New User of Forum, 1997 Mustang 3.8L V6 Tensioner arm/pulley removal problems - Ford Mustang Forum
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post #1 of 8 (permalink) Old 12-20-2009 Thread Starter
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New User of Forum, 1997 Mustang 3.8L V6 Tensioner arm/pulley removal problems

Hello everyone,

I'm new to this forum and love mustangs.
My 1997 Mustang V6 Belt tensioner arm is broken and completely jammed in place. I've tried to loosen it every way possible; i.e. hexagonal allen wrench attached to long pole for leverage, tapping allen wrench with hammer, WD-40 to help loosen, etc.

I ended up stripping the bolt that holds the belt tensioner arm to the engine, so I tried to use a bolt removal/extractor tool from craftsman after drilling through the bolt and the extractor ended up breaking off inside the bolt :shiny: great news, right? luckily I was able to get most of the broken piece out.

At this point, I'm at a loss. I have no more good ideas of how to get this bolt out. The main problem is, after all the years my mustang has been driven, the constant strain and heat build-up has most-likely "melted" the bolt into place.

One last idea I have involves heating the bolt with a torch to help with loosening it but I don't want to spend another 15 bucks on a burnz-o-matic blow torch.

Any ideas what-so-ever will be greatly appreciated.
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post #2 of 8 (permalink) Old 12-20-2009
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Welcome to AFM. We'll find you some help in here.

1965 Mustang Coupe
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post #3 of 8 (permalink) Old 12-20-2009
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I think at this point, you are better off getting a whole new bracket assembly from a junk yard.....

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post #4 of 8 (permalink) Old 12-20-2009
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Welcome to AFM.

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post #5 of 8 (permalink) Old 08-09-2010
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Don't worry, I had the same problem

So last Friday I had the same problem you have, and I've realized that's because both the bearing bolt and belt tensioner bolt are reverse threaded. So I reefed on the belt tensioner arm hard enough I actually broke it off. So now I have the spring loaded half of the tensioner still attached to the engine block, which of course I did like you and stripped it. BTW, it's a torx (star) type socket about 8mm (or i think 3/8 ? in standard) and I'm pretty sure it's reverse threaded. So I know this post was a while back but if anyone gets into this situation again and have stripped the tensioner bolt. Just grind/drill off the head of the bolt ONLY so the whole belt tensioner assembly slides off. Then take either a monkey wrench or pipe wrench or grind the bolt square so you can get a crescent wrench on it to remove it REVERSE thread!!! I'm going to test the reverse thread theory and will let you know what happens, if anyone has any more insight or knows more than me (and there are plenty of people that do) please offer us your wisdom,
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post #6 of 8 (permalink) Old 08-09-2010
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okay, now I got it

Alright, so this is verified by test...

The torx (star) pattern bolt securing the entire tensioner assembly to the engine block is regular direction threaded. Also of note, it is not a blind hole, so the thread and bolt can go all the way thru. When the motor is cool, it is very difficult to remove, this is because of the different materials and the repeatative heating and cooling of those materials (ie aluminum and different grades of steel). So my recommendation is to let the motor heat up to operating temp, then try and remove said bolt, or if you can't or just want a crappy challenge, then you can pry the tensioner apart and grind the head of the bolt off so you can slide the rest of the tensioner off and replace the bolt. Or you can just heat it all up via running the engine and it should come off...also when reinstalling, use anti-seize ( I also put a little dab of thread locker on the last threads to contact the hole, not needed, I'm just paranoid) DO NOT OVER TIGHTEN when reinstalling!!!!!!!!!!!

The hex head bolt securing the bearing (pulley, wheel, whathaveyou) IS REVERSE THREADED!! Do not do what I did and reef on the thing until you break off the arm of the tensioner! If the bearing on the tensioner is bad, it is much easier to replace only the pulley and not the whole tensioner assembly. SO yes, this one is reverse threaded.

Recap: Tensioner assembly = torx ( T-50 i think), regular thread
Tensioner Pulley only = hex head (18mm i think), reverse thread

Hope this helps someone out there from doing what the two of us both did!
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post #7 of 8 (permalink) Old 08-10-2010
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Thanks for trying it out and sharing your results!!! Sorry you had such bad luck in the first place...

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post #8 of 8 (permalink) Old 01-21-2013
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Thumbs up Tensioner arm bolt stripped, too

I know some of these posts are dated, but they are never the less helpful to those who don't pull maintenance under the hood of a Mustang very often.

My grandson has a 1997 3.8 vehicle. The bearing was frozen on the pulley of the tensioner, so like several posts on this and several other forums, I was unaware that it was left hand thread and busted the bracket. I was trying not to double-down on dumb by twisting off the bolt that holds the tensioner assembly to the engine block.

The bolt supposedly has a T50-Torx head, but because of rust and previous service, it was stripped. A T55 was too large. An 8mm hex/allen head worked better but was still insufficient to break it loose with out further stripping it.

I had no torch, but I did have a little Dremel tool with lots of little cutting disks. I pried the cover of the spring off and managed to get most of the 'guts' of the assembly removed. That exposed the part of the casting through which the bolt goes. As it is countersunk, I had to cut and chip enough of the casting away to get a large a pipe wrench as would fit onto the bolt head. BTW, I had removed the anti-freeze reservoir for more maneuver room.

After grinding and chipping away enough of the casting, I could get a pipe wrench on the bolt--with just enough wiggle room to break it loose. I suppose if I had had this on a hoist or at least jacked up and removed the tire, I could have thrown some heat on the back of the head of the bolt--but I didn't. I was able to clean up the threads on the bolt and file down the marks from the pipe wrench, to salvage the bolt. I suppose in a perfect world, it should have been replace--but it ain't a perfect world!!

The re-assembly was pretty quick, and a large pry bar for a little 'reef' got the belt back on--and it is back running.

This appears to be a high failure rate component. Thanks for the many posts; I wish I had read them BEFORE beginning the project.
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