clean or replace ATX timing belt tensioner?

[Huntervf]

I'm replacing a timing belt on a 93 ATX tomorrow (Thursday). The belt is very loose and I figure the tensioner is either bad or all gunked up. The problem is I can't get a new tensioner until Monday, and this guy needs to get on his way to Washington state ASAP. So, my question is this...in cases where the tensioner isn't functioning properly, is the problem usually just gunk in the tensioner, or can the tensioner just fail and not be salvagable? Thanks in advance for the help!

 

[sdpatt]

Are you referring to the tensioner's gas piston? I have not heard of them failing, but it is not impossible for that to happen. Until you take it apart and look at it, you are only guessing that the tensioner is the cause. You won't know if the gas piston is healthy or not until you remove it from the engine and try to compress the piston with a C-clamp or vise. It should take quite firm pressure to compress it.

If it seems to be healthy, check the bolt in the center of the tensioner pulley. The pulley's hub is eccentric and can be adjusted to provide more or less clearance when the belt is being installed. It can be set to have the piston fully stroked and have little pressure on the belt when the belt hass stretched due to age. The tensioner pulley hub bolt should normally be left alone as changing the hub's position will slightly alter the tension of the belt once installed. I am thinking that this is the problem with your belt.

There is no way to know without taking it apart and inspecting for the cause. I'll bet your tensioner is fine.

 

[F-22 Raptor SHO]

Chris:

As I didnt actually show you the tensioner device when I compressed it nor did show it to you as I installed it on mine, there are actually two parts: the pulley and the piston. You will be able to tell right away if the piston is bad when you go to compress it. Either it will or it wont. If the piston is in good order, it could be that the pulley bolt it loose or as you said gunked up and possibly on the short end of the elipse.

Being that Saturday was my first time, I dont have the experience to back up my conclusion as Scott does, it seemed pretty clear to me that the piston is a tough bugger and more than likely not the problem.

Quote from Chris on Saturday: "So long as you know how to put that tensioner back on then we are set, cause I know where every other part on this table goes".

 

[Huntervf]

LOL yeah I'm a newbie to ATX repairs eek!

Thanks much for the info! I'll post tomorrow with what I find thumbs_u

 

[sdpatt]

Here are a couple of shots of the tensioner on the 3.2L. The pulley in this installation made it difficult to install the belt because of the eccentric location that shortened the belt's path even before the tensioner was unpinned. You can see the drill bit inserted through the small holes to hold the piston in the compressed position.

 

[Huntervf]

Well, it would appear that the tensioner itself was indeed bad. First of all, I assume it's not normal to be able to compress the tensioner piston by hand...yes it felt tight but with a firm grasp I could push the piston down with my hand. Went ahead and put the new belt on, rotated the crank about 5 turns or so and it's the same story...belt goes tight then loose, and the tensioner moves back and forth as if it's not even resting on that piston.

Managed to track down a new tensioner, $111.00 and the part will be in tomorrow, so in the meantime I have a 93 ATX on jackstands in the garage

If anyone has any more experience on the ATX timing belt setup and has some advice let me know. The porblem is the belt goes tight, then loose, etc. And like I said, as I turned the crank I could clearly see the tensioner moving around, and it seems to me that a tensioner is supposed to keep constant pressure on the belt. Anyway, it's a learning experience for the Chrisman thumbs_u

 

[ISHOU]

You can compress the piston with your fingers if your Superman! I've never read a post here about the ATX timing belt tensioner going bad. How many miles on car? I wondered if I should have replaced mine when I did my 100k in June but since they seem durable, I didn't.

 

[F-22 Raptor SHO]

As I compressed the piston with my Craftsman Vise, I was whincing at the amount of force I needed to apply before I stuck the drill bit in. Superman would have a tough time pushing it in, heck even the hulk or Aspect couldnt do it.

The new tensioner will fix that tight loose problem. How is that bearing on the pulley?

 

[Steve Hoxsie]

I'm also in need of a tensioner for a ATX. Where did you get one for $111.00

Thanks,
Steve

 

[Huntervf]

Ok...the job is all done, here's a followup:

Harold Ziegler Ford in Plainwell is one of the better Ford dealers I've been to. The parts dept. staff are friendly and they actually know a fair amount about Taurus SHO's. Also, the SVT/SHO Society has discounts with them They were able to get a new ATX tensioner within a day...got on their locator and found a tensioner in Grand Rapids, and the next closest one was Louisville Kentucky eek! Now, I did talk to another Ford dealer before calling Harold Zieglers, but they wanted $160.00 for the tensioner!! Not sure if that included the pulley or not...our club discount at Zieglers is only %10 so I don't see the big difference in cost, so be aware when you're calling around should you need one. I did try a few generic parts stores, none had a listing for the tensioner so this is likely a dealer only part.

It comes from the factory pre-compressed with a nifty custom designed pin holding the piston down. Obviously I put that little jewel right in my toolbox for the next ATX timing job I do thumbs_u Installed the tensioner & timing belt, put everything back together and it worked like a charm. As far as the tensioner going bad, it wasn't a slow process. The car in question is a 93 ATX that just turned 150,000 miles, he was on his way from Washington state to Michigan when he started hearing clicking/rattling noise from under the hood, which was the timing belt loosening up and slapping the timing belt cover. it was a sudden thing, so apparently the tensioner just gave up the ghost all at once.

As to why the tensioner failed...I found a slight oil leak coming from the seal on the rear camshaft sprocket. Oil was seeping all the way down to the bottom of the timing belt cover, and the tensioner was quite caked up as well. The rubber seals on the far left of the middle timing belt cover near the tensioner were basically mutilated...I'm guessing that something similar happened to the the tensioner itself and any rubber seals that may be in there, and it eventually weakened enough to fail. I suppose it could have simply failed due to age, but given the rarity of this failure I would have to attribute this failure to the oil leak. So for any of you ATX'ers with a leaking rear cam sprocket seal you may want to pay close attention to your timing belt tensioner!

Thanks Scott and all the others who helped me out on this. Though I've worked on quite a few MTX's and helped out with Mike Ivey's ATX, this was the 1st solo ATX timing belt job I've done, and aside from the bad tensioner it was a smooth, successful repair...thanks!!! beer

<small>[ September 15, 2002, 10:25 AM: Message edited by: Huntervf ]</small>