Camshaft replacement

davidfox123 · #1

Hi, I've just been told by the garage that my camshaft is very worn, so bad that the tappets (rockers?) can't be adjusted. I can't find a supplier for a replacement, any ideas and is this common? Also would be good to know if it can be replaced without removing engine. It's ina Land Rover so I can remove front end. Thanks

#2

I've had a small fleet of Maxi Diesels since 1986 and have never seen a LD28 have camshaft trouble. I have about 20 cars, and even with 250K miles (maybe 350k kilometers?) have never seen a worn cam lobe. I'm not going to talk the people down, but it is highly unlikely.

What problem did the engine have to get to this point?

Is this for an economic stimulus?

davidfox123 · #3

It has a ticking noise which is worse when hot. I'm not sure of the mileage but it has been in the Land Rover for 12 years and wasn't new when installed so could be 150K miles easily. I do trust the garage but by the sound of it maybe worth a 2nd opinion?

#4

If the cam is too worn to be adjusted you are probably also looking at serious oil delivery issues that should be cooking bearings as well. Pull the oil cap while the engine is running and look at the lobes spinning and see if there is oil splashing on the lobes and rockers. If there isnt I could do a writeup on how to do it, it can be done in car if the front clip, or pieces of the clip are removed.

#5

Take to a different shop to make sure a valve adjustment bolt isn't loose. You can't run engine with valve cover off unless you want to take a oil bath. (have to adjust when hot)

Listen to engine and determine if it is Crankshaft speed or Valve speed (valve speed is half of crank speed)

Take all the belts off (to eliminate alternator and vacuum pump)

Check center large bolt on harmonic balancer. I bought a maxi-diesel that had it loose, and it sounded/felt like a rod bearing ready to fail. Took it apart and balancer was loose, crank & crankshaft key was worn.

Refer to first suggestion, take to another shop.

davidfox123 · #6

Hi, I think you're right, a second opinion is needed. It's definitely a valve adjustment problem. It's also worse on part throttle or when under virtually no load. Maybe that's because it's so noisy when under load I just can't hear it! It's a Land Rover after all.

#7

I have a similar noise for the last 6k or so (miles). So far I haven't found the problem, but it's not the "accessories" on the front of the engine. I think it may be one of the injectors going bad, but it could be something internal. However the engine performs fine and the noise does not seem to have changed any in the last 8 month or so since I noticed it.. This started prior to my setting valve lash so it doesn't seem to be related to that.

Will check the harmonic balancer next.. Thanks diesel-man.

Rufus

#8

i had a intermitant tappet rattle once.after about 12 months 2 exhaust valve seats fell out.

often see worn camshafts.you may get a few lobes that loose the hardened surface.this is a fatigue issue and is random.

no rotating cam follower to get stuck on a LD28[RD28 are dreadfull]

oil quality and temperature.hard to guess the service history and life spans of conversion engines.

#9

You can replace an L-series cam with the engine still in the car!

However, you must make the ole' wooden wedge to keep the timing chain tensioner bound, down under the cam gear, or you'll have to do a LOT more work. Details for this procedure can be found online, on Datsun Z car sites.

As for getting a new cam, if you can find a good donor car or even just a head with a good cam, you can used it on your car. But you MUST use the donor tappet/lash pads in their original order to retain the nice wear pattern they should all have, each one particular to its cam lobe. Of course, you should also use the cam bearings/tower mounts from the new donor cam, as well.

#10

240ZD wrote: However, you must make the ole' wooden wedge to keep the timing chain tensioner bound, down under the cam gear, or you'll have to do a LOT more work.

Hammer that wedge in tight! otherwise youll take a nice 2 hour job and turn it into a full on weekend killer!

Datsun chain wedge

I recommend making the bottom part about 3/4 inches wide, I made mine 2" thick as described and I dropped the chain.

#11

This man has LD28 cams for sale cheap.

davidfox123 · #12

Thanks all, got a 2nd opinion & he managed to adjust the tappets but camshaft is wearing. Now the challenge is to find a replacement. Anybody help. Either need UK or international shipping?

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