How important is it to torque to factory specs?

How important is it to torque nuts/bolts to factory specs on the NSX?

How important is it to torque nuts/bolt to factory specs on other cars?

Do they torque to factory specs at the dealership?

I do understand that the size of the bolt/nut is related with the require torque to tighten it. Is this general guessing good enough?

Is there certain areas or components that require more accuracy?

Does book time and Mitchell include the time to it lookup and torque everything in their time estimates?

All the independent shops that I go to, never even bother to lookup the factory torque and never use a torque wrench, unless they are working directly with engine internals.

I personally torque all bolts/nuts to factory specs on my NSX because of the aluminum parts. And it lets me sleep at night knowing it was done right. I have the extra time to research the factory torque spec and torque each one accordingly. I don't have a boss breathing down my neck to get the car out the garage.

If you have ever accidentally over torqued a bolt the threads have now stretched a very small amount. The factory torque specification gets thrown out the window from that point forward. I've seen this one guy on a WRX ALWAYS torque to factory specification on suspension. He removed and re-used hardware all of the time. This past summer one of his camber bolts came out.

The "stuck-up" NSX owner answer is yes. The general answer is - it depends. Engine internals always yes. Bolting your cruise control unit into your car no.

vsy05 said:

How important is it to torque nuts/bolts to factory specs on the NSX?

I personally torque all bolts/nuts to factory specs on my NSX because of the aluminum parts.

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You already give the answer yourself. For me, it's not only the aluminium but I also want to be sure that screws don't come loose. It's a much smaller range between too loose and overtorqued. Some of the OEM screws are quite intelligent. I once stripped a new water pump screw (dummy me) because I went with 22 Nm instead of 12 by fault. It cut off the head and didn't harm the threads. These coated screws are very critical to torque.

I've three different torque wrenches I always use, purchased only for the NSX and don't have an air tool which is only needed for the pulley for sure, the axle nut and the exhaust screws maybe. It's very advisable to use cermatic paste on the threads.

I'm really curious because I recently went to my friends repair shop and started to talking to the mechanics. After observing them for a while, I never saw them use a torque wrench or researching proper torque specs.

I asked them about it and they said it wasn't really that critical. They said even dealers don't torque them exactly. And I can't recall ever seeing any other mechanics at other independent shops use one.

I could understand why, because it would take twice as long to fix anything. They are on a major time constraint.

vsy05 said:

I asked them about it and they said it wasn't really that critical.

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They're maybe right on cars mainly made out of steel. The range between too loose and stripped is much wider. Personally, I wouldn't trust them my NSX at all.

The tools don't cost a fortune and it's pure fun hearing and feeling the click the wrench makes. Yes, I'm obsessed of it. :tongue: So, on my car there's near to none screw that is not torqued correctly with the wrench.

Note that auto and other manufacturers torque virtually every bolt using either hand or robotic tools. Even in large-scale electronics manufacturing in Asia, screws that hold down printed circuit boards are torqued.

I use a torque wrench on virtually every bolt on all my cars, not just the NSX. And when I did my timing belt, I even used a small torque wrench on the "millions" of bolts holding on all the covers. As a result, for other than bolts that some other mechanic touched, I've never had a bolt strip or come loose in my "few" decades of working on my own cars. It may take a little longer, but I keep my cars for typically 10 to 15 years or more, so it matters to me.

Your mileage may vary.:biggrin:

All engine bolts = Yes (especially spark plugs).

Chassis bolts = If you have a good "feel" for torque you're probably OK.

I would think that if someone was using an old torque wrench that was hardly ever calibrated it would mess up the final torque. When I was in the Air Force working on the RC-135's our torque tools routinly went in for calibration. I also have a set of torque tools for the nsx but I wonder how percise they are after 8 years.

pgilliam1 said:

All engine bolts = Yes (especially spark plugs).

Chassis bolts = If you have a good "feel" for torque you're probably OK.

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+111

Putting a motor back together piece by piece/internal motor build or replacing a clutch is a must.

almost anything else you can eyeball or feel if you trust yourself. If not, go by the book..

1st== buy three torque wrenches,1/4",3/8",1/2"
2nd == all engine, transmission,suspension,steering,&brake hardware should
be torqued (when a car is assm. every piece of hardware is torqued)
3rd== make sure you have the correct bolt where it belongs,a grade 8.8 or 10.9 requires different torque values (just dont replace a bolt and because it threads in and assume its the correct hardness for the application )
4th== dont assume what you see in a shop is always done correctly because
its not ,trust me (40 yrs exp.)
5th== follow the manual or ask on prime,
6th== the fact that you can watch people in shops put wheels on ,do brake
work,engine work, transmission work and never use a torque wrench is
a testament to the engineering of these products.:wink:

99 rs said:

The "stuck-up" NSX owner answer is yes. The general answer is - it depends. Engine internals always yes. Bolting your cruise control unit into your car no.

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So, the way I understand stand what you are saying is that any NSX that wants to make sure the bolts are torqued correctly is stuck up?

The only caveat I've found in the NSX shop manual is the torque spec for the oil pan attaching bolts. The torque spec in the manual will cause the oil pan gasket to squish out the sides too far.

Q said:

The only caveat I've found in the NSX shop manual is the torque spec for the oil pan attaching bolts. The torque spec in the manual will cause the oil pan gasket to squish out the sides too far.

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Nice point. While I've changed mine a few weeks ago I let it be good at 10 Nm (instead of 14 Nm) as I felt that 10 Nm is pretty enough for these. If the gasket settles or starts sweating I still can go for more.

