LR UCA - Top Bolt Size

mrvandelay

mrvandelay

New member
Anybody know the correct socket size for the top bolt on the LR UCA? I don't have anything that fits on it and would like to order the proper size.
 
Register to hide this ad
bofa said:
Maybe a silly question... but have you tried measuring it?
Click to expand...

Amazingly enough, I haven't yet. I suppose I need to track down a digital caliper to get it right. Just wondering if anyone knew already so I can order a socket in confidence.
 
harper7 said:
You are right!Fixed!! 150 ft/lbs
I just used "really f'n tight" with my 2ft long 1/2" drive breaker bar anyways as my biggest torque wrench only goes to 100 ft/lbs. Hasn't moved in 2+ years.
Click to expand...

I was gonna ask, does it really matter that much.

The mechanic looked like they tried to tighten as tight as possible and that's about it.
 
I would say yes it does matter that's why they put a specific number on it:boink: You certainly don't want that coming loose on you while you're cruising down the highway at 75mph do you?
 
Qjake said:
I would say yes it does matter that's why they put a specific number on it:boink: You certainly don't want that coming loose on you while you're cruising down the highway at 75mph do you?
Click to expand...
There's a specific torque called out for every bolt on the truck.
By all means use a torque wrench if you don't feel like you can judge how tight it is .
My arm is calibrated and certified by 30+ years of being a mechanic and turning wrenches... or was that my mental state!

IMO and experience...some bolt torques are more critical then others for exact torques and are tightened by experience and common sense.Big 32mm that holds the caster angle needs to be real tight.
What that 150 ft/lbs torque they call out tells me as a mechanic is that it needs to be really tight to hold the caster setting and a breaker bar or long wrench is needed for leverage to get a lot of torque. Everyone's experience varies so if you don't feel comfortable with how tight you think it is.... use a torque wrench by all means. If the torque isn't enough though it would be a gradual loosening,not all of a sudden, and your caster will go out of spec and will be very noticeable ,not fall off. My caster and alignment have been the same for over 2 years and have done some high speed runs offroad that really worked the control arms and tested it's tightness so mine definitely has enough torque.

In the real world of auto mechanics a vast majority don't use a torque wrench on every bolt and nut and go by feel unless it needs exact torque as determined by experience . Exact torques and sequences need to be used on bearings,gaskets ,gears ,transmissions,engine internals and such. I personally have never seen a guy do an alignment and use a torque wrench.....and I've watched.

In my world of jet engine overhaul......every bolt and nut get torqued with the bolt threads wet with jet engine oil. The 28 that I torque on the RB211 that hold the fan disc to the shaft before the blades go in are brought up to torque in 3 stages ,60,90 and then 120ft and have an exact sequence and must be witnessed by 2 people to sign them off. The Trent 800's I work on have a 200,240 and then a final 280ft/lb torque and torque multipliers are used to get that high of a torque. These are critical torques.
 
harper7 said:
There's a specific torque called out for every bolt on the truck.
By all means use a torque wrench if you don't feel like you can judge how tight it is .
My arm is calibrated and certified by 30+ years of being a mechanic and turning wrenches... or was that my mental state!

IMO and experience...some bolt torques are more critical then others for exact torques and are tightened by experience and common sense.Big 32mm that holds the caster angle needs to be real tight.
What that 150 ft/lbs torque they call out tells me as a mechanic is that it needs to be really tight to hold the caster setting and a breaker bar or long wrench is needed for leverage to get a lot of torque. Everyone's experience varies so if you don't feel comfortable with how tight you think it is.... use a torque wrench by all means. If the torque isn't enough though it would be a gradual loosening,not all of a sudden, and your caster will go out of spec and will be very noticeable ,not fall off. My caster and alignment have been the same for over 2 years and have done some high speed runs offroad that really worked the control arms and tested it's tightness so mine definitely has enough torque.

In the real world of auto mechanics a vast majority don't use a torque wrench on every bolt and nut and go by feel unless it needs exact torque as determined by experience . Exact torques and sequences need to be used on bearings,gaskets ,gears ,transmissions,engine internals and such. I personally have never seen a guy do an alignment and use a torque wrench.....and I've watched.

In my world of jet engine overhaul......every bolt and nut get torqued with the bolt threads wet with jet engine oil. The 28 that I torque on the RB211 that hold the fan disc to the shaft before the blades go in are brought up to torque in 3 stages ,60,90 and then 120ft and have an exact sequence and must be witnessed by 2 people to sign them off. The Trent 800's I work on have a 200,240 and then a final 280ft/lb torque and torque multipliers are used to get that high of a torque. These are critical torques.
Click to expand...

You are exactly right. Most torques are calculated values and are the minimum value required to do the job. In some cases due to specific materials and deformation of threads you should only torque to specified value. In other cases the value is minimum and going over that value is no big deal. The problem is knowing what the application is and that is where experience comes into play. In the example Harper gives above notice how he said "threads wet with jet engine oil." If this were done dry it would change the torque specs a lot, but only experienced mechanics (and a few engineers) would know that. Next time someone is fooling around with a torque wrench do a little experiment: Torque a bolt dry and then oil it and repeat. Big difference.
 
You must log in or register to reply here.

Members online

Total: 372 (members: 1, guests: 371)

Forum statistics

Threads
278,309
Messages
3,554,075
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top