another ? about my 1st 741 build

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challenger57

cuda57
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This is about the whine in my 741 build. I removed the 3rd member and did another paste ring pinion wear pattern keeping tension on the ring gear as suggested. I have a great pattern on the drive side but none on the coast side. I rechecked my backlash, it was a bit tight-.002 to .003. I also rechecked my pinion depth, it was 2.770 as stamped on the pinion with 15" lbs. torque of preload on the old inner bearing which was good. My actual ? is when do i tighten the pinion nut to 120 ft lbs. Just for the sake of knowledge I tightened the pinion nut after checking my pinion depth. It went to 2.775. Is this normal or should I have 2.770 after tightening the pin nut. In all my on line info no one mentions this. Also when I pulled the rear the wear pattern on the new gears suggested according to the diagrams that I should decrease the backlash. Help here is needed!!!
 
The depth should be at the indicated distance when the pinion is torqued fully and this normally means a rotating torque figure of 15-20lb feet without the seal installed. BTW, you need a rotating torque type torque wrench to measure this. Not a normal torque wrench... If your backlash is tight when the pinion isn't torqued fully you're already off. Can you post clear pics of the patterns?
 
moper said:
The depth should be at the indicated distance when the pinion is torqued fully and this normally means a rotating torque figure of 15-20lb feet without the seal installed. BTW, you need a rotating torque type torque wrench to measure this. Not a normal torque wrench... If your backlash is tight when the pinion isn't torqued fully you're already off. Can you post clear pics of the patterns?
Click to expand...

I think you mean inch/pounds

http://www.pirate4x4.com/tech/billa...Ring and Pinion installation instructions.pdf

If you only have .002-.003 BL you need to reset everything.
 
Yeah, thanks cracked...my bad...lol. But it is not a normal click or beam type type torque wrench. It's got a dial type gage and is much more sensitive.
 
moper said:
Yeah, thanks cracked...my bad...lol. But it is not a normal click or beam type type torque wrench. It's got a dial type gage and is much more sensitive.
Click to expand...

No big...

Yes, something like this to set pinion preload.
288929.jpg


I have a 0-75 inch/pound model.
 
I am using a digital torque wrench that vibrates at set torque. When the job is done do I leave the pin nut at 15-20" lbs and use red loctite or do I tighten to 120ft lb or so. It looks like my backlash is to tight. I orderd the dvd I saw going around in here, maybe that can shed some light on my issue. Maybe i can get some pics of the pattern. Thanks
 
First, that wrench isnt what you should be using. Because it requires more torque to initiate rotation than continue it. You need a dial type wrench like the above. Mine's an older Snap On but same same. Second, you dont torque the nut to 15-20lbs. that's your problem. You have to torque it to spec which is 240 pound FEET. Then you have to rotatie it using the right dial type wrench and if it's les than 15 INCH pounds, you need to remove pinion shims. If it's more than 15 INCH pounds, you need to remove shims from the pinion. You dont torque the pinion nut to 20 inch pounds. You torque it to 240 pound feet to checkthe preload. It's a balancing act to get the pinion depth and preload right. but you'll find that if you do, the backlash will be a peice of cake to get right and the pattern will come right in for you. BTW, I use good bearings with the IDs enlarged as "checking bearings" for the various pinion types. It goes a lot faster that way...
 
challenger57 said:
I am using a digital torque wrench that vibrates at set torque. When the job is done do I leave the pin nut at 15-20" lbs and use red loctite or do I tighten to 120ft lb or so. It looks like my backlash is to tight. I orderd the dvd I saw going around in here, maybe that can shed some light on my issue. Maybe i can get some pics of the pattern. Thanks
Click to expand...

Like Moper said your using the wrong type of torque wrench. You need a rotating dial type like pictured above (preferred) but a beam type will work, just a little harder to use. And the 15-20 inch lbs. you refer too is the rotating torque of the pinion bearings, not the amount you torque the pinion nut. You achieve the pinion bearing rotating torque by adding or subtracting pinion bearing shims like mentioned earlier. You always torque the pinion nut to 240 foot lbs. after you change the pinion bearing shims so you get the correct rotating torque reading. The rotating torque is the first thing to set right after you set the pinion depth. Once you get the pinion depth set and the pinion bearing preload set then you install the carrier and set the backlash and check the pattern with checking grease.

I know most of what I said is redundant but sometimes a different spin on things will click. Hopefully this helped.
 
Thanks guys, now i understand more about the 15-20 inch lb. and why it needs to be done with out the seal installed causing drag. Thanks
 
They really aren't hard to assemble, you just need to know what to use, and how the parts interact. I'll also add sometimes the instructions are a little vague...lol.
 
I removed the carrier assembly and used a proper depth gauge and discovered my pinion needed to go .015 deeper. I removed the pinion and used the correct amount of shims to get it to the manufactorers dimension and got it exact. Now just waiting for my dial in. lb torque wrench to arrive. I think because the pinion was not deep enough that is why I only got a pattern on the drive side of the ring gear.
 
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