I have everything together to change timing belt/water pump/t-stat. I have on hand the oil seals for the cmashafts and the crank in case they need replacing. I have been un able to loacte the information to answer some questions that I have about replacing these seals. It is possible the crank seal is leaking-there is a little oil comming out the bottom of the lower belt gaurd. I will not know about the camshaft seals until I get into it. There is a lot of feedback about changing these seals, some say don't do it if they are okay and others say change them while you are there. Anyways...here are some questions I have not been able to find answers for.

Camshaft:
1. To remove the sprocket, the locking plates must be removed? Is the it held on by the camshaft sprocket bolt? After the plate is removed, how is it lined up when putting it back on?
2. If the camshaft sprocket bolt is removed, should it be replaced with a new one? Bentley says to replace many bolts once removed, in a lot of cases lock tight is okay. Is this one of those cases?

Crank seal:
1. How is this removed?
2. Do any bolts need to be replaced?

... because I don't know enough about the other stuff. I also have new cam and crank seals handy, just in case. Depending on the miles on your car, it may be a good idea to replace the seals while doing the TB, even if they are not leaking right now.

Per Audi, many bolts must be replaced each time they are removed. The reason is that bolts stretch when tightened, and the stretch is permanent. Most shops and mechanics don't give a damn an reuse every bolt. I'm very careful with that sort of thing and would replace the bolt. A stretched bolt will be impossible to torque properly.

I'll answer your questions in ALLCAPS, so don't take it as I'm yelling. :-)

1. To remove the sprocket, the locking plates must be removed? YES

Is the it held on by the camshaft sprocket bolt? YES

After the plate is removed, how is it lined up when putting it back on? ONLY GOES ON ONE WAY, JUST BE SURE THAT THE LARGER HOLE ON THE PLATE IS FACING INBOARD WHEN REINSTALLING. THIS IS FOR PROPER TIMING INDICATION (i.e. REMEMBER THAT THE LARGER HOLES OF THE L & R CAMSHAFTS MUST POINT TOWARD EACH OTHER). JUST REMEMBER WHICH SIDE OF THE PLATE FACES YOU & WHICH SIDE FACES THE ENGINE (SAME GOES WITH THE CAM SPROCKETS). ***YOU WILL NEED A GEAR PULLER TO REMOVE THE SPROCKETS*** THE TECH ARTICLE SHOULD HAVE MENTIONED THAT. BE SURE TO USE THE CRANK & CAM HOLDING TOOLS SINCE YOU'RE REMOVING THE SPROCKETS, OR YOU'LL BE SORRY. I'VE SET THE TIMING BY EYE SIGHT ALONE AFTER A BELT BUSTED, & IT'S NOT FUN. I USED FINGERNAIL POLISH (NOT MINE), & DREW A STRAIGHT LINE STARTING FROM THE LARGE HOLE SIDE OF THE LOCKING PLATE, ONTO THE CAM SPROCKET FOR REFERNECE MARKS. I DIDN'T MARK THE BOLT SINCE IT MAY CHANGE ONCE TORQUED. JUST BE SURE YOU MADE REFERENCE MARKS ON EACH CAM SPROCKET & THE CRANK SPROCKET TO CORRESPOND WITH THE TIMING BELT MARKS BEFORE REMOVING THE T-BELT. YOU'LL NEED TO MATE THOSE MARKS BACK UP BEFORE TENSIONING THE BELT & TORQUEING THE CAM BOLTS.



2. If the camshaft sprocket bolt is removed, should it be replaced with a new one? Bentley says to replace many bolts once removed, in a lot of cases lock tight is okay. Is this one of those cases? I DIDN'T, HOWEVER YOU CAN NEVER GO WRONG REPLACING ANY BOLTS. I'VE REPLACED SEVERAL OTHER BOLTS (NOT T-BELT RELATED) WITH OTHER HEAD TYPES, SIMPLY BECAUSE I DON'T LIKE ALLEN HEAD BOLTS. ESPECIALLY THE ONES ON THE CRANKSHAFT. I WANT TO CHANGE THOSE BADLY.

I'VE NEVER CHANGED EITHER TYPE OF MY SEALS, SO I'D ASK A PROFESSIONAL. HOPE THIS HELPS.

reused bolts. That is very highly illegal by FAA laws. We kept tons of old bolts locked in a large wooden box, which was locked in a supply closet. The company knew that FAA inspectors wouldn't search supply closets, so it was the proper place to conceal illegal activity. If just one would've ever been found by FAA, they would've immediately shut the entire company down. However, they're still in business today.

I don't know if there's any relation or not, but they serviced Reba McEntire's Gulfstream--before it crashed & killed all of her band members in the 90's. They continue to service John Travolta's Gulfstream, as far as I know. But he has several planes for back-up. So if John ever goes down (I don't wish upon anyone) there may be a connection. But that's all conspiracy theory hogwash. For the record: I didn't work there when Reba's plane was serviced.

reaches the yield stress of the material. The Bentley manual clear states which bolts need repalcing after removing (e.g., the front drive axle bolt). Most bolts are not tighened up to their yield stress nor do they reach the yield point under their operating loads. Engineers (such as me) usually specify bolt torques to develope 80% of the proof strength of the bolt for static applications. For the cam bolts, which are tightened to 52 lb-ft, no replacement is specified. But the center crankshaft bolt (148 lb-ft + 1/2 turn) is always replaced after removal.

