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ok my daughter cherokee has the 4.0 in it and it has a little over 200k on it. I am a diesel guy and we have to adjust the valve lash on our motors every 100k or so. Do i need to have it adjusted on her motor. thanks for any advice

COSXJFAN

No, hydraulic lifters.

Howler_GT

No adjustment available.

Torque the rockers down to specs and leave it.

Does it TICK? Like they need adjusting?

That tick is installed at the factory. It engages sometime after the original warranty runs out. Its designed to maintain itself until you trade/sell/junk the Jeep.

5-90

No.

I know, even some Diesel hydraulic valvetrains want periodic adjustment - but you're dealing with way higher spring seat pressures, and wear is a factor. (I've worked variously as an automotive wrench, a heavy Diesel wrench - class four trucks and up - and as an industrial mechanic - stationary engines, hydraulics, forklifts, AGE, pumping setups, off-highway equiment, ... So, I do know where you're coming from.)

If you're worried overmuch, do this:

1) Remove valve cover.
2) Make sure both valves on a given cylinder are closed.
3) Torque rocker arm pivot screws to 19 pound-feet.
4) Rotate engine, move to next cylinder. Repeat.
5) After six repeats, reinstall valve cover. Return to service.

NOTES:
- Yes, I have noted that rocker arm pivot screws can loosen over time - there's a lot of repeated stress on them, and some of it is sidewise stress (instead of straight tension.) Anytime I service the rockers, I'll: remove the screws, chase out the holes, clean the screws with carburettor cleaner and/or a wire brush/wheel, apply LocTite #242 (or equivalent,) install and torque.
- If you disassemble that far, you won't go amiss putting a bit of assembly lube between the pivot and rocker stamping. Probably not strictly necessary (unless you wipe the thing clean and dry,) but it's cheap insurance.
- Closing the valves probably isn't necessary, but it isn't not necessary - and it makes sure you get consistent torque on the rocker arm pivot screws.
- Deformed/yield limit exceeded screws may be replaced with standard hardware store items - I tend to use socket heads, just because I like them.
- I have only really serviced the rocker screws simply because I had them exposed anyhow - which means I was either servicing a leaking valve cover or I'm reassembling the head after I'd peeled it off for some reason. I've not noted a periodic adjustment being necessary - my 88 hasn't even had its valve cover off, and the noise it makes isn't valvetrain - it's piston slap... The odometer quit working the fifth time I'd swapped out the transmission (finally going from that wretched Peugeot to an Aisin,) and that was at 330Kmiles...

NB: Getting the valve cover to reseal can be a pain in the **** - I've modified the manual procedure slightly. The use of LocTite #518 Gasket Eliminator is preferred for a gasket-enhancing sealant...

1) Clean the mating rails of the valve cover and cylinder head thoroughly. Brush, the rinse with carburettor cleaner. Let dry fully.
2) Take your replacement gasket. Apply a light, even coat of LocTite #518 (preferred) or RTV black (perfectly acceptable) to both sides of the gasket.
3) Set the gasket in place.
4) Set the valve cover in place.
5) Start all screws. Tighten to finger tight only.
6) Go have coffee and a sammich. Come back in an hour.
7) Torque the valve cover screws. Torque spec is A) on my site in the Tech section, and B) very low! Somewhere around 60-85 pound-inches, I bleieve. This gasket crushes easily!
8) After torqing the screws, let it set up for at least a couple of hours (overnight is better) before returning to service.

LocTite #518 is great stuff - I keep a tube on hand just on account of 'cause. It first saved my **** on a transmission casing on an old Massey-Fergusson that had been converted to a forklift (M-F didn't even know what I was talking about when I was trying to order parts for it!) and I haven't been without it as a backup since. I don't use it often, but I'm awfully glad to have it when I need it...

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ok wasnt sure apreciate the info