need opinions, chain tensioner upgrade

[Andy911sc]

Alright guys, I don't know who all has been following the resurrection of my 1982 911sc from a 16 year garage slumber.

I talked to my mechanic yesterday to get ready for sending the car to him for state inspection, ride height adjustment/alignment and some other checks.

He just brought to my attention about the chain tensioner upgrade. Unfortunately I am at the end of my budget with everything. So here is my dilemma.

Either A)let the car sit for a few more months (it's also summer and I would like to drive it) and get the upgrade or B) can I get away with the tensioner safety gaurds that I read about which is a 28 dollar a piece part from automation.com and use them this summer as a safety net/insurance plan (just in case) and upgrade to the tensioner kit this winter when I have more of a budget back.

If I go with choice B, I would be getting new chain rails and all while I am in there.

[Grady Clay]

Andy (Andy911sc),

Go with “Plan B”.
There are Factory ‘rebuild kits’ (a complete set of seals and pieces) for your tensioners.
Install the Jerry Woods Ent. ‘safeties’.
Install new chain ramps.

‘While you are there’, inspect the chains for ‘stretched length’ (you can replace them with ‘split-link’ chains if necessary.
Inspect all the sprockets.
You can (should?) replace the two cam oil lines.
This is a good opportunity to check the cam timing.

I’m in favor of rebuilding the earlier (‘Turbo’) tensioners compared to installing the more complicated (Murphy is in charge) ‘Carrera’ tensioners that are no more reliable.
The only significant ‘improvement’ is the Carrera tensioner can continue to be driven while failing (it refills with engine oil).

Best,
Grady

[Andy911sc]

Grady,

Thanks, this helps my decision a lot. I tried to look on PP for the rebuild kits. Do you know where I could find them? I did notice that PP has the guards for less than automation.com.

Also thanks for the recommendations on inspecting everything and replacing the chain rails.

Andy

[ajwans]

Google for 911-105-901-01 that's the kit part number. Equally important, check that you have the wide idler arms in there. If you have the spacers between the tensioner and the idler arm then find a set of wide arms.

andy

[Andy911sc]

Thanks, does anyone have information on rebuilding the tensioners.

[Jim Richards]

Originally Posted by Grady Clay

Andy (Andy911sc),

Go with “Plan B”.
There are Factory ‘rebuild kits’ (a complete set of seals and pieces) for your tensioners.
Install the Jerry Woods Ent. ‘safeties’.
Install new chain ramps.

‘While you are there’, inspect the chains for ‘stretched length’ (you can replace them with ‘split-link’ chains if necessary.
Inspect all the sprockets.
You can (should?) replace the two cam oil lines.
This is a good opportunity to check the cam timing.

I’m in favor of rebuilding the earlier (‘Turbo’) tensioners compared to installing the more complicated (Murphy is in charge) ‘Carrera’ tensioners that are no more reliable.
The only significant ‘improvement’ is the Carrera tensioner can continue to be driven while failing (it refills with engine oil).

Best,
Grady

I did just as Grady recommended when I rebuilt my former '73 911E's 2.7RS-spec engine a few years back. At the time, a significant number of people were having problems with their Carrera tensioner "upgrades," so I opted for the 930 tensioners + safety collars.

[Grady Clay]

Originally Posted by Andy911sc

Thanks, does anyone have information on rebuilding the tensioners.

I recall the Factory kit comes with instructions.
There are also instructions in the 911 ('72-'83) Factory Workshop Manual, Vol. I, Section 1, p.p. 5.1-2/5 and 5.1-2/6.

You will find the exploded diagram in PET (Porsche's on-line or CD parts manual) helpful.

Best,
Grady

[ajwans]

Originally Posted by Andy911sc

Thanks, does anyone have information on rebuilding the tensioners.

John Walker did a nice description here.

andy

[Andy911sc]

Thanks guys. This is going to save me a boat load. Now I can do the work and I have a spare $200 in the budget yet. If I will need to use all that. Just guestimating.

One final question: Looking at it, I think I can manage doing this without dropping the engine. What do you guys think?

[Grady Clay]

No need to drop the engine.

Remove the muffler.
Support the engine and remove the two rear engine mount bolts.
Carefully drop the rear of the engine a couple of inches – check the position of fuel lines, oil lines, breather hoses, wiring harness and everything else between the engine and chassis.
Do NOT stress anything.
Remove the rear (tin) pan.
The oil-out pipe will be in the way but you can disconnect the support strap and maneuver past it.
You may need to take the engine mount assembly off the engine to get to one of the chain ramp bolts (I don’t remember).
The chain covers are now accessible.

The important ‘hazard’ is having the engine suddenly drop while you are trying to ‘inch-it-down’.
Use an adjustable jackstand or something to prevent this possibility from stressing the hoses, etc.

You will find the muffler straps and flange bolts difficult to remove. Use penetrating oil and heat.
It is best to use an oxy-acetylene torch to remove the muffler flange bolts.
Drive to a shop with three new bolts and a gasket and have someone do this for you ($10 & 6-pack).

Many remove the rear bumper for easier access but it can be done without removing the bumper.

Does anyone have something to add? It has been decades for me.

