cam chain tensioner on rear head?

[zuup_2000]

Sorry if this is a stupid question, but the cam chain on the rear head is sloppy. Is there supposed to be a wear block or tensioner on it like the front head has? here is a pic of the area in question.
I am new to these engines, and the crappy taurus manual I have doesnt cover the SHO engines. Thanks for any help, and dont laugh at me too hard.

 

[Sh03d]

Not a dumb question at all.

I believe the rear tensioner is flipped so that the wear block is pointed downward. That's what I remember from my tear down. And that chain does look a little sloppy. How many miles do you have on your car?

P. S. Posting pictures like you did is always a great idea when you have a technical question.

 

[zuup_2000]

The car is a 1992 MTX w/167,000 miles. Im getting ready to do the upper 60K, and fix my electrical problem I had with my blown IRCM.
The rear chain has quite a bit of play. The wear bar on the front head is worn but still good, and the chain is nice and tight.

 

[zuup_2000]

I looked a little closer after you had mentioned it being flipped upside down compared to the front. It does have the same type of tensioner/wear bar, and its facing down like you said. I guess its time to scrounge one up since the chain is really sloppy. I have read that they are dis-continued, so where is the best place to find one? parts cars?
I did notice that the wear bar on the rear head is bright orange in color, but the front one is black. Does this sound normal, or is it an aftermarket wear bar.

 

[TRSCobra]

The tensioners with the orange heads (delrin?) were used on the later model SHO's, starting in 92 or 93 im not sure. The black ones are from the older engines. Someone may have changed one of the tensioners at one point in time. I got a set of orange ones out of a 93 3.2 car and put them in my '90 3.0 motor.

From what I hear, they don't go bad, but they do get clogged. If you take them off and remove the roll pin, you can easily clean them with a carb or brake cleaner.

 

[F-22 Raptor SHO]

that front wear bar looks pretty bad. The chain is worn to the point where the notches on the chain are down to surface of the bar. Mine looked like this:

Upon closer inspection you see that the foot is grooved pretty badly:

Note the front and rear tensioners are not the same. So if you do scrounge one up, note they arent interchangeable front to rear. You might find that if you clean the tensioner off with berrymans focusing onthe oil weep port on the bottom, that the tensioner works fine. You still have a worn foot though.

 

[SHOtimer]

I have had great luck with many tensioners just taking them out disassembling them, cleaning them and then reinstalling them. The insides get all gummed up and they do not keep tension anymore. Your wear boot will still be worn, but the tensioner will keep the chain tight. I would take the tensioner out, remove the pin and completely clean it out, reinstall it and be good as new.

Doug

 

[zuup_2000]

Is it pretty straight forward as far as removing the tensioners? Do I have to pull the cam sprockets and chains, or will the tensioners come out with the sprockets still in place.

 

[NotSoSlowSHO]

I find it easiest to remove the cams. Im not sure if you can even get the sprockets off without removing the cams.

Not sure though!

 

[Rockledge]

My '94 tensioners have the orange heads. Both had some decent meat left on them when I had the covers off several months ago, but I took them off anyway and soaked them in a gallon of Berrymans. I did not take them entirely apart like some others have done, which involves pulling the little pin out etc. They seemed to be working fine so I put them back on and considered myself fortunate.

IMO, it is precisely this type of area on the SHO engine that makes an occasional Auto-Rx treatment a good idea.

 

[SHOtimer]

Is it pretty straight forward as far as removing the tensioners? Do I have to pull the cam sprockets and chains, or will the tensioners come out with the sprockets still in place.

On the rear head it is not necessary to pull the cams to get the tensioner out, on the front it is. You just have to reassemble everything perfectly back and time it perfectly, oh, and torque it perfectly.

Doug

 

[jelloslug]

The "orange head" vs "black head" is not a real difference. A new tensioner has a whitish head, the coloring is caused by oil staining the plastic. As long as the head has plastic on it, the tensioner is good. The vast majority of so called "bad tensioners" I have come across were really 2 things: A very gummed up tensioner (just take it apart and clear it well) and a stretched timing chain (just replace it).

 

[SHOWYA]

I think you do not need to replace the tensioner. If you are able to turn the crank clock wise you should be able to see that the slack will come off. I also experience this when i switched my cams. But after turning the cams a couple of times i can see that the tensioner 'starts working' when the cams are turning. If you do hear some kind of knocking on the top of the heads then you do need to replace them.

Have somebody turn the crank for you with a braker bar and you will see how that slack comes off. The reason is that the pressure from the springs on the lobes may force the cam to turn back a bit making it slack. This is only when the engine is off. Try it and you will see it work!