84 K10 acted like it hit a boulder and stopped rolling, but no boulder - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MountainGoat1966 · 10-16-2014, 08:45 PM

I was driving home the other day after cutting firewood, was using 4x4 mode offroad, but had the transfer case in 2H with hubs still locked in on the decent road.
Going about 5 MPH since the road is real bad and I had a heavier than normal load.
All of a sudden, the truck made a clunk and stopped rolling, just like I had hit a boulder.
Put it in reverse and was able to move backwards.
Unlocked the hubs and I was able to continue driving forward.
I suspect the front pinion bearing, as it was rough and made noise when I installed a limited slip carrier about a month ago but did not have the money for it and needed the 4x4 mode working due to mud.
I was hoping it would have lasted longer.
Now, I will obviously need to replace the front pinion bearing, but don't want to deal with the crush sleeve crap.
I saw somewhere (but can't find it now) there is a solution that uses shims and is much easier to set the preload.
It's a stock 8.5" 10 bolt axle.

**Yukon Jack** · 10-17-2014, 12:19 PM

Could be bearings in your transfer case and when you put it in reverse it cleared the offending bearing. That happened to my Rockwell T221 - took out the rear output bearings. It was in 2H when it happened to me.

MountainGoat1966 · 10-17-2014, 01:09 PM

The transfer case was rebuilt a number of years ago, and always had a weird vibration at highway speed, it would come in and go out, repeatedly at a steady rate.
I'm not going to rule out the T case but I sure hope I can get a couple more years out of it before I need to do anything with it.
Everytime I drive the truck, that vibration bothers me.

TRUCKGUY · 10-21-2014, 06:17 PM

Try adjusting your shifter on the t-case

MountainGoat1966 · 10-30-2014, 10:32 AM

I finally got the ambition to start taking things apart, I found the bolt that locks the spider gear cross pin had worked loose and was sitting on the bottom of the housing.
Got lucky, no damage to the gears, bolt was still straight and only a small gouge in the cross pin.
Reassembled the front differential and everything seems normal again.

BLT gmc · 10-30-2014, 12:30 PM

Excellent, Bruce

10-16-2014, 08:45 PM	#1
MountainGoat1966 Registered User Join Date: Jan 2010 Location: northern arizona Posts: 259	84 K10 acted like it hit a boulder and stopped rolling, but no boulder I was driving home the other day after cutting firewood, was using 4x4 mode offroad, but had the transfer case in 2H with hubs still locked in on the decent road. Going about 5 MPH since the road is real bad and I had a heavier than normal load. All of a sudden, the truck made a clunk and stopped rolling, just like I had hit a boulder. Put it in reverse and was able to move backwards. Unlocked the hubs and I was able to continue driving forward. I suspect the front pinion bearing, as it was rough and made noise when I installed a limited slip carrier about a month ago but did not have the money for it and needed the 4x4 mode working due to mud. I was hoping it would have lasted longer. Now, I will obviously need to replace the front pinion bearing, but don't want to deal with the crush sleeve crap. I saw somewhere (but can't find it now) there is a solution that uses shims and is much easier to set the preload. It's a stock 8.5" 10 bolt axle. __________________ "Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know."

10-17-2014, 12:19 PM	#2
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,686	Re: 84 K10 acted like it hit a boulder and stopped rolling, but no boulder Could be bearings in your transfer case and when you put it in reverse it cleared the offending bearing. That happened to my Rockwell T221 - took out the rear output bearings. It was in 2H when it happened to me. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

10-17-2014, 01:09 PM	#3
MountainGoat1966 Registered User Join Date: Jan 2010 Location: northern arizona Posts: 259	Re: 84 K10 acted like it hit a boulder and stopped rolling, but no boulder The transfer case was rebuilt a number of years ago, and always had a weird vibration at highway speed, it would come in and go out, repeatedly at a steady rate. I'm not going to rule out the T case but I sure hope I can get a couple more years out of it before I need to do anything with it. Everytime I drive the truck, that vibration bothers me. __________________ "Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know."

10-21-2014, 06:17 PM	#4
TRUCKGUY Registered User Join Date: Jan 2005 Location: Nortonville, Ky Posts: 407	Re: 84 K10 acted like it hit a boulder and stopped rolling, but no boulder Try adjusting your shifter on the t-case __________________ Dan. 55 F100 panel truck project 64 350/th400/10bolt short fleet 66 F100 302/C6/9" short fleet 67 IH 4x2 304/t984speed D44 373 locker lwb box 67 IH 4x4 304/t98 4speed/d44/d60 4.10'slwb box 67 IH Travelall 4x4 304/t98 4speed/12bolt/10bolt 81 2wd short fleet current build! 83 350/700r4 short fleet 88 k5 12" lift 3/4 ton swap mud toy 96 Dodge 3500 CUMMINS/5speed/4x2 97 Pontiac Trans Am WS6/LT1 383/6speed/T-tops

10-30-2014, 10:32 AM	#5
MountainGoat1966 Registered User Join Date: Jan 2010 Location: northern arizona Posts: 259	Re: 84 K10 acted like it hit a boulder and stopped rolling, but no boulder I finally got the ambition to start taking things apart, I found the bolt that locks the spider gear cross pin had worked loose and was sitting on the bottom of the housing. Got lucky, no damage to the gears, bolt was still straight and only a small gouge in the cross pin. Reassembled the front differential and everything seems normal again. __________________ "Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know."

10-30-2014, 12:30 PM	#6
BLT gmc Registered User Join Date: Feb 2014 Location: West Iowa Posts: 1,106	Re: 84 K10 acted like it hit a boulder and stopped rolling, but no boulder Excellent, Bruce



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