Thread: lash caps

One of the benefits would be less wear and tear on the top of the valve stem, lot cheaper to replace valve caps than valves, but that only works if the valve caps are made well enough to do the job and it seems that Land Rover caps are not, regards Frank.

If the caps were hard enough then the rockers would wear i guess, its a catch 22 situation.

They also spread the load progressively from the small diameter valve stem to the rocker surface of the arm.

Recently someone put up images of worn rocker arms - In this case the lash caps were obviously harder than the arms.

I suspect the problems people are having are because it is now a long time since 300tdi was OEM controlled specifications. In the original setting you would have the valve stem and rocker arms of similar hardness and the lash caps marginally less surface hardness... With the glut of aftermarket parts it is probably difficult to buy a set of valve stems, lash caps and rocker arms all of appropriate hardness.

I will still take worn lash caps over worn rockers or valve stems any day!!!!
It is not a challenging task to check the caps when doing the tappets at 10 thou oil change...

Steve

So Roverrescue are you saying to replace them every 10k service or is that only a wear check? Jim

Steve, what about the blokes getting 100's of klms. instead of thousands, all that ground up metal will not all end up in the oil filter, it will cause damage before it's picked out of the oiling system.
Last time I did a head gasket I checked the lash caps and they were in great condition as were the rocker arm pads, obviously original from when the motor was first built, (400,000klm+).
The genuine Land Rover lash caps I bought to replace them at the coming head change are stuffed from brand new, if Land Rover are going to put their Name on these products the least they can do is check that they are servicable, Regards Frank.

I service the engine by engine hours
Oil/filter change and check tappets at 100 hour intervals (roughly 7500km)
It is easy enough to visual the lash caps when you do the tappets (might add 30 minutes to the job)

My current engine is fast approaching 300 hours. This will be 4th oil change. (Did a run in change)

Rocker arms are from original 1995 engine
lash caps are from turner in UK
valve stems are whatever Turner puts into their performance head

No appreciable wear in the first 200hours (very limited time frame I know).



Frank it is very dissapointing that LR OEM parts are so poor... I would still be hesitant to change them to a known harder compound as some suggest as compared to rocker pads or valve stems the caps are cheap!

I wish I had the forsight to mic the new "Turner" caps when I built the engine up just to measure wear rates... I am happy to do this at the 300 hour service if someone has some new ones from Turner to compare to???


This whole lash cap thing seems to be more prevalent now than say 10 years ago (we prob need someone like JC to chime in here) I wonder what is a happening at the materials side of things? If it is a newish problem something must have changed?

S

Frank,
Forgot to mention,
If those caps you bought only lasted 100km they are made of the same cheese as 10 spline axles and will hardlly do any damage floating around

Seriosuly though, wouldnt the majority of the cap still be sitting on the stem like a collar. It is only the centre depressed portion that can get smashed to little bits??
If the whole cap is gone I wonder if the clearances were too loose?

S

Steve, the caps pictured in my post at post #30 300tdi valve lash caps disintegrating are brand new straight out of the packlets, the shiny spots are from lightly rubbing them on emery paper on a flat surface to show up the hollows. Also on some of the caps I put a straight edge (engineers steel ruler) across the top of the caps, with less than 3" hanging over the side the end of the ruler was toching the table, a slope across the top of the cap of at least 1/32".
I reckon that these caps are probably hard enough, but their distorted shapes (no 2 alike) would be the cause of rocker arm pad wear as well as the cap.
I am going to use these Crane lash caps and see how they go.
I noticed in the thread above that the rocker arms that wore out were either new LR ones or Aftermarket, so that might explain the damage there, Regards Frank.