Tensioners - (for the timing chain) - what's the deal?

[Longtrail]

Hey Folks,

The more I go down the rabbit hole with this timing chain job the more I realize the small nuances make a difference in overall project success... Today, I'm trying to figure out the procedure with the timing chain tensioners. Having watched many YouTube videos and posts on the web I'm seeing a pattern where if the tensioners are not properly prepared and installed it can lead to poor results. The Land Rover manual has this:

Other articles talk about clicking sounds, pushing the piston below the body of the tensioner, etc. Also, there are posts that talk about applying pressure to the guide when the grenade pin is pulled... On the long DIY Timing Chain thread it mentions this from the Jaguar forums:

Dave Tibbs also has this to say about the chain guide and tensioner that I think is a critical step.
- The Jaguar service manual is specific about a step I've seen other guides miss: after pulling the pin out of the tensioner to release the tension, you need to push on the tensioner blade enough for the tensioner to hit the ratchet stop - if you can push the tensioner back in, you haven't got it yet.
- When pushing on the tensioner blades in order to allow the tensioners to hit their ratchet stop, the service manual states to use considerable force - they are not ****ing around here. In the end I had to lever it hard with a socket extension bar in order to get it to ratchet. The "click" isn't as audible as the service manual implies, but you'll know when it's done as you won't be able to push the tensioner blade back.

I'm curious if others can shed some light on this procedure as details are a little sketchy. Here's the most comprehensive video I found, does this stack up with peoples experience?

https://www.youtube.com/watch?v=AgkDu4Y1A7w

Here's the Jaguar video:

https://www.youtube.com/watch?v=OdOgMGzLGeg

Thanks, Longtrail

 

[Longtrail]

Any thoughts folks? Anyone done this and have a good story to tell?

 

[Longtrail]

I ended up pulling the grenade pins before installation, then using some channel locks (per the video above) to squeeze it back in again. One of the tensioners with the grenade pin removed was very tight initially (I used a vice to get it moving); the tensioner pin then rachets back in. To reset the tensioner pin you have to squeeze it all the way back in (using a nut to get it below the face of the tensioner) and then it's "springy" again, here as some images:

Pin removed and tensioner at full extension:

On the way back in:

Further back in but just prior to the point where it's springy again (the face of the tensioner has to go in even more than shown):

When I installed the tensioners and pulled the grenade pin I was pulling the chain guide away from the tensioner and heard a nice snap as it released on to the chain guide.

 

[dlimanov]

are they not pre-primed from the factory? what’s the purpose of the procedure?

 

[ktm525]

i think he pulled the pins before install? Or pulled the pins before the chain/tensioner was proper.

 

[Rover Range]

are they not pre-primed from the factory? what’s the purpose of the procedure?

There's no oil in the tensioner, from the factory.
The internal spring mechanism is locked and loaded, until you pull the pin.

 

[Longtrail]

are they not pre-primed from the factory? what’s the purpose of the procedure?

I believe they are pre-primed but that's also why I was asking the question, go back to the original post and see what I posted from the workshop manual; they spell out this procedure but it's not clear to me why??? I did it anyway!...

 

[Longtrail]

i think he pulled the pins before install? Or pulled the pins before the chain/tensioner was proper.

I did but only because the manual says to do this; I wouldn't have pulled the pins unless told to do so. I understand that it's easy to accidently pull the pins during installation but that wasn't the case for me.

 

[Longtrail]

There's no oil in the tensioner, from the factory.
The internal spring mechanism is locked and loaded, until you pull the pin.

Correct, but why the procedure, do you do it when changing the chains?

 

[Rover Range]

You absolutely don't pull the pin, until everything is assembled.