Odd problem- rearend not centered? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

TugOwar · 01-16-2011, 08:44 AM

dana60 rear end with leaf springs

When I put the 700r4 transmission in my GMC I went with a one piece drive shaft fabbed up by Drive Shafts Unlimited in San Antonio. It works great.

However, something (rear end?) is off center. The drive shaft doesn't pierce the center of the hole through the cross member, it sits closer to one side. This only becomes a problem when I add a bit of cargo. A few hundred pounds is enough to make the drive shaft rub against the SIDE of the cross member, not at the top as if the springs/shocks were bottomed out.

Stand at the front of the truck and look down the sides of the truck you can see the passenger side rear tire sticks out from under the fender slightly more than the drivers side tire.

I'm not sure where there is any place to make adjustments. If the saddles are welded to the axle housing (are they?) it's not like the rear end can slide to one side. The U-bolts are tight, I've checked. Where to go from here?

cdowns · 01-16-2011, 10:20 AM

to center the rear you need to cut the saddels off reposition rear axel and weld the saddels back on

redbaron69 · 01-16-2011, 10:26 AM

cdowns is correct, but why is it like this? has the rear been changed? i would inspect the rear and see if the perches are were they should be.

TugOwar · 01-16-2011, 10:32 AM

I haven't changed the rear end but perhaps it was before I bought it. Will check saddles at first opportunity. Thanks for replies.

**special-K** · 01-16-2011, 11:27 AM

How do the shackles look? I think I would pick up a set of u-bolts,cut the old ones off,and insure all is good with the center in,unless you can find something else more obvious. Take a measurement center of front hub to center of rear hub on each side and compare. I think it sounds shifted to the side more than crooked front to back,though. The springs and shackles could be racked. I've seen this before. The rear spring hanger was actually tweaked causing the spring pack on one side to roll to one side a bit. The problem there,as seen once axle was removed,was the tube on one side was loose from the differential housing. This was on a 14-bolt. It appeared to never be welded.

redbaron69 · 01-16-2011, 11:44 AM

good info special-k

71swb4x4 · 01-16-2011, 11:52 AM

Is the rearend off when you measure where the tires sit in the wheel wells? Maybe the crossmember is off, or the hole in it is off. It was built 40+ years ago when manufacturing processes weren't quite what they are today.

**special-K** · 01-16-2011, 12:04 PM

I didn't mention it,but it's possible the frame is tweaked. It's just real hard to check unless it's obvious,which I'll assume it isn't.

TugOwar · 01-16-2011, 12:36 PM

Quote:

Originally Posted by special-K

I didn't mention it,but it's possible the frame is tweaked. It's just real hard to check unless it's obvious,which I'll assume it isn't.

This is my worst fear to be honest. I've so much time and effort in this truck I'd really hate to find out the frame is wrecked.

TugOwar · 01-16-2011, 12:38 PM

Quote:

Originally Posted by 71swb4x4

Is the rearend off when you measure where the tires sit in the wheel wells? Maybe the crossmember is off, or the hole in it is off. It was built 40+ years ago when manufacturing processes weren't quite what they are today.

There is a visible difference when standing at the front of the truck and looking down each side.

sjarrett71 · 01-16-2011, 12:47 PM

Would leaf spring bushings make this happen? I mean if one side was totally shot and the other wasn't, would it make it shift over? Just an idea.

powerdriver 1958 · 01-16-2011, 12:52 PM

A busted center bolt would do it .

darkone · 01-16-2011, 02:45 PM

nvm

mr48chev · 01-16-2011, 03:56 PM

Quote:

Originally Posted by sjarrett71

Would leaf spring bushings make this happen? I mean if one side was totally shot and the other wasn't, would it make it shift over? Just an idea.

Take a good look at the springs an make sure that they are sitting straight to the truck and not off to one side a bit.

powerdriver 1958
Re: Odd problem- rearend not centered?
A busted center bolt would do it .

That too. Check and make sure that the spring stacks are straight and not out of kilter a bit.

A lot of these trucks got abused pretty hard early in their lives when they had to work for a living. Hauling heavy loads and being left loaded for periods of time is/was rough on the suspensions.

TugOwar · 01-16-2011, 09:30 PM

Thanks very much the all the replies, lots of good info/ideas. Give me plenty to do when the weather clears up and I have the time.

jbclassix · 01-16-2011, 09:32 PM

Make sure one of your springs isn't in backwards... Don't ask me how I figured out they only go in one way.

67C10BUB · 01-16-2011, 09:39 PM

The input shaft in the rearend should be offset (at least on the 12 bolt it is offset to the passenger side about 1"). I know mine doesn't go though the hoop completely centered. It is to the passenger side about .5".

