aggieengnr

My truck has 104,000 miles on it. Bought it when it had 95000 back in Jan. I'm assuming the valves haven't ever been adjusted on it.

My question is, would it be a good idea to adjust them, or should I leave them alone? I've never done any kind of valve adjustment on any motor, so I'm not too keen on doing it myself unless it's a fairly straightforward and simple task. I know i'd need feeler gauges to do this. Will it help out my mileage and performance to have them adjusted? Wonder what a ballpark price range would be to have a credible mechanic to adjust them for me?


Also, on a totally different subject, Is it a straight-up swap to switch an NV5600 tranny for a g56? are the splines on the input shaft from the clutch different? What about the speedo wiring and transfer case? Drive-shafts the same length? My 3rd gear synchronizer is about shot and I wouldn't mind having a quieter 6-speed rather than the chattering the NV5600 is infamous for.

thanks in advance

rich

valves on the cr dont require any adjustment till over 120k, last time i had any adjustments on a truck done it was about 200.00 look in the help section their is a guy there called tejas that got one out of corpus mite get some info on that

BLACKBEAR

If you will read the book on your truck you will find out what you should do!!

rich

dont always believe the book it is wrong on some things

aggieengnr

Thanks rich, I appreciate it.... Blackbear. I don't have a book for my truck. It didn't come with one when i bought it used. Don't jump to conclusions; you seem quite rude when you do that. These forums were made for these type of questions, so if you don't have a nice comment, try and keep it to yourself. Thanks

rich

i had the 03 in the shop once and it had about 120k and i asked my mechanic about it and he said that the newer motors needed a lot more miles on them unlike the 12v. the book says 135k to 150k but it also says to replace the fuel filter every 15k when its never good to let them get over 12k

cody459

Like rich said its good to do it at about 120k or a little over, just had mine done for 160.00. Valve adjustment is part of good maintenance, and its good that people ask these question to insure their trucks last.

enafzige

Although the book doesn't say to do it until the 100k mark or so, many have found the valve lash to be out of spec new off the show room floor!

The higher hp you're running, the more often you should check the lash. In fact, those running extreme power check after every pull...this is also a great time to notice a dropped valve, etc.

No doubt, you'll notice smoother idle, and maybe even better fuel mileage depending on how bad they are.

If you were closer, I wouldn't mind at all to show you how. I'd recommend trying it yourself, or at least getting someone to do it that will let you watch and explain things so you'll be able to do it yourself later.

Here's from the manual:

STANDARD PROCEDURE - VALVE LASH
ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash measurements
AND adjustments should only be performed
when the engine coolant temperature is less
than 60° C (140° F).
The 24–valve overhead system is a “low-maintenance”
design. Routine adjustments are no longer
necessary, however, measurement should still take
place when trouble-shooting performance problems,
or upon completion of a repair that includes removal
and installation of the valve train components or
injectors.
(1) Disconnect battery negative cables.
(2) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Using the crankshaft barring tool #7471–B,
rotate crankshaft to align damper TDC mark to
12:00 o’clock position.
(a) If both number one cylinder rocker levers are
loose, continue to next step.
(b) If both number one clylinder rocker levers
are not loose, rotate crankshaft 360 degrees.
(4) With the engine in this position, valve lash can
be measured at the following rocker arms: INTAKE
1–2–4 / EXHAUST 1–3–5. Measure the valve lash by
inserting a feeler gauge between the rocker arm
socket and crosshead (Fig. 32). Refer to VALVE
LASH LIMIT CHART for the correct specifications. If
the measurement falls within the limits, adjustment/
resetting is not necessary. If measurement
finds the lash outside of the limits, adjustment/resetting
is required.
VALVE LASH LIMIT CHART
INTAKE EXHAUST
0.152 mm ( 0.006 in.)
MIN.
0.381 mm (0.015 in.)
MIN.
0.381 mm (0.015 in.)
MAX.
0.762 mm (0.030 in.)
MAX.
note:
If measured valve lash falls within these
specifications, no adjustment/reset is necessary.
Engine operation within these ranges has no adverse
affect on performance, emissions, fuel economy or
level of engine noise.
(5) If adjustment/resetting is required, loosen the
lock nut on rocker arms and turn the adjusting screw
until the desired lash is obtained:
˛ INTAKE 0.254 mm (0.010 in.)
˛ EXHAUST 0.508 mm (0.020 in.) Tighten the
lock nut to 24 Nm (18 ft. lbs.) and re-check the valve
lash.
(6) Using the crankshaft barring tool, rotate the
crankshaft one revolution (360°) to align the
damper TDC mark to the 12 o’clock position.
(7) With the engine in this position, valve lash can
be measured at the remaining rocker arms: INTAKE
3–5–6 / EXHAUST 2–4–6. Use the same method as
above for determining whether adjustment is necessary,
and adjust those that are found to be outside of
the limits.
(8) Install the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(9) Connect the battery negative cables.


Hope this helps,

--Eric

leonesm

I did mine at 100k and again at 200k. It needed adjustment both times. Each time the truck idled smoother and quieter when I finished. I'm not sure about the milage gains but it certainly was worth it in my opinion.

It's something that you could easily do yourself. You'll need a set of feeler gauges with the bent tip, a good set of allen wreches, metric box end wrenches, and a socket & ratchet to turn the crankshaft. I can't remember the sizes off the top of my head.

aggieengnr

Thanks a bunch fellas! I figured somewhere around 100k it'd need the valves looked at. Not quite sure yet whether or not I wanna go ahead and check 'em, or wait till 120k. I checked the hours on it the other day and it has 3415 hours on it as it sits right now.....and the clock's sitting at about 104,600, so that's an avg of 30.6 mph.... Kinda low, so from the looks of the bed when I got it and it being an SL model, I knew it was a ranch truck (a.k.a. lot of idling and put-putting around in the pasture). Question is... with a lot of excessive idling, think the valves might be outta adjustment a bit?

I know it clatters quite a bit when the motor is still cold. When she warms up, no more clatter... that's what got me thinkin it might not hurt to have the valves checked.