Outer Limits 4x4 Board

guys,

tapets on the rockers of the TB42 in my GQ are given me the sh1ts.
they are very loud.

I have just put a fully recoed head on and adjusted them up etc.

and the noise returns.

I have tightened them 4 times now and after about 200kms the noise returns in the tapets to rather loud again.

i finally noticed that some spacer washers were no where to be found in the front rocker, i noticed movement back and forth in the front rocker rather than the normal up and down.

I put some spacer washers in, and there is no movement forward or back along the rocker shaft of any of the rockers or between and of the springs etc.

I tighten them to 0.38mm which is the measurement in the manuel

and the noise has returned again after about 150km, is generally not noisey in tapets when cold but give it 2 mins to warm up and its noisey......

any ideas how i can stop these from coming loose or wat ever they are doing?

cheers

screwy

The valve rocker pads on my TD42 were very badly worn making valve adjustment very difficult with a feeler guage. Before i replaced them all, i set valve clearance with a dial guage to 0.35mm (fact spec) instead of a feeler guage which quietend them down a fair bit. There should be washers either side of the rockers from memory--there should be movement in the direction of the shaft but not any other way. Make sure the small oil feed hole is facing the right way in the rocker shaft.

Nick

Screwy_ScrewBall wrote:I have just put a fully recoed head on and adjusted them up etc.

What was the nature of the reconditioning???, was it a full job or just a surface cut and a clean up?.... what did you supply them with ...EXACTLY.

Screwy_ScrewBall wrote:I have tightened them 4 times now and after about 200kms the noise returns in the tapets to rather loud again.

no mention of the lock nuts actually being loose ... are they loose or are you just reseting the clearance and retightening again?

Screwy_ScrewBall wrote:I finally noticed that some spacer washers were no where to be found in the front rocker, i noticed movement back and forth in the front rocker rather than the normal up and down.

This relates to my first question......
Did you send the rocker gear in with the head ????
If you did then its time to make a phonecall....

Some-one has obviously not correctly refitted the shims ( in this case at all ! )

Screwy_ScrewBall wrote:I tighten them to 0.38mm which is the measurement in the manual

Are you using a tension wrench and tensioning the locknuts to the correct tension ( it will be in the book ).
Also the clearance youve listed "0.38mm" is that done with the engine hot or cold ?????? (answer also in ya book)

Screwy_ScrewBall wrote:and the noise has returned again after about 150km, is generally not noisey in tapets when cold but give it 2 mins to warm up and its noisey......

What condition is the oil & oil filter in ....overdue
How much oil is present on the rocker setup with the engine running (need to remove the rocker cover and run the engine to check this)
Did you put the head gasket on the right way some brands and indeed some heads require a gasket to be fitted in one specific mannor, failer to do so and there can be water restriction/oil restriction, even more care is needed when an "O"ring gasket is used.......

Screwy_ScrewBall wrote:any ideas how i can stop these from coming loose or wat ever they are doing?
cheers
screwy

Yep .......

after your a little more descriptive as to "what they are doin" exactly !
.
..
...
....
.....

V8Patrol wrote:What was the nature of the reconditioning???, was it a full job or just a surface cut and a clean up?.... what did you supply them with ...EXACTLY.

i supplied the full rocker gear and the head.
It had a decent job done, all corroded water jackets welded and re drilled, all new valve stem seals and a couple of new exuast ports themselves. full machine job and chem clean amoung a coupla other things.

It was complete when they recieved it and in bits when i got it back. they chem cleaned all the gear.
i had the shaft and the shaft and the rest in a plastic bag.

I used all the parts to assemble the rocker as per the manuel.
i had 4 spacer washers in the bag and i put them all in the back rocker as the book only mentioned washers to go in there and none for the front, the movement was perfect with all 4 would have been a touch loose with 3.

I tightened them all up to .38 which is factory spec and tightened all nuts to factory spec.

V8Patrol wrote: no mention of the lock nuts actually being loose ... are they loose or are you just reseting the clearance and retightening again?

just re setting them, the nuts are not loose any of the time, they are still tight.

