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Topic: Replacing Shocks with Koni's and Lug Nut Torque (Read 1509 times) previous topic - next topic

Replacing Shocks with Koni's and Lug Nut Torque

After much research, using the ForeForums great search capability, and advice from Barry & Cindy and Barry Beam, I'm ready to start.

Starting with the front end:

    • Received my Koni FSDs from Summit Racing.
    • Bought 3/4" sockets and wrench from Harbor Freight per Dick Mason
    • Raised the coach all the way and put in the safety blocks
    • I've loosened the lug bolts using the X-12 torque multiplier (Wow it works great)
    • Jacked up the front end (I found that a 20 ton bottle jack works best, a 12 ton works OK, a 6 ton wouldn't even budge one side.
    • Placed safety supports under the cross beam supporting the wheels so that the front end weight is now on two jacks and two stands.

It sure is great to have all these resources available as I launch into this significant adventure.

Harvey
Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #1
Harvey,

I am very impressed.  As a younger man I once changed shocks on my 1964 Ford Falcon and that was pretty easy.  Would never think of tackling shocks on our U320.  Keep in mind that most shops charge somewhere between $80 to $125/hour --so you are saving a lot of money.

Keep safe and let us know about your next project.
George Stoltz.  Retired from full-time living in a great Foretravel and now are back to living in a traditional sticks and bricks in Florida.

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #2
Harvey,

What torque multiplier did you use?  The times12 website for TIA products list theirs at $619.  Ouch!
John Cooper
'91 GV 36'
Oshkosh chassis
Cat 3208T 300HP

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #3
I concur on the ouch.  However, I followed the lead of another Foretravel poster (don't remember who) and found one on EBay for $350.  While still pricey I am glad that I bought it - It is a great easy to use product.  It works like a charm on both the front and back wheels. 

In addition to removing my wheels for service, for whatever reason, I can periodically check the torque on my wheels myself per the maintenance schedule.  I just sit on a stool in front of the wheel and can walk the tool around the whole ten lugs either loosening them or tightening them in just a few minutes without moving. 

I don't have a 3/4" impact wrench so I have to use the X-12 to loosen the lugs.  I can then spin them off with my 1/2" impact wrench.  On reassembly, I lightly oil the bolts and tighten the lugs with the impact wrench.  Then using a 1/2" torque wrench set to 38 ft-lbs (38*12 = 456), I use the X-12 to torque the lugs to the proper rating.  (The torque wrench needs to be the click type for ease of use this close to the ground.)

My justification on the cost of the tool:  Living in Ridgecrest CA, next to Death Valley, it's over a 100 miles to the nearest service center.  This is a Cummins Coach Care in Bakersfield.  On my last service there they forgot to tighten the oil filter and it started to leak oil big time as I pulled out of a camp ground (about 200 miles later) and stopped to attach my toad.  It was hand loose.  This was close to a disaster situation if I had not caught it when I did.  On further checking underneath I found that they had lubed the rear end drive shaft zerks but missed the whole front end.  Bottom line:  I only trust myself or the folks in Nacogdoches.  (I have had great service at FOT and trust them but it's a long trip from California.)

BTW:  I am preparing a description of my Koni replacement experience for posting later on this site.  I decided time wise, and with  the ease of removing the wheels, I'm going to do the brakes next winter when I have more time.
Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #4
I second Harvey's bad experience at Cummins in Bakersfield.  The RV tech is arrogant and a snob.
I will very carefully research any future Cummins facility, but Bakersfield CA is a place I would not re-visit or recommend.

Looks like I will ask MOT to see if the front end Zirks were touched.
George Stoltz.  Retired from full-time living in a great Foretravel and now are back to living in a traditional sticks and bricks in Florida.

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #5
Harvey,

I'd be careful oiling wheel lugs.  Torque recommendations are usually based on dry bolts unless specified.  If lug nuts don't spin on freely, try wire brushing the studs.  If that doesn't work, try another nut.  If it still sticks, replace the stud.  You could be seriously over-torqueing your bolts.

Regards,

Brett
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #6
CORRECT.

Wheel lug bolt/nut torque is based on clean DRY threads.

Brett Wolfe
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #7
My thanks to both of the Bretts. 
Apparently I made a poor, what I thought was a, logical assumption.
Any suggestions on how to correct my situation?
Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #8
Harvey,

I would do NOTHING. 

