1HD-T Camshaft installation (1 Viewer)

[jasonMartins]

Hey Guys

I am doing a full rebuild on my 1HD-T engine. Yesterdaay i failed installing the Camshaft and i am trying to figure out what went wrong.

So what happend:
i placed the camshaft on the cylinder head, block on TDC and puted al the bearings on. i've seted the Torque wrench to 6 Nm (53Lbs) and started to tighten the bolts in the sequence as shown in the manual. While tightening the last bolts (13 and 14) the camshaft broke in 2 pieces between valve 11 and 12.

I have propably misunderstood the manual thinking that "several passes" also means several steps in torque? do i need to tighten the bolts directly with the full torque?

i now ordered a new camshaft but it would be great, not breaking that one again.... the engine must be running in 2 weeks as we are planing vacation then... i prefer having some fun with the vehicle than still rebuilding my engine then

Thank you for your help

 

[chapel gate]

No.
Tighten in very small increments until the cam is seated and the bolts are hand tight.
Then torque to spec.

Where do you get 6nm from?

 

[jasonMartins]

ok, so smaller than 6nm steps?
i was thinking 3 steps should be ok, so 18/3 = 6

 

[mudgudgeon]

ok, so smaller than 6nm steps?
i was thinking 3 steps should be ok, so 18/3 = 6

If the cam is pushing against valve springs as you tighten it down, you need to tighten each bearing cap bolt literally 1/4 of a turn each, then move on to the next one.
If you follow the FSM faithfully, there'll only be a couple of cam lobes pushing against valve spring pressure. Pay particular attention to the bearing caps either side of these lobes. Tightening them down bit by bit sets the pace for tightening down the others.

Be careful to keep each cap tightening down evenly, if one bolt on a cap gets tightened down more than the other, the cap can end up skewed and bind on the locating bushes

 

[chapel gate]

ok, so smaller than 6nm steps?
i was thinking 3 steps should be ok, so 18/3 = 6

Forget the torque wrench until the cam is seated.
More like 20 steps... I've never counted.

 

[Dave 2000]

Remember to double check cam timing, if wrong then you can easily bend valves, assuming you haven't already?

Regards

Dave.

 

[jasonMartins]

Thanks guys for your help i highly appreciate that.

About the timing i am aware of that.

So to make it clear, i should tighten all bolts by hand, then tighten in 1/4 rotation steps in the sequence like shown in the manual until all bolts are tight (no gap between bearing am cylinder head) and then tighten with the torque wrench?

 

[jasonMartins]

Hey guys

The camshaft will arrive today. Can anyone confirm that my understanding was right?

Thanks