4.7 Timing Chain Cover Replacement

[snaps]

This should probably be in the repair subforum but im still a newb and cant post there.

Im having a slow drippy drippy of coolant and oil (separately from different sources) from the front end of my 4.7 and im going to just replace all the possible culprits in one fell swoop. Ive ordered an new timing chain cover plate and gasket along with a new front main seal and harmonic balancer. Im waiting to order a water pump until I get a look at the current one since its working fine currently (gasket might be leaking). My thermostat is also working fine so I may just blast it with some brake clean and reinstall it in the new tc cover.

Im just looking for some wisdom as to potential pitfalls of this job or other maintenance that should be done while im tearing into that area.

Thanks in advance

[snaps]

After doing a but more reading, im going to go ahead and spring for the water pump and thermostat...

[Yjsaabman717]

My only advice is to use a vacuum cooling system filler. I've had too many bleeder screws pull the threads out of the aluminum housing, I don't touch them anymore.

[snaps]

So I spent this past Saturday swapping my timing chain cover and everything attached to it. I found a thread on another forum about timing chain covers pitting through to the block and dumping coolant into the oil so I bought a new cover casting. I'm glad I did because upon removing my water pump I found a pitted mess inside the housing.



Granted this is pretty far from catastrophic but eventually could have cause big issues. If the housing pits badly, there will be little to no circulation of coolant from the impeller on the WP. Pitting further will dump coolant into the block..

Just as a reference here is the new casting.



My WJ has 165k miles on it and multiple previous owners so I imagine one of them put hose water in for coolant. I guess there's a reason HOAT coolant is mandatory WJs.

Here's a shot of the shiny new casting sticking out like a soar thumb in my mess of an engine bay.

[snaps]

And to enable all the stuborn people who refuse to buy an FSM here is the write up for timing chain replacement along with all the attached items.

Tools you’ll need:
6mm bolt extractor
6mm socket
14mm socket
15mm socket
18(I think)mm socket
Locknut wrench
Small 3 jaw puller
14x1.5x120mm bolt
http://www.mcmaster.com/#91180a802/=119oxw2
Channel locks

Probably forgetting something

Things I replaced in the process of doing this swap:

Water pump
http://www.summitracing.com/parts/gm...view/make/jeep

Harmonic balancer
http://www.summitracing.com/parts/rn...FQ-raQodptED3Q

Thermostat
http://www.summitracing.com/parts/cw...view/make/jeep

Thermostat housing
http://www.summitracing.com/parts/rn...FQmqaQodz1AD8Q

Felpro timing chain gasket (4.7 V8) (included front main seal)
http://www.summitracing.com/parts/fe...FQyHaQodzzoH5w

(obviously) 4.7 V8 Timing chain cover
Ebay

First step is to remove the fan attached to the water pump. It is Right Hand threaded onto the water pump shaft with a fairly large nut. I used a locknut wrench to loosen it and then just spun it off. It’s much easier to take the radiator fan shroud off with this removed.

Next remove the radiator fan shroud. On a new WJ there are 4 x 10mm bolts holding the shroud to the front clip. Mine only had 1 bolt tab still attached and was held on with a few zipties. My rad fan was electric so the only other thing attaching it was an electrical plug. Apparently some models have a hydraulic fan the taps the power steering pump. No clue how to detach those fans.

With that all off, drain the coolant out of the radiator via the petcock on the bottom driverside. If you haven’t stripped the shit out of the bleed screw at the high point of the housing, open that up and allow the coolant to drain out of the block into the radiator and out into your catch pan (or driveway since your catch pan is too small… ask me…)

Next take the serpentine belt off. I did this by taking a 2’ breaker bar and a 15mm socket on the bolt in the center of the idler pulley and rotating the pulley arm to release tension on the belt. Remove the belt and then slowly release the idler pulley until it hits the stop inside the assembly. Letting it fly back will probably cause problems and result in you needing a new idler assembly.

Remove the baffle box from the throttle body. Use a flat blade screw driver to loosen the band clamp in the throttle body and it slides right off. There are 4 clamps on the air filter side that pop off as well and it comes out as one piece

Remove the AC compressor and alternator. I can’t remember bolt sizes but it’s not difficult to do. The AC compressor hoses do not have to be disconnected for this. With the baffle box out you can just set the compressor and alternator on the intake manifold.

Remove the idler pulley assembly by removing the 1x 15mm bolt that holds it to the timing chain cover.
Disconnect the hose attached to the thermostat housing. The factory clamps are easy to momentarily loosen with channel locks and the hose should slide off.

Remove the thermostat housing and thermostat. The two 6mm bolts holding the housing to the TC cover are notorious for stripping so I just started off with bolt extractors and went easy on it to break them loose. No issues and no rounded off bolts. The thermostat is held in by the housing so it will fall out if you aren’t careful when removing the housing.

