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10-24-2012, 11:55 PM | #1 |
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Noise When in Neutral
Start off i have a 350 mated with a sm465 transmission and a np208 transfer.
axles are dana up front and gm corp 12 out back 1/2 ton i just got the truck back on the road. today was the first real test drive. everything is great off the line, shifts smooth engages good. but as soon as i start to decelarate it starts to make a grinding noise, if i put it in neutral it makes it more and if i push the clutch in it doesnt go away. espcially does it when i put the truck in neutral down hill if i put it back into gear it goes away right away. what could this noise be? all fluids are topped off with fresh oil.
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-25-2012, 03:15 PM | #2 |
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Re: Noise When in Neutral
I have been doing a little research on drive line noises. One thing I was finding is that the pinion could be something that is causing this. The truck has a 4 inch lift new u joints.
The axles are new and the only thing different to this truck when I had the cover off the rear it looked good it had a little surface rust because the where not used In 10+ years. The gears are 4.11s in guessing someone swapped them. How can I tell that the pinion has the correct backlash? Posted via Mobile Device
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-25-2012, 03:32 PM | #3 |
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Re: Noise When in Neutral
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1999 Chevy K2500 RCLB 350 4L80e 2004 Chevy 3500 C&C Dmax Allison |
10-25-2012, 04:13 PM | #4 |
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Re: Noise When in Neutral
my 1/2 did the same thing. turns out my pinion nut backed off. i couldnt tell till i had the drive line out then i could move the yoke around
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ASA Chapter Lead-New Mexico/Arizona 75 C10 Scottsdale. 454/400th. 373 rear 76 C20 Custom Delux 350/4 speed 411 Posi rear |
10-25-2012, 04:55 PM | #5 | |
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Re: Noise When in Neutral
Quote:
i am thinking of tearing the rear end down this weekend and checking all the bearings. how can i tell if the pinion is out of spec just if the yoke moves a lot?
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
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10-25-2012, 08:26 PM | #6 |
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Re: Noise When in Neutral
I tightened it back up for a month or so and rebuilt the rear end. The truck isn't my dd though. It maybe. Sees 100 miles a month.
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ASA Chapter Lead-New Mexico/Arizona 75 C10 Scottsdale. 454/400th. 373 rear 76 C20 Custom Delux 350/4 speed 411 Posi rear |
10-25-2012, 09:36 PM | #7 |
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Re: Noise When in Neutral
could it be the piolt bearing? i know mine makes noise just like that.
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1986 c20 "the hillbilly" 350 sm465 3.42gears 21mpg at 70mph 1985 k30 "the ice cream truck from hell" no rust az truck 197-8??? c30 "ramp truck" 454 1978 monte carlo 350 350th with 2.73 gears. no rust. sc car |
10-25-2012, 10:22 PM | #8 | |
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Re: Noise When in Neutral
Quote:
i checked and there is alot of play in the rear yoke a lot more than the front i took some pictures of it one way and then the other and you can tell. does this mean that there isnt enough shims in there and the pinion is sitting to far forward away from the ring gear? here is a link to my build it is only one page. so you guys can see what i have done. http://67-72chevytrucks.com/vboard/s...d.php?t=527797 everything worked great in the old truck. the only thing different is the axle.
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) Last edited by threeonthetree; 10-25-2012 at 10:27 PM. |
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10-26-2012, 12:13 AM | #9 |
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Re: Noise When in Neutral
The thing is i think the noise is coming from the front end.
I have a big hole in the floor because this is an auto cab. the tranny doesnt vibrate when the noise happens it only makes the noise at speeds of 55 to 45 slowing down on off gas. no noise in the stall could it be a front end bearing. the transfer is in 2wd and makes the noise in 4
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-26-2012, 07:06 PM | #10 |
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Re: Noise When in Neutral
Check the spud shaft between the trans and tranfer case, ive seen those as well as trans output/ t case input shaft wear and cause quite a bit of slop. Most of them were only ten spline there so a little wear makes for a lot of movement.
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10-27-2012, 06:00 PM | #11 |
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Re: Noise When in Neutral
could this be a driveshaft problem
i have excesive stick out? what is proper stick out of a np208 transfer case.
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10-27-2012, 06:39 PM | #12 |
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Re: Noise When in Neutral
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-27-2012, 06:44 PM | #13 |
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Re: Noise When in Neutral
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-28-2012, 02:41 AM | #14 |
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Re: Noise When in Neutral
is the angle to extreme in the second pic.
is the stick out exxssseeive?
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Smoking Tires Since 1992 1969 c10 AKA SIN 1985 SSWB TRAZER (super short wheel base) |
10-28-2012, 04:34 AM | #15 |
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Re: Noise When in Neutral
Ahh! I stand corrected then, Thanks for clearing that up.
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10-28-2012, 01:22 PM | #16 |
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Re: Noise When in Neutral
do you think that this is my problem?
when i push the truck back and forward i can see the driveshaft pushing the transfer case up and down. anyone if this is i will have it lengthened this week
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