Lash Valve Adjustment

[Ken Sair]

I just had my Lash Valve adjusted in April at 40,000 miles (CAT in El Paso TX). The engine is a CAT C-9. The service manager said based on my miles driven per year I should have the lash valve adjusted every 30,000 miles. This seems awfully soon as I think the CAT manual says something like 150,000 miles for the next one.

Any thoughts on this? Seemes like he is drumming up more business at that mileage.

Ken Sair  2007 Contessa

[Joel Ashley]

Ken-

The "universal" maintenance schedule (general practice for all diesel motor homes) I use as a rough guide indicates the valve lash (I assume you don't actually mean "lash valve") should be checked the first time after 10,000 miles or 12 months; mine was checked at 11,000 and 24 months.  I'd say I'm close enough judging by CAT's recommendations below, and there is plenty of leaway mileage-wise:

"When should I perform my valve lash adjustments?
On new, rebuilt, or remanufactured engines, the initial valve lash adjustment is required due to initial wear and seating of valve train components. After the initial valve lash adjustment, future adjustments are required at an extended interval. If downtime is an issue for you, contact our field service advisor to have a technician come to your facility on your schedule.

Depending on engine model the maintenance intervals are as follows:

C9, C-10, C-11, C-12, C13, 3406E, C15, and C-16 On-Highway Engines:

Initial - Between 15,000 and 60,000 miles which is between the first and fourth oil change.
After Initial - Every 300,000 miles or 50,000 gal of fuel or 6,000 Service Hours or 3 years (which ever comes first)."

Your 40,000 adjustment is fine if it's the first;  after that your mechanic may be in the ballpark if you put at least 10,000 miles per year on your coach (...or 3 years (which ever comes first)." )  He just should have put it in terms of time, not mileage.

[Chuck DuFault]

Ken - call the CAT hot line at 877-777-3126.  The CAT recommendations for my C-12 is around 30,000 miles for the initial adjustment and then additional valve adjustments are required at 240,000 miles.  These are "RV Recommendations" put out by CAT.  Chuck and Donna

[Ken Sair]

Thanks Chuck. I think my papers on the C9 say 150,00 for the second one. Gonna be a lot more than 3 years to get to that figure.

[Ken Sair]

chuck, I just checked my 'CAT ' information. Says the first should be done bewteen 15,000 and 60,000. However, the PM level 2 says 3 years - 240,000 miles or 4,200 hours. This is from the RV Recommendations printout. That makes things not so clear. Guess I'll drop a dime on CAT although every time I talk to them I get different answers.

[Joel Ashley]

At your current mileage rate, the 3 year interval is your obvious choice, whether you go by the CAT recommendations (from their website) that I included in my reply of Aug. 15th or by your "RV Recommendations printout".  Mileage CAT gives would be relative to an over-the-highway truck;  your motorhome doesn't gather 80,000 miles a year - 3 circumtransits of the earth.

If you're still concerned, contact Brett Wolfe of the CAT RV Club:  wolfe10@earthlink.net;  he'll give you advice as reliable as it comes.

Though CAT no longer manufactures RV highway engines, they are committed to support of existing owners;  you can ask for help here, the CAT RV Hotline 1-877- 777 - 3126.  But I would consider whatever Brett says as good as gold.

-Joel