Best,
Grady

[1982911SCTarga]

I'm wondering why you feel compelled to go in right now and rebuild the tensioners?

Brian

[Andy911sc]

Thanks guys. I feel that I have been pointed in the right direction with this. I'm confident I can handle this now that I have advice from everyone with experience.

exhaust bolts are a pain, but I'll get it done. It's not my first rodeo.

I just ordered the rebuild kits from the local dealer. Their price surprisingly match that of what I found online. This also gives me a chance to inspect the engine mounting hardware and replace my lower valve cover gaskets.

If you guys are interested in seeing my resurrection and progress check it out. New to Pelican and new 911 owner

[Andy911sc]

Originally Posted by 1982911SCTarga

I'm wondering why you feel compelled to go in right now and rebuild the tensioners?

Brian

Car has been sitting in one spot since 1995. I am resurrecting it from this slumber. I just don't want any surprises and don't want to have my first drive in the car be a failure because I just ignored something. Yeah I was able to turn the engine over by hand, so I know nothing is seized up and the tensioners are doing there job, but I don't want them failing on me once I put them under load and stress at high rpm's.

[jstobo]

I have two NOS rebuild kits with old tensioners and instructions from Porsche workshop manal. I installed the Carrera tensioners instead of rebuilding mine. I'll sell them for $25 each includes shipping. Let me know.

[porwolf]

Originally Posted by Grady Clay

No need to drop the engine.

Remove the muffler.
Support the engine and remove the two rear engine mount bolts.
Carefully drop the rear of the engine a couple of inches – check the position of fuel lines, oil lines, breather hoses, wiring harness and everything else between the engine and chassis.
Do NOT stress anything.
Remove the rear (tin) pan.
The oil-out pipe will be in the way but you can disconnect the support strap and maneuver past it.
You may need to take the engine mount assembly off the engine to get to one of the chain ramp bolts (I don’t remember).
The chain covers are now accessible.

The important ‘hazard’ is having the engine suddenly drop while you are trying to ‘inch-it-down’.
Use an adjustable jackstand or something to prevent this possibility from stressing the hoses, etc.

You will find the muffler straps and flange bolts difficult to remove. Use penetrating oil and heat.
It is best to use an oxy-acetylene torch to remove the muffler flange bolts.
Drive to a shop with three new bolts and a gasket and have someone do this for you ($10 & 6-pack).

Many remove the rear bumper for easier access but it can be done without removing the bumper.

Does anyone have something to add? It has been decades for me.

Best,
Grady

Hi Grady,

you describe a partial engine drop. Does your recommended procedure mean that the transmission can stay attached as is? How about the shifter linkage etc?

[Andy911sc]

Originally Posted by jstobo

I have two NOS rebuild kits with old tensioners and instructions from Porsche workshop manal. I installed the Carrera tensioners instead of rebuilding mine. I'll sell them for $25 each includes shipping. Let me know.

I wish you would have gotten ahold of me earlier. I already ordered the ones from the dealer today.

[Andy911sc]

porwolf,

are you thinking about doing the same thing?

[porwolf]

Originally Posted by Andy911sc

porwolf,

are you thinking about doing the same thing?

Yeah, thinking, looking at all options. I don't feel I have an urgent need now with my original 50,000 miles on the 79 SC and I cannot detect any lose chain noises. I was more seriously thinking about upgrading to Carrera tensioners a couple of years ago. But then the kits were offered for $350,-. Now it is 3 times that much! So, maybe, just as a precautionary fix I could install the collars. I will probably give it more time. And since I owned the car since it was new, and I never raced it or drove it extremely hard, I guess my original tensioners have some more life in them. And for the SCs, as I read here, chains jumping the sprockets is a rare occurrence. For the time being, I will carefully watch out for chain noises. I hope I am doing the right thing.

[Andy911sc]

Originally Posted by porwolf

Yeah, thinking, looking at all options. I don't feel I have an urgent need now with my original 50,000 miles on the 79 SC and I cannot detect any lose chain noises. I was more seriously thinking about upgrading to Carrera tensioners a couple of years ago. But then the kits were offered for $350,-. Now it is 3 times that much! So, maybe, just as a precautionary fix I could install the collars. I will probably give it more time. And since I owned the car since it was new, and I never raced it or drove it extremely hard, I guess my original tensioners have some more life in them. And for the SCs, as I read here, chains jumping the sprockets is a rare occurrence. For the time being, I will carefully watch out for chain noises. I hope I am doing the right thing.

Wonder why they jumped in price so much. Yeah the collar system seems to be an ample saftey substitute over the over priced Carrera Tensioner.

Does anyone have the gap spec for between the safety collars and tensioner body?

[Andy911sc]

Originally Posted by Grady Clay

I recall the Factory kit comes with instructions.
There are also instructions in the 911 ('72-'83) Factory Workshop Manual, Vol. I, Section 1, p.p. 5.1-2/5 and 5.1-2/6.

You will find the exploded diagram in PET (Porsche's on-line or CD parts manual) helpful.

Best,
Grady

I just picked up the rebuild kits from the dealer on saturday and they didn't coming with instructions. I told them the pages you referenced above and I am still waiting to here back from them. Does anyone have these instructions handy to email me or something.