S4-on-your-back-door

TB AT 45* I desided to change my TB after I notice that the TB was riding back and forth on the driver side cam sprocket and was close to the end on the passanger side.The previose owner had the TB change but did not fill the tensioner with oil(new boot thow). After tearing in deeper i notice that they didnt change the pulleys or changed the water pump but all cams look good(he must hav been on a buget) So my question is this, I set my crank at 45*and locked it, I didnt check to see if i was at BDTC i just turned it to 45*and locked it. I marked my cams and took off the belt. Did I mess up? Also the belt that was on the car was good as new but this belt has the indentation on top of the teeth. The belt I have doesnt, which belt is the newer design, both are contin. belts? 87s4 auto 104,000mls

dr bob

The difference between TDC-45 on the #1 compression stroke and TDC-45 on #1 exhaust stroke is the position of the cams. If the timing belt was done before, there should be easily identifiable marks for the TDC point (notches in the back of the can gears) and the 45 degree point (maybe paint or other mark). With the crank locked at either -45, you can spin the cams safely to get them to the right positions.

S4-on-your-back-door

so im ok then? just route the TB and make sure my cam marks line up with notches and put some tension on the belt and turn a few time to make sure everything is lining up rite?

pmotts

Yo make it sound so simple but yeah, that's it pretty much. Of course your notches won't line up at 45. When at T/O how well were they lined up?

S4-on-your-back-door

T/O? at TDC drivers side was dead on passanger side slightly off to the left. At 45* I just locked and marked, the cams at the notches pretty strait forward on that.

docmirror

You took off the cam covers, and actually marked the camshaft in relation to the cam journal cap? I think what you meant is that you marked the cam PULLEY, not the shaft. If so, then yes, you just route the belt from the crank, around the oil pump and up over the left pulley, then the WP, then the right pulley, tensioner, rollers, etc. Follow the marks you made as you disassembled. Load the tensioner with the right lube, and tension it up some. Remove the lock, and turn it to 0 TDC. check the pulleys for tick marks on the pulley lining up with the backing plate, and then roll it around a few times to verify your work. Retention and put all the stuff back on the front of the engine.

The belts for that year must be the HTD (high torque design) type. The tooth will be rounded, almost half moon shaped. Some HTD belts have a small divot in the center of the tooth, and this is a more modern belt. While it's apart, check the quality of the pulleys. At your mileage they should be okay, but it's best to check for discolored area of the pulleys, or a clear indication of depression of the ridges, leaving a semi-sharp ridge rather than a smooth half-moon mating surface for the belt.

Doc

S4-on-your-back-door

Thks Doc, yes i checked the pulleys and there all A-OK. This is my first TB change and beleive it or not I was removing the belt in just over a half hour( it helped that i had already removed fan shroud)since TB was done before, the damper and crank pulleys just slid rite off (easy as eating pie).

pmotts

OK, the PS side is slightly retarded. It would interesting to see a pic to compare how much.

dr bob

Is it retarded a whole tooth? If so, just loosen the belt and walk the belt back over the gear as you put a little rotational force on the bolt holding the gear on. Retension and test again.

S4-on-your-back-door

just 1/2 a tooth if that not sure on how to take pic and post.

dr bob

This is a tough call. The belt will only stretch with time. Seems they never shrink... So the temptation would be to advance the cam gear to end up with half a tooth advanced, then let the belt stretch and the cam to go back slightly. Before doing that though, I'd carefully inspect the paint on the cam covers. Flakey cam cover paint is a critical factor in the next decision. If the paint is tired or flakey, the covers come off, the cams get indexed with a dial indicator, the covers get painted, new gaskets go on, maybe new polished or plated bolts, etc. Surely you can see how cam cover paint condition affects engine performance. It's an indirect path, I'll be the first to admit.

I was thinking about using that Wurth silver wheel paint, followed by a few passes with the clear, to index my cams just right.

S4-on-your-back-door

Ive painted covers red to matck red lettering that i had powder coated intake and valve covers are in silver, looks good

Mrmerlin

Hi Bob, I might like to offer this, if you try the clear coat there is a small chance that you might end up with yellow cam covers depending on the amount of clear that you use, once the clear gets hot a few times it seems to start yellowing, for a test try spraying a section of the cam covers you have with the coatings you want to use and try it like that for a while , if your going to get the cam and intake recoated i would suggest a single color system no clear that also goes for using the powder coat, as one other lister has also noted, that their intake and covers have now turned to yellow after being powdercoated and cleared, I have seen the paint clear coat turn yellow as well after a few heat cycles FYI. Stan

S4-on-your-back-door

hey bob question, while replacing my timing belt (belt is already on) i tried to advace the cam so that the hash mark on passager side would line up ( off by half a tooth) this was done with belt tensioned. I know that it wouldent work( the cam wont move unless i moved crank ) and i dont know why i treid dou. anyway i loosen the cam bolt and clunk valve hit the piston at TDC, this happened twice. question is i dont believe that valve spring pressure is strong enuff to have bent a valve or is it?