911SC Chain tensioner safety collars!

[nick3814]

Hi folks, I live in the UK and own a 1983 911SC, it has the regular chain tensioners still fitted (94,000mls) and I've been pondering over fitting the Carrera style tensioners this winter when I take her off the road for a couple of months. However I've been party to a a few conversations on UK sites about the sudden failure of these units with catastrophic results. With this in mind I have purchased a pair of safety collars from PP, a much cheaper option and piece of mind as well.
Has anyone on here fitted these recently? They seem simple enough but my problem is getting the plunger (end of the tensioner that moves back and forth) far enough out to fit the collar with the correct allowance which is a total of 9mm. I've attached a photo of one of my tensioners to show how short the plunger appears at about 4-5mm at the most.



Any advice would be great, thanks

[914efi]

I made a pair recently, very simple. I made sure that they bear on the OD of the tensioner body and not on the stamped section. I think I put extra holes in also to allow oil to flow into the tensioner, but I don't remember!

[914efi]

I found a photo, I just made a 'strap' that went across but had room on the sides for oil.

[Max2.0]

I'm wondering if your current Tensioners are a bit "soft"???

Had plenty of room on my '83SC units to install them..

[nick3814]

The photo of mine was taken last December, done a couple of thousand miles since then including a trip to Lemans without any problems, I remember when I took the photo I tried the chain for its tension and it was very stiff no flex in it so tensioners didn't appear soft?

Did you have to take the tensioners off to fit the collars or are those new tensioners you have fitted?

[Max2.0]

Hmmm....

I removed my Tensioners, fitted the Locks, and reinstalled the Tensioners.

It was tight work, but all went together in the end, and ran great...for several thou...

Then I traded the old Tensioners out for a set of the Carrera Oil Pressure Tensioners!

I am hoping there is NO catastrophic failure in my future!!!

[Scott R]

First time I tore my motor down I found one of those collars floating around inside the chain box and the other was cut by the chain. It broke right where the tiny allen screw went it, kinda useless since when the tensioner failed the chain just chewed through the collar on its way down.

[nick3814]

Its been suggested to me that these SC tensioners can be rebuilt, does anyone know how and where to get the parts?

Cheers

[EarlyPorsche]

Rebuild the tensioners using parts from this site then install the collars. I think they are far more reliable and durable than the pressure fed ones. Mechanical things with nuts and bolts are great as safety devices in an engine case as they work regardless of the engines status. The oil fed ones creep me out because I have heard of plenty of those breaking just the same.

[EASYDRIVE]

Hello Guys

I have just bought the chain tensioner collars and I am wondering if they need to be well tight to the shaft or with some play. Thanks for the help

[proffighter]

Leave about 1.5-2mm of space. The tensioner needs some movement. When I bought mines, there was a piece of aluminium included to adjust the clearance...

[alimh]

I don't know if I have this backward but I'm thinking the 1.5-2 mm gap needs to between the tip of the plunger and the safety collar. Previously I was thinking that it had to be between the top of the plunger housing and the collar. Is this correct?

[proffighter]

Here you can see the space needed:

[tazzieman]

After reading all the threads , I went the Carrera upgrade with the modification which apparently bulletproofs the system. Apparently , I guess I'll know over the next decade or so!
Limiting Travel of the Pressure Fed Tensioners

[ajwans]

Originally Posted by nick3814

Its been suggested to me that these SC tensioners can be rebuilt, does anyone know how and where to get the parts?

Cheers

911-105-901-01 Chain Tensioner Rebuild Kit

Pelican is showing these as NLA but it's been like that
for years and I have bought them from other suppliers
so they still exist.

You need 2 kits.

andy

[robertp]

Originally Posted by nick3814

Hi folks, I live in the UK and own a 1983 911SC, it has the regular chain tensioners still fitted (94,000mls) and I've been pondering over fitting the Carrera style tensioners this winter when I take her off the road for a couple of months. However I've been party to a a few conversations on UK sites about the sudden failure of these units with catastrophic results. With this in mind I have purchased a pair of safety collars from PP, a much cheaper option and piece of mind as well.
Has anyone on here fitted these recently? They seem simple enough but my problem is getting the plunger (end of the tensioner that moves back and forth) far enough out to fit the collar with the correct allowance which is a total of 9mm. I've attached a photo of one of my tensioners to show how short the plunger appears at about 4-5mm at the most.



Any advice would be great, thanks

I have same issue. right side no problem, left side not enough room.

[Coastr]

I rebuilt my tensioners and there wasn't enough room to fit them on the shafts. So I left them out. You'll know if the tensioners are getting loose when you let off the throttle and it sounds like someone rattling chains in a tin can.

[manbridge 74]

Following the factory procedure for rebuilding and bleeding gives plenty of room.

[RDM]

Like Scott R posted 12 years ago, I found a collar in my oil sump when dealing with broken head studs. Not big on this solution....

[Kraftwerk]

Years ago I bought the safety collars then hesitated to install them in fear they someday / somehow unscrew and float around the chain tensioners chains etc. Seems like adding a variable that could potentially be a negative. That was 45,00 miles ago, I no longer worry about my chain tensioners.