Recovery Points (1 Viewer)

gaijin

GOLD Star
Joined
Dec 9, 2012
Messages
3,808
Does anyone know what the torque for the front recovery points bolts is?
I looked in the manuals but could not find the recovery points.

ARB specs 88 ft-lb for the bolts on their recovery points - I suspect that's pretty close to the OEM bolt torque.

HTH
 

gaijin

GOLD Star
Joined
Dec 9, 2012
Messages
3,808
I think that's the best we have and it is more realistic value than the 73 ft-lb caliper bolts torque.

Found 77lb-ft speced for Tacoma ARB front bumper, but that has 2 M12 and 4 M10 bolts. We only have 2 M12 on the recovery point. https://www.catalograck.com/ImgVD/ARB/3423150i.pdf

Out of curiosity, I checked the installation instructions for the Kaon LC200 recovery points and found 126 Nm (93 ft-lb):

KaonRP.jpg


Don't overthink it - 88 ft-lbs looks like it splits the difference between 73 and 93. After all, how confident are you of the accuracy of your torque wrench?

HTH
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
10,065
Location
Central Texas
I think that's the best we have and it is more realistic value than the 73 ft-lb caliper bolts torque.
Found 77lb-ft speced for Tacoma ARB front bumper, but that has 2 M12 and 4 M10 bolts. We only have 2 M12 on the recovery point. https://www.catalograck.com/ImgVD/ARB/3423150i.pdf
I’m curious what’s unrealistic about using the value published for the same thread diameter, pitch, length and grade bolt in an application that sees tremendous amounts of shear force. These bolts likely came out of the same parts bin.

Note that rear lower shock bolts are the same except for length, and specify 72.

A8B1D4FD-066D-4BB0-9EE2-95C9097597CE.jpeg


0A30FFA9-605F-40A6-B665-67FBC5199096.jpeg
 
Joined
Aug 13, 2021
Messages
408
Location
The Great PNW
The recovery point has only 2 bolts that have to take the weight of the truck if not more when you use a snatching rope. There is little stuff to take the shock (spring, hydraulics) or distribute the load (3 more shocks).
I agree that until someone does the engineering calculus or comes with a value from Toyota is just a guess.
I took Kaon value assuming someone there did the engineering. I may be wrong, and they just have good insurance.
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
10,065
Location
Central Texas
The recovery point has only 2 bolts that have to take the weight of the truck if not more when you use a snatching rope. There is little stuff to take the shock (spring, hydraulics) or distribute the load (3 more shocks).
I agree that until someone does the engineering calculus or comes with a value from Toyota is just a guess.
I took Kaon value assuming someone there did the engineering. I may be wrong, and they just have good insurance.
I really don’t think there is a problem with the increased values, after all the whole idea of the ARB stuff is that it is rated. I just disagree that it is unrealistic to use the brake caliper value. If you look at what those bolts have to deal with in that application.. most likely thousands of pounds of shear force, mainly because they are so close to the axle the leverage against them is huge.
 
Joined
Aug 13, 2021
Messages
408
Location
The Great PNW
For brake bolts sheer force is mostly what they resist. Recovery bolts have to deal with other forces as recovery is seldom done in ideal conditions.
Then there are 4 calipers each with 2 bolts on the truck. They do different load but there are more than 2 bolts.
Then the brakes never take full shock of the car weight, because they just lock up and the tires slide/ABS kicks in.
 

linuxgod

SILVER Star
Joined
Jan 17, 2016
Messages
5,266
Location
Chicago, IL, USA
Torque until you break a bolt, then drill it out and work backwards from there on the right torque spec ;)
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
10,065
Location
Central Texas
For brake bolts sheer force is mostly what they resist. Recovery bolts have to deal with other forces as recovery is seldom done in ideal conditions.
Then there are 4 calipers each with 2 bolts on the truck. They do different load but there are more than 2 bolts.
Then the brakes never take full shock of the car weight, because they just lock up and the tires slide/ABS kicks in.
I think you are discounting the strength needed for resisting shear.

You don’t get shear strength without clamping force to provide the friction, and you don’t get clamping force without tensile strength in the bolt.

At 69ft-lb a course thread 10.9 M12 bolt will produce almost 12,000 lb of clamping force. I’m having trouble finding numbers for fine thread, but it is likely even higher.

So apparently toyota felt at least 24,000lb of clamping force was necessary for each caliper… but pulling a 6klb vehicle at an odd angle might somehow need more? Why wouldn’t they just run the brake calipers at a higher value if it had some benefit and the bolt were good for it?

Btw we can easily put more force on the brakes than traction with a road would provide, by doing a brake stand. Now I’m curious so I might measure the distance from the hub center line to the caliper bolts and do the calculations based on gear ratios and torque available at a given RPM. But rest assured, it’s a s***load.
 
Joined
Aug 13, 2021
Messages
408
Location
The Great PNW
Hi LC guys, can you tell me if you have one or two loops in the back?
On my LX I only had one in the front and one in the back. I added one more in the front and I'm wandering if I'm missing one in the back to.
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
10,065
Location
Central Texas
Hi LC guys, can you tell me if you have one or two loops in the back?
On my LX I only had one in the front and one in the back. I added one more in the front and I'm wandering if I'm missing one in the back to.
My 2013 has a recovery loop on the passenger side and a tie-down loop on the driver side.

