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Chris
Chris, Shop Foreman
Category: Jeep
Satisfied Customers: 3163
Experience:  Jeep Certified Master Tech
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Working on 2002 jeep grand cherokee with 4.7. Put timing

Customer Question

working on 2002 jeep grand cherokee with 4.7. Put timing chain and new gears ,tensioners and guides on. Put on according to specs and all gears in proper places with dots and v8s in 12 positions on cams and idler at 12 and crank gear at 6 with all colored
links in place too. I tried starting and nothing so i know its still outta time. I got #1 cyl to tdc but noticed harmonic balancer isnt at tdc mark on motor. but cams are still at 12 position. whats best way to fix this problem and easiest?
Submitted: 1 year ago.
Category: Jeep
Expert:  Brad replied 1 year ago.

Good evening and welcome to JustAnswer!!!

The first thing you will need to do is remove the timing chain cover and the valve covers and see what is out of time.. Do you know if the timing is exactly as the picture I attached?

Talk soon,

Brad

Customer: replied 1 year ago.
It was when I first started. But something is still outta time. I think it's crank.with #1 cylinder up timing mark should be on mark on block but its not.
Expert:  Brad replied 1 year ago.

If you have #1 @ TDC and the balancer isn't lined up with TDC then yes you will need to tear it down and get it back right.. But being this it's out of time you may have bent valves since you have tried to start it, so get it back in time then do a compression check before putting it all back together so if it's 0 psi you won't have to tear it apart again..

Customer: replied 1 year ago.
What would happen it is put crank on TDC and moved chains on cam gears to match?
Customer: replied 1 year ago.
With cam gears at 12 positions (v8).
Expert:  Brad replied 1 year ago.

If your not sure on how to install the timing chains then I attached the directions:

INSTALLATION

  1. 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 2 mm 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
  2. Position primary chain tensioner over oil pump and insert bolts into lower two holes on tensioner bracket. Tighten bolts to 28 N·m (250 in. lbs.).

    CAUTION: Overtightening the tensioner arm torx® bolt can cause severe damage to the cylinder head. Tighten torx® bolt to specified torque only.

  3. Install right side chain tensioner arm. Apply Mopar® Lock N, Seal to torx® bolt, tighten bolt to 17 N·m (150 in. lbs.).

    NOTE: The silver bolts retain the guides to the cylinder heads and the black bolts retain the guides to the engine block.

  4. Install the left side chain guide. Tighten the bolts to 28 N·m (250 in. lbs.).

    CAUTION: Overtightening the tensioner arm torx® bolt can cause severe damage to the cylinder head. Tighten torx® bolt to specified torque only.

  5. Install left side chain tensioner arm. Apply Mopar® Lock N, Seal to torx® bolt, tighten bolt to 17 N·m (150 in. lbs.).
  6. Install the right side chain guide. Tighten the bolts to 28 N·m (250 in. lbs.).
  7. 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
  8. 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
  9. Lubricate idler shaft and bushings with clean engine oil.
  10. 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.

  11. Align left camshaft sprocket “L” dot to plated link on chain.
  12. Align right camshaft sprocket “R” dot to plated link on chain.

    CAUTION: Remove excess oil from the camshaft sprocket bolt. Failure to do so can result in over-torque of bolt resulting in bolt failure.

  13. 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.
  14. 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

    CAUTION: Ensure the plate between the left secondary chain tensioner and block is correctly installed.

  15. Install both secondary chain tensioners. Tighten bolts to 28 N·m (250 in. lbs.).

    NOTE: Left and right secondary chain tensioners are not common.

  16. Before installing idler sprocket bolt, lubricate washer with oil, and tighten idler sprocket assembly retaining bolt to 34 N·m (25 ft. lbs.).
  17. Remove all locking pins (3) from tensioners.

    CAUTION: 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.

  18. Using Special Tool 6958, Spanner with Adaptor Pins 8346, tighten left and right . camshaft sprocket bolts to 122 N·m (90 ft. lbs.).
  19. 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
  20. Lubricate all three chains with engine oil.
  21. After installing all chains, it is recommended that the idler gear end play be checked. The end play must be within 0.10–0.25 mm (0.004–0.010 in.). If not within specification, the idler gear and idler shaft must be replaced.
  22. Install timing chain cover and crankshaft damper
  23. Install cylinder head covers .

    NOTE: Before installing threaded plug in right cylinder head, the plug must be coated with sealant to prevent leaks.

  24. Coat the large threaded access plug with Mopar® Thread Sealant with Teflon, then install into the right cylinder head and tighten to 81 N·m (60 ft. lbs.)
  25. Install the oil fill housing.
  26. Install access plug in left cylinder head
  27. Install power steering pump.
  28. Install radiator fan
  29. Fill cooling system
  30. Connect negative cable to battery.
Customer: replied 1 year ago.
I know yr showing me what should be done . But am no shade tree mechanic . If I have to I will redo my work . But if crank is on TDC and rotate chains on cam gears won't that work too?
Expert:  Brad replied 1 year ago.

You will need to verify the idler/crank(Primary) are lined up correctly... Then once the primary chain is set then set the plated links on the idler thru the holes then allign the camshaft. Then install the tensioners and you can recheck all lines.. Since it's a timing chain engine there is no need to spin it until it lines up to check..

Glad I could help,

Brad