New 3vze heads are in, few questions
10-13-2010, 07:47 AM
#1
New 3vze heads are in, few questions
I got my reman heads in the other day. I am still working on pulling out my old heads. All I have left it removing the camshaft pulleys and intake manifold. I am unsure how to make sure pulleys go on the right way in relation to camshaft position. Is the pulley keyed so it only goes on one way? If that's the case, do I put the pulley on the new heads and twist it around until the up arrow, or mark are straight up lined up with the marks again?
Also, do I indeed have to remove the camshafts to pull the heads?
Also, do I indeed have to remove the camshafts to pull the heads?
10-13-2010, 08:38 AM
#2
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,252
Likes: 0
Received 820 Likes
on
648 Posts
Yes, yes, and yes.
The camshaft pulleys aren't really keyed; they have a 5mm pin (called a knock pin) that fits in a hole on the end of the camshaft and on the pulley. That pin could be bent; if so replace it. So the pulley can only "fit" on one way. Note that the left and right pulleys are identical but installed flipped over (compared to each other). Make a note which is which before you pull them off.
The when you drop the camshaft onto the head, the position is wholly arbitrary. So rotate the cam/pulley until the the mark is straight up at TDC, then put on the timing belt.
Yes, you cannot get to all the head bolts without removing the camshaft. Does your reman head come with camshafts? Probably not.
Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on. A 1 1/8" wrench will also work, a Crescent wrench will not. You'll probably need to rig up a 2x4 'strut' to hold the wrench; you don't want it pressing on the aluminum head with the full torque of the camshaft pulley bolts.
The camshaft pulleys aren't really keyed; they have a 5mm pin (called a knock pin) that fits in a hole on the end of the camshaft and on the pulley. That pin could be bent; if so replace it. So the pulley can only "fit" on one way. Note that the left and right pulleys are identical but installed flipped over (compared to each other). Make a note which is which before you pull them off.
The when you drop the camshaft onto the head, the position is wholly arbitrary. So rotate the cam/pulley until the the mark is straight up at TDC, then put on the timing belt.
Yes, you cannot get to all the head bolts without removing the camshaft. Does your reman head come with camshafts? Probably not.
Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on. A 1 1/8" wrench will also work, a Crescent wrench will not. You'll probably need to rig up a 2x4 'strut' to hold the wrench; you don't want it pressing on the aluminum head with the full torque of the camshaft pulley bolts.
10-13-2010, 09:21 AM
#3
Contributing Member
Join Date: Apr 2006
Location: TENN Native Languishing in Virginia
Posts: 4,787
Likes: 0
Received 34 Likes
on
14 Posts
"Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on."
I don't recommend this as it puts undue stress on the cam. It's not difficult to build a tool to hold the pulley while you loosen the bolt.
I don't recommend this as it puts undue stress on the cam. It's not difficult to build a tool to hold the pulley while you loosen the bolt.
10-13-2010, 09:25 AM
#4
You can remove the heads without removing the cams, you do not have to remove the head bolts to pull the heads. It's kind of tricky as you have to sort of wedge the bolts up, though, because they want to keep falling back in the holes.
However, you cannot reinstall the heads with the cams in place.
However, you cannot reinstall the heads with the cams in place.
10-13-2010, 09:55 AM
#5
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,252
Likes: 0
Received 820 Likes
on
648 Posts
"Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on."
I don't recommend this as it puts undue stress on the cam. It's not difficult to build a tool to hold the pulley while you loosen the bolt.
I don't recommend this as it puts undue stress on the cam. It's not difficult to build a tool to hold the pulley while you loosen the bolt.
While I have a lot of respect for TNRabbit's opinions, I have to disagree with this. The cam is forged steel about 25mm in diameter. The flats cast into it are designed to fit a wrench. The commercially available tools for holding the pulley place 100% of the torque resisting force on two tiny points on the side of the pulley webs, which themselves are only about 5mm thick. But holding the pulley alone doesn't allow you to remove the bolt, it has to stop the cam from turning. And all the pulley can do is transfer all of the torque to the single 5mm knock pin.