01-16-2011, 08:44 AM	#1
TugOwar Registered User Join Date: Sep 2004 Location: Pleasanton, TX Posts: 1,723	Odd problem- rearend not centered? dana60 rear end with leaf springs When I put the 700r4 transmission in my GMC I went with a one piece drive shaft fabbed up by Drive Shafts Unlimited in San Antonio. It works great. However, something (rear end?) is off center. The drive shaft doesn't pierce the center of the hole through the cross member, it sits closer to one side. This only becomes a problem when I add a bit of cargo. A few hundred pounds is enough to make the drive shaft rub against the SIDE of the cross member, not at the top as if the springs/shocks were bottomed out. Stand at the front of the truck and look down the sides of the truck you can see the passenger side rear tire sticks out from under the fender slightly more than the drivers side tire. I'm not sure where there is any place to make adjustments. If the saddles are welded to the axle housing (are they?) it's not like the rear end can slide to one side. The U-bolts are tight, I've checked. Where to go from here?

01-16-2011, 10:20 AM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Odd problem- rearend not centered? to center the rear you need to cut the saddels off reposition rear axel and weld the saddels back on __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

01-16-2011, 10:26 AM	#3
redbaron69 Registered User Join Date: Jan 2009 Location: marion nc Posts: 588	Re: Odd problem- rearend not centered? cdowns is correct, but why is it like this? has the rear been changed? i would inspect the rear and see if the perches are were they should be. __________________ 69 short fleet 350/350 "under construction" 70 short step 307/3 speed

01-16-2011, 10:32 AM	#4
TugOwar Registered User Join Date: Sep 2004 Location: Pleasanton, TX Posts: 1,723	Re: Odd problem- rearend not centered? I haven't changed the rear end but perhaps it was before I bought it. Will check saddles at first opportunity. Thanks for replies.

01-16-2011, 11:27 AM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: Odd problem- rearend not centered? How do the shackles look? I think I would pick up a set of u-bolts,cut the old ones off,and insure all is good with the center in,unless you can find something else more obvious. Take a measurement center of front hub to center of rear hub on each side and compare. I think it sounds shifted to the side more than crooked front to back,though. The springs and shackles could be racked. I've seen this before. The rear spring hanger was actually tweaked causing the spring pack on one side to roll to one side a bit. The problem there,as seen once axle was removed,was the tube on one side was loose from the differential housing. This was on a 14-bolt. It appeared to never be welded. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

01-16-2011, 11:44 AM	#6
redbaron69 Registered User Join Date: Jan 2009 Location: marion nc Posts: 588	Re: Odd problem- rearend not centered? good info special-k __________________ 69 short fleet 350/350 "under construction" 70 short step 307/3 speed

01-16-2011, 11:52 AM	#7
71swb4x4 Senior Member Join Date: Nov 2003 Location: Brookings, SD Posts: 10,497	Re: Odd problem- rearend not centered? Is the rearend off when you measure where the tires sit in the wheel wells? Maybe the crossmember is off, or the hole in it is off. It was built 40+ years ago when manufacturing processes weren't quite what they are today. __________________ Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs.

01-16-2011, 12:04 PM	#8
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: Odd problem- rearend not centered? I didn't mention it,but it's possible the frame is tweaked. It's just real hard to check unless it's obvious,which I'll assume it isn't. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

01-16-2011, 12:47 PM	#11
sjarrett71 Registered User Join Date: Dec 2006 Location: Rolla, MO Posts: 2,463	Re: Odd problem- rearend not centered? Would leaf spring bushings make this happen? I mean if one side was totally shot and the other wasn't, would it make it shift over? Just an idea. __________________ -Scott-

01-16-2011, 12:52 PM	#12
powerdriver 1958 Kid's Mechanic Join Date: Nov 2006 Location: Kansas City Posts: 8,241	Re: Odd problem- rearend not centered? A busted center bolt would do it .

01-16-2011, 02:45 PM	#13
darkone Registered User Join Date: Sep 2010 Location: none Posts: 239	Re: Odd problem- rearend not centered? nvm Last edited by darkone; 01-16-2011 at 02:46 PM.

01-16-2011, 09:30 PM	#15
TugOwar Registered User Join Date: Sep 2004 Location: Pleasanton, TX Posts: 1,723	Re: Odd problem- rearend not centered? Thanks very much the all the replies, lots of good info/ideas. Give me plenty to do when the weather clears up and I have the time.

01-16-2011, 09:32 PM	#16
jbclassix Junk Yartist Join Date: Jul 2009 Location: Greeley, CO Posts: 2,203	Re: Odd problem- rearend not centered? Make sure one of your springs isn't in backwards... Don't ask me how I figured out they only go in one way. __________________ -Jeremy YOU ONLY FAIL IF YOU STOP TRYING 70 Crew Cab Build Link 70 GMC Suburban 4X4 build thread 95 Yukon Daily Driver Rebuilding an NP205

01-16-2011, 09:39 PM	#17
67C10BUB Registered User Join Date: Aug 2010 Location: Alta Loma, CA Posts: 610	Re: Odd problem- rearend not centered? The input shaft in the rearend should be offset (at least on the 12 bolt it is offset to the passenger side about 1"). I know mine doesn't go though the hoop completely centered. It is to the passenger side about .5". __________________ 67 5.3L Build



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