Im about to change a timing belt for my boss. Ive done this on multiple swaps before but for ***** and giggles, I looked up the FSM for 96-00 civic's. The manual says to torque the crank pulley bolt to 14 foot pounds then 90 degrees afterwards. Yes, thats correct 14 LBS!!!!! Its just weirding me out because for a DOHC engine its' 130 lbs. This is the first time Ive looked at the FSM. Has anyone torque it to 14 lbs and it didnt come loose? Any input would be great. Couldnt find my answer on other threads so dont flame me too hard. TIA.

 

Obviously, you are not familiar with "Torque Angle". A low target starting torque specification is typically established and then the bolt is turned beyond that point by a specified angle... in this case, 90 degrees. The torque spec on a '92-95 Civic is 112 ft/lbs. which is lower than the torque spec on a "B" series engine. If you torque a "B" series crank pulley bolt to 14 ft/lbs, then torque it to the proper final spec of 132 ft/lbs... you will see that the distance traveled will be greater than 90 degrees... and less than 120 degrees.

In short, Torque Angle is a TWO STEP process... first a torque spec AND an additional tightening of the bolt/fastener a specified angle beyond the initial spec.

 

If it's a manual car you can put the transmission in 5th to hold the engine, then tighten conventionally to the spec (130 or 140 ft lb) with a torque wrench. Automatic cars have the problem of the engine moving, so that is where the 90 degree specification is useful. You can do that with an impact gun without needing to stop the engine.

Whatever you do, it needs to be tight. The pulley will come off if you leave the bolt loose.

 

I'll be honest, I've torqued many a crank pulley on and I basically just either use the large hex tool and two breaker bars and tighten until I can't anymore, or use an impact until it stops moving. When the torque spec is 110+ ft/lbs, you're not likely to get it "too tight".

 

Thanks for all the input. And yes, I was unfamiliar with "torque angle" as I have never heard that term before. Like I stated, I've done multiple swap jobs using only my "on the job" experience so when I actually looked at a FSM, needless to say, I was surpised to see such a low foot pound spec. Didnt want to ruin my bosses DD. Thanks again.

 

I just did this recently. When you order this bolt from Honda, the manufacture provides you with instructions on how new torque spec and procedure for tightening. They updated it because they changed the design/material of the crank bolt. So when you order the new bolt, there will be instruction included in the packaging.

 

Torque angle is not better or worse... just different. The Germans have been using it for years. When you have angle specs like 45' or 90'... you can eyeball it and be pretty accurate. Things get dicey when it is a weird spec... like rod bolts on a K20A2. The spec is 14 ft/lbs + 56'... that one is hard to eyeball !!!

 

I got the new bolt too and it came with the instructions. I have a stock 1997 Civic HX with 310k and MT. I decided to use the old bolt and original FSM instructions since it was a bit simpler than the new bolts.

I kind of want to understand the "why" behind the new instructions though just because I am curious.
Old bolt instructions : torque bolt to 14 ft-lbs + 90 degrees
New bolt instructions : 1) Tighten bolt to 145 ft-lbs then fully loosen it again
2) Tighten bolt to 20 ft-lbs + 60 degrees
3) Install accessory belts and run engine for 3 minutes.
4) Stop engine and torque bolt an additional 30 degrees.

What is the reason for the more involved spec of the new bolt ? Why is there an initial torque to 145 ft-lbs (which is then backed out) and then the "final torquing of 20 ft-lbs + 60 degrees + run engine for 3 minutes wiht belts on + 3 degrees ?

I am asking why, not how btw. I already have completed the job.

 

The first spec is to get the bolt material close to it's yield... then you loosen it and finally re-torque. The new spec is just slightly tighter than the OE spec. 20 ft/lbs + 90 degrees compared to 14 ft/lbs + 90 degrees. The three minutes in between the 60 degree and final 30 degree torque steps allows the bolt to heat up and then cool to stabilize the material.