850T5 Cam Followers

[Ben C via CarKB.com]

Is changing cam followers straight-forward, or are there any hidden
nightmares to worry about?

 

[Mike F]

Is changing cam followers straight-forward, or are there any hidden
nightmares to worry about?

Assuming you know about the timing belt issues, then there's a couple of
gotchas with taking the upper half of the head off (to get the cams
out). If it doesn't come off evenly, i.e. if one side come up before
the other, you'll break a little (very important) piece of the casting
off. And it's glued down with a special sealer (no gasket) that needs
to be spread evenly with a roller. And this sealer makes it tough to
pull the upper part of the head up evenly, there's a special tool just
for this job.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

[Tim..]

Assuming you know about the timing belt issues, then there's a couple of
gotchas with taking the upper half of the head off (to get the cams
out). If it doesn't come off evenly, i.e. if one side come up before
the other, you'll break a little (very important) piece of the casting
off. And it's glued down with a special sealer (no gasket) that needs
to be spread evenly with a roller. And this sealer makes it tough to
pull the upper part of the head up evenly, there's a special tool just
for this job.

To add what Mike has knowledgeably said, you need a device (volvo tool or
your own made one) to pull the top half back down onto the lower when you
re-assemble (against the pressure of the valve springs) and also some wire
both ends to fasten the cams to the top half as you lower them down. There
is an off-centre slot in the dissy end of both cams you can slide a piece of
flat metal into to lock them at 'tdc' position also.

You need about 8 pairs of hands at this stage!

The cam pulleys will need to come off, mark their position relative to the
shafts with tippex or similar prior to releasing them- on some cars they are
NOT keyed to the shaft. Beware.

I would strong recommend using the puller when releasing the top cover to
ensure it comes up evenly- as Mike said you will break the casting if it
does not. It is located on about 8 dowels and it can be tight to release,
but sometimes they pop up of their own accord.

The tools I have are made a-la Haynes from 3 old plugs, the insultor and
innards drilled out and some thread welded on with a cross piece and nut on
the top. The cross piece straddles the cam cover. Install plugs in 1,3 and 5
and you can pull the upper half down squarely very easily, or conversely let
it spring up evenly.

With respect to the sealer, Volvo sell both the removal thinners and the
proper sealer stuff to re-assemble it with.

On *no* account *ever* use instant gasket, or worse silicone, or anything
else. You will have leaks all over the shop if not worse. The Volvo sealer
comes with a fine hair roller, which after you have removed the old sealer
with the thinners you apply a very thin layer with the roller.

The new tappets must be soaked in clean engine oil for 24hrs first, and
during this time use your fingers below oil level compress and release
several times to prime them afew times.

Hope this helps.

Tim...

 

[Ben C via CarKB.com]

I managed to pull the cam cover down with the cams resting in place on the
head. You need to do this very slowly & evenly, but it works. To compress the
cam-belt tensioner, I placed it on a sissor jack and lifted it against the
subframe bolt. Again, you have to do this very slowly to allow the piston
time to retract, but it works. Working on a Tank range has it's disadvantages,
not least an M1 Abrams firing in your left earhole when you are trying to
line the pulleys up, but I did find the job to be not beyond DIY capability.
Thanks for your advice.

[quoted text clipped - 7 lines]

pull the upper part of the head up evenly, there's a special tool just
for this job.

To add what Mike has knowledgeably said, you need a device (volvo tool or
your own made one) to pull the top half back down onto the lower when you
re-assemble (against the pressure of the valve springs) and also some wire
both ends to fasten the cams to the top half as you lower them down. There
is an off-centre slot in the dissy end of both cams you can slide a piece of
flat metal into to lock them at 'tdc' position also.

You need about 8 pairs of hands at this stage!

The cam pulleys will need to come off, mark their position relative to the
shafts with tippex or similar prior to releasing them- on some cars they are
NOT keyed to the shaft. Beware.

I would strong recommend using the puller when releasing the top cover to
ensure it comes up evenly- as Mike said you will break the casting if it
does not. It is located on about 8 dowels and it can be tight to release,
but sometimes they pop up of their own accord.

The tools I have are made a-la Haynes from 3 old plugs, the insultor and
innards drilled out and some thread welded on with a cross piece and nut on
the top. The cross piece straddles the cam cover. Install plugs in 1,3 and 5
and you can pull the upper half down squarely very easily, or conversely let
it spring up evenly.

With respect to the sealer, Volvo sell both the removal thinners and the
proper sealer stuff to re-assemble it with.

On *no* account *ever* use instant gasket, or worse silicone, or anything
else. You will have leaks all over the shop if not worse. The Volvo sealer
comes with a fine hair roller, which after you have removed the old sealer
with the thinners you apply a very thin layer with the roller.

The new tappets must be soaked in clean engine oil for 24hrs first, and
during this time use your fingers below oil level compress and release
several times to prime them afew times.

Hope this helps.

Tim...