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torque for shank bolts

noonenosthis1
Explorer
Explorer
Hi all,

I've gone from an Excursion to an F350 for towing. The F350 is taller than the Ex so I've turned my hitch upside down and now I need to retorque the shank bolts. What is the correct torque for those bolts?

Thanks
20 REPLIES 20

BarneyS
Explorer III
Explorer III
Subject has been covered and question answered. Thread closed.
2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch (Sold)
Not towing now.
Former tow vehicles were 2016 Ram 2500 CTD, 2002 Ford F250, 7.3 PSD, 1997 Ram 2500 5.9 gas engine

Lynnmor
Explorer
Explorer
Hannibal wrote:


I said nothing of bending anything. For someone to junk a perfectly good hitch because it doesnโ€™t satisfy your perception of how you think it should be, makes my point. The only reason for the shim is customer perception.


OK, we will call is squashing the ball mount till it meets the shank. Reese makes a shim to fill the gap in their sloppy parts to prevent that squash. Shim it or junk it, fitting parts that need to be squashed is something that is unacceptable to anyone that understands. I was not satisfied with such a fit, so I milled and fitted things properly.

Hannibal
Explorer
Explorer
Lynnmor wrote:
Hannibal wrote:
The only reason for the shim is customer perception. On my Reese HP, I torqued the shank bolts to the 250 ft/lbs max on my torque wrench. Then a couple of grunts with a breaker bar. The shim prevents rattles, nothing else.


Bending the sides of the ball mount till they meet the shank, or crack, is not something that I would do. If you have that much play that it would rattle, shim it or junk it.


I said nothing of bending anything. For someone to junk a perfectly good hitch because it doesnโ€™t satisfy your perception of how you think it should be, makes my point. The only reason for the shim is customer perception.
2020 F250 STX CC SB 7.3L 10spd 3.55 4x4
2010 F250 XLT CC SB 5.4L 5spdTS 3.73
ex '95 Cummins,'98 12v Cummins,'01.5 Cummins,'03 Cummins; '05 Hemi
2017 Jayco 28RLS TT 32.5'

Grit_dog
Nomad III
Nomad III
Bolt tension (not torque, you torque bolts to a specific tension) is not special to shank bolts whatever those are. No matter how special some people think it is especially.
Side grade and thread pitch you can easily find the reccomended torque. Not a science project.
Or just make them really tight.....
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ€ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

Lynnmor
Explorer
Explorer
Hannibal wrote:
The only reason for the shim is customer perception. On my Reese HP, I torqued the shank bolts to the 250 ft/lbs max on my torque wrench. Then a couple of grunts with a breaker bar. The shim prevents rattles, nothing else.


Bending the sides of the ball mount till they meet the shank, or crack, is not something that I would do. If you have that much play that it would rattle, shim it or junk it.

Baja_Man
Explorer
Explorer
As stated....check with manufacture, most have their installation instructions posted on their website. I just torqued mine to 257 ft./lbs per my manufacturer (Blue Ox- BXW2000).
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Hannibal
Explorer
Explorer
The only reason for the shim is customer perception. On my Reese HP, I torqued the shank bolts to the 250 ft/lbs max on my torque wrench. Then a couple of grunts with a breaker bar. The shim prevents rattles, nothing else.
2020 F250 STX CC SB 7.3L 10spd 3.55 4x4
2010 F250 XLT CC SB 5.4L 5spdTS 3.73
ex '95 Cummins,'98 12v Cummins,'01.5 Cummins,'03 Cummins; '05 Hemi
2017 Jayco 28RLS TT 32.5'

Lynnmor
Explorer
Explorer
Then there is the issue that these parts are often made so poorly that a shim is required. Discussing torque specifications when assembling junk parts is a guessing game at best. I milled the opening so that it is straight and parallel and then fitted a shim to take up the gap.

Half a$$ed shim fix

BenK
Explorer
Explorer
To the PMs here so that not have to post them one by one...

Yes, ask 10 folks about this and you'll get 11 answers...why my comment says to check your OEM manual/specification

Fasteners/fastening has whole college courses on this and many write their graduate thesis's on this

Yes, some of these answers are okay enough, but some of the advice might go beyond the plasticity of the fastener (can reuse the fastener) and into yield (one time use and a throw away fastener...to losing its clamping force)

Yes, there is/are several threads about going past plastic and into yield with ARP head bolts/studs. Special application to solve an OEM's poor selection in fastener size/numbers/etc...but this is not that case and going beyond plastic and into yield a bad thing for this OP's application

The engineer/design has calculated the clamping force required to hold the assembly together, plus some safety factor (margin). It can be one fastener or spread over several fasteners. Fasteners should NOT be used as a shear device...a hardened shear tube should be used in addition to the fastener



This link explains it best:

What is Proof Load of a Bolt and How is it Different from Yield Strength?


The green zone is why several opinions are okay, they are still in the plastic range...but they may not have the clamping force the designer/engineer spec'd out...and...might not hold and/or come loose during high dynamic loading(s)
-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...

drsteve
Explorer
Explorer
My buddy runs an auto repair shop, he has a monster torque wrench. Many places do. Ask around.
2006 Silverado 1500HD Crew Cab 2WD 6.0L 3.73 8600 GVWR
2018 Coachmen Catalina Legacy Edition 223RBS
1991 Palomino Filly PUP

CaLBaR
Explorer
Explorer
Reese states 300 ft-lbs on their installation instructions. If you don't have 300 ft-lb torque wrench the instructions also state 150 ft-lbs and then another 1/4 turn so that is what I did. That other 1/4 turn is a real pain even with a 3 foot breaker bar.
2018 Grand Design Reflection 297RSTS
2019 RAM 3500 SRW Big Horn 4x4, 6.7 Cummins/Aisin
2007 Rockwood 8298 SS (Traded in 2018)
2009 Toyota Tundra 4x4 Crew Max 5.7L (Traded in 2019)
HP Dual Cam Sway Control
Prodigy Brake Controller

TBammer
Explorer
Explorer
jfkmk wrote:
TBammer wrote:
Get the biggest breaker bar you can find for the socket that fits the bolt. Then get a 4 foot length of cheater pipe to go over the breaker bar. Then have your biggest/strongest friend lean on it until he can't lean no more. But my last reading was like 300-400 ft/lbs.

Or you can take it some place where they actually use a torque wrench.


Yeah, or you can do that, which is prolly the best move.
2016 Chevy 2500 HD, 6.0 gasser, 4.10 dif
2019 Arctic Fox 25W
Reese Pro-Series WD Hitch

Grit_dog
Nomad III
Nomad III
Scientifically, as tight as I can get with a 1/2 drive ratchet or my air impact on middle setting. Couple hundred ft lbs.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ€ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold

SDcampowneroper
Explorer
Explorer
asme spec. 250 lb./ft for 3/4" nc gr. 5 dry bolt in that application. Torque is not an issue as much as shear load because the bolt is not so much a connection as it is subjected to side shear load. Lubes reduce torque spec. depending on type. Machine oil to moly paste, makes a big difference. Moly can reduce torque by 50 %