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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Alan Baker on May 28, 2013, 04:23:14 AM

Title: Torque
Post by: Alan Baker on May 28, 2013, 04:23:14 AM
Some time ago one of the more cleaver gurus posted a chart showing the proper torque wrench setting to get the proper torque at the working end of a 12 to 1 torque multiplier wrench.
I've checked the archives and can't spot it. Did one of you save it and will you share. If I do get my hands on it I will put it in a baggie and keep it in the bag with the wrench.

Thanks
Alan Baker
'84 Eagle 10
6 V 92 turned up to around 350
presently suffering a bogie leaning to the left
Title: Re: Torque
Post by: Ed Hackenbruch on May 28, 2013, 05:49:23 AM
I ain't a clever guru of anything, but the answer is 10 to 1. ;D
Title: Re: Torque
Post by: sommersed on May 28, 2013, 06:42:51 AM
10 lbs of Torque on a 12 to 1 Multiplier would produce 120 ft/lbs
20 lbs of Torque on a 12 to 1 Multiplier would produce 240 ft/lbs
30 lbs of Torque on a 12 to 1 Multiplier would produce 360 ft/lbs
40 lbs of Torque on a 12 to 1 Multiplier would produce 480 ft/lbs

However, the decision to use any Multiplier to produce Torque, is, in my opinion, an iffy procedure.  Releasing Torque, fine, applying Torque, not so much.

Ed   
Title: Re: Torque
Post by: luvrbus on May 28, 2013, 06:53:30 AM
Yep I agree Ed the more connections like a scoket,extension and the torque wrench on a multiplier it gets way off on torque lbs
Title: Re: Torque
Post by: Jon on May 28, 2013, 07:15:17 AM
A long time ago when I bought mine at a FMCA convention the salesman (who happened to be the owner of the company) suggested if the torque is to be 480 ft. lbs. for example, set the torque wrench to 45 ft.lbs. instead of the 40 that would seem correct to compensate for drive train losses.

I have no idea how he determined this other than probably trial and error, or maybe he was just making stuff up. It sounded reasonable so that is what I have been doing.
Title: Re: Torque
Post by: bevans6 on May 28, 2013, 07:53:42 AM
Correct, there is about a 15% to 20% loss in the planetary gears inside, depends on the geartrain design.  The 12:1 is the mechanical movement ratio normally.  One converter I bought had an instruction sheet with the torque ratios on it, but I never used it but once - the 3/4" drive stub sheared off the first nut I tried to undo.  I didn't take it back since I was putting roughly twice the rated torque through it at the time.  Driver's side wheels the first time I took them off after I bought the bus.  Snap-on 1" drive impact gun turned up to 145 psi took them off at the end of the day.

Brian
Title: Re: Torque
Post by: Ed Hackenbruch on May 28, 2013, 11:41:14 AM
 The instructions that came with mine said to multiply by 10 when using a torque wrench with it,.....45 lbs to get 450 lbs, 48 lbs to get 480 lbs, 50 lbs to get 500 lbs, etc.....using a factor of 10 does allow for the loss as Brian said.
Title: Re: Torque
Post by: gus on May 28, 2013, 12:33:44 PM
It depends on if the TM has a handle and how long? Torque is a factor of total handle length.

As already stated, TMs are not meant for tightening, just loosening. There is a risk in doing this.

My TM is a 60:1 and I don't have the nerve to use it for tightening, but it sure does loosen nuts in a hurry!!
Title: Re: Torque
Post by: Ed Hackenbruch on May 28, 2013, 01:00:35 PM
Gus, the 12 to 1 doesn't have an attached handle. You use a 1/2 " drive ratchet to take anything off. To tighten you can use a torque wrench with it. Whole different animal than your 60 to 1.    :)
Title: Re: Torque
Post by: luvrbus on May 28, 2013, 01:05:00 PM
I would not trust your tools formula Ed even a impact gun changes when one adds a socket or extension so will a breaker bar,I like Brian's formula more realistic to me  

