How to measure high torque values?

[ChazzC]

a u joint clunk comes with serious vibrations, a clunk from excessive differential backlash wont, but i also think they fed you a line of sh!t about it being because the it was an s10 chassis (witch it is), it sounds more like that rear end was put together on a friday at 4 in the afternoon and maybe was at the extreme end of the spec for allowable backlash when it left the factory, and with some wear was probably out of spec, ive driven several s10's and s10 blazers, none had any audible clunk from the differential. That being said, excessive backlash on the diff of something low powered like a 4.3 s10 will likely not cause any catastrophic damage, im sure it would be a flintstone mobile and in the junkyard long before the diff let go

Mine only had ~ 60K on it when it was totaled; I’d have to scan a photo of what it looked like after it rolled into the ditch (surprisingly calm as I sat there waiting for things to stop spinning & rolling, and I was talking to 911 - hanging upside down - before the witnesses got to me).

 

[mbond]

There is too much interesting stuff on this thread!

First, let me echo Susquatch and say don't use anything except a manual tool if you care about the exact torque. Even the government via the NBC recognizes that any other method is too unreliable. Only the 'turn of the nut' method is acceptable for slip critical structural steel connections, and impact tools are the worst. Turn of the nut is easier to measure than the torque and leaves a visible trace for building inspectors. The thread pitch of the bolt gives the exact torque via a simple calculation

In addition to load cycling metal fatigue issues, pre-stressed connections can have another advantage. They don't move (strain) when external loads are applied - as long as those loads are within the stress envelope of course - because of course, the strain has already happened! This technique is frequently used when affixing components in vibration and shock environments.

There is a lot more to say, but I am being paged by my better half

 

[phaxtris]

Mine only had ~ 60K on it when it was totaled; I’d have to scan a photo of what it looked like after it rolled into the ditch (surprisingly calm as I sat there waiting for things to stop spinning & rolling, and I was talking to 911 - hanging upside down - before the witnesses got to me).

definitely a Friday at 4pm assembly then, But on the bright side you made it out of a roll over!


@David do you have any unusual tire wear ? i just skimmed a video changing a lca, i see those lca frame bushings are in a slotted hole without a cam bolt/cam washer, if those suckers are not fully torqued you would get some clunks as lca moves around driving, you're alignment would be all over the place as well giving you some weird tire wear. It would likely be torqued enough that a tire wiggle wont show it, but if you get under there with a pry bar and you can move that lca bushing around in the frame mount that could be your culprit, at least another free item to check

 

[David]

definitely a Friday at 4pm assembly then, But on the bright side you made it out of a roll over!


@David do you have any unusual tire wear ? i just skimmed a video changing a lca, i see those lca frame bushings are in a slotted hole without a cam bolt/cam washer, if those suckers are not fully torqued you would get some clunks as lca moves around driving, you're alignment would be all over the place as well giving you some weird tire wear. It would likely be torqued enough that a tire wiggle wont show it, but if you get under there with a pry bar and you can move that lca bushing around in the frame mount that could be your culprit, at least another free item to check

Tires are brand new and I've probably only put maybe 1000kms on the truck since I bought it in September. Haven't noticed any odd wear patterns and it drives exactly as I would expect.
I did notice today that the clunk only happens on straights, never around a corner which leads me to suspect the sway bar links.

 

[Elektrishun]

@David

Could be something simple that you're overlooking...

 

[David]

You mean I should take some of the crapola out of the box???

 

[Elektrishun]

You mention that the "clunk" happens while driving on a bumpy road.

Have you tried finding a stretch of road where you can safely try to reproduce the sound?

Windows rolled down so that when you ride over that spot that causes it to "clunk" it may be more driver's side vs passenger side?

Or even have someone else drive over that spot while you stand off to either side to hear what it sounds like?

 

[Chicken lights]

a u joint clunk comes with serious vibrations, a clunk from excessive differential backlash wont, but i also think they fed you a line of sh!t about it being because the it was an s10 chassis (witch it is), it sounds more like that rear end was put together on a friday at 4 in the afternoon and maybe was at the extreme end of the spec for allowable backlash when it left the factory, and with some wear was probably out of spec, ive driven several s10's and s10 blazers, none had any audible clunk from the differential. That being said, excessive backlash on the diff of something low powered like a 4.3 s10 will likely not cause any catastrophic damage, im sure it would be a flintstone mobile and in the junkyard long before the diff let go

It would be interesting to compare notes. I definitely had a ujoint on the big truck make a clunk like when shifting from reverse to first, like hooking to a trailer. It also definitely was beyond saving for awhile, but besides the clunk I couldn't notice it driving

I had a shot ujoint on my f350 front driveshaft too

I'm in no way saying you're wrong.... just enjoying the back n forth. I'm always open to learning from others

 

[phaxtris]

It would be interesting to compare notes. I definitely had a ujoint on the big truck make a clunk like when shifting from reverse to first, like hooking to a trailer. It also definitely was beyond saving for awhile, but besides the clunk I couldn't notice it driving

I had a shot ujoint on my f350 front driveshaft too

I'm in no way saying you're wrong.... just enjoying the back n forth. I'm always open to learning from others

I've never had a bad u joint without a vibration, but I think it's less noticeable if you drive that vehicle all the time, in a big truck it's probably even more difficult to feel, the mass of the vibrating driveshaft is so small compared to the rest of the truck, then if you have an air suspended cab, and your likely much lower driveshaft speed in a big truck vs a pickup

I've probably changed 20 or 25 u joints on my own vehicles over the years, my current welding truck eats rears to the tune of 1 every year and a half or so (something is slightly out, and it lives a hard life) , the vibration is not always readily apparent, but it's always there, with every vehicle, but, if you only drive one vehicle at highway speeds it's hard to detect because the vibration occurs slowly over time, you get used to it, until you drive something else

in my experience the only time you really get a *clunk* is when all of the needle bearings are gone from two opposing caps and the nubs are starting to wear down, but preceding that you get weird clinking noises, sometimes with squeaks, and always some vibration at highway speeds

Here is the u joint I changed last week, I knew I had a bad one but couldn't pinpoint which one (I figured it was the rear), so I continued to drive it until it was dicked enough to find easily, no clunks, just clinks squeeks and highway vibration

And 2 days later when the new u joint came in ( I thought I had a spare...I did not), still no clunks

And the offending u joint, I have changed one that was worse, both opposing caps were missing all needle bearings, and the nubs were worn down to about 70%, that did clunk, but it also vibrated, it was a slowish 300km drive home with that