... the ones mentioned in the manual. For example, I did replace the bolts that need to be losenend when aligning the car.

did you replace all the recomended bolts?

*saves thread*

I'd rather they be shut down than to have a plane full of passengers killed because one of the engine mounting bolts broke. I personally never took the risk of using old hardware.

Nevermind, I don't want to know...

;-)

I do not believe this is one of those "should be replaced" bolts as long as it's not damaged. Do make sure you apply the proper torque when refastening though!

public safety, you are requried to report it or face crimminal prosecution? I work in the nuclear industry and Title 10 of Code of Federal Regulations, Part 21 (10 CFR 21) has this requirement (under this law, I could face up to 10 years, and/or a fine up to $100K).

I heard a story about a nuclear physicist accidentally pouring a liter of highly radioactive material down the drain and into SF Bay (in the '70s). I trust the person who told me this, and he said there was no way this story would have ever seen the daylight and it was all hushed up, with people in the know fearing for their lives.

They aren't exactly tightened a lot, and I don't think they'll stretch permanently.

I'll replace head bolts, and flywheel bolts after 1 use. Plus any other bolt which looks like it should be replaced! ;O)

This may be a broad stoke of a specific instruction on fastener replacement.
I have held an airframe repairman ticket since the early '80's, and have not been aware of any FAA mandate that suggests removed bolts are catagorically unsuitable for reinstallation.
Every approved repair on an aircraft has it's instructions. And all modifications and repairs must be done in an approved manner. If the specific instructions say to not reuse the fasteners, then DON'T. Otherwise a certain amout of common sense prevails even in the aviation industry.

Regards

CalG

I'll add my $.02 here on the camshaft bolts:

1) I'm a firm believer in replacing bolts/nuts/whatever when the book says to. I've seen what happens when these bolts don't get replaced; not a pretty picture. There are plenty of people who will say "I've re-used them plenty of times, and look at me" ... That's fine, but I'm not a lucky person :)

2) Whenever you see a bolt that says "tighten to XXX torque plus 1/2 turn" it's the kind of bolt you want to replace.

3) The camshaft bolt is the exception to that. It doesn't get exceptionally tight (just 30Nm) and the extra 1/2 turn is just to push the sprocket on to the taper on the camshaft. Just use the camshaft holding tool (3243) or you'll never get the torque right.


The only other note on the camshafts is that you're supposed to remove the two inner bearing caps before removing the outer caps if you take the camshaft out. And MAKE SURE YOU PUT THEM BACK IN THE SAME PLACE AND ORIENTATION. That's so important they draw a box around it in the manual. When you put them back on, tighten the outer two first in an alternating diagonal sequence, then the inner two (installation is ... opposite of removal)

There's also a huge difference between maintaining commercial aircraft and privately-owned aircraft. The FAA requirements for maintenance basically say to follow manufacturer's instructions to the letter - then they have safety requirements for the manufacturer. Obviously things aren't always perfect, so we get airplanes like the MD Flying Death Trap (formerly the MD-80, currently the "Super" 80 ... either way I wouldn't fly in one).

Maintenance of commercial aircraft generally has a great deal of oversight that even people who are involved don't always know about. An NTSB investigation into an incident involving a commercial airliner is an amazing thing to watch. The intensity of such an investigation keeps you pretty safe in terms of ending up at the bottom of a river at your employer's behest, but if you screw up and (for example) an AirTran 737 skids off a runway, your workplace will be pretty miserable until you decide to find another job.

There's not the same level of oversight on privately owned aircraft because if one of those goes down there's not the same risk of adverse economic impact - the US economy depends heavily on air travel, and if people are afraid to fly because the constantly hear about airplanes dropping out of the sky, that's trouble.

Well, I don't know his address, but I did notify the local FAA office anonymously. I never heard anything after that.

I sent an anonymous tip. It was pre 9/11, so things were kinda lax. That's still no excuse.

The owner of that company, & several other companies (including a cement & construction company, which BTW built that very airport) supposedly has close ties to some good "fellas" in Chicago. So, that's not a far-fetched scenario. Last I heard, they were going to merge with Lufthansa. The owner also owns an F-5 fighter jet (along with a few other personal corporate jets) that he bought from Israel. He flew it into our airport while still commissioned for military service. In other words, he was packin' heat. He got a slap on the wrist by the FAA & local airport authority, & his new toy was stripped of it's goodies immediately & grounded. He paid an undisclosed hefty fine, which doesn't matter since he's on Forbe's top 200 richest men in the world list every year.

engine mounting bolts on the fixed cowls. Those were specifically prohibited to be reused after an overhaul. At least according to Rolls Royce.