25mm cam, or 5mm knock pin and 5mm side-loaded web; which is going to fail first?
Having said that, I will point out that the design torque on the cam bolt is not so high that a well made pulley-holding tool can't safely resist the torque. And the pulley-holding tool has the advantage that it can be used in the few cases where you need to remove the pulley without removing the valve cover.
But as many of us have learned, that bolt can often require far more than design torque to remove. So if I were removing that bolt for the first time, and I had access to the cam wrench flats, I would use the wrench flats. Otherwise I would be risking the pulley and knock pin by trying to hold the pulley, when what I really need is to hold the cam.
Just one man's opinion.
10-13-2010, 10:29 AM
#6
Yes, yes, and yes.
The camshaft pulleys aren't really keyed; they have a 5mm pin (called a knock pin) that fits in a hole on the end of the camshaft and on the pulley. That pin could be bent; if so replace it. So the pulley can only "fit" on one way. Note that the left and right pulleys are identical but installed flipped over (compared to each other). Make a note which is which before you pull them off.
The when you drop the camshaft onto the head, the position is wholly arbitrary. So rotate the cam/pulley until the the mark is straight up at TDC, then put on the timing belt.
Yes, you cannot get to all the head bolts without removing the camshaft. Does your reman head come with camshafts? Probably not.
Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on. A 1 1/8" wrench will also work, a Crescent wrench will not. You'll probably need to rig up a 2x4 'strut' to hold the wrench; you don't want it pressing on the aluminum head with the full torque of the camshaft pulley bolts.
The camshaft pulleys aren't really keyed; they have a 5mm pin (called a knock pin) that fits in a hole on the end of the camshaft and on the pulley. That pin could be bent; if so replace it. So the pulley can only "fit" on one way. Note that the left and right pulleys are identical but installed flipped over (compared to each other). Make a note which is which before you pull them off.
The when you drop the camshaft onto the head, the position is wholly arbitrary. So rotate the cam/pulley until the the mark is straight up at TDC, then put on the timing belt.
Yes, you cannot get to all the head bolts without removing the camshaft. Does your reman head come with camshafts? Probably not.
Last, you might note that there is a 27mm hex-flat cast into the middle of the camshaft. You can use that to keep the cam from turning when you remove the bolt holding the pulleys on. A 1 1/8" wrench will also work, a Crescent wrench will not. You'll probably need to rig up a 2x4 'strut' to hold the wrench; you don't want it pressing on the aluminum head with the full torque of the camshaft pulley bolts.
Any advice to reinstalling the cams from the remans after removing them for installation? I have the correct torque procedure from the FSM (found in the sticky on this forum!). Should the lifters just push right down when the cam lobes come in contact and while torquing them?
and everybody likes pics...
10-13-2010, 10:39 AM
#7
Registered User
Join Date: Sep 2007
Location: San Francisco East Bay
Posts: 8,252
Likes: 0
Received 820 Likes
on
648 Posts
You might consider using assembly lube (something like http://www.permatex.com/products/aut...embly_Lube.htm)
particularly on the cam surfaces, and probably on the cam journals. I used it because I had it, so I can't say what would happen if you didn't. Supposedly, it provides lubrication for for those few seconds after startup until you pump oil into those places.
particularly on the cam surfaces, and probably on the cam journals. I used it because I had it, so I can't say what would happen if you didn't. Supposedly, it provides lubrication for for those few seconds after startup until you pump oil into those places.
Trending Topics
10-13-2010, 01:08 PM
#8
Registered User
Even though the heads are supposed to be in spec, give a check on the valve lash, it is so much easier to replace any of the shims if necessary when the heads are off the truck.
Thread
Thread Starter
Forum
Replies
Last Post
the1998sr5
95.5-2004 Tacomas & 96-2002 4Runners
15
07-14-2020 08:35 PM
88yodabasket
86-95 Trucks & 4Runners
15
07-13-2015 01:32 PM
