Roof AC bolts

[bmulvenna@hotmail.com]

2004 Dynasty.

Anyone know if there is a recommended torque for the 4 hold down bolts for the roof top AC units.

Thanks 

[Walker]

From memory, I think it is 40-50 in/lbs.

[JDCrow]

I’d never guessed that. Thanks! For me, seal starts to squish, say “click” out loud and call it good. Used the new 1 piece rubber seals BTW, awesome 

[Tom Cherry]

1 hour ago, JDCrow said:

I’d never guessed that. Thanks! For me, seal starts to squish, say “click” out loud and call it good. Used the new 1 piece rubber seals BTW, awesome 

FWIW.  I was starting to torque mine dow with a calibrated torque wrench.  Really low torque, but the AC’s were starting to move and I was 2 turns already. I quit. That was in the spring of 5he second year….probably had 75 nights and 7K on it….as I bought it new.  Attended the Lazy Days HVAC seminar. Some one asked that question. Yes, 45 inch pounds.  The instructor said to be careful. If there were no leaks and the AC’s had been in use to not go crazy.  The spec is for a new install….maybe good to check if you just bought a new MH, or after a month or so on a new install.  He said they replaced a lot of gaskets because folks would routinely keep tightening.

From my manufacturing days on carburetors where we had a highly sophisticated 7 spindle dynamic measuring inline torque system where the bolts were run down at a fast speed…then as the gasket compressed, the guns would go to a criss cross sequence and measure all 7 fasteners.  When one hit the 15 inch pound (memory) spec, that gun shut off….then as each hit the spec they would all eventually slow down.  Then there was a pause and all 7 would start at a low or slow speed and perform a 100% QA audit.  This was a gasketed joint….much thinner than the foam gaskets.  We learned a lot about elastic compressed joint fastening.  We spent upwards of $400’K in 1981 to ensure the tops were fastened properly..  FORD actually bought the new systems,  We also put a 4 spindle driver system on the flange or the throttle plate that screwed to the intake.  FORD reported a 90% reduction in “rough idle” warranty after the new tooling has been in olace for a year.

They made our competitors install the same system.  Ny take….and what the Lazy Days tech said.  Check it with a hand help nut driver and deep well socket.  Snug it  a little, but don’t try to retorque it unless there is a leak or vibration.

I know folks that retorque frequently….so it is a personal decision.  Just passing on a comment from the folks that work on them daily

[JDCrow]

27 minutes ago, Tom Cherry said:

FWIW.  I was starting to torque mine dow with a calibrated torque wrench.  Really low torque, but the AC’s were starting to move and I was 2 turns already. I quit. That was in the spring of 5he second year….probably had 75 nights and 7K on it….as I bought it new.  Attended the Lazy Days HVAC seminar. Some one asked that question. Yes, 45 inch pounds.  The instructor said to be careful. If there were no leaks and the AC’s had been in use to not go crazy.  The spec is for a new install….maybe good to check if you just bought a new MH, or after a month or so on a new install.  He said they replaced a lot of gaskets because folks would routinely keep tightening.

From my manufacturing days on carburetors where we had a highly sophisticated 7 spindle dynamic measuring inline torque system where the bolts were run down at a fast speed…then as the gasket compressed, the guns would go to a criss cross sequence and measure all 7 fasteners.  When one hit the 15 inch pound (memory) spec, that gun shut off….then as each hit the spec they would all eventually slow down.  Then there was a pause and all 7 would start at a low or slow speed and perform a 100% QA audit.  This was a gasketed joint….much thinner than the foam gaskets.  We learned a lot about elastic compressed joint fastening.  We spent upwards of $400’K in 1981 to ensure the tops were fastened properly..  FORD actually bought the new systems,  We also put a 4 spindle driver system on the flange or the throttle plate that screwed to the intake.  FORD reported a 90% reduction in “rough idle” warranty after the new tooling has been in olace for a year.

They made our competitors install the same system.  Ny take….and what the Lazy Days tech said.  Check it with a hand help nut driver and deep well socket.  Snug it  a little, but don’t try to retorque it unless there is a leak or vibration.

I know folks that retorque frequently….so it is a personal decision.  Just passing on a comment from the folks that work on them daily

The units are heavy, I can see not going overboard for sure

Not to hijack, you’ll appreciate this 

https://www.wsj.com/articles/at-ford-quality-is-now-problem-1-11659758404

Ford set aside 4 billion dollars in 2021 for warranty repairs, 4 billion 

Edited September 18, 2022 by JDCrow

[Chuck B 2004 Windsor]

If I remember correctly it is 4 INCH pounds.

 

[Tom Cherry]

6 minutes ago, JDCrow said:

Not to hijack, you’ll appreciate this 

https://www.wsj.com/articles/at-ford-quality-is-now-problem-1-11659758404

Ford set aside 4 billion dollars in 2021 for warranty repairs, 4 billion 

In the early 80’s, Ford made us set up a Statistical Process Control department.  Head to report directly to Plant Manager.  Every Ford supplier CEO or Division President was required to attend a 5 day seminar in Dearborn or Farmington Hills.  The edict came from Ford’s purchasing department.  I had already been assigned the SPC head duties. By coincidence, I got put into one of the Top Dog Seminars.  Dr. Deming was the lecturer for an hour each day…but he had a “staff” from UT Knoxville that Ford funded.  It was a hoot.  “We ain’t gonna….” was the cry and the Deming Staff took names. Next day, that individual was 100% business as Ford VP Purchasing called him or his boss.

FORD reduced their warranty costs unbelievably in the next 10 years.  We were a Q-101 site and had a full time Ford QA REP on site EVERY DAY. We got elevated to the coveted Q1 classification. 

Seems like that has disappeared.  Wonder about the reliability of an EV without the SPC Systems that most big chip vendors use?  Thanks….

7 minutes ago, Chuck B 2004 Windsor said:

If I remember correctly it is 4 INCH pounds.

 

From another site’s posts.  I remember it well as the LD tech emphasized the SNUG part and said that you would eventually pull it down tight….like maybe 1/8”.  This states it well, based on my memory.

The 4 hold down bolts should be tightened by finger in an 'X' pattern until 'snug'

The torque valve you is in INCH Pounds and is 40/INCH LBS

The new roof gasket is 1" thick and when properly torqued down it will be compressed by half ----A/C pan should be elevated above roof so that rain/water/evap drip pan run off can flow around/under A/C pan and not accumulate.

The hold down bolts should be dry...no lubricant--no locktite etc.

After installation of a new roof gasket you should check the 'tightness' of the 4 hold down bolts after couple trips (traveling will set gasket).

40 INCH LBS -----------OR just 'SNUG'

[Chuck B 2004 Windsor]

You are correct, the manual says 40 inch pounds, sorry.

[bmulvenna@hotmail.com]

Thanks to all.