scrappydoo

Now im in two minds here. Ive got a lower front brace which needs to be attached to my car and dont know whether to use a torque wrench or go to the garage to get it down. The bolts require a torque of 187-Nm. Now is this alot of torque to put on a bolt thus does it require an air gun or will i be safe to do it myself with a calibrated wrench? The brace will tie the suspension lower arms on the crossmember together so i dont want this bolt working free as you can imagine the consequences.

Also, can garages adjust the torque on these air powered guns or do they just tighten it up to silly amounts?

Thanks for any help

Jono

sti-04!!

a calibrated wrench with a pole on the end usually does the trick when i am on site right upto over 300Nm

JayPSC

Yeah but the wrenches are calibrated to the length of the wrench, with the extension pole you'd have to recalculate.

Jay

sti-04!!

air gun is still no good to measure torque though!

BOB.T

Air guns are adjustable but you can't set a specific torque. 187 Nm shouldn't be an issue to most garages

vindaloo

Nope, big bar just makes it easier. Torque at the gauge is the same regardless of bar length.

J.

CrisPDuk

To be honest mate, I wouldn't worry to much about the torque setting, especially if it is a road car with rubber bushes. Just do the bolts up to FT (******* tight) when you re-assemble. You only need to start worrying about torque settings on your motor & driveline, that includes your ally's btw, you should never over tighten wheel nuts as you end up putting stresses into the wheel that it wasn't designed to take. I've seen the result of the centre of a wheel shattering on a car due to overtightening, and the results ain't pretty

Chip

No it is not. The torque at the required point will actually decrease if you put an extension bar on it and keep the desired reading the same. DO NOT do it on your strut brace.

If you need to extend the bar to achieve the required torque you must adjust the torque wrench setting to suit.

Chip.

scrappydoo

Thanks for the comments guys,

As a few have said i think if i place a bar over the wrench that it will indeed affect the forces/torque involved, (if i remember from my physics days) its something to do with moments isint it? You chance the distance, you chance the torque at a point.

Tbh guys im just worried that 187 Nm maybe alot of torque to load onto a bolt especially if i keep aplying force over and over again in the case of using a wrench as oposed to a gun.

Chip

Scrappy,
What size are the bolts.

Chip

scrappydoo

I have no idea chip as i havnt unscrewed them yet but i can tell you they hold the lower suspension to the cross member, a horizontal V-shape if you will. I will check on the workshop manual, but they look pretty big. Aparently you are suppose to properly tighten them up when the car is on the ground to avoid damage to the bushes.

scrappydoo

Just quickly looked under the car and it has a big capital M wriiten on the bolt if thats any help.

Chip

Scrappy,
If it's about a 7-7.5mm bolt with 8.8 written on the top then it'll have a maximum torque of about 360Nm.

Chip.

scrappydoo

Cheers chip mate,Thats big torque, i guess i will be safe.

I will have a closer look with a torch in a minute. I was thinking that it would be better to tighter it up maually to the desired torque level rather than just relay on the garage guns which are hardly adjustable.

thanks

Jono

IPKIS

the 8.8 on top of the bolt is the grade

use a torque wrench not a gun a normal 2ft long torque wrench will do 187nm
it won't be hard to pull.
i do 250nm to 1500nm all day long at work

1500nm is a ****** though even with a six foot long torque wrench

Chip

Remember as well that once the torque wrench has clicked that the required level has been obtained. Dont be tempted to re-click the torque wrench just to check if setting had been reached as you will overload the bolt by quite a bit.

Chip.

scrappydoo

Ok guys it says 10 on the bolt not M as i couldnt see it properly. I take it the larger the number the grerater bolt strength yeh?

IPKIS
A 6ft long torque wrench. dam!!!

IPKIS

well we do have an 8 footer for 2000nm

i work on trains by the way
the lowest we use is around 150nm

scrappydoo

wow!! it gets worse lol

IPKIS

gets worse sometimes we need to use torque expanders on the 2000nm ones to take em up to 3800




and people wonder why i have a bad back

Chip

We use hydraulic torque heads to do up studs of up to 4" dia. Their small compact little things but do they put out some torque. Up to 30000Nm.

You really know when youve used one of them for a few hours.

Chip.

scrappydoo

LOL@you guys

IPKIS
I just imagined you stood about 20ft from the bolt with a ladder type bar yanking away. lmao

IPKIS

i wish

Leslie

Its the torque wrench which decides the torque which is applied, not the length of the bar on the wrench.

Les

Chip

Is it really?

Chip.