boxpin Posted February 26, 2014 Report Share Posted February 26, 2014 I am getting mixed messages when it comes to using grease on TTY bolts. I have read a few articles and am finding that they vary on whether or not to use a lubricant on the bolts. Here are a couple examples: A Yes vote: As with conventional head bolts a good thread and under bolt head lubricant is still important. Lubricants reduce the amount of friction between the fastener and the surface it contacts while being tightened. A quality thread lubricant will convert more of the torque to more usable clamping force instead of having it lost to friction. A No vote: TTY bolts are generally installed dry. Tend not to apply any oil, grease, assembly lube or sealer around the bolt threads. The main reason why is due to the fact lubricants lessen friction every time a bolt is tightened. This truly increases the torque load around the bolt, which may overload and stretch a TTY bolt too far, leading to it to break. So which is it? My last engine I used it on both the head and threads, seemed to work fine. Link to comment Share on other sites More sharing options...
BLUE965T Posted February 26, 2014 Report Share Posted February 26, 2014 I,m not sure about Volvo, But I am a tech at lexus and I am currently rebuilding one IS250 engine after another and the Lexus service manual states to thoroughly lube the head bolts before installation Link to comment Share on other sites More sharing options...
Piston Slapper Posted February 26, 2014 Report Share Posted February 26, 2014 In the cylinder head installation instructions in VIDA it says: Caution! Make sure that no fluids are present in the cylinder head bolt threaded bores. And says nothing about lubing them. Link to comment Share on other sites More sharing options...
boxpin Posted February 26, 2014 Author Report Share Posted February 26, 2014 I,m not sure about Volvo, But I am a tech at lexus and I am currently rebuilding one IS250 engine after another and the Lexus service manual states to thoroughly lube the head bolts before installation In the cylinder head installation instructions in VIDA it says: Caution! Make sure that no fluids are present in the cylinder head bolt threaded bores. And says nothing about lubing them. ...and its still a tie Link to comment Share on other sites More sharing options...
Piston Slapper Posted February 26, 2014 Report Share Posted February 26, 2014 ...and its still a tie I'm sorry, but if you consider information straight from VIDA specific to the application vs some random third party lexus hearsay to be a tie... you probably shouldn't be touching head bolts. Link to comment Share on other sites More sharing options...
Brad850 Posted February 26, 2014 Report Share Posted February 26, 2014 I posted this before (Volvo 5.0 gave me this I believe) Check out the very top in parentheses.. When I reassembled my intermediate block I lubed mine with motor oil. Link to comment Share on other sites More sharing options...
Volvo5.0 Posted February 26, 2014 Report Share Posted February 26, 2014 I always lube the threads and the washer surface under the head of the bolt. If you've ever installed them dry and heard the horrendous noise produced (when doing the final angle torque), you would know something's not right. Link to comment Share on other sites More sharing options...
DAYWALKER Posted February 26, 2014 Report Share Posted February 26, 2014 I just make sure all the bolt hole Is clean and used regular motor oil. This way it won't be to slippery or too dry. I'm pretty sure either way is fine because you can never get It exactly right according to the spec. To make you feel Better. I did a very stupid thing while torque down the head gasket. When I was nearly done. I realize that I was looking at the removal sequence rather then the torque down sequence. I'm surprise that the gasket didn't blow yet or warp the head. Link to comment Share on other sites More sharing options...
Brad850 Posted February 26, 2014 Report Share Posted February 26, 2014 I'm sorry, but if you consider information straight from VIDA specific to the application vs some random third party lexus hearsay to be a tie... you probably shouldn't be touching head bolts. You said vida doesn't mention lubing them or not lubing them. You gave no useful input, and somehow you feel the need to be snobby about it like always. Link to comment Share on other sites More sharing options...
BLUE965T Posted February 26, 2014 Report Share Posted February 26, 2014 "make sure no fluid is in the bolt holes" means just that. That doesn't say not to lube the bolts. It says that because if there is fluid in the bolt holes the fluid will cause hydraulic pressure in the bolt holes when the bolt is screwed in and will give false readings . Link to comment Share on other sites More sharing options...
DAYWALKER Posted February 26, 2014 Report Share Posted February 26, 2014 "make sure no fluid is in the bolt holes" means just that. That doesn't say not to lube the bolts. It says that because if there is fluid in the bolt holes the fluid will cause hydraulic pressure in the bolt holes when the bolt is screwed in and will give false readings .correct me if I'm wrong. I thought the head bolt hole goes straight down to the pan. Link to comment Share on other sites More sharing options...
Volvo5.0 Posted February 26, 2014 Report Share Posted February 26, 2014 "make sure no fluid is in the bolt holes" means just that. That doesn't say not to lube the bolts. It says that because if there is fluid in the bolt holes the fluid will cause hydraulic pressure in the bolt holes when the bolt is screwed in and will give false readings . correct me if I'm wrong. I thought the head bolt hole goes straight down to the pan. The bolt holes don't go all the way down. When pulling the head, coolant and oil find there way into the bolt holes. Definitely need to blow them out with compressed air before re-assembly. Link to comment Share on other sites More sharing options...
Piston Slapper Posted February 26, 2014 Report Share Posted February 26, 2014 That doesn't say not to lube the bolts. It doesn't say not to cross thread them either. Instructions not saying to do something means it's not something you need to do. Link to comment Share on other sites More sharing options...
Volvo5.0 Posted February 26, 2014 Report Share Posted February 26, 2014 Here you go. From the latest (legal) version of Vida. Notice how it also states to use NEW bolts, for anyone thinking it's OK to re-use head bolts.... Link to comment Share on other sites More sharing options...
Piston Slapper Posted February 26, 2014 Report Share Posted February 26, 2014 Here you go. From the latest (legal) version of Vida. Notice how it also states to use NEW bolts, for anyone thinking it's OK to re-use head bolts.... ~snip~ At least they capitalized your name for your account... mine is all lower case Link to comment Share on other sites More sharing options...
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