First Q is how many of you have actually changed a tire and pulled a wheel on your C3?
I plan to renew my wheels..'78 SA..and want to pull them one at a time in the garage so I can do a really good job on the factory aluminum wheels..as well as replace old lug nuts where chrome is missing..


I had new BFG P 255/60 R15 RWL tires installed 8 months back by a local tire shop..So NO I don't have a flat....
But I CANNOT BUDGE THE LUG NUTS.. even in a warm garage after putting PB Blaster on them..over 100 foot pounds of torque tried..
DO the aluminum wheels gall with the steel lugs?


SO final questions ARE
...WHAT is the torque value for stock lug nuts on factory aluminum wheels for the '78 Corvette???????? is there any tightening sequence for the five lug nuts?


I suspect the tire shop used an impact wrench to secure the lug nuts when they replaced the tires and balanced them etc..No telling what they had that air tool set at..


I plan on talking to them tomorrow..perhaps, weather permitting take the car in and have them loosen/break free the lug nuts so I can use the lug wrench to remove them one at a time to do the job on the wheels.
I'm really GLAD I have never had a flat on the Corvette on the highway........................
I'm no stranger to changing tires.......but maybe it's just old age that makes the small job difficult for me..
Any help on the various questions would be appreciated.best regards, Jim

 

I hand torque these wheels...and basically all wheels to 100 lbs/ft of torque.

Depending on the amount of salt exposure...I seriously doubt your lug nuts seized to the wheel....but anything is possible.

Do not be surprised if they snap a lug stud. Because if they POUNDED on the wheel lugs...they can snap. Hopefully they don't when they go to break these loose.

DUB

 

using a 4 way lug wench,hit it with a hammer in a clockwise direction.Then try loosening it.Sometimes tightning it a little helps. If that doesn't work put apiece of 4'pipe on the lug wrench,that should give you enough leverage.

 

Hand tighten and use a torque wrench set at 100 ft=lbs. The shop probably tightened them with an impact gun set to who knows what torque...hope they don't break a lug nut loosening them....

 

78 owner's manual tells you 90 ft lbs. Nuts should be tightened alternately and evenly to the correct torque.

 

Personally I use a 1/2 drive 24 inch breaker bar to loosen any lugs if impact not handy.
The crappy gm lug wrench is not very long if that's what you're using and 100ft or more can be difficult with one.
Sounds like an excuse to buy an electric impact gun from Harbor freight myself...

 

I comply with what I believe is in the manual, 80 ft-lbs, no lube of any kind, never had one loosen or bind up.

 

Extreme worse case...use a very small drill bit and drill in the center of the lug nut. Then, shoot PB blaster into hole..let sit and the lug should come right off. Had to do it to one of mine, after the lug nut was spinning the lug stud.

 

Thanks, DUB, I Didn't want to exert excessive torque..Wheels and tires have never been wet..and unlike Nicholson in that movie.."Terms of Endearment"..never driven into the ocean..
No salt used on roads here in Oregon...or calcium chloride..When my son Josh gets down for the Christmas time..


Will see what we can do...and I agree that oftimes..a bit of tightening can loosen things up......
B4 you get the cheater bar out...
Studs were all in great shape 6 mos ago when we did the brakes and tires etc..
When we put the wheels back on with the new lugs......should we add a drop of oil to the stud threads..or a dab of white lithium grease..?OR loktite blue?


We will recheck all the lugs after a few dozen miles to insure all is snug..Jim

 

THANKS ALL.I must have missed the wheel lug tightening info in my owner's manual..Funny how one usually reads/absorbs just the stuff he's looking for at the moment...


Won't use any lubewhen I reinstall wheels and lugs..alternatately tighten lugs all around until seated..then torque up alternately ..


Good tip on drilling the old lug nuts if stubborn and then PB Blasting them..Hopefull, won't need to do that..but that's a handy tip when one is replacing the lug nuts..Will let you know how it goes..Do have a good torque wrench, 1/2 drive..and know how to use it..jim.

 

Put a jack under the frame and lift the vehicle weight off the wheel but keeping the rubber on the ground, use the socket and an 18-20 inch breaker bar to loosen the lug nuts about a half turn each, then 1 turn each. Once they are all loose, raise the vehicle and remove the lug nuts and the wheel. Hope that works.

