A/C Tensioner Studs

1986 328

Working on belts for the first time and trying to get the compressor out of the way. As others have mentioned, the A/C belt tensioner bracket studs get in the way of siding the compressor out and to the side... You can see I have a double nut (green circle) and have used a bit of force but it's not giving up... Just checking this is the best way to deal with this... I sprayed some penetrating oil and plan to let it sit overnight.

Am I just not giving it enough force or is there something else at play?
View attachment AC-TensionBolts.pdf

 

Now with a photo that should render itself automatically.. No green circle but you can see the stud with the double nut... Not turning.... Imagine the photo turned 90 degrees clockwise..
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They can be stubborn. You might need a proper stud puller. Don't ruin the thread, that stud is not going to be available at Home Depot.

 

Put a bit of gentle heat on the nuts and then let it cool down- then try wd 40 or similar. The steel stud is in the alloy and can get a bit corroded, the heat should help.
It is generally a good idea to use a nickle based grease on the threads where alluminium and steel meet- you caa find it on amazon or e bay.

 

I used a stud extractor and replaced ALL of the studs with measured length bolts . It mad the next belt service easy. Just an FYI

 

The compressor will come out with all the studs removed but it is tight. I would take some time and work on the stud. It has to be able to come out. My last belt change took 4 weekends and hurt like hell.

 

By the way, I only needed to remove that one stud from the engine for the compressor to swing out of the way. You do have to remove the the timing belt cover and the crankshaft pulley to make more room.

 

A stud is a superior clamping device. I once had an engineering professor tell me,"a bolt is an accountants decision, a stud is an engineer's decision".

 

All that is true, until you run out of space...

 

What I didn't mention was I used an adjustable bracket with a sanyo compressor and eliminated the Ferrari belt adjustment pulley system. I also replaced all of the studs that hold the belt covers with bolts . A stud is a cheap substitute for a good bolt. This from a mechanical engineer.

 

If you use a stud and get too aggressive, usually all you strip is the threads of the nut or on the stud where the nut is turning. If you use a bolt and get to aggressive, you will strip the aluminum timing belt cover in this case.

 

I think you have it backwards. But I am just an Electric Engineer.

 

I guess that's why we use torque values.

 

On my '83 I spent quite a while trying to get the York compressor to swing out of the way. One stud was in the way for like 1/2". I could not get the stud out. I've never seen a stud extractor, so I was using two nuts but with reserve as I didn't want to snap it off. I Finally gave up, buttoned it up & took it to a Ferrari mechanic who used the same technique as I but with more oomph and got it out.

 

Initial torque is meaningless after years of possible corrosion...torque value is for proper assembly, not to make it easy to remove...

 

Regarding the stud vs. bolt discussion. No matter bolt or stud. For repeated loosening and retightening, the thread in the aluminium should be reinforced. For example with Helicoil.
On my late carb engine the timing belt cover of the rear cylinder head is fitted with bolts instead of studs. And there are Helicoils in the heads.


Best Regards
Martin

 

Torque values are not the issue, it is still much easier to strip aluminum with a bolt than a stud. Your putting the load on the cam belt cover/thread interface with a bolt rather than between the nut and stud threads with a stud. Better get you a box of helicoils or threadserts.

 

Got all three studs out.. Used heat gun and tapped the studs lightly with end of a wrench.. On the long studs where the threads are deep, Im not sure the heat did much but maybe it traveled up the stud....

But, I have still run into space issues. Indeed still having trouble swing it around. One obvious issue is the alt belt still on. Without taking the tensioner brake off, can't pivot the alternator enough for the belt to clear the pulley. Thought that would be easier after getting compressor out of the way, but probably a testament to my intelligence.. : ) With the alt belt out of the way, MAYBE I can clear the gas tank and water pump, but it's very tight..

I think I recall Rifledriver stating that he knows of no production minded shop that does not remove the compressor.. Even if I wanted to I can't find someone locally that works with R-12... Drain or re-fill... Im sure you guys here that are experts must get some laughs out of us first timers...

 

I'm sorry telling you this. I ran into the same problems many years ago. In times when was not so easily available like today I asked Mike Elliott, the former owner of Superformance in the UK. And he told me that I had to remove the studs on the compressor as well.
This is a major PITA, but actually worked.
What do you mean with 'tensioner brake'?

Best from Germany
Martin

 

I didn't have a working system so when I did my 1st belt service I removed the compressor. I did the usual conversion to 34 along with a new sanden compressor. All of the future belt changes I just dumped the freon and pulled the compressor. Re-installed and re-charged the system.

 

Probably the best solution. Cost of a recharge is not worth the pain of trying to get the compressor out of the way with the hoses attached.
At least me will never to it again.
The only reason I did that once was, because shortly -a few weeks- after a A/C recharge my waterpump failed. And on early carb cars you have to go through the whole dismantling job like for a timing belt job.

Best Regards
Martin

 

Oh I didn't mention but I modified my (77) timing belt cover so I didn't have to remove it when my WP went. Read and learned about it on this site years ago.