Torqing head bolts - stripped?
07-21-2006, 02:19 PM
#1
Registered User
Thread Starter
Join Date: May 2006
Location: Duluth, Georgia
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
Torqing head bolts - stripped?
95 4Runner SR5 185k. I just installed my head bolts per the manual....apply a bit of oil to the bolts, tightened them in sequence up the 30 ft lbs. Marked the head bolt with paint...tightened 90 degrees, then another 90 degrees. On the last tightening sequence a couple of bolts almost seemed to strip because they seemed to slip somewhat, as if it was easier to turn them the last little bit. Is this because of the oil I applied to the threads and underside of the bolts? Maybe I put too much oil on them? Has this happened to anyone else? I really don't want to take them out now and re-torque.
Please help.
Thanks,
Brian
Please help.
Thanks,
Brian
07-21-2006, 08:22 PM
#4
Registered User
Join Date: Jul 2005
Location: Seattle, WA
Posts: 135
Likes: 0
Received 0 Likes
on
0 Posts
also make sure before you put the bolts in to blow out the holes because there is most likely some oil down in there which can give you false torque readings and maybe a feeling of a stripped bolt. Good luck!
07-22-2006, 02:11 AM
#5
Registered User
Join Date: Mar 2004
Location: Salem,Oregon
Posts: 511
Likes: 0
Received 0 Likes
on
0 Posts
Its quiet possibly just your head gasket compressing as it should only in an uneven fashion.
Back everything off then try going over the sequence a few times only instead of the last 90* go 30#+90* then maybe 45* or less. once you have done that 3 or 4 times (yes I know its tedious, I did mine about 6 times per head) then make 1 final pass at the proper spec 30#+90*+90* and you will feel much better about the way the bolts torque down. What I find amazing is that if you do it once as you already did mark the head bolts with paint all in one direction then do as I suggested and back them off (this is EB's Idea by the way) you will find that your paint marks are far different than what they where the 1st time you did it. The bolts will actually screw in a little more each time even though your torque spec is actually less than the initial try. From what I understand it helps to seat the threads properly and gets a much more uniform clamping pressure. Its really clamping pressure we are looking for so the more freely the bolt turns (especially under load) the better your clamping pressure and that's where the multi sequence comes in for bedding the threads properly.
Also remember that your block surface and head surface should be ABSOLUTLY spotless dare I say sterile for proper gasket bonding.
OK enough rambling from me Maybe Ted (Engnbldr)will chime in as he is my source for this tidbit of very useful information.
Back everything off then try going over the sequence a few times only instead of the last 90* go 30#+90* then maybe 45* or less. once you have done that 3 or 4 times (yes I know its tedious, I did mine about 6 times per head) then make 1 final pass at the proper spec 30#+90*+90* and you will feel much better about the way the bolts torque down. What I find amazing is that if you do it once as you already did mark the head bolts with paint all in one direction then do as I suggested and back them off (this is EB's Idea by the way) you will find that your paint marks are far different than what they where the 1st time you did it. The bolts will actually screw in a little more each time even though your torque spec is actually less than the initial try. From what I understand it helps to seat the threads properly and gets a much more uniform clamping pressure. Its really clamping pressure we are looking for so the more freely the bolt turns (especially under load) the better your clamping pressure and that's where the multi sequence comes in for bedding the threads properly.
Also remember that your block surface and head surface should be ABSOLUTLY spotless dare I say sterile for proper gasket bonding.
OK enough rambling from me Maybe Ted (Engnbldr)will chime in as he is my source for this tidbit of very useful information.
07-22-2006, 04:14 AM
#6
Contributing Member
Originally Posted by Ganoid
Its quiet possibly just your head gasket compressing as it should only in an uneven fashion.
Back everything off then try going over the sequence a few times only instead of the last 90* go 30#+90* then maybe 45* or less. once you have done that 3 or 4 times (yes I know its tedious, I did mine about 6 times per head) then make 1 final pass at the proper spec 30#+90*+90* and you will feel much better about the way the bolts torque down. What I find amazing is that if you do it once as you already did mark the head bolts with paint all in one direction then do as I suggested and back them off (this is EB's Idea by the way) you will find that your paint marks are far different than what they where the 1st time you did it. The bolts will actually screw in a little more each time even though your torque spec is actually less than the initial try. From what I understand it helps to seat the threads properly and gets a much more uniform clamping pressure. Its really clamping pressure we are looking for so the more freely the bolt turns (especially under load) the better your clamping pressure and that's where the multi sequence comes in for bedding the threads properly.
Also remember that your block surface and head surface should be ABSOLUTLY spotless dare I say sterile for proper gasket bonding.
OK enough rambling from me Maybe Ted (Engnbldr)will chime in as he is my source for this tidbit of very useful information.
Back everything off then try going over the sequence a few times only instead of the last 90* go 30#+90* then maybe 45* or less. once you have done that 3 or 4 times (yes I know its tedious, I did mine about 6 times per head) then make 1 final pass at the proper spec 30#+90*+90* and you will feel much better about the way the bolts torque down. What I find amazing is that if you do it once as you already did mark the head bolts with paint all in one direction then do as I suggested and back them off (this is EB's Idea by the way) you will find that your paint marks are far different than what they where the 1st time you did it. The bolts will actually screw in a little more each time even though your torque spec is actually less than the initial try. From what I understand it helps to seat the threads properly and gets a much more uniform clamping pressure. Its really clamping pressure we are looking for so the more freely the bolt turns (especially under load) the better your clamping pressure and that's where the multi sequence comes in for bedding the threads properly.
Also remember that your block surface and head surface should be ABSOLUTLY spotless dare I say sterile for proper gasket bonding.
OK enough rambling from me Maybe Ted (Engnbldr)will chime in as he is my source for this tidbit of very useful information.
Thread
Thread Starter
Forum
Replies
Last Post
kgcwb44
86-95 Trucks & 4Runners (Build-Up Section)
4
01-29-2023 10:02 AM
GreatLakesGuy
The Classifieds GraveYard
8
09-04-2015 09:27 AM
whereAreMyPants
86-95 Trucks & 4Runners
2
07-22-2015 03:32 AM
