Rear LCA bolt

[regal81455]

Does anyone know what size and thread the rear LCA bolts are?

I replaced my LCAs with Freedom Off Road units and reused the bolts since they did not come with new. Recently I've started getting a popping noise coming from my rear. A visual/physical inspection yielded nothing. Now I suspect the LCA bolts might be the problem since....

It turns out according to ALLDATA those bolts should not be reused. They must be stretch to yield or something. I'd like to pick up new bolts today since I'm already going to Fastenal for another reason. It would be nice if I could figure this out without having to remove one from the truck to determine.

Any help would be great if someone out there knows.

Tx in advance-

 

[GIJoe2010]

Hmm, good to know as I’m working with installing some Clayton rear UCA/LCAs this weekend.

Standing by . . .

 

[DILLIGAF]

Pretty sure I just got Grade 10.9 , M16 x 1.5 100mm long from Fastenal when I installed my Clayton Offroad Arms. But I got thicker washers and the bigger lock nuts.

Your Clunk is probbaly from not torqueing them down enough

 

[regal81455]

I torqued to spec. 148# + a 90* turn. As mentioned, this leads me to believe they are torque to yield which is why ALLDATA is saying don't reuse. I'm willing to bet the stretched even more and are not holding the torque value.

AND......

After a quick look on mopar parts online, I was able to answer my own question - it appears the bolt is a M16x1.50x100.00.

So mystery solved!!

 

[GIJoe2010]

Pretty sure I just got Grade 10.9 , M14 x 1.5 100mm long from Fastenal when I installed my Clayton Offroad Arms. But I got thicker washers and the bigger lock nuts.

Your Clunk is probbaly from not torqueing them down enough

Good to know thanks

 

[GIJoe2010]

I torqued to spec. 148# + a 90* turn. As mentioned, this leads me to believe they are torque to yield which is why ALLDATA is saying don't reuse. I'm willing to bet the stretched even more and are not holding the torque value.

AND......

After a quick look on mopar parts online, I was able to answer my own question - it appears the bolt is a M16x1.50x100.00.

So mystery solved!!

Awesome

 

[Daw14]

Yes definitely torque to yield,that plus 90* is a dead give away

 

[GIJoe2010]

So we need 4 of these bolts, M16 x 1.5 100mm???

 

[regal81455]

I would think it might depend on the manufacturer you by your LCAs from becuz they may supply hardware with them but FO did not but yes you would need four of those + nuts & washers.

I priced both from Fastenal and the stealership - standard 10.9 fine thread hex head bolts, nylocks, & washers was around $98 from Fastenal. The stealership was $94.

Still weighing it but might just buy the OEM since you know OEM lol.

 

[GIJoe2010]

I’m gonna try my local hardware store and see what they got. Thanks

 

[DILLIGAF]

I have a commercial Fastenal account, Its literally 1/2 price over OEM... lol...

 

[GIJoe2010]

I have a commercial Fastenal account, Its literally 1/2 price over OEM... lol...

Nice

 

[regal81455]

We have healthy commercial account too. Bolts like eveything else right now experiencing shortages...costs going up up and away!!

 

[ram1500rsm]

I’ve reused the same bolts and nuts 3 times. I had the stock arms replaced with Mevotech, then FO, then Claytons. Torqued all 4 arms to 190ft/lbs.

 

[regal81455]

I’ve reused the same bolts and nuts 3 times. I had the stock arms replaced with Mevotech, then FO, then Claytons. Torqued all 4 arms to 190ft/lbs.

Nice - after seeing the price of replacements I retorqued mine yesterday. They definitely had come loose even with threadlocker applied. They were also definitely the source of my clunk as it is now gone. I don't know if that means they've lost elasticity or what but will replace them before too long.

I'm towing a 7k # TT with my family fairly consistently - not interested in a possible failure at the worst moment, just too much to lose over $100. Everyone's mileage may vary.

 

[retired]

those are a big strong bolt a zinc plated 10.9 bolt 16mm with 2.00 pitch will handle over 230 ft/lbs of torq so with 1.50 pitch even more.

 

[retired]

I guess it would be a cool experiment to torq them to 148 ft/lbs and then see how much torq it takes to do the extra 90 degrees. if you don't have a beam torq wrench or digital just set your click one to 230 ft/lbs and see if it clicks before it hits 90 degrees.

 

[ram1500rsm]

I guess it would be a cool experiment to torq them to 148 ft/lbs and then see how much torq it takes to do the extra 90 degrees. if you don't have a beam torq wrench or digital just set your click one to 230 ft/lbs and see if it clicks before it hits 90 degrees.

This ^ it makes me wonder if 148ft/lbs +90* is just too much torque on those bolts. they're beefy bolts so that's why im not sweating torquing them at 190 and reusing them as needed. My Haynes manual calls for 225ft/lbs on those bolts. no TTY specs.

 

[bigred90gt]

Yes definitely torque to yield,that plus 90* is a dead give away

I doubt you are yielding an M16 bolt at 148 ft/lbs.

https://www.engineeringtoolbox.com/metric-bolts-maximum-torque-d_2054.html

Not sure why they would spec it to a torque value, then an additional 90 deg turn. Something is off with that. So, they want you to torque it to a specific value, then keep going to an unknown value? That seems like a huge liability should something fail.

 

[retired]

I doubt you are yielding an M16 bolt at 148 ft/lbs.

https://www.engineeringtoolbox.com/metric-bolts-maximum-torque-d_2054.html

Not sure why they would spec it to a torque value, then an additional 90 deg turn. Something is off with that. So, they want you to torque it to a specific value, then keep going to an unknown value? That seems like a huge liability should something fail.

that is common way to tighten certain fasteners and quite reliable if done properly. cylinder heads are done this way.