At 456 ft-lbs lightly oiled, you are slightly overstretching the threads, but not to a point where this should be dangerous.

And, as always when the wheels have been removed, re-check torque after a few hundred miles.  I would set the torque wrench that time to just slightly less than the 456-- all you are doing is insuring that they have not loosened.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #9
Tell me again what the torque should be set at on lug nuts?  This time I will write it down.
George Stoltz.  Retired from full-time living in a great Foretravel and now are back to living in a traditional sticks and bricks in Florida.

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #10
Brett,

Did you get the fact that the torque is based on a dry stud from Alcoa?  I just spoke with a friend of mine who said he went to a lot of trouble to find out that in fact Chevrolet's wheel torque settings were (at least at the time he called) based on a light oil applied because that is what was on the studs during assembly.  l came across the following adjustments to torque values:

Oil                                     Reduce torque 15% to 25%
Dry Film (Teflon or moly based)    Reduce torque 50%
Dry Wax (Cetyl alcohol)               Reduce torque 50%
Chrome plating                          No change
Cadmium plating                       Reduce torque 25%
Zinc plating                        Reduce torque 15%

Other tables show somewhat different values including different values for course or fine thread but in all cases the correct torque is approximately 20% less for oil on plain steel while plated and oiled steel the correct torque is about 55% less.  The question is whether or not the increased clamping force will over stretch the studs if in fact the correct torque is based on a dry stud. 
John Cooper
'91 GV 36'
Oshkosh chassis
Cat 3208T 300HP

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #11
John,

Torque values are always spec'd for clean, dry threads unless a certain lubricant is specified.  Over torquing risks exceeding the yield strength of the fastener, causing plastic deformation and shortening its life.

Regards,

Brett
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #12
"Threaded fastener analysis has shown that most of the energy applied goes into overcoming the friction that exists under the head of the fastener and in the threads...Together these two sources can typically be as much as 80% to 90% of the applied torque energy, leaving as little as 10% of the energy to transfer into clamp load...the presence of dirt on the threads can increase the amount of friction....a drop of oil under the head of a fastener can reduce the friction and allow more energy to flow into the clamp load, which can overtighten..." - 2007 Quality Magazine.  >:D
1994 U225
build #4514

Re: Replacing Shocks with Koni's and Servicing the Brakes

Reply #13
snip

This is a Cummins Coach Care in Bakersfield.  On my last service there they forgot to tighten the oil filter and it started to leak oil big time as I pulled out of a camp ground (about 200 miles later) and stopped to attach my toad.  It was hand loose.  This was close to a disaster situation if I had not caught it when I did.  On further checking underneath I found that they had lubed the rear end drive shaft zerks but missed the whole front end.  Bottom line:  I only trust myself or the folks in Nacogdoches. 

Note to Harvey:

Based on your experience with the partial chassis lubrication done by Cummins in Bakersfield, CA I decided to play it safe and have MOT grease all the Zirk (spelling?) fittings on our coach.  I just could not get it out of my head that perhaps they had done the same partial lubrication to our coach.

It is important that we all share these experiences with each other.
George Stoltz.  Retired from full-time living in a great Foretravel and now are back to living in a traditional sticks and bricks in Florida.

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #14
George,
I look at the following site first, plus I also post there:  http://www.rvservicereviews.com/
But you can't depend on it 100% , cause some folks just don't know what to look for until it bites them, and then its to late.
Pat

1994 U225
build #4514

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #15
Harvey,

I carefully went through the Alcoa Wheel Service Manual (mine is dated Jan '99 - proper for my 2000 coach) and determined that you did it exactly correctly!

For hub located wheels as mine and I assume all Foretravels are, they say (on pages 22, 23, and 24) to lightly lubricate the threads and the 2 piece washer/nut, then torque to a value of 450 to 500 lb-ft.

Earlier in the manual, they talk about stud located wheels where the nuts have a ball shape bottom.  Here they caution to NEVER lubricate the ball portion of the nut or wheel, and they give separate torque values for dry and lubricated threads.  I think this causes a lot of confusion.

I am not sure whether my Alcoa manual came with the Foretravel, or if I acquired it soon after my coach.  The date indicates it may be standard in the documentation package and you all may have it.

