[ToonRboy]

From there you can tap a bolt through the body which hits the arm to keep tension. Simple as that.

Well, I'm not sure that's entirely accurate Jason - don't you have to remove, tap, block-up the oil supply tube first?

Dan, look at the "blow-up" pic of the actual hyd unit. It's built like the Golden Gate Bridge! The thermo de-tensioner (mechanical) is built like toaster. It'll work, but I've skipped a tooth on one once before (after belt removed and replaced for a leaky cam hub seal). Lucky that was all that happened! The hard part on these is you have to crank down on it (it has a 3/8" drive square hole you put a ratchet with extension on) to set tension & then, when pointer is set to a tick mark, tighten the lock-down nut. You almost need three arms for this procedure. If you torque too much, you cannot back down to the mark, you have to release & start all over again. -No doubt this is where most screw this up. The difference is: with the hydraulic unit, you set the initial tension on full loose, with the mechanical unit, you set initial tension full tight - comprende?

Alfisto Steve pointed out on a previous post that the mechanical de-tensioner was designed to work with the newer T-belt with the slightly longer, rounded teeth. Which means different crank and cam hubs as well. The GTV6/Milano have the shorter, square teeth belts that require more tension. Makes perfect sense to me.

 

[alfaromeo1green]

Toonr,
Thanks for all the expertise. I think I will see if I can find a rebuildable hydro unit. Perhaps I'll wait to look for one until I get the car apart, and see that I am in fact running a mechanical unit now! After all, I just going by maintenance records, which show the mechanical conversion on a shop ticket. I will run a request in the "parts" section if I need to.
Thanks again,
Dan

 

[Alfissimo Int.]

Well, I'm not sure that's entirely accurate Jason - don't you have to remove, tap, block-up the oil supply tube first?.

Yes, but fixed tensioner is another post. Did not want to get detailed with it. Just the jist.

Mechanical tensioner is very simple to install but one must be careful of how much force is used. I really do not force the 3/8 square notch and use needle nose pliers on the bearing to seat needle just slightly below mark. You can hold it there with the square notch and tighten bolts to hold tensioner in place. Just need to switch wrenches with 1 hand while holding tensioner up. Not too bad.
But hydraulic is just a piece of cake and with all the springs and hardly any movement in the tensioner there is a really slim chance it can ever slip time.

J

 

[ToonRboy]

Yes, but fixed tensioner is another post.

I'd argue that the last eight posts should have been on a separate thread. But that's neither here nor there. You're right in this case as he (supposedly) already has the mechanical unit and therefore, the oil blockage work has already been performed. Thanks for your excellent input Jason. Always welcome.

Personally, I found holding the tension with my right hand (right handed) while torquing-down the hold-down nut on bottom/left of the mechanical unit took three or four tries for me (this was on my previous Gold Milano 2.5). Much more a "piece-of-cake" than this hydraulic unit IMO.

If you install the hydraulic unit wrong, it can slip. The whole reason for this thread was to try to answer many of the questions that have come up on this issue (over and over again) with respect to why/where they leak and how to install it correctly & why, when installed correctly, they can't slip. I did not bother to get into how the unit works as this has been covered in previous threads & the Busso document posted here has a summary as well. However, if there is any part of this thread that someone doesn't quite understand, please feel free to post (other than the silicon thing).

 

[RexCars]

Transaxle or Not

The other thing to keep in mind is that transaxle cars have the drive shaft connected to the engine at all times, since the clutch is in the transaxle case. When you shut down one of these cars, the drive shaft sometimes rocks the engine backwards. The hydraulic tensioner can handle this, the mechanical one cannot.

In short, the mechanical tensioner is fine for the 164, but less than fine for the GTV-6/Milano.

Rex

 

[Alfissimo Int.]

I'd argue that the last eight posts should have been on a separate thread. But that's neither here nor there. You're right in this case as he (supposedly) already has the mechanical unit and therefore, the oil blockage work has already been performed. Thanks for your excellent input Jason. Always welcome.

Personally, I found holding the tension with my right hand (right handed) while torquing-down the hold-down nut on bottom/left of the mechanical unit took three or four tries for me (this was on my previous Gold Milano 2.5). Much more a "piece-of-cake" than this hydraulic unit IMO.

If you install the hydraulic unit wrong, it can slip. The whole reason for this thread was to try to answer many of the questions that have come up on this issue (over and over again) with respect to why/where they leak and how to install it correctly & why, when installed correctly, they can't slip. I did not bother to get into how the unit works as this has been covered in previous threads & the Busso document posted here has a summary as well. However, if there is any part of this thread that someone doesn't quite understand, please feel free to post (other than the silicon thing).