I have no idea why I am even into this discussion I gave my 12:1 multiplier (Proto) away years ago I thought was the most non essential tool I owned

good luck
Title: Re: Torque
Post by: Ed Hackenbruch on May 28, 2013, 01:16:12 PM
I am going by the manufactures instructions Clifford.  :)  They should have done the testing to come up with the figures,.......gotta trust them just like i gotta trust that a tire can support x number of lbs. at a certain air pressure. ;D
Title: Re: Torque
Post by: luvrbus on May 28, 2013, 01:44:20 PM
Easy to test yourself Ed, I don't understand why people would even need one for 500 or 600 lbs at my age I can still do 500 lbs with my Proto Torque wrench
Title: Re: Torque
Post by: Ed Hackenbruch on May 28, 2013, 05:12:04 PM
Reason i bought one was because the first time i went to take a couple of wheels off i had nothing that would do the job,....and my neighbor who was a long time busnut and owned 3 buses at the time also didn't have anything that worked. A friend of his who also had a bus loaned me the 12 to 1 and that worked. Liked it enough that i bought my own because i knew later on that the others were going to have to come off too. Side benefit was i found that i could torque them back on to within a lb. or two of whatever i wanted.  All of this is why nobody but me puts my wheels back on....when torqued to the proper range they are easy to take off.
Title: Re: Torque
Post by: luvrbus on May 28, 2013, 05:35:16 PM
I never torqued but 1 lug nut on each wheel nut Ed then I set my impact and went to work they would all ways be within a  1 or 2 pounds if checked, you younger guys like work better than us older folks as the song says "Old age and treachery over comes youth and skill" a little never seize on the nuts and aluminum wheels I was good to go I never lost a wheel ,stretched a stud or broke a stud

David Georgy at South Oregon Diesel his guy cost me wheel one time with a 1 in impact that is only wheel damaged I ever had

Without a shop,big air compressor and the tools I can see where a multiplier would be good for you guys I just never had a need for one so I gave it away to someone here and he uses it from time to time 

I hope the guy that started this thread doesn't think a multiplier is going to help him with a low and leaning bogie on his Eagle maybe to remove the tire lol

good luck 
Title: Re: Torque
Post by: Boomer on May 28, 2013, 07:33:31 PM
Clifford I think you need to have your favorite machine shop make a  1 7/8 two piece, clamping, ratcheting, torque multiplier for the Eagle torsion push rods.  Then I can borrow it from you, lol   
Mark
Title: Re: Torque
Post by: Lin on May 28, 2013, 09:04:59 PM
I have a 40:1 torque multiplier also.  It's great for effortlessly loosening lugs.  I doubt I could get to accurate for tightening though.  I think tightening could be practical with a 12:1 though.  Ed's ratio sounds good.  You could try it out and test it when the right torque wrench is around.  Up until now, I have used my body weight hanging on a 3ft bar to get withing the right range.  A couple of weeks ago though, I found a wrench that would do the job at a flea market.  I'm guessing it was worth the $30. I paid.

Clifford, you will have to understand that most of us can't hand tighten lugs to 450 ft/lbs like you can.
Title: Re: Torque
Post by: Alan Baker on May 29, 2013, 03:03:41 PM
Right you are. The wheel comes off and the proper shims are installed.

Alan
Title: Re: Torque
Post by: Dave5Cs on May 29, 2013, 11:20:36 PM
I use my 60:1 easy off and coupled with a 3/8 torque wrench set at 8.2 ft/lbs allows 15%, to put back on, a dream. Matter of fact I just got 18 Radius Rod bushings and locks from Luke. so I will need to pull tires again soon.  ;D

Dave5Cs
Title: Re: Torque
Post by: gus on May 30, 2013, 04:18:30 PM
Dave,

I seriously doubt your TM is anywhere near accurate in spite of the math.

I have the same one and don't have the nerve to try it your way, there is just too much room for error.

I never again want to have to replace stripped wheel studs!

The safest is a lug wrench and a bar of proper length for your weight. No possible way to overdo it that way unless you jump on it!!