You are better served using an adapter in the tow hitch though.. this should be far stronger than either of the existing recovery options.
 
Joined
Jun 5, 2022
Messages
26
Location
Toronto
My 2013 has a recovery loop on the passenger side and a tie-down loop on the driver side.

You are better served using an adapter in the tow hitch though.. this should be far stronger than either of the existing recovery options.
2010 LX 570 - Canadian truck -
Front: 2 tie down, and 2 recovery loop/point
Rear: 1 recovery loop on the left, 1 tie down on the right

Since I have 2 recovery points in the front are they sufficient?
And for the back, I am planning to install a tow hitch recovery receiver, the Factor 55 is what I am leaning towards.
 

turbo8

Supporting Vendor
Joined
Jun 3, 2013
Messages
834
Location
Las Vegas, NV
So I was pretty confident with the factory front tow hooks until I bent one, not from a pull but hitting it off-roading. Which made me go down the rabbit hole.

I ran a FEA on them. I'm not sure on the steel used for them, but I hope they were made from something like 4130. The results are they probably will start to fail around 5000lbs.
1669276220718.png


That is why I made some new recovery points. Which are rated for 10,000lbs with a good safety factor. These also gives more clearance while off-roading and have radius edges so soft shakles can be used.
1669276467439.png

1669276546846.png
 

CharlieS

GOLD Star
Joined
Feb 4, 2005
Messages
6,329
So I was pretty confident with the factory front tow hooks until I bent one, not from a pull but hitting it off-roading. Which made me go down the rabbit hole.

I ran a FEA on them. I'm not sure on the steel used for them, but I hope they were made from something like 4130. The results are they probably will start to fail around 5000lbs.
View attachment 3176702

That is why I made some new recovery points. Which are rated for 10,000lbs with a good safety factor. These also gives more clearance while off-roading and have radius edges so soft shakles can be used.
View attachment 3176708
View attachment 3176710
Impressive that you have the skills to do this!
 

bloc

SILVER Star
Joined
Sep 19, 2008
Messages
10,065
Location
Central Texas
So I was pretty confident with the factory front tow hooks until I bent one, not from a pull but hitting it off-roading. Which made me go down the rabbit hole.

I ran a FEA on them. I'm not sure on the steel used for them, but I hope they were made from something like 4130. The results are they probably will start to fail around 5000lbs.
View attachment 3176702

That is why I made some new recovery points. Which are rated for 10,000lbs with a good safety factor. These also gives more clearance while off-roading and have radius edges so soft shakles can be used.
View attachment 3176708
View attachment 3176710
I really, really appreciate it when people come to the table with actual data.

If it’s not too much trouble can you run that again without the L shaped tie-down bracket to see whether it changes the strength appreciably?

Also you’d sell one or two of those new parts if you were so inclined.
 
Joined
Jul 3, 2008
Messages
4,011
Location
Illinois and Alaska
So I was pretty confident with the factory front tow hooks until I bent one, not from a pull but hitting it off-roading. Which made me go down the rabbit hole.

I ran a FEA on them. I'm not sure on the steel used for them, but I hope they were made from something like 4130. The results are they probably will start to fail around 5000lbs.
View attachment 3176702

That is why I made some new recovery points. Which are rated for 10,000lbs with a good safety factor. These also gives more clearance while off-roading and have radius edges so soft shakles can be used.
View attachment 3176708
View attachment 3176710
These models assume an infinitely rigid mounting point, though.

The model needs to take into account the shear loads on the bolts and relatively thin frame compared to the recovery point.

You may very well changing the failure point from the stock recovery point to the frame itself.
 
Joined
Apr 27, 2011
Messages
7,811
Location
San Diego
These models assume an infinitely rigid mounting point, though.

The model needs to take into account the shear loads on the bolts and relatively thin frame compared to the recovery point.

You may very well changing the failure point from the stock recovery point to the frame itself.

Exactly. Has to perform as a system with FMEA to control failure modes.

That said, @turbo8 , appreciate the input and analysis. I'd be very interested in a similar type of recover point but for the rear, as it only has a recovery point installed on the passenger side. Too often I'm actively using the hitch for a carrier in overland mode. And still need to recovery friends, so having a balanced pull using a bridle from two points would be nice.
 

turbo8

Supporting Vendor
Joined
Jun 3, 2013
Messages
834
Location
Las Vegas, NV
These models assume an infinitely rigid mounting point, though.

The model needs to take into account the shear loads on the bolts and relatively thin frame compared to the recovery point.

You may very well changing the failure point from the stock recovery point to the frame itself.
Total agree. I just wanted something low profile.
 

turbo8

Supporting Vendor
Joined
Jun 3, 2013
Messages
834
Location
Las Vegas, NV
I really, really appreciate it when people come to the table with actual data.

If it’s not too much trouble can you run that again without the L shaped tie-down bracket to see whether it changes the strength appreciably?

Also you’d sell one or two of those new parts if you were so inclined.
Pm me
 

Users who are viewing this thread

Top Bottom