Mechanics

TIMING CHAIN INSTALATION

2002 Jeep Cherokee

Engine Mechanical problem
2002 Jeep Cherokee V8 Four Wheel Drive Automatic 149, 00 miles

I am trying to reassemble this cherokee for a friend and need the timing chain diagram.I did not tear this down and really have very little jeep exsperience. I have been a tech for 10 years with toyota and GM not real fond of jeep please be a life saver.
This is a 2002 jeep grand cherokee with a 4.7 v8
AD
Avatar
John baer
October 19, 2008.



See below


http://www.2carpros.com/forum/automotive_pictures/12900_tc2_1.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_tc1_1.jpg


Rasmataz
Oct 19, 2008.
To install:

Using a vise, lightly compress the secondary chain tensioner piston until the piston step is flush with the tensioner body. Using a pin or suitable tool, release ratchet pawl by pulling pawl back against spring force through access hole on side of tensioner. While continuing to hold pawl back, Push ratchet device to approximately 2mm from the tensioner body. Install Special Tool 8514 lock pin into hole on front of tensioner. Slowly open vise to transfer piston spring force to lock pin.

Position primary chain tensioner over oil pump and insert bolts into lower two holes on tensioner bracket. Tighten bolts to 250 inch lbs. (28 Nm).

WARNING
Over-tightening the tensioner arm Torx ® bolt can cause severe damage to the cylinder head. Tighten bolt to specified torque only.

Install right side chain tensioner arm. Apply Mopar ® Lock N, Seal to Torx ® bolt, tighten bolt to 150 inch lbs. (17 Nm).
NOTE
The silver bolts retain the guides to the cylinder heads and the black bolts retain the guides to the engine block.

Install the left side chain guide. Tighten the bolts to 250 inch lbs. (28 Nm).
WARNING
Over-tightening the tensioner arm can cause severe damage to the cylinder head. Tighten bolt to specified torque only.

Install left side chain tensioner arm. Apply Mopar ® Lock N, Seal to bolt, tighten bolt to 150 inch lbs. (17 Nm).

Install the right side chain guide. Tighten the bolts to 250 inch lbs. (28 Nm).

Install both secondary chains onto the idler sprocket. Align two plated links on the secondary chains to be visible through the two lower openings on the idler sprocket (4 o’clock and 8 o’clock). Once the secondary timing chains are installed, position special tool 8515 to hold chains in place for installation.

Align primary chain double plated links with the timing mark at 12 o’clock on the idler sprocket. Align the primary chain single plated link with the timing mark at 6 o’clock on the crankshaft sprocket.
Lubricate idler shaft and bushings with clean engine oil.
Install all chains, crankshaft sprocket, and idler sprocket as an assembly. After guiding both secondary chains through the block and cylinder head openings, affix chains with a elastic strap or the equivalent, This will maintain tension on chains to aid in installation.
NOTE
It will be necessary to slightly rotate camshafts for sprocket installation.

Align left camshaft sprocket “L” dot to plated link on chain.

Align right camshaft sprocket “R” dot to plated link on chain.
WARNING
Remove excess oil from the camshaft sprocket bolt. Failure to do so can result in over torque of bolt resulting in bolt failure
.
Remove Special Tool 8515, then attach both sprockets to camshafts. Remove excess oil from bolts, then Install sprocket bolts, but do not tighten at this time.

Verify that all plated links are aligned with the marks on all sprockets and the “V8” marks on camshaft sprockets are at the 12 o’clock position.
WARNING
Ensure the plate between the left secondary chain tensioner and block is correctly installed.

Install both secondary chain tensioners. Tighten bolts to 250 inch lbs. (28 Nm).
NOTE
Left and right secondary chain tensioners are not common.

Before installing idler sprocket bolt, lubricate washer with oil, and tighten idler sprocket assembly retaining bolt to 25 ft. lbs. (34 Nm).

Remove all locking pins from tensioners.WARNING
After pulling locking pins out of each tensioner, do not manually extend the tensioner(s) ratchet. Doing so will over tension the chains, resulting in noise and/or high timing chain loads.

Using Special Tool 6958, Spanner with Adaptor Pins 8346, tighten left and right. camshaft sprocket bolts to 90 ft. lbs. (122 Nm).

Rotate engine two full revolutions. Verify timing marks are at the following locations:

primary chain idler sprocket dot is at 12 o’clock

primary chain crankshaft sprocket dot is at 6 o’clock

secondary chain camshaft sprockets “V8” marks are at 12 o’clock

Lubricate all three chains with engine oil.
After installing all chains, it is recommended that the idler gear end play be checked. The end play must be within 0.10–0.25mm (0.004–0.010 in.). If not within specification, the idler gear and idler shaft must be replaced.
WARNING
Do not use oil based liquids to clean timing cover or block surfaces. Use only rubbing alcohol, along with plastic or wooden scrapers. Use no wire brushes or abrasive wheels or metal scrapers, or damage to surfaces could result.

Clean timing chain cover and block surface using rubbing alcohol.
WARNING
The 4.7L can use a special RTV sealer instead of a carrier gasket to seal the timing cover to the engine block, from the factory. For service repairs, Mopar ® Grey Engine RTV must be used as a substitute, if RTV is present. If the front cover being used has no provisions for the water passage O-rings, then Mopar ® Grey Engine RTV must be applied around the water passages.

Inspect the water passage O-rings, if equipped for any damage, and replace as necessary.
Apply Mopar ® Grey Engine RTV sealer to the front cover following the path above, using a 3 to 4mm thick bead.

Install cover. Tighten flange head fasteners in sequence as shown in to 43 ft. lbs. (58 Nm).

Install the A/C compressor and generator.

Install crankshaft damper.

Install accessory drive belt tensioner assembly. Tighten fastener to 40 ft. lbs. (54 Nm).

Install lower radiator hose.

Install both heater hoses.

Install cylinder head covers.
NOTE
Before installing threaded plug in right cylinder head, the plug must be coated with sealant to prevent leaks.
Coat the large threaded access plug with Mopar ® Thread Sealant with Teflon, then install into the right cylinder head and tighten to 60 ft. lbs. (81 Nm).

Install the oil fill housing.

Install access plug in left cylinder head.

Install power steering pump.

Install radiator fan.

Fill cooling system.

Connect negative cable to battery.


http://www.2carpros.com/forum/automotive_pictures/52960_0900c1528004332b_1.jpg



Compress and lock the primary chain tensioner—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c1528004332c_1.jpg



Secondary timing chain tensioner preparation—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c1528004332d_1.jpg



Timing chain system and alignment marks—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c15280042375_1.jpg



Camshaft positioning—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c15280042377_1.jpg



Use the Timing Chain Locking tool to lock the timing chains on the idler gear—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c1528004332e_1.jpg



Timing chain cover bolt torque sequence—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c15280042374_1.jpg



Crankshaft timing marks—4.7L engine


http://www.2carpros.com/forum/automotive_pictures/52960_0900c15280042376_1.jpg



Cylinder head access plug locations—4.7L engine

I hope this helps

Jnovack
Oct 19, 2008.
Hi
i am doing this on a 3.7 same timing system. The plated links on the
cam chains do not align perfectly with the windows in the idler as shown in pic but are either slightly higher or lower.I get better alignment when biased lower and would say its like 1/2 a tooth low? From being perfect. Is this normal?
AD


AD