Saturday, January 15, 2011

Timing Belt Changes

Sooner or later every car owner is faced with the timing belt dilemma and when to replace it. It takes a mechanic a good 4 hours to replace a timing belt ($35) and a water pump ($75) and his labor @ $100 hr, so an easy $500 job at least. The other question is time or mileage more important? suppose you have a car that is 20 yrs old like the Capri, yet the miles are only 60k. That means it has been driven very little per year. But time does erode and corrode engine parts even if not driven much, belts become rigid, crack and metal rusts if not maintained. Even driving a car only a few miles a day lubricates your car so that it remains in good shape. Just parking it will ruin it over time.

Capri recommends you change the timing belt at 100K in the manual, yet, others seem to think at 60K or 80K. On average, the service manual presumes you have the car and drive it 10K at least per year and in 10 yrs, it will be 100K, time to change the water pump and belt (like Subaru Outbacks). Belts are well made and made to last 10 years if in operation. The bottom line is that if your timing belt has obvious wear and cracking in places, it is a good time to pay the cost. Since most cars have the water pump in the same location, might as well do that also, otherwise, you will bear the costs twice.

The good news is that the Capri engine is non-interference. So, if you are driving and the car suddenly just dies and you glide off to the side of road, the belt probably broke. Since the motor is non-interference, that means no damage should occur to the engine, the pistons did not clash with the valves and vice versa. So, no worries there.

Changing the belt is made long and hard because of the lack of space in the Capri engine area and because so many things need to be removed and set aside just to really do the job. For the DIYer, expect the job to take longer to do both items and you will have a sore back unless you have a lift.

Parts to buy in advance

Timing Belt
Valve Cover Gasket
Front Crankshaft Seal
A tube of High Temperature Silicon Sealant
Accessory Belts (optional)
1 gallon of Anti-Freeze (optional)
Woodruff Key (optional)
Camshaft seals (optional)
Check for leaks and replace them if necessary.
Water pump (optional)

What to Do

Drain the coolant
Remove all things that would prevent you from removing the valve cover.
Remove the upper radiator hose
Remove the two water hoses connected to the thermostat housing.
Optional: Remove the cooling fans and the radiator. This will give you a lot more room to work. Disconnect the lower coolant hose from the radiator (accessible from the trap door on the debris shield underneath) and remove the two upper bolts holding the radiator in place. Lift out the radiator and carefully put it aside. Be careful not to damage the cooling fins on the radiator. The are easily distorted.
Note: If you lift out the radiator, the fans come with it and you save yourself a bit of hassle trying to loosen up those 8 corroded bolts that bolt the fans to the radiator.

Remove the A/C belt
Loosen the tensioner bolt, pivot bolt, and lock bolt on the power steering housing until the belt can be slipped off.
Optional: Disconnect the ignition wires from the plugs.
Remove the spark plugs. This will make it easier to turn the engine later.
Optional: Remove the Valve Cover and oil dipstick. You do not need to remove the valve cover, however, if the oil dipstick does not come out, access is more restricted.

Set engine timing to TDC on #1 cylinder.
Crack the 3 bolts holding the water pump pulley on before loosening the belt. If you do happen to remove the belts before loosening the water pump pulley bolts, you can hold the pulley in place by wrapping the belt back around the pulley and holding it tightly, as close to the pulley as possible.
Remove the alternator belt.
Loosen the alternator tensioner bolts. The bottom bolt can be difficult to get to.
Remove the water pump pulley.
Remove the accessory belt pulley from the crankshaft pulley. Remove the crankshaft timing belt and related items
Remove the upper, mid and lower sections of the timing belt cover.
Remove timing belt tensioner spring.
Loosen timing belt tension pulley. Put car in neutral.

IMPORTANT: MARK TIMING BELT WITH WHITEOUT\CHAULK FOR ROTATION DIRECTION BEFORE YOU REMOVE IT!

Using a suitable socket, rotate the crankshaft pully clockwise two complete turns. (The transmission should be in neutral for this.) Continue rotating until the "E" (exhaust)mark on the right camshaft pulley lines up with the "E" mark engraved on the cam dust cover and the "I" (intake) mark on the left camshaft pulley lines up with the "I" mark on the head. This must be exact.
Before removing the old belt, count the teeth/spaces between all the points that the belt touches on the 3 wheels. Next, mark the starting "space", and ending space on both the belt and cams. This is easily done with some WhiteOut. Remove the belt. Transpose the marks from the old belt onto the new belt, and count the spaces to make sure that they are correct. Finally, match the new marks on the new belt with the marks on the cams/crankshaft.
Inspect the timing belt tension spring, it should be 2.3" end to end. If not replace. Check the tension idler wheels. They should be free to spin, if not replace.
The crankshaft woodruff key should be used to align easily the marks on the belt with the E and I V-notches on the rear plate. Make sure to also align the crankshaft pulley at the bottom with the timing mark on the engine block. All three must be perfectly aligned.
With old belt removed, tighten tension pulley with spring fully extended. Then, install the new belt. Keep tension on the opposite side of the tensioner as tight as possible while all marks are exactly matching. CAUTION: Do not rotate the belt counterclockwise.
Clamping the cams in positions aids the solitary mechanic in reinstalling the belt by 'locking' the cam wheels into position.

Place Cresent wrench on each cam at the bolt-shaped section of the cam between the #1 and #2 lobes. Position wrenchs such that they overlap and C-clamp them together to hold camshafs in position.

Inspect and Replace the Front Crankshaft Oil Seal also, replace if needed. Replace cam seals, if needed.

Install crankshaft timing belt pulley retainer and bolt. Then, turn the crankshaft two full turns and check for alignment of the three wheels (the two overhead cams and the camshaft). If not aligned, remove the belt and rest time.
Loosen tensioner pulley bolt to allow tension spring to tighten bolt. Tighten tension pulley retaining bolt and rotate engine two full turns again to ensure the timing marks are spot on their marks (E, I, timing mark).
Measure the timing belt tension between the camshaft pulley. Deflection should be between 8.5-11.5 mm.
Now, reinstall the three timing belt covers.
Install the crankshaft damper, pulley and support plate then tighten retaining bolts. Install water pump pulley and tighten bolts. Install the generator and power steering belts, dipstick and spark plugs\wires.
After everything is back together, start engine. If it runs poorly or had poor compression, the timing belt is NOT exactly on the E, I and Timing V-notches. If this is the case, you'll have to take all apart again to fix!

2 comments:

Anonymous said...

excellente info ,thank you much

Grant Duffield said...

Great write up! I am getting ready to tackle this project in the coming weeks. TeamCapri.com has some good info concerning Capri maintenance and the like, as well.
Thanks Again!