I don't think you can install the hydraulic wrong IMO. With all the tension springs this unit has it is very hard to get it wrong. Install the unit, rotate engine twice to seat belt with tensioner loose, then press on tensioner unit against belt and tighten down. To me the setting tension on Hydraulic is much easier to install than mechanical.

The hydr. Tensioner is fool proof. Almost all V6's in Europe and abroad still use the hydraulic tensioner. I have been passing on the silicone tip to all my customers that want to go mechanical. I offer them a new bearing and rebuild kit with advice on how to do it right so it will not leak. My point is, if you have a unit keep it. If you want a unit find a complete unit with everything to rebuild it. Reverting back is a cinch!

All the other seals in the kit work fine except for piston shaft seal and inner feed stud seal a bit loose too. I use a little silicone on that one too but not really needed. Main leak is piston shaft.

Just my point of view.

Jason

 

[ToonRboy]

And the debate goes on...

The hydr. Tensioner is fool proof.

I suppose that's why over the years there's been so much dislike and angst towards the bugger. So much so that Alfa NA posted a bulletin to replace them with the mechanical unit. Are all those DIY'ers and mechanics fools then?

Ever since alfaromeo1green posted that timeless question (that he could have answered himself had he spent a moment to do his own research. read this thread in it's entirety, or search this site), this thread has gone off course with personal opinion rather than staying close to factory procedure.

So Jason, since you say "Reverting back is a cinch!". I would ask that you state your price for providing such service for the DIYers that can't decide what silicon to use, or the Alfa owners who would rather not get their hands dirty. Also, what would Alfissimo charge to remove/rebuild/replace a timing belt with hydraulic unit as opposed to replacing a timing belt with a mechanical unit?

 

[alfaromeo1green]

Toonr,
Again, sorry for the hijack. I did ATTEMPT to search, but the search function on this site is so horrible (no offense, Simon, etc.) that I have switched to using google to search this BB. I appreciate your insight on the rebuild process.
As Adam Sandler said " Proceed!"
Dan

 

[Alfissimo Int.]

I suppose that's why over the years there's been so much dislike and angst towards the bugger. So much so that Alfa NA posted a bulletin to replace them with the mechanical unit. Are all those DIY'ers and mechanics fools then?

Oh come on... the sarcasm is BS here?? I have given you plenty of info on this subject to make your tensioner oil free and the proper way to tension it. I find it easy as pie, same with mechanical. I seem to find more people that like these rather than the mechanical. You know exactly why they disliked them if they did and why Alfa NA had a TSB to replace it. Common knowledge.

Now, All the dislike and issues over the years over this unit are valid but that was before we all really figured out a way to fix it and make it work properly. I remember Sperry had a better kit back in the day to seal them up. I opted for silicone which works well. I do not think alfa took the time to figure out a fix for the problem and opted for a new cheaper non hydraulic tensioner to deal with the issue.
Please do not put words into my mouth with you last comment. I by no means ever said anyone was a fool. Fool proof is figure of speech.

If you read and follow the manual it is very simple to tension this hydraulic unit. Like I said there is not much play in it to begin with. Not much room for error at all...hence fool proof!


n., pl. figures of speech.

An expression that uses language in a nonliteral way, such as a metaphor or synecdoche, or in a structured or unusual way, such as anaphora or chiasmus, or that employs sounds, such as alliteration or assonance, to achieve a rhetorical effect.

adj. Foolproof
1. Designed so as to be impervious to human incompetence, error, or misuse: a foolproof detonator; a foolproof safety lock.
2. Effective; infallible: a foolproof scheme.


Ever since alfaromeo1green posted that timeless question (that he could have answered himself had he spent a moment to do his own research. read this thread in it's entirety, or search this site), this thread has gone off course with personal opinion rather than staying close to factory procedure.

I don't think it has gone off course. I think all the information you need is here. There is not much more to talk about.


So Jason, since you say "Reverting back is a cinch!". I would ask that you state your price for providing such service for the DIYers that can't decide what silicon to use, or the Alfa owners who would rather not get their hands dirty. Also, what would Alfissimo charge to remove/rebuild/replace a timing belt with hydraulic unit as opposed to replacing a timing belt with a mechanical unit?

I do not provide such a service for DIYers. The info is all here for free.


What would I charge for removal rebuild and replace? Depends. If it is a simple easy and clean procedure not much. Check my site for Hr rates.
To rebuild unit if you sent it to me, rebuild kit + 1 hr.

