Torque Multiplier

[enrare]

I'm needing to replace a pinion seal on a Dana 80 in my Dodge truck. Pinion nut calls for a 440-500 ft. lbs torque spec. Don't think my Craftsman 1/2" torque wrench is up to the job and torque wrenches up to the task are big money. I'm thinking my only semi-affordable option is a torque multiplier off ebay or the classifieds. My question is would you buy a used one? I'm not familiar with them and if they get out of accuracy/calibration or some kind of concern with a used tool of this nature. I see on ebay new Nieko or Genius multipliers in the torque range I need for a little over $200. Used Williams or Proto units are around $300+.
I'm getting together a parts and tools price list to do this myself, then will call some shops and see how much it will be to hire it out.

 

[joeswamp]

Are torque multipliers supposed to be used for tightening? I would think the variable friction inside could cause some inaccuracy.

 

[dsmnickk90]

http://www.tooltopia.com/precision-instruments-c4d600f.aspx
3/4" drive torque wrench for under $350 and goes to 600ft/lbs

Cheaper option
http://www.tooltopia.com/mountain-16600.aspx
Under $300

 

[Alchymist]

Torque wrench extension. Make your own.
http://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm

 

[blacK20]

I don't think a torque multiplier will be very accurate when used with a torque wrench, even if you know the bias ratio.

 

[jrlp]

Go shade tree! Impact that thing on there!

 

[Ditchdigger]

Pinion nut calls for a 440-500 ft. lbs torque spec.

I don't think a torque multiplier will be very accurate when used with a torque wrench, even if you know the bias ratio.

With an acceptable torque variance of 12% I bet it would be fine. The proto torque multiplier I used to use advertised 5% accuracy.

http://www.grainger.com/Grainger/PROTO-Torque-Multiplier-3YW21?Pid=search

 

[enrare]

Thanks for the links, for some reason I thought a torque wrench in the 600ft/lbs was going to be twice those prices. Guess I was thinking this because the only place I have seen torque wrenches that size has been the tool truck brands or Grainger. My concern with a 4 foot torque wrench is having enough swing room to operate it under the truck.

http://www.tooltopia.com/precision-instruments-c4d600f.aspx
3/4" drive torque wrench for under $350 and goes to 600ft/lbs

Cheaper option
http://www.tooltopia.com/mountain-16600.aspx
Under $300

 

[dsmnickk90]

Thanks for the links, for some reason I thought a torque wrench in the 600ft/lbs was going to be twice those prices. Guess I was thinking this because the only place I have seen torque wrenches that size has been the tool truck brands or Grainger. My concern with a 4 foot torque wrench is having enough swing room to operate it under the truck.

If you get the back up high enough I dont see it being a problem. Their is almost a Central lighting on tool topia for $250

 

[jetmech09]

Get a smaller torque wrench, do the math, make a longer handle with one of those weird socket things that change the direction. The little square looking thing.

 

[blk00ss]

A good 1/2" impact will be plenty. Don't get too caught up in torque numbers.

 

[marcusicp]

Count the treads the stick out past the nut, mark the shaft and nut before you remove it and spin it off with an impact gun. When you put it back on very slowly run it up with an impact gun until you have the right number of threads sticking out and you line up your marks.

 

[GSteg]

A torque wrench on a torque multiplier is okay. They're not used just for removing tight nuts.