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Haakon

Call me Ken, whoreken
Timing belt tensioners - old school manual vs automatic.

Is it just a matter of the manual ones requiring less fuck ups to get tension right or is there really an advantage of modern spring (or hydraulic) tensioners?

Never really thought about it, all my earlier cars had manual ones i happily set by feel. Am buying a timing kit for Mums i30 and can choose. If I recall it’s got a manual tensioner in it now and all the early cars with this engine did but this one was probably built with an automatic one.

Probably overthinking it, but the manual one is a lot cheaper.
 

Flow-Rider

Wheel size expert
Timing belt tensioners - old school manual vs automatic.

Is it just a matter of the manual ones requiring less fuck ups to get tension right or is there really an advantage of modern spring (or hydraulic) tensioners?

Never really thought about it, all my earlier cars had manual ones i happily set by feel. Am buying a timing kit for Mums i30 and can choose. If I recall it’s got a manual tensioner in it now and all the early cars with this engine did but this one was probably built with an automatic one.

Probably overthinking it, but the manual one is a lot cheaper.
Auto tensioners are to stop people under or over tightening belts, more trouble in the long run if you ask me. They leak out fluid over the years, usually costly to replace, people try to reset them too fast and it cracks the body of tensioner or they blow a seal. If it's got one factory fitted, just replace it because they get weaker over time.
 

Haakon

Call me Ken, whoreken
Auto tensioners are to stop people under or over tightening belts, more trouble in the long run if you ask me. They leak out fluid over the years, usually costly to replace, people try to reset them too fast and it cracks the body of tensioner or they blow a seal. If it's got one factory fitted, just replace it because they get weaker over time.
It’s got a solid manual one in it now, the option is the auto one with the internal spring (not hydraulic but the ones you turn with a hex to line up the pointer). I think it was built with the auto one, but I bought it on its second belt. The mechanic Mum will probably use seems ok if I’m not around to do it.

It doesn’t use plastic rollers and it doesn’t drive the water pump off the timing belt, it’s got good old fashioned keyed pulleys, so am pretty relaxed about this one. It’s a bloody good engine from a servicing standpoint. The whole thing is a solid little thing actually…

The older Renaults I had had a spring on the tensioner that was there to set the tension then you locked it down - an idiot proof manual tensioner which would never come loose which was a neat design.
 

Flow-Rider

Wheel size expert
It’s got a solid manual one in it now, the option is the auto one with the internal spring (not hydraulic but the ones you turn with a hex to line up the pointer). I think it was built with the auto one, but I bought it on its second belt. The mechanic Mum will probably use seems ok if I’m not around to do it.

It doesn’t use plastic rollers and it doesn’t drive the water pump off the timing belt, it’s got good old fashioned keyed pulleys, so am pretty relaxed about this one. It’s a bloody good engine from a servicing standpoint. The whole thing is a solid little thing actually…

The older Renaults I had had a spring on the tensioner that was there to set the tension then you locked it down - an idiot proof manual tensioner which would never come loose which was a neat design.
Looks like a copy of an old opal T belt adjuster, I suppose it doesn't really matter, it's not like your Mum is going to drive it like a race car.
 

Haakon

Call me Ken, whoreken
Looks like a copy of an old opal T belt adjuster, I suppose it doesn't really matter, it's not like your Mum is going to drive it like a race car.
Nah, it’s a country car too so its engine gets a very easy life - no short cold trips and no long periods of idling. The chassis gets a harder time given they’re a few kms into the bush on dirt roads…

Just my OCD suddenly wanting to know the pros and cons of the two approaches to tensioners ;)
 

link1896

Is not a gynaecologist but will look at your fork
Does the timing system have a belt keeper around the crank pulley? If not, I’d kinda fall towards the automatic tensioner. As flow points out, shorter life but kinda more idiot proof if installed correctly

I managed to reuse many Subaru hydraulic tensioner back in the day, using a g clamp, taking 2 minutes to slowly reset. But I did replace the bearings in the pulley.
 

Haakon

Call me Ken, whoreken
Does the timing system have a belt keeper around the crank pulley? If not, I’d kinda fall towards the automatic tensioner. As flow points out, shorter life but kinda more idiot proof if installed correctly

I managed to reuse many Subaru hydraulic tensioner back in the day, using a g clamp, taking 2 minutes to slowly reset. But I did replace the bearings in the pulley.
Ive installed many many manual tensioners, I am comfy getting the tension right.

But as I've always had european cars, never had much to do with those hydraulic belt tensioners. Older ones all manual, newer ones use the internal spring type ones. Mum's Magna had one, did the vice over a minute or two trick on that ok - I found it disconcerting the belt would go really slack between the front cam pulley and the water pump when the engine was turned off as the rear cam pulled the tensioner in from valve springs pushing against it...

For the Hiundy they're using the euro style spring auto tensioner, not the hydraulic one. Another point of evidence that the i30 was developed explicitly for the european market perhaps?
 
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Flow-Rider

Wheel size expert
I had done about 8 years of fleet servicing, I can't recall finding a loose timing belt with a fixed tensioner unless there were other issues like worn bearings or an ancient belt with cracks. I suppose when you start going to the longer belts on the quad cam stuff it might become as issue. A lot of the early Mitsubishi stuff with belts had hydraulic tensioners that just failed left, right and centre.
 

Dales Cannon

The Olden Dazed
Staff member
I had done about 8 years of fleet servicing, I can't recall finding a loose timing belt with a fixed tensioner unless there were other issues like worn bearings or an ancient belt with cracks. I suppose when you start going to the longer belts on the quad cam stuff it might become as issue. A lot of the early Mitsubishi stuff with belts had hydraulic tensioners that just failed left, right and centre.
Too many tensioners, probably only needed one.
 

Dales Cannon

The Olden Dazed
Staff member
QUOTE: "Typically, hydraulic tensioners can operate with a larger range of dynamic belt lengths than mechanical tensioners. Due to the length of stroke of the actuator and the lever design the hydraulic tensioner system is particularly suitable for large V6 or V8 applications. The high unidirectional damping characteristics make it suitable for controlling the dynamic belt behaviour on applications with high dynamic loads."
 

link1896

Is not a gynaecologist but will look at your fork
I had done about 8 years of fleet servicing, I can't recall finding a loose timing belt with a fixed tensioner unless there were other issues like worn bearings or an ancient belt with cracks. I suppose when you start going to the longer belts on the quad cam stuff it might become as issue. A lot of the early Mitsubishi stuff with belts had hydraulic tensioners that just failed left, right and centre.

Mitsuboshi belts on a Mitsubishi just to do everyone's head in?
 
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