Chassis bolts: Guys, be sure use a torque wrench, for example for the front beam. I agree that those 10 Nm screws like ABS lines or so are not that critical.

Does the factory have a specialized tool for controlling the torque on fasteners you can only get an open-end on, e.g. locknuts on tie rods?

(I can picture how such a tool could be made, but I don't know if they exist.)

I torque everything and I'll only skip on non-essential brackets.

It nearly doubles the shop time IMHO due to the time looking for obscure torque values.

I don't think you can do it in a normal shop for normal customers. They ONLY place I've seen it done is Ferrari of Beverly Hills. The shop area could double as a surgery room and the technicians DO run around in white lab coats. Then again when I dropped my buddy off to pick up his F car, the bill for a standard oil change was just a tad over $1200. (This about about 5 years ago, one line item was $7.50 for topping off the windshield fluid among other things).

open-end on, e.g. locknuts on tie rods

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Yes, they use crows feet, or similar.

http://www.finishing.com/118/94.shtml

Drew

drew said:

(This about about 5 years ago, one line item was $7.50 for topping off the windshield fluid among other things).

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Why is that not a shock...

Tom239 said:

Does the factory have a specialized tool for controlling the torque on fasteners you can only get an open-end on, e.g. locknuts on tie rods?

(I can picture how such a tool could be made, but I don't know if they exist.)

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yes they do ,you have to understand most cars are built in a sub-assembly procedure, things are accessible during production that are not when you have a finished product (thats what mechs. complain about) if you turn wrenches everday its true you get a feel, but if you dont your torque wrench is your friend, as far as locknuts on tie rod ends , in production toe is adjusted on a road speed dyno ,and then they crank down on the lock nut (if you look at the size of the lock nut compaired to the size of the tie rod ,there is no way you could overtighten unless you are a hell bent on screwing it up and even then i doubt it , most of you guys are so consciencious i would probably let you work on my 97 (which is more than i can say for alot of my mech. friends ):smile:

BTW: How in the heck does the factory apply the fasteners without any visible evidence of using any tools? It's like they use padded drivers or twist these things on with their fingers.

Even the closest tolerance wrench I have leaves minute fastener distortions, shiny spots and other marks. Makes me feel like a monkey.

The factory applied fastener appear to have be completely untouched, unmarred and perfectly shiny/coated. If it wasn't for the fact that it is torqued down to 300ft/lbs in its current state, I would think that the fastener applied using only a cotton glove.

Drew

drew said:

BTW: How in the heck does the factory apply the fasteners without any visible evidence of using any tools? It's like they use padded drivers or twist these things on with their fingers.

Even the closest tolerance wrench I have leaves minute fastener distortions, shiny spots and other marks. Makes me feel like a monkey.

The factory applied fastener appear to have be completely untouched, unmarred and perfectly shiny/coated. If it wasn't for the fact that it is torqued down to 300ft/lbs in its current state, I would think that the fastener applied using only a cotton glove.

Drew

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LOL, i know what you mean, in production they they put in a screws with torque spec guns and do not leave a mark,you take it out with a screw driver
and bingo its marked , its like the hardware is coated for one direction only,but i know this is not the case, ever since i can remember japanese hardware was always top shelf (a hardware vendor told me he supplied two auto manufs, landed a contract with honda, first order was returned not up to their spec, said these people are serious ! the other two never complained. In 86 we built a limited run of a certain model with a nippon denso supplied digital instrument panel , Superintendent of soft trim tells me Our spec would only accept a 1% defect rate, we ordered 1500 IPs,they sent 1515 , 1500 good ones and 15 units marked defective !!!

Is there a recommended manual or site to find the various torque values?

kwinkler said:

Is there a recommended manual or site to find the various torque values?

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They all can be found in the service manual you find in the wiki/faq

Torque to factory spec is important in:
Engine internals
Suspension
Steering
Wheels and brakes


Although not all dealerships torque other parts to factory specs.
all non critical parts don't need exact factory torque.

A.S. Motorsport said:

Torque to factory spec is important in:
Engine internals
Suspension
Steering
Wheels and brakes


Although not all dealerships torque other parts to factory specs.
all non critical parts don't need exact factory torque.

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is this not what i said in post 10

kwinkler said:

Is there a recommended manual or site to find the various torque values?

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Yes, it is called the shop manual.:wink:

As has been said, engine internals and suspension torque for sure. IF you were a pro mechanic on aluminum engines your "feel" will help you in any case as there certainly are times that the factory setting will just not get it, such as the oil pan mentioned. I was a pro and i find i often give the fastener another two pounds are so while occasionally i find my gut tells me to stop early. The dozens of 10mm(head) bolts are the problem children as torque wrenches just sometime don't handle these small bolts right, so don't be afraid to use your judgment on these. Keep in mind that you are likely stretching bolts on the engine while misc brackets and such don't want to see any real stretch. Oh yeah, try your torque wrench against another. Price may matter on a torque wrench. I own snap ons click types. I also have a small 1/4'" beam type wrench which i got for the diff preload. I've tried it on valve covers and oil pans(non X) and find even with it's extreme accuracy you just can't torque these parts. So do develope a feel and don't even try to torque them, again talking oil pans and valve covers that do not bottom out(X valve covers bottom out so they can be torqued). Remember, doing any fasteners into aluminum threads as almost all of ours are, is the big leagues so being vary slow and careful is imperative. While i haven't used it much on the X, i use a lot of anti-sieze on my DD's. Any fastener that can get water into the threads is subject to siezeing from corrosion.