Master
Hi
I cant find in the rave what lube to use on the td5 head bolts or if they are meant to be done dry.
I know most use some engine oil under the head washer and on the threads and considering the difference that different lubes can have on torque id like something firm so i know i am not going past the curve in the elastic of bolt and losing tension when tightening
this is a rough guide on the difference's
Example - Reduction of Torque when Bolt is Lubricated
No lube 0 Graphite 50 - 55 White Grease 35 - 45 SAE 30 oil 35 - 45 SAE 40 oil 30 - 40
The maximum tightening torque for a slightly lubricated 1" Grade 5 coarse bolt is 483 lb ft. Dry bolt torque is approximately 30% higher - or 628 lb ft.
Tdry = (483 lb ft) (1 + (30%) / (100%))
= 628 lb ft
If the bolt is lubricated with SAE 30 oil - the torque compared to a dry bolt is reduced with approximately 40%.
TSAE30 = (628 lb ft) (1 - (40%) / (100%))
= 377 lb ft
Note that if torque specified for a dry or slightly oiled bolt torque is applied to a lubricated bolt - the bolt may overload and break.
td5 head bolt.PNG
TopicToaster
SupporterOriginally Posted by lyonsy
In the refit section of RAVE.
Step 5 says:
hope that helps.5. Lightly lubricate threads and beneath heads of
cylinder head bolts with clean engine oil.
Not saying this is the best lube, and nor do I have any experience .. just pointing out what RAVE says.
EDIT: and as it doesn't specifically say what type of engine oil, I suppose it's assumed that it will be the recommended TD5 engine oil of between a 5W30 and 10W60 rating.
hope that helps.
Arthur.
All these discos are giving me a heart attack!
'99 D1 300Tdi Auto ( now sold :( )
'03 D2 Td5 Auto
'03 D2a Td5 Auto
Swaggie
SubscriberThe best AFAIK
100-9910 ARP Ultra Torque Assembly Lubricant | eBay
Also look at the youtube.
Regards Philip A
Master
Thanks AK83 what i was looking for.
PhilipA that may be so but it will change the torque value IE when using oil over dry you have to decrese torque by 30-40% go to a moly grease it may be 50%, if the arp stuff as as good as it says it could be a 60% decrease in torque to get the required load/stretch so following the factory specs will mean you go well past the elasticity curve of the bolt loose clamping force and most likely break a bolt. torque-to-yield-fasteners-5-638.jpg
Moderator
Mark, I went with the ARP lube several years ago (Tdi) just for the consistency.
Have a read of their white paper and see what you think.
Swaggie
Have done too many to count, ive only ever used engine oil. Lightly. Don't overthink it.
Jc
The Isuzu 110. Solid and as dependable as a rock, coming soon with auto box😊
The Range Rover L322 4.4.TTDV8 ....probably won't bother with the remap..😈
Master
Yeah the arp stuff looks the goods.
But my worry with it is that it will lube to well and go past the point of no return and loose pressure on the head (not something i want on a new 3k head) but it also may be ok due to the deg method over straight torque value
And all the info i can find on the arp lube is for non torque to yield bolts and studs
ill have a think and may get some and an extra 2 studs and do a length measurement and see if there is any difference in length of the bolts.
Swaggie
We lightly oil, torque 1st and then go back over at the same Nm to ensure evenness , then begin the angle torquing sequences. It really is that simple...
The Isuzu 110. Solid and as dependable as a rock, coming soon with auto box😊
The Range Rover L322 4.4.TTDV8 ....probably won't bother with the remap..😈
ChatterBox
EXACTLY
AT RESTYou'd know Justin as it's your lively hood and you have to guarantee the work. Too many times home mechanics don't follow instructions and want to reinvent the wheel, then when they get into trouble its never their fault.
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