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03-08-2017, 09:28 PM | #1 |
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Join Date: May 2007
Location: ALTON, IL.
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i messed up...
I slightly overtightened my pinion nut to 35 in. lbs. Time to tear it back down for new crush sleeve, run it, or back it off to 25 in. lbs. (spec)???
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03-09-2017, 12:50 AM | #2 |
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Join Date: May 2009
Location: Fort Worth, TX
Posts: 6,370
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Re: i messed up...
If this is a high performance build, A pinion spacer & shims should be used in place of the crush sleeve on GM corporate diffs.
10 inch pounds isn't the end of the world, I'm guessing this is with a seal? Try seating the bearing & races if you haven't already, A few taps on the back of the pinion, & a few taps the the yoke with a brass drift will do. Recheck rotational torque. (Rotate pinion between taps) If it's still at 35 in. lbs., It will run there! Just be easy on the break-in....Drive around the block, Park the truck & let it cool 30 minutes, Repeat 4 or 5 times. If you just not happy because the specs, Replace the sleeve & try again, I wouldn't recommend un-crushing on a fresh build. |
03-09-2017, 01:06 AM | #3 |
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Re: i messed up...
Thanks Cline. Not too high perf. 454- 480 HP. Yes it is with a seal. Seated bearings before I put the carrier in. I back nut off to 10 in. lbs. and went back to 24 in. This is where I messed up??
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03-09-2017, 01:19 AM | #4 | |
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Re: i messed up...
Quote:
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" |
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03-09-2017, 11:46 AM | #5 |
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Location: sumterville, florida
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Re: i messed up...
+2 in 35 in # don't hurt anything. (Don't back it off!)
what is strange to me is this seating thing. drive the cups home, drive or press on the large cone - done. what is there to seat? |
03-09-2017, 10:02 PM | #6 | |
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Location: Fort Worth, TX
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Re: i messed up...
Quote:
Once you crush the sleeve to far.....It's DONE, It will never space the bearings with them amount of force it was designed to once you back off the nut. Sometimes the races don't get seated all the way using drivers on initial install. |
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03-10-2017, 03:04 AM | #7 |
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Location: ALTON, IL.
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Re: i messed up...
Cline. I'm working on a 12 bolt. Also adding a Detroit truetrac along with the gears. So your thinking I should do away with the crush sleeve and go with the spacer and shims? I'll have to look into that. Thank you OK got a set coming from Ratech. says to start with spacer and 3 shims, torque nut to 125 Ft.lbs. check preload (25 in. lbs.?)
Last edited by ratfreak8871; 03-10-2017 at 03:22 AM. |
03-10-2017, 11:01 AM | #8 |
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Location: Falls City, Nebraska "100 Miles From Nowhere"
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Re: i messed up...
Pinion bearing preload for new bearings and gears in a truck-12 bolt is 13 -15 in-lbs...6 - 7 in-lbs (used)
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Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American" |
03-10-2017, 02:36 PM | #9 |
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Location: ALTON, IL.
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Re: i messed up...
I've found the specs all over the place from as low as 13 in to as high as 29in. Should I shoot for the middle and go 20 in maybe?
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03-10-2017, 08:50 PM | #10 |
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Join Date: May 2009
Location: Fort Worth, TX
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Re: i messed up...
The specs I have are the same as Ironangel's (Yukon Gear & Axle specs), I don't know where my factory service manual is right now......But generally the factory rotational torque spec are higher to go along with different break-in procedures.
20-25 in. lbs. is OK on any Corporate differential except a 7.5" (less) or a 10.5" (more), Bigger Dana diffs can call for up to 55 in. lbs.!! |
03-14-2017, 09:45 PM | #11 |
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Join Date: May 2007
Location: ALTON, IL.
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Re: i messed up...
Thank you for all the help guys! I have all the parts and ready to go but work and weather are keeping me from it right now. I'll have to keep you updated.
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