main bearing cap bolt torque

callum

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Apr 27, 2010
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just want to check if the haynes is telling the truth saying these are 103nm + 90 degrees. mid way through the job replacing big ends and its getting to the limit of my strength with the torque wrench. i'm also terrified of snapping a bolt.

are they really to be this tight?

off to check the toyota fsm now to see if it says the same, but as i say, i'm terrified of breaking the bolts.
 

joinerman

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76Lb/ft + 90 degrees.

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Bat21

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callum said:
just want to check if the haynes is telling the truth saying these are 103nm + 90 degrees. mid way through the job replacing big ends and its getting to the limit of my strength with the torque wrench. i'm also terrified of snapping a bolt.

are they really to be this tight?

off to check the toyota fsm now to see if it says the same, but as i say, i'm terrified of breaking the bolts.
Wooooo hang on a minute, what are you doing ferking about with the main bearing caps while replacing the big ends :o

The big end bolts are 37N-m +90 degrees!
 

Dave Docwra

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You would be best adviced, to replace the bolts that have been renewed & fitted as they will be stretched :(
 
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callum

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well thankfully i came here for for a look and hit the fsm to verify. indeed i had my bolts mixed up. thankfully i did not have my first bolt to 103nm, so disaster averted and they are now all at the correct torque, although the 90 degree turn did require quite a lot of force.

speaking of disaster averted, hopefully if i'm very clever i'll be able to upload a picture of my shells. a few tiny crater marks on some and most looked not too bad apart from cyl. 4 top. glad i changed them.






having done that, when rolling around i foudn one of the anti roll bar attachments at the back had broken though... sigh explains my squeak at least.
 

Bat21

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callum said:
..... although the 90 degree turn did require quite a lot of force.
Were you a good boy and mark them with Tippex like uncle Bat told you **HERE** :D
 

BobMurphy

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callum said:
its getting to the limit of my strength with the torque wrench.


OK, I know this job has been finished, but I just replaced the cylinder head on my 1KZ-TE motor.

The 18 head bolts are torqued-up to 29 Ft-Lbs then +90 deg, then + a second 90 deg - in the prescribed sequence.

They do require a surprising amount of strength and I only used the torque wrench for the 'torque' bit.

I then marked the front face of each bolt with a paint marker and used a 24" power bar for the two 90 deg turns. Each turn was done slowly and carefully. These things are tight :shock: .

I used new head bolts, lightly oiled and blew out the threaded holes in the block with compressed air at 150 psi.

I think I would have been well above the upper limit of my middle-sized torque wrench had I used it all the way through (the big one is a 3/4" drive 50-300 ft-lbs certified monster. That would have been over-kill :lol: ).


Bob.
 
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