As far as how to revert to hydraulic, it is fairly simple, remove plug and stud, replace stud with feed stud. I like to drill smooth hole through plug but not too much that I can't you a hex wrench to put it back in.
Red loctite the plug and put it back in. I like this method as I do not like the oil return to run through threads.
Install o-rings on stud, little silicone (permatex grey or blue, or wurth dp300), Install belt, install tensioner (with lock tool or nail, screw works as well) carefully over stud and o-rings, I like to use my own saliva as a lubricant as not to nick the o-rings.. Attach arm spring. Now follow instructions, rotate twice to seat belt while using some slight pressure with your hand on top of tensioner body (not really needed but just in-case), once belt is seated and back at TDC, Rotate engine twice again(for good measure), press down on top of tensioner and tighten two tensioner bolts. Let out lock tool and that is it.

Fixed is similar set-up except I like to check for 1/4" belt deflection between cams and check tensioner every 15K miles.

Rebuilding is not difficult. After 1 time of doing it you will be a pro at it. It is as simple as removing old o-rings and replacing. Piston seal can get hard over the years but if rebuilt at every timing belt it should be simple to remove and with sealant even easier. Just be careful not to score the inner seal wall. Piston seal housing can be removed with a press or with a hammer (use a piece of wood, not direct metal to metal of course).
Make sure oil galley for feed stud is clean clean clean as even small amounts of dirt can nick o-rings.

For the cost of the rebuild kit every timing belt you save yourself tons of money over the mechanical and you feel secure in driving your vehicle again.

Jason

 

[ToonRboy]

Well Jason, we must be living in different worlds because in my whole Alfa-owning life, I have heard nothing but bad from the general populace about this hydraulic unit and every mechanic (if he's gonna be servicing your car & not just providing advice) would advise me to go with the mechanical unit. 70% of posts you read here or at GTV6.org about DIYers that have rebuilt their's, report it was leaking right away. This isn't sarcastic BS either my friend. This is fact.

No doubt there have been proponents of the original unit, you being one of them and now me as well. I want to thank you for carrying the re-build kit as I could not find one anywhere else. Even though the top plunger gasket disintegrated in my hands when I opened the baggie to inventory the parts

I agree that once you rebuild one correctly and successfully, it becomes relatively easy (like anything else), & I hope this thread has all the info necessary to help any first-time DIYer to get it right.

Since you find it easy as pie, I'd just like to glean some more pointers from you as there were a couple of steps that were a PITA for me. Refer to first page first post image.
1) What is your method of getting the unit back on the oil feed tube without dropping the Preload Spring (11)?
2) How do you handle getting the Reaction Spring (17) hooked back onto the bottom pin on Plate (2) with the Sleeve (19) still on it and what is the best way to get the Lockring (8) back on there?

Many thanks,

 

[Graham D]

1) What is your method of getting the unit back on the oil feed tube without dropping the Preload spring (11)?
2) How do you handle getting the Reaction Spring (17) hooked back onto the bottom pin on plate (2) with the Sleeve (19) still on it and what is the best way to get the Lockring (8) back on there?

1. Use assembly lube on the oil feed tube, hold the preload spring in place with your left hand and pursing your lips just so and slide the detensioner into place. You may still drop the spring a time or two - until you get your mouth right - but remember, the third time's the charm.
2. You'll need a 1/4" drive 1/4" size deep socket and a small hammer. Eat your Wheaties, then grab the lower eye of the bottom spring between the thumb and index finger of your right hand and push the eye down and over the lower pin. Next, with your left thumb and index finger, place the clipring against the end of the lower pin. With your right hand, push the business end of the 1/4" socket between your lelf thumb and index finger. Your left hand, now holding the socket against the clipring in position, frees your right pick up your hammer and, giving a gentle tap, drive the clipring home. Accessability makes all the difference; most difficult, GTV-6 with the hood on, easier on Milano / 75, 164 easiest of all.

 

[Alfissimo Int.]

Well Jason, we must be living in different worlds because in my whole Alfa-owning life, I have heard nothing but bad from the general populace about this hydraulic unit and every mechanic (if he's gonna be servicing your car & not just providing advice) would advise me to go with the mechanical unit. 70% of posts you read here or at GTV6.org about DIYers that have rebuilt their's, report it was leaking right away. This isn't sarcastic BS either my friend. This is fact.

I agree that this tensioner has a bad rep. But since we all have found a solution to the problem I know it is a good tensioner. The reason people go with the mechanical is due to the fact people do not know how to rebuild them not to leak. I am providing some information on how to do that. I have never had one leak. So at this point in time, right now, these are very good tensioners if you rebuild them correctly. I know that most have issues with them, but I also know many with 0 issues and some with 100K on theirs with no leaking. It is all about the quality of the rebuild, the minor tricks to keep it from leaking that will save this tensioner from going down as the worst tensioner ever. I think the mechanical that your mehcnaic advises you to use is wrong. I would cherish these tensioners. Fix it the way I have advised and I am sure it will not leak for many miles to come.

