Valve lash on newer compacts and old. Do you have Hydraulic lifters?

[Glen Watkins]

That is good to know. Thanks for the info FB!

 

[Tx Jim]

I checked the service for the new 4000 series deere USA engine and they do not have valve lash. Must be hydraulic lifters. The real deere engines and not Yanmar. I do not know how far back you go in years for a USA deere engine before you see the primitive design and need to lash a valve. Its old school design less engineering and less money. Japanese motorcycle engine design did away with lash 20 yrs ago. At least Honda did.

4720 has hyd cam followers.

Part Number: RE520885
Part Price: 17.58 USD
Description: FOLLOWER,HYDRAULIC

 

[fuseboxer]

4720 has hyd cam followers.

Part Number: RE520885
Part Price: 17.58 USD
Description: FOLLOWER,HYDRAULIC

You infer the need for valve lash and or service and that is incorrect below is copied from the service operational manual for a JD4720 = NO VALVE LASH it may use follower part no RE520885 but that is not a service required lash or part.



Every 200 Hours
Change engine oil and filter.

Inspect alternator belt.

Check air restriction indicator light.

Check wheel bolt torque.

Every 400 Hours Change engine oil and filter (if John Deere PLUS-50 is used).

Change transmission oil and filter.

Clean transmission suction screen.

Replace fuel filter.

Every 600 Hours Check engine low idle speed.

Check air filter intake hoses and clamps.

Change front axle oil.

Check front axle thrust bolt torque.

Check brake adjustment.

Yearly
Change engine oil and filter if less than 200 hours of operation.

Drain water from fuel tank and replace fuel filter.

Check all hoses and clamps.

Every 1200 Hours

Check and clean inline hydraulic filter.

Check engine valve clearance. See your John Deere dealer.

Every Two Years or 2000 Hours

Flush and replace factory coolant. Flush cooling system and replace coolant with John Deere COOL-GARD engine coolant.

Service fuel injection nozzles.

 

[fuseboxer]

Part Number: RE520885
Part Price: 17.58 USD
Description: FOLLOWER,HYDRAULIC


I think I misunderstood you. You are agreeing that a "REAL" JD engines, not Yanmar, has no need for valve lash. They use of a form of hydraulic compensation.

 

[KennyG]

I checked the service for the new 4000 series deere USA engine and they do not have valve lash. Must be hydraulic lifters. The real deere engines and not Yanmar. I do not know how far back you go in years for a USA deere engine before you see the primitive design and need to lash a valve. Its old school design less engineering and less money. Japanese motorcycle engine design did away with lash 20 yrs ago. At least Honda did.

Yeah, I'm a little dated. My 2320 (Yanmar) is my first John Deere. Other than that, almost all my tractor experience comes from ones built in the 30's, 40's and 50's. I've had a lot of motorcycles, but none with hydraulic lifters. The "shim and bucket" designs always tightened up with wear.

 

[fuseboxer]

Upon closer inspection of service requirements of current deere engines both Yanmar and USA engines it looks like All require checking valve lash at 1200 hrs. Why check at 500 hrs if the same Yanmar engine is now a 1200hr check.

 

[RoyJackson]

Upon closer inspection of service requirements of current deere engines both Yanmar and USA engines it looks like All require checking valve lash at 1200 hrs. Why check at 500 hrs if the same Yanmar engine is now a 1200hr check.

Might be harder valve seats now...as some (if not all) vehicle manufacturers added once unleaded fuel was mandated. In the case of diesels, it's not unleaded fuel, it's ULSD (Ultra Low Sulphur Diesel).
I use an additive, Power Service, which aids in upper cylinder lubricity. Been doing this since I bought my 790 (in 2004) and read a couple posts on the effect of low sulphur diesel on older diesel engines.