Engine/Transmission (1998.5 - 2002) Valve lash adjustment

[madmax4688]

Ok according to the owners manual you should adjust the valve lash at 130k. I bought the truck with that milage and dont think it was ever done. I now have 166k on her and I belive its very over due. I can hear eccesive light tapping while driving. My question is how much am I looking to pay to have it adjusted or should I try doing it myself. Im 28 and a 3rd gen mechanic. I just dont do it for a living and have never done lash adjusting before. I also need to know what other special tools besides a feeler gauge I might need. Sometimes I just let the professionals do it and pay them for no headache which has come back to haunt me (ever had a transmission shop lie before?).

 

[ctd8999]

Valve adj.

Mad, No special tools needed look on here for instructions. If you can't find them PM me and I'll explain. I do mine . 008 intake . 018 exhaust. Thanks Steve B.

 

[RCook]

Here's the skinny I have collected on adjusting valves:



ISB Valve Adjustment



TOOLS NEEDED

Big channel lock for timing cover

Small mirror for viewing timing marks more easily

22mm or 7/8 socket, w long-handled ratchet, for turning engine via alternator

15mm ratchet wrench or socket, for removing valve cover

9/16 wrench (longish box-end works well), for adjuster nuts

5 mm hex key, for adjusters

Feeler gauges



Steve St. Laurent:

I finally was able to get around to adjusting my valves since I have 100,000 miles on the truck. Here's what I found - intake valves were from . 012-. 015 (optimum is . 010 (. 25mm) - spec is from . 006-. 015) and exhaust valves were . 021-. 024 (optimum is . 020 (. 51mm) - spec is from . 015-. 030). I was blown away that they were still within spec after 100,000 miles - and I haven't been exactly easy on the engine. I set mine slightly tight at . 008 (. 20 mm) on the intake and . 018 (. 46mm) on the exhaust. A note to anyone adjusting theirs - there is a lot of play in the Y from the camshaft to the valves on the 24v engine. I adjusted mine and then cranked the engine over and then rechecked them - it took about 6 times of adjusting them before the numbers were consistent on the next rev (I've adjusted TONS of valve trains over the years BTW). I continued to adjust them until I was able to get a consistent reading for 2 revolutions after I adjusted them.



LSMITH:

I have played with settings all over the map and found with my combo . 007 (. 178mm) and . 016 (. 406mm) is the right spot, it frees up the top end tremendously. . 012 (. 305mm) and . 025 (. 635mm) has great low end



Chad Sheets:

Back all the adjustment nuts off on all rockers, then run them down with your fingers until they touch (you will only be able to run down the rockers with no tension on them... the ones with tension will have to wait their turn on the next round when you rotate the engine 360 degrees. Zero the gauge out and adjust for ever how many mm or whatever measurement you want to use.



1. Put cyl #1 on TDC by using the TDC mark behind the crank case breather on the front of the engine. You will have to remove the breather (if it's an automatic, or the timing cover if manual)... I believe it unscrews. You will see "TDC" stamped at 12 o'clock inside the case and a mark on the fuel pump timing gear. Put that mark on the 12 o'clock TDC position.



2. Remove the valve cover, and mark the following INTAKE valves with a paint marker, 1,2,4.



3. Now mark EXHAUST valves 1,3,5. with the paint marker. You should have 6 rockers marked now.



4. Adjust the INTAKE valves somewhere between . 15mm and . 38mm. , I shoot for the middle of the road . 25mm. (per LSMITH - . 20mm)



5. Adjust the EXHAUST valves now between . 38mm and . 76mm. , again I shoot for middle of the road about . 57mm. (per LSMITH - . 40mm)



6. Give all the rockers a good wiggle before removing the gauge to make sure all the play is out of them.



NOW ROLL THE ENGINE OVER 360 DEGREES (180 degrees on the timing mark) AND ADJUST THE 6 ROCKERS NOT PAINTED.





R Cook:

It's not difficult, especially if you've ever adjusted valves before. I've done mine 4 or 5 times now. I don't bother with the paint. I write down where they are when I first measure them, and what I adjust them to. After the first couple of times, they haven't changed much.



I did them again a few weeks ago, and after I thought I had them right, measured all again and had to refine the adjustment on a few. After turning the engine over three times and re-checking and re-adjusting, I got them really right. It seems to me that it's as important to have them all the same as it is to have any one particular measurement. My engine runs the smoothest it ever has after this careful adjustment.