No doubt there have been proponents of the original unit, you being one of them and now me as well. I want to thank you for carrying the re-build kit as I could not find one anywhere else. Even though the top plunger gasket disintegrated in my hands when I opened the baggie to inventory the parts

Interesting?

I agree that once you rebuild one correctly and successfully, it becomes relatively easy (like anything else), & I hope this thread has all the info necessary to help any first-time DIYer to get it right.

Since you find it easy as pie, I'd just like to glean some more pointers from you as there were a couple of steps that were a PITA for me. Refer to first page first post image.
1) What is your method of getting the unit back on the oil feed tube without dropping the Preload Spring (11)?
2) How do you handle getting the Reaction Spring (17) hooked back onto the bottom pin on Plate (2) with the Sleeve (19) still on it and what is the best way to get the Lockring (8) back on there?

Many thanks,

As far as the the preload spring, it is a pain but I gently slide body on feed stud it close enough to back plate that I can fit spring in. (I know this seems primitive but it works) I place the spring on the tensioner back first making sure it is secure on the tensioner body and touching plate. I use a flat head screw driver to lever the spring under the plate lip. You have to work at it and sometimes the spring gets caught on a link with the back plate lip but that gives you a chance to rest and do it again. LOL.

Press on tensioner body into the belt and lever it in at the same time. Best way to describe it.

Reaction spring, I use pliers to pull it on to the pin. This fasten it with whatever lock ring you use. There are 2 types. I use the later style that slides in a groove and locks in. Pretty simple.

That's how I perform that install.

 

[ToonRboy]

Ok basically the same things I did (covered in post#12 on page#1).

Thanks fellas, all good!

 

[Naplesworkshops]

We are going through the same thing right now...

I can't seem to get the oil galley plug out. It is not an allen screw but a simple straight bladed screw driver slot.

Has anyone installed a hydraulic tensioner without removing this plug?

 

[ToonRboy]

Haven't you heard? "Reverting back is a cinch!"

Ya' know, right now you are at an interesting decision point that could save you some work. You can leave the oil gallery plugged and convert the Hyd de-tensioner into a manual tensioner (ala Alfa Heaven "Stay Belt"). By drilling and then tapping the housing cover (25) you can install bolt to press-down on plunger assy. I'm not sure if they keep spring (14) in there. I would consider spot welding an aluminum nut to the underside of the cover to provide more strength and ability to lock-nut from the top.

If you're intent on going hydraulic, then you're going to have to remove the plug without damaging anything. I'd try one of those Craftsman spiral screw extractor sets & hope the gallery pin will fit back in there...

 

[alfaromeo1green]

OK detensioner experts. I have a question. I'm rebuilding the old-school detensioner, and the spring with the rubber sleeve (I think its called the reaction spring) is a little beat up. I don't think it will break, but I was considering replacing it, but the only ones beefy enough (in the hardware store) have more spring tension. Will more spring tension cause problem? I bought one with the same tension, but its a chintzy wire spring, not like the OEM piece. I could use the original, but I'm not keen on it.

Thanks,
Dan

 

[ToonRboy]

I guess it depends on where you live. But some don't believe in the premise of why this "de-tensioner" was invented. e.g. expansion/contraction of alloy block, heads, whatever. The idea being that it keeps the belt tension about right regardless of engine temperature. If the premise is true, the belt would get overly tight when the engine is hot (and could snap), or get overly loose when cold (and skip). The last couple of days here it's been 0F or less (-20F last night with wind chill). Things tend to shrink in this sort of weather.

Take a read on that Busso document provided by Rex. It reads like: "Who's on first?", but I think you'll probably conclude that it's part of a balanced set of springs. I'd get a replacement OEM unit. Probably cheap as everyone (in the U.S.) has been chucking 'em in favor of the mechanical unit for years.

Let me ask this. Based on what you understand the reaction springs purpose to be, does it tension or de-tension the belt?

 

[Graham D]

It's called a 'de-tensioner' because of how it functions. The large intenal spring on top of the hydraulic piston overtensions the belt for startup, then engine oil pressure below the piston offsets that spring pressure, thus the de-tensioning. The bottom spring provides all the necessary belt idler tension when the engine is running.

 

[alfaromeo1green]

I agree with Graham's analysis (not just because he's a good guy). I've looked at this contraption and come to the same conclusion. I may replace the spring to save the worry.........
Dan

 

[John Brase]

What tensioner is this?

You guys have inspired me to rebuild my tensioner, along with a complete top end rebuild. I have started taking things apart and digging through some years of accumulated grunge and came across this. WHAT TENSIONER IS THIS?? I was expecting to find a stock hydraulic one but this clearly isn't it.