Dick


Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #16
Thank you very much Dick.
Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #17
Dick Mason was kind enough to send me copies of the relevant pages from the Alcoa Wheel Service Manual dtd Jan 1999.
See the attached pages 22, 23, and 24 ( 3 attachments ).
The diagrams match my situation exactly.

Audrey & Harvey Nelson
2000 U-320, 40' towing 2014 Jeep Grand Cherokee
nelsonah@ieee.org

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #18
Here is the link to the 2008 Alcoa manual:
http://www.alcoa.com/alcoawheels/north_america/en/hdtt/tech_service/Service_1120_2008.pdf

For those of us with stud located wheels the torque information (on page 32) with 30 Wt oil is 350 to 400 lbs. and dry is 450 to 500 lbs.  It would seem that if one had used oil on the studs and torqued them to the dry torque they were over torqued by 100 lbs., not an insignificant amount.  I personally would worry about the conditiion of the studs.  I'm also worried that the tire company installed my wheels with an impact wrench and did not torque them claiming that their impact wrenches provided the correct torque.  I will have to ge a torque multiplier so that I can make use of my 250 ft. lb. torque wrench.
John Cooper
'91 GV 36'
Oshkosh chassis
Cat 3208T 300HP

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #19
John,
Thanks for the newer copy of the Alcoa manual.  It was comforting to see that their recommendations for installing both stud located and hub piloted wheels have not changed from my earlier edition.  As it is obvious that over the years Foretravel has used both types of aluminum wheels, (sorry about my earlier assumption) I thought I would try to summarize both types in one place.

There are two systems of ensuring the accurate centering of the wheel to the axle used by Alcoa:

1.  Stud Located

This system uses the lug nuts to accurately center the wheel on the axle.  The lug nuts have ball shaped ends which nest in ball shaped openings on the surface of the wheel.  This is the system used by most automobiles, at least by all the cars I have ever owned.

The manual states that if these studs and lug nuts are assembled dry, they should be torqued to 450 to 500 lb-ft.  If the threads are lightly lubricated, the torque should be 350 to 400 lb-ft.  NEVER allow any lubrication on the ball surface of either the nut or the wheel!  Stud located Alcoa wheels use right handed threads on the right and left handed threads on the left side of the vehicle.

2.  Hub Piloted

This system uses a large precision hole in the center of the wheel fitting snugly over a machined series of lugs protruding from the axle to center the wheels.  The wheel has a flat surface around the stud holes, and the lug nut is a two part unit with an attached swiveling flat washer.  You should generously lubricate the wheel pilot hole and the machined lugs on the axle, and lightly lubricate both the stud and the joint between the nut and the washer, then torque them to 450 to 500 lb-ft.  Hub piloted Alcoa wheels use metric sized studs and nuts and are right handed threads for both sides of the vehicles.

As with any wheel, you should always recheck the torque after driving for about 100 miles or so, and then periodically to verify that they stay tight.

Dick

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #20
Dick, Am I to assume that my 95 with BUDD type wheels is what you are terming Stud Located. On mine the rear wheels have a threaded stud that fastens the inner wheel to the hub and a nut that fastens the outer wheel.  Maybe I have the wrong terminology but I have always heard them called BUDD wheels. ?

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #21
Gary,
Yes your descriptioin of BUDD wheels (Sorry,I am not familiar with the term although I had them on my previous SOB motorhome) exactly matches the Alcoa description of Stud Located Wheels.  In my description I did not go into the fact that the rear duals are separately attached.  The inner wheel is fastened with a long cylindrical nut.  Alcoa calls this the inner cap nut  This is threaded on the inside to fit the stud, has a ball end to locate the wheel, and is threaded on the outside to fit the outer wheel lug nut.  The end of this cap nut is usually square for tightening.  The outer wheel is then placed over the threads of the inner cap nuts and attached with ball ended lug nuts.

Dick

Re: Replacing Shocks with Koni's and Lug Nut Torque

Reply #22
Apparently The Budd Company was the originator of the design for their namesake wheels.  Since Budd still exists, Alcoa apparently is using a generic name.  You can still get Budd wheel studs and nuts as well as the special square 13/16" socket for the inner nut (sleeve).
John Cooper
'91 GV 36'
Oshkosh chassis
Cat 3208T 300HP