Something interesting I found out (ATX Timing belt tensioner)

[hawkeye18]

Ok folks, story time again!

So I'm replacing a failed timing belt tensioner on my 94 ATX. I look in the factory pub and there's this whole big sequence about rotating the off-center pulley with a special tool and a torque wrench that gets no mention whatsoever in the SHOPP procedure. (Beth, you might want to add something about that in there... I'll send you appropriate pictures)

So this time, when I get to that point, I look at my tensioner pulley, and sure enough... it's rotated so that it's as far away from the belt as possible.

So how do I rotate this thing? There are what appear to be dracula bite marks on this thing; I can't get an allen wrench in there cos it's circular. I don't have the ford tool and have no idea where to get one that day... when all of a sudden an idea pops into my head...

I'm a solder tech in the navy, and one of the tools we use to form wires around a post terminal is a set of round-nose pliers:

Being that I do a lot of solder work on the side, and those are somewhat useful tools to have, I had purchased a set... at where else? Michael's. Yeah, the arts & crafts store. My wife keeps dragging me there for stupid stuff and I saw those there - they were like $4.99 so I got a set. I had had these for a year already, and they had never been used...

It turns out that those fit perfectly into the holes of the tensioner pulley, and the handles are short enough to use while the engine is in the car, even if you have big manly hands. And, it's quite easy to rotate the pulley to whatever position you need, and if you're by yourself it's a simple matter to slip that 14mm socket in there while you hold the pliers in place with your other hand.

I just rotated mine so that it was closest to the belt. This gives you more time on the belt, as the tensioner doesn't extend as far to give the same amount of pressure. And the less the tensioner has to extend, the less it goes bad...

Every ATX owner should have a pair of these. Now I'm gonna take my bad tensioner piston apart and see if there's any way to refurb these things... somebody's got to. There aren't any new ones, and the ones in use aren't getting any newer...

 

[93rev2sev]

Cool on ya for the pliers!

I took a tensioner apart once and found that all the stuff inside had leaked out. I determined that it wouldn't be too hard to refurb a tensioner...as long as you were willing to destroy a good one to find out the viscosity of the goop inside.

 

[hawkeye18]

Cool on ya for the pliers!

I took a tensioner apart once and found that all the stuff inside had leaked out. I determined that it wouldn't be too hard to refurb a tensioner...as long as you were willing to destroy a good one to find out the viscosity of the goop inside.

My bad one isn't shot completely, and it's still leaking some stuff out. It doesn't seem to bee too thick... maybe about the consistency of ATF? I don't know how it maintains pressure, though. One would think a spring would work just as d#*^ well. These stupid hydraulic tensioners remind me of the hydraulic trunk closer on Jezza's Mercedes 600 Grosser ("That's brilliant actually, because what I've found really difficult to do, is this... *thunk*"). Oh well, I guess I'll find out this weekend. I'll take pictures of the disassembly and post them up here for all y'all's reading pleasure.

 

[93rev2sev]

There is a spring inside there. But it takes some time for it to overcome the viscosity of the fluid.

I think that you should be able to install a zirk fitting in the bottom of the tensioner and shoot grease into it every oil change...after a while, though, that grease will make quite the mess out of your oil pump area.

 

[LOUDSHO92]

We are working on refurbishing them.

 

[hawkeye18]

Well the normal failure mode is the shaft seal failing/leaking, right? So theoretically if one were able to either find one that fit and/or get new ones manufactured, that should solve the problem. Other than a groove on the top of the piston, which isn't really a big deal...

 

[93rev2sev]

Yes, the shaft seal fails, but not the way you might be thinking...at least with the one I took apart...

It seemed that the seal had broken free of the cylinder and rubbed the wall as it rode up and down with the shaft. This, in turn, made it seem impossible to get another seal to stay in place. Maybe you will come to a different conclusion...I hope so.

 

[shocrates]

It's not in the SHOPP procedure because it's not a necessary step if the timing belt tensioner is being removed to replace the belt etc.. If this step is added to SHOPP, it should be noted that the procedure for adjusting the tension by rotating the eccentric hub of the tensioner pulley with the special tools and torque wrench only needs to be followed if the tensioner pulley is being replaced or the bolt that secures the eccentric hub is loosened.

What groove on top of the piston?

 

[hawkeye18]

The shop manual states that you need to rotate the pulley if you are replacing the timing belt.

The groove I speak of is the groove that is left where the pulley assembly rides on top of the tensioner piston.

Edit:

NOTE:
If a new timing belt is being installed, perform steps 10 through 13. If the original timing belt is being used, go to step 14.

10. Position Timing Belt Tensioner Tool T93P-6254-B using power steering pump support (3C511) holes.

11. Hand-tighten timing belt tensioner idler pulley bolt.

12. Using Inch Pound Torque Wrench D81L-600-A or equivalent, rotate Torque Wrench Attachment T93P-6254-A clockwise to 0.5 N-m (4.3 lb-in).

13. Tighten timing belt tensioner idler pulley bolt to 36-50 N-m (27-37 lb-ft). Then remove Belt Tensioning Tool T93P-6254-B.

 

[shocrates]

On none of the good TB tensioners I have is there a groove on top of the piston. I suspect it's because of the tensioner failing and allowing the pulley arm to move back and forth excessively, wearing a groove in the normally flat piston top.

I know what the manual states. To do it properly you also need the tensioner tool, torque wrench adapter, and low scale torque wrench. After owning those tools for almost a decade I can say I've never used them. Maybe sdpatt will see this thread, as he is the one that advised many years ago not to loosen the TB tensioner pulley bolt.

 

[hawkeye18]

Eh, I don't have a TQ wrench that goes that low, I don't have the ford tool, and I don't have the adapter thingy. But what I do have is a fairly well calibrated torque arm and a desire not to have to change that stupid tensioner out again any time soon.

 

[projectSHO89]

I went through this drill with the tensioner almost 7 years ago on what is now my 94 ATX (it was Jerry's back then).

You can read about my fun and games here: http://shoforum.com/showthread.php?t=12362&highlight=ATX+timing+belt+tension

I also used a similar set of pointed-noise pliers (I'm also an electronics tech who has done a lot of soldering) to pre-position the tensioner.

Steve

 

[Pleky]

Wow I guess I'm luckier than I thought. A few years ago I had to change the water pump and cam seals, and that necessatitated the timing belt removal. I think that was maybe my 5th month of SHO ownership. My first timing belt change too

Long story short, I just used a breaker-bar to move then tensioner away when removing/placing the belt. Worked fine until I mothballed the car a few months ago.

 

[Earthshaker]

We are working on refurbishing them.

How is it going on the refurb? We need a new one or one that's been rebuilt.

 

[shopartsnw]

We are still working on the rebuild. We are trying to get more information on how the tensioners were originally built (type and quantity of fluid). In the mean time we can only offer good used tensioners as we find them.

Mike

 

[Off Road SHO]

We are still working on the rebuild. We are trying to get more information on how the tensioners were originally built (type and quantity of fluid). In the mean time we can only offer good used tensioners as we find them.

Mike

Mike,

Call me or PM me.

Tom

 

[whiteguy3]

9 times out of ten, the tensioner fails due to to the seal leaking and the fluid runs dry. I got tired of them too. Now I run a manual tensioner using the stock hydrolic housing. Piece of cake to remove and will never wear out. Just forget it Jason and switch to making a manual tensioner!

 

[hawkeye18]

yeah, instead of finding a working tensioner, I wrecked the car. Problem solved!