Next remove the water pump. 8x 15mm bolts, 3 of which are through holes into the block. Take note of which bolts went in which holes. The short ones thread into the TC cover, the long ones thread into the block.

Disconnect the top end hose from the radiator to TC cover. There is another factory hose clamp holding this hose to the TC cover. I used channel locks to get it to slide down the hose and left it there so I wouldn’t lose it in the meantime.

Remove the harmonic balancer. There is 1x 14mm bolt threaded into the crankshaft that holds the HB on. I had to wedge a long flatblade screw driver into the HB to serve as a stop against rotation and used a 2’ breaker bar to loosen the 18mm (I think) bolt. It takes some balls but it is right hand threaded (lefty loosey) and will eventually break loose. Penetrating oil may help but I didn’t need it.

With the bolt out, you’ll need a 3 jaw puller to get the HB off the crank shaft. There is a $150 mopar puller that is pretty much a one trick pony for 4.7 harmonic balancer removal. F*** that S***. I had no issue using the smallest puller from the Harbor freight 3 pack. I think it was $20 for the set. It should slide off the crankshaft with relative ease.

With all those things off, all that’s left is to remove the 11x 15mm bolts holding the TC cover on. With those out, give the top hose connection neck a good yank and it’ll come off. Depending on how well you drained the coolant there may be a bit that comes out of the block ports.

I also installed an new front main seal. This is easier to do with the new TC cover prior to installation. The seal came with the felpro TC cover gasket I bought.

Install the new TC cover. I don’t think the gasket is reusable and mine was in shit shape anyway so I put a new felpro gasket on. There are alignment shims pressed into the block that hold the gasket in position. The new TC cover goes on just like the old one came off. Put all 11x 15mm bolts back in the holes they came out of and get everything snug. Don’t torque them yet.

Install the new water pump onto the TC cover. The WP I bought came with a gasket installed but to be safe I put a layer of high temp RTV on the inside of the gasket seal. Install bolts in the holes they came out if. Now torque the 11 TC cover bolts, 5 WP bolts, and 3 WP/TC cover bolts to 40 ftlbs.

Install the new thermostat and thermostat housing into TC cover. Align the thermostat in the housing correctly and bolt it back in the same orientation it came out. Torque the two bolts to 115 INCH Pounds. INCH!!!! NOT FOOT! Reinstall the hose from the radiator to the thermostat using the factory clamp.

Install harmonic balancer. There is also another one trick tool from mopar that costs $160 for installing a HB in the 4.7. see comments above… The bolt that held the HB on the crankshaft is too short to use to pull it back onto the shaft. It is a 14x1.5x100mm bolt. I bought a 14x1.5x120mm bolt from Mcmaster Carr. $5 shipped and arrived in 48 hours. Align the shaft key and lightly tap the HB to get it started, then thread in the longer bolt and tighten until it starts to slip down the shaft. Keep tightening until the longer bolt bottoms out in the hole then switch to the bolt that holds it in the shaft. Tighten the rest of the way down and torque to 130 ftlbs. You’ll have to use the flatblade screwdriver as a stop to torque it down.

Reinstall the idler pulley. One of the TC cover bolts serves as a stop for the idler assembly. Torque to 40 ftlbs.

Reinstall the serpentine belt. Using the breaker bar and 15mm socket, move the idler pulley over to allow the serpentine belt to slip easily over it. Slowly release the pulley until tension is applied to the belt. Serpentine routing path is easy to find by googling “Chrysler 4.7 serpentine path”.

Reinstall the hose from the TC cover top to the radiator using the factory clamp.

Reinstall AC compressor and alternator. Not hard, no instruction needed.

Refill the coolant system with either a 50/50 (summer) or 70/30 (winter) mix of HOAT coolant/distilled water. I use Zerex G-05 since the Mopar brand is a bit pricey and its essentially the same thing. Remove the bleed screw on the highest point of the TC cover. Remove the radiator cap and start filling the system with your coolant mix until coolant comes out of the bleed hole on the TC cover. This step is critical to evacuating all the air from the coolant system. Reinstall the bleed hole screw. Top off the coolant reservoir.

Reinstall the fan shroud and clutch fan.

Crack open a beer and marvel at the shiny new casting now bolted to the front of your greasy 4.7.

Hope this helps someone. If I forgot anything, oh well.
I also realize that I probably didn’t need to replace all of these things but none of them are terribly expensive parts so I figured it would be worth the learning experience.

[ELLLLLIOTTTTT]

Great writeup, thanks for sharing!

[Kraqa]

Lots of work into this. Great job!