 

If it doesn't come loose with your breaker bar (DO NOT USE your torque wrench to loosen anything) then slip a length of pipe over the breaker bar handle for leverage. They'll come off!

 

Everyone who works on a car needs an electric impact wrench. Less than $100 guarantees that any lug nuts [that some dumbs4!+ cranked down with his BF air impact] will come off easy. And, when you are pulling them ALL to clean them up for next year, that is FOUR TIMES as good.

Harbor Freight or Northern Tool will have them at reasonable cost.

{Sounds like the perfect Christmas present to me. }

Ho - Ho - Ho!!

 

Will look into an electric impact wrench at Harbor Freight...Don't own a compressor these days..jim

 

Hey Jim, I use a 1/2" breaker bar with a deep well 3/4" impact socket on my lugs. Breaker bar will break them loose, especially if you slip a length of pipe over the end.
I don't recommend using an impact wrench on your lugs. On mine it chipped the chrome on the lug nuts over time and then they began to rust. So I no longer use an impact except maybe to run them in or out but not to break them loose or tighten them. I have seen "soft" type impact sockets just for this purpose of not chipping the chrome, but don't have any of those myself.
The torque for my 77 corvette with aluminum wheels is 85 lb/ft.

For the 78 my manual says 80 lb/feet with the aluminum wheels.
Most shops will tighten to 100 lb/ft if they don't know the actual number. Still that isn't likely going to damage anything.

The break loose torque on any nut and particularly a lug nut is going to considerably higher than the tighten spec.

 

well, went to the local hdw store and had them cut a 30" length og steel pipe w/1" ID
Fits over my venerable Craftsman 1/2 drive socket wrench handle nicely.With a 3/4" socket, easily broke one lug nut loose..
The rest will follow suit..


SO problem solved with a 5.00 cheater bar. I'll floor jack the car up a bit one wheel at a time, loosen all the lugs,remove the wheel-tire..,and get on with my small winter-garage project.
Thanks to ALL who helped with info and advice..
Merry Christmas to all!Jim

 

Glad it worked for ya, Jim. Merry Xmas!

 

Hope the sun shines a bit up your way for the holidays, Jim

 

I know you are NOT going to add lubrication...becasue you 'said' so in your next post......but this is for others who may not know this stuff.

IF...and I mean IF you add any lubrication to the wheel studs it should ONLY BE a very, very light oil. And when you apply it...take paper towel and wipe it off. All you want is a very, very, very light film.

Because...lug nuts should be tightened DRY like it is written in service manuals. Because ANY lubrication DOES EFFECT the torque value. This is not my opinion ...but it is fact. As you can see in the chart in the link I provided.

http://www.engineeringtoolbox.com/to...ts-d_1693.html

SO...DO NOT USE ANTI-SEIZE!!!!!!!!!! And if you do...you have to adjust the torque you apply. Or wheel bearing grease or even 30W oil...adjust your torque. ALL of these effect the torque where it should be decreased do to the added lubrication on the threads.

I would NOT use Loc-tite of any type.

And as for the torque...use what you want. I would use 100 lbs/ft. And I snug and tighten them in a 5 point star pattern. In 30 years...not one problem at all. The thread count can take it with no problems. And what is 'funny'...which I showed the guys I trained in the past. I would torque a lug nut to 90 lbs/ft and get my torque wrench to click. Then I would set it to 100 lbs/ft. And then when I tightened it again...I barely had to turn the lug nut to get it to click. So...from 90 lbs/ft to 100 lbs/ft does not require a full turn on the lug nut. But as I wrote...do as you wish.... beacsue if my memory serves me correctly. 100 lbs/ is what the 1984 to current Corvettes take as torque for the lug nuts. AND this is also taking into consideration the previous comment I made about lubricants on the threads.

And for those who may not know this...back in the day...the lug nut torque was 60 lbs/ft....which I would NEVER do. REGARDLESS of what was written in the assembly manual. I actually ahve tried it and I felt really weird when the torque wrench clicked. It seemed to be barely above hand tight.

DUB

 

GLAD to read you got it.

DUB