash is beginning to stack up, and I'm interested in alternatives.

I've got two of them from past replacements that ran out of lubricant and began chirping. They look great otherwise...hardly any marks on the gear, O-rings are pliable, etc. I drove out the roll pin from the gear and attempted to get it dislodged from the shaft with no dice.

Not wanting to proceed any further and damage it, I thought I'd get on a few Taurus sites and see if anyone has done it. I haven't found anything in that vein so far, including a general 'net search.

Has anyone taken one of these apart before? If so, what did you find out?

[Automender12345]

I tried taking one apart and could not get the gear off the shaft. I tried heating it and hammering on the shaft just to mushroom the shaft. Unless you can either straighten the shaft or machine a new bushing I don't think you can rebuild one. I was not able to determine the failure mode that causes the chirping. I figure it is a wiped bushing of bent shaft.

Mine failed during a 12 hour 75 - 80 mph drive down to Florida in July heat. I had 70K on the car.

[joeasheville]

There's a plug on the side that looks about the right size for a zerk...has anybody tried pulling out the plug, installing a zerk, and greasing one up?

[JW657]

I have a bad one sitting right in front of me. I'm going to see if I can tear it apart. I'll post pictures later tonight, if I'm successful.

[JW657]

I got it apart. I ruined two hack saw blades doing it.

The shaft is pretty much totally held in by the gear. I couldn't get the gear off though. If you manage to remove the gear without damaging casting or shaft, then it will come apart. As for rebuilding, I would say probably not. The shaft has wear grooves in it. The one I have would need to be replaced, I'm not sure where you would find a good replacement. I'm guessing the inside has wear as well.

The one I took apart had in/out play and no side play. I would say the shaft is bad from lack of lubrication. The shaft had thick, black grease like deposits and varnish. I'm not sure what's causing the in/out play yet.

I'll post pictures later.

Also, I drilled out that welch plug. There's some kind of powder behind it, kind of like sawdust. There's nothing really useful or interesting behind it. I decided to drill into it some more and you end up hitting the shaft.

[joeasheville]

JW, you are the man.

Thanks for posting the pics later. Not sure how I can remove that gear without destroying it...it's cast iron I think. If other folks can rebuild these things...surely there's a way for the shade tree to do it also.

[JW657]

Here we go...


Here you can see all of the components, minus the roll pin.


You can see one of the wear grooves I was walking about.


I drilled out the welch plug and there was some kind of powder behind it, kind of like saw dust. I cleared out some of the powder and drilled a bit deeper, I hit the shaft almost instantly.


The gear was in very good shape and is VERY securely attached.


That's the gear end of the casting after cutting it in half.


The shaft end sits against that, there's no washers or anything.


The one and only washer. It did have some wear but not a lot. It goes between the gear and casting.

The casting is very easy to cut through, but the shaft is incredibly hard (giggity) to cut through. The first hack saw blade broke in half shortly after hitting the shaft, the second had pretty much no teeth left by the time I was done. My arm hurts a little from it. I was gonna give up and use the angle grinder if I broke the other blade.

You can insert a hex socket into the end of the shaft, that might be a good way of holding it in place while you remove the gear. My first idea was to lock the gear between two blocks of wood in a vise and turn it with a hex socket, it didn't work because the gear chews through the wood and turns. I also tried hammering the shaft out but that didn't move it.