Timing Chain - Rattles/Chatters
CATEGORYEngine
SECTION
2
PAGE
30
ISSUE
05/93-0330
CODE
215
Subject:
Changing the Timing Chain: Engine In Vehicle
Application:
900, 9000 1985-
A worn timing chain can result in a customer complaint of chain rattle and/or chatter. Fluctuations in timing may also occur on cars with an EZK (TZ59) ignition system, which can cause driveability or detonation complaints. When the chain wears and stretches, the chain tensioner compensates for this at the ratcheting mechanism allows movement in this manner. Should you have a customer complain of chain noise, the chain can be replaced with a service chain developed for this purpose. Follow the Action outlined below.
In order to replace the chain with the engine installed in the vehicle, the chain guides and camshaft sprockets must be in good condition. Inspect both items with the chain tensioner and camshaft cover removed prior to performing any additional work.
Cars Affected:
900 1985-
9000 1986-
Parts (Figure 1):
Timing Chain Replacement Kit 83 94 678
(Consists of: Holder for chain (Fig. 1-1) 83 94 652 (over camshaft sprocket) Assembly tool for chain riveting (Fig.1-2)83 94 645 Chain breaker (Fig. 1-3) 83 94 637 Chain link (Fig. 1-4) 83 94 660)
Chain (2.0L) 75 00 697
Alternative chain, open with link 93 21 837
Chain (2.3L) 74 83 761
Alternative chain, open with link 1993- 93 21 845
Action:
1. Disconnect the battery terminals.
2. Remove the ignition discharge module (IDM) if so fitted, spark plugs and camshaft cover. Place shop rags in the cylinder head to prevent debits from entering the engine through the spark plug holes.
3. Align the crankshaft and camshafts with their respective timing marks. Lock the flywheel in place using special tool P/N 83 92 987. See Figure 2, A & B.
3. Check the timing chain for wear by removing the chain tensioner plug with spring and locating stud (plastic) and then removing the chain tensioner. Do NOT change the position of the plunger.
Under no circumstances should the chain tensioner extend by more than 11 mm. If it exceeds this measurement, the chain should be replaced. The tensioner does not need to be replaced. See Figure 3-A.
NOTE:
On 900 models the AC compressor must first be removed. On 9000 models equipped with a B234 engine, the power steering fluid reservoir must first be removed. On all 9000 models the torque stay must be removed.
4. Inspect the sprockets and chain guide for wear.
The surface between the outer grooves of the chain guide should not indicate any contact marks. If this surface does show signs of wear, the guides will also have to be replaced (see Figure 3-B). In that instance, the repair will have to be carried out in the usual way (i.e. engine out of car).
If the wear on both the sprockets and guides is acceptable, replace the chain as described below.
5. Cover the surrounding area of the chain with cloth. Secure the chain on both sides with tie straps. See Figure 4.
6. Separate the chain by pressing out a link with special tool P/N 84 94 637 and then use a pair of pliers to remove the link. See Figure 4.
7. Using chain link 83 94 660, join the new chain to the old. Be careful to prevent the chain from failing down and becoming entangled. See Figure 5.
8. Make certain that the new chain is properly positioned around the camshaft sprocket on the inlet side and fasten the end to the old chain.
NOTE:
On 1987 and earlier cars, remove the oil pipe.
9. Fit chain support 83 94 652. Remove the protective cloth and tie straps. See Figure 6. Remove the flywheel locking tool from Step 2.
10. Holding the old chain in your hand, with the new chain resting over your hand, carefully install the new chain by rotating the engine with the crankshaft pulley bolt wrench (P/N 83 92 961).
NOTE:
To avoid the chain from doubling over at the crankshaft, be sure to keep it under tension the entire time as it is installed.
11. When the new chain has been installed so that only a few links are still resting on the camshaft sprocket on the inlet side, protect the area surrounding the chain with a cloth. Remove the old chain link and chain. (See Figure 7).
12. Using a chain link, join the ends of the new chain together and pull the chain around until the link is midway between the legs of the chain support. See Figure 7.
13. Remove the chain link and fit a new chain lock.
Check that the inserts marked with a "2" are fitted in the tool. Then, place the plate of the chain link in the tool and fit it over the link on the chain.
Press the plate in place with a force of 10 N-m (7.4 ft.lb.).
See Figure 8.
14. Reverse the insert in the press tool and position it with the V-notch straight above one of the pins of the link.
Using the press tool, peen overthe end of the pins using a force of 15 N-m (11 ft.lb.).
Repeat on the other pin of the link.
15. Check the riveting by using a micrometer to measure the diameter of the chain link pins. The correct measurement is 3.4-3.6 mm. See Figure 9.
Remove the protective cloth. Remove the chain support, and if previously removed, fit the oil pipe (where applicable) connected to the cylinder head.
17. Fit the chain tensioner as follows:
a. Prepare the chain tensioner for mounting by pressing down the ratchet and pressing in the plunger.
b. Fit the chain tensioner and seal. Tighten to a torque of 63 N-m (47 ft.lb.).
c. Place the spring and locating stud (plastic) in the hole in the chain tensioner.
d. Fit the plug.
Check that the O-ring is in place.
Tighten the plug to 22 N-m (16 ft.lb.).
As the plug is being tightened, the spring presses out the tensioning arm and causes the chain to be tensioned.
See Figure 10.
18. If the AC compressor, power steering fluid reservoir and torque stay were previously removed, replace them. Turn the engine over one revolution and check to see that the crankshaft and camshaft are lined up with respective timing marks.
19. Fit the camshaft cover, spark plugs and ignition discharge module (if previously removed).
20. Reconnect battery terminals.
Warranty Information:
For warranty repairs where the chain has not broken, time allowances are:
Model Operation No. Time Allowance
900 All 21531 1.9
9000 All 21531 1.5
Note:
Add comment in your 9000 Failure Code/Flat Rate Manual on pg. 2-11 that operation nos. 21521, 21526, and 21527 only apply if chain has broken. Make a similar note in your 900 Failure Code/Flat Rate Manual on pg. 2-15 about Operation Nos. 21532 and 21521.
Add Labor Operation Number 21531 to your DCS Labor Op. Table. Beginning year is 85 and ending year is 99. Transmission code is 8 and engine code is 1. Description is "R & R Timing Chain (In-Car)".