V8Patrol wrote:This relates to my first question......
Did you send the rocker gear in with the head ????
If you did then its time to make a phonecall....

Some-one has obviously not correctly refitted the shims ( in this case at all ! )

I refitted everything, the rocker was all in bits, there were spacer washers missing as best i can tell.
I have since fitted some but the noise still returns........

ideas???

V8Patrol wrote:Are you using a tension wrench and tensioning the locknuts to the correct tension ( it will be in the book ).
Also the clearance youve listed "0.38mm" is that done with the engine hot or cold ?????? (answer also in ya book)

engine hot and torqued as per the book, i dont guess engine work.

V8Patrol wrote:What condition is the oil & oil filter in ....overdue
How much oil is present on the rocker setup with the engine running (need to remove the rocker cover and run the engine to check this)
Did you put the head gasket on the right way some brands and indeed some heads require a gasket to be fitted in one specific mannor, failer to do so and there can be water restriction/oil restriction, even more care is needed when an "O"ring gasket is used.......

New oil and filter a coupla weeks ago, there is oil on the gear when i pull it apart to adjust HOT, but havent checked runnning.
there seems to be less than i would of thought should be there, but there is oil.
Head gasket is on correctly, it cools fine, its not blown and fuel economy is farely good again.

the one thing that i am wondering now is......

-------------------------------------------------------------------------------------

WOOP.... wat is this about a small oil feed hole in the rocker???

i paid no attention to this when putting the shaft back together as it wasnt mentioned in the manuel.

how does this work? obviously its bolted down to the head so oil gets up there through the mounting points but if there are holes in the shaft for the rockers them selves i paid them no mind?

the thing is, that when i reset the tapets, they are out by abit, but nuts arent loose.....

cheers

screwy

Well it sounds as if you've managed to correctly refit all the bits ......

Next question.....

What nic are the cam and lifters in ?????

A worn cam / lifters will decrease engine performance / ecconomy and will make for a "noisey engine"

253's are really bad at chewin cams n lifters to bits, the lifters will actually wear away to a point where you could call em "Bowls", yet the engine will still run and not all the lifters will be noisey ....one or two tho will drive ya nuts !

I know we're not talking 253's here but have a gander in ya book n see what the "actual lift" should be, this is the measurement that the cam lifts the rocker by. While non std cams will have an increased amount of lift the differance wont be that great unless your running a super lumpy cam and judging by the way it sounded last time I heard it ....its stock !

Only other suggestions I could make is ......
1#
grab a micrometer and measure the feeler guages you are using..... is the 0.38mm feeler guage ACTUALLY 0.38mm?
2#
Try resetting the clearance to 0.35mm instead of the 0.38mm. If thats an improvement then maybe go down to 0.32mm, but I wouldnt go much further than that.
3#
try setting the gap while the engine is running....ok its not an easy thing to do and its messy as all hell ( ya dad will hate ya for the oily mess ), but this way you can actually set the rockers so they are quiet and once done then check the gap.... this usually shows up as to how worn a cam / lifters are. TIP: grab an old rocker cover and cut the very top off so that the sides are as high as posiable, this will catch most of the oil before it makes the old mans driveway or lawn.... also use a drop sheet

Setting the clearances on chevs is best done as in number 3# ( you'll need to know this if you ever get around to putting in a decent motor )

the cam and lifters are ok, the thing is quite for a little while, a week of driving gets them to loosen again or watever.

this time im only going to adjust the front rocker and see if it quites down. then ill add another spacer if need be.

the only thing is the oil holes in the rocker rod itself???

right way up or down?

wats the deal here.....

This MAY not apply to a TB 42 but in a TD42, the rocker shaft has a small hole which aligns with a coresponding hole in the support. This feeds oil to the rockers themselves. There is a scribed mark showing which way it has to be installed. Hopefully it would be obvious if this hole was not lined up--there would be no oil getting to the rockers. I found it very difficult to properly adjust clearances with a feeler gauge because of how worn the pads were.

Nick

ill have to pull it apart me thinks

Just buy some "WYNNS Tapet Shhhh"

Shorty40 wrote:Just buy some "WYNNS Tapet Shhhh"

i wish