![]() |
Register or Log In To remove these advertisements. |
|
|
![]() |
|
Thread Tools | Display Modes |
|
![]() |
#1 |
Registered User
Join Date: Jul 2003
Location: So. Cal.
Posts: 389
|
I had a lower a-arm u-bolt break. You should change yours too.
My 68 is a half-ton and came with drum brakes. On these trucks, the lower control arm shaft attaches to the crossmember with two 3/8 u-bolts. Chevy increased the size of these on disc brake trucks because they were breaking.
I finally had one break that I'm sure was 35 years old. Luckily for me it was in a parking lot. I was just idling in reverse with the wheel cranked. SNAP. Not 5 minutes before I was on a major freeway doing 80mph. It was quite surprizing. So from my experience, I urge all of you to upgrade these bolts for safety. Early Classic has a 9/16 thread ubolt kit that they sell when upgrading to disc brakes. I just finished installing them and I feel much better and safer.
__________________
1968 Chev SWB with 1998 Corvette LS1 305hp and 320 ftlb to the wheels (stock engine!) AEM EMS and wideband O2 sensors Bowtie Overdrive's 700R4, stage 3 Baer 4 wheel discs and 20s http://iciclelanding.com/aperture?album=2049&view=album |
![]() |
![]() |
![]() |
#2 |
Firefighter
Join Date: Feb 2001
Location: Yellville, Ar, USA
Posts: 1,943
|
OOH, That sounds suprizingly familiar my 67' GMC did the exact same thing in reverse when turning to the right in my buddy's driveway, I had to call another buddy to get the parts and a jack for me, right before I had been on the highway running 65-70 mph. Then I had the same thing happen about a year later on the same side the passenger's when turining to the right hard.
Has anyone else had this problem? ![]()
__________________
'72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA ![]() ![]() |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jul 2000
Location: Victoria,BC, Canada
Posts: 1,300
|
I think we should lobby for a recall.
![]()
__________________
71 GMC 1500 LWB |
![]() |
![]() |
![]() |
#4 |
Registered User
Join Date: Sep 2002
Location: upland, california
Posts: 146
|
Ya i had one break and i didnt know it. I finally drove it home(about 15 miles) and noticed that one side was sitting lower and i looked down at the arm and it was hanging down on one side. I was pretty lucky that the arm never dropped!!!!!!!
Chris |
![]() |
![]() |
![]() |
#5 |
My other Love
Join Date: Aug 2001
Location: Castlegar B.C. Canada
Posts: 4,085
|
ok Im gonna go into my garage and look right now!
__________________
![]() Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life |
![]() |
![]() |
![]() |
#6 |
My other Love
Join Date: Aug 2001
Location: Castlegar B.C. Canada
Posts: 4,085
|
nope not broken, so that wasn't the clunk im hearin, but my steering box must of just started leaking, oh well
__________________
![]() Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life |
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Jul 2003
Location: So. Cal.
Posts: 389
|
I've driven my truck hard for about 8 years. I guess I got a lot of use out of that u-bolt.
__________________
1968 Chev SWB with 1998 Corvette LS1 305hp and 320 ftlb to the wheels (stock engine!) AEM EMS and wideband O2 sensors Bowtie Overdrive's 700R4, stage 3 Baer 4 wheel discs and 20s http://iciclelanding.com/aperture?album=2049&view=album |
![]() |
![]() |
![]() |
#8 |
Finish the'71..or bust!
Join Date: Jun 2003
Location: Nashville, TN.
Posts: 441
|
Speaking of U-Bolts...
I believe it may be a good idea to occasionally check the U-bolts that attach the rear axle to the trailing arms (on coil type rear suspension).
While redoing my 71 I removed the bed and while I have it off decided to replace some brake lines and brake components, the real coils, differential seal and gasket...whatever I noticed needing work...and do the painting of all that stuff. I even had a new driveshaft fabbed up for it. ![]() Now that I had a good, open view of the rear workings I noticed that the cups that hold the coil springs in place were rusted through on one side. The lower cups are perfect for holding water... There are also brackets that hold the aformentiond rear axle u-bolts in place atop the trailing arms which have a raised 'lip' around them...thus trapping water also. One of the u-bolts on my truck was rusted down to about half of it's original thickness where water had collected atop the bracket. Like I told my wife...the more I dig into this project...the more stuff I find to replace. I might have an original bolt or two left when its all over. LOL. ![]() |
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Apr 2000
Location: Leesburg, GA
Posts: 746
|
Same thing happened to my brother-in-laws 65 C-10. He was slowly taking a turn and one snaped. You can get the 1/2" U-bolts from your local Chevy dealer. I will be upgrading to the 1/2" when I re-do my front suspension.
__________________
FOUNDING MEMBER OF THE DRUM BRAKE CLUB Second Owner 70 C-10 Second Owner 93 GMC C1500 Third Owner 99 C2500 Crew Cab Short Bed |
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Nov 2002
Location: Redding California
Posts: 223
|
Not just the older ones do this. My 71 did the same thing and it has the disk brakes up front. If you haven't replaced them do it before it's to late.
__________________
1971 Chevy Cheyenne 383/350 LWB 2wd Built to use, and look good. ![]() |
![]() |
![]() |
![]() |
#11 |
Registered User
Join Date: Jul 2002
Location: St. James, MO
Posts: 1,239
|
I had one break on my '67. Made him darned hard to steer
![]()
__________________
'69 Longstep K-10: 327/SM465/T-221/Closed Knuckle Dana44/12-bolt. |
![]() |
![]() |
![]() |
#12 |
Firefighter
Join Date: Feb 2001
Location: Yellville, Ar, USA
Posts: 1,943
|
Sounds contageous!!
![]() ![]()
__________________
'72 Chevy SWB 350 Auto '67 GMC LWB 350 4 speed '70 Chevy 4x4 Stepside 350 Auto Yellville, Ar. USA ![]() ![]() |
![]() |
![]() |
![]() |
#13 |
Wiseass secured himself a BAN
Join Date: Nov 2000
Location: MOON!!!
Posts: 2,282
|
Wow I am paranoid now..... Where can we get them 1/2in u-bolts for the front A-arms? Besides Early Classic.
|
![]() |
![]() |
![]() |
#14 |
THE QUICKER FIXERUPER
Join Date: Jul 2002
Location: Ok
Posts: 615
|
So for the upgrade all we have to do is drill the holes larger in the crosmember. sounds like a good Idea.
|
![]() |
![]() |
![]() |
#15 |
Wiseass secured himself a BAN
Join Date: Nov 2000
Location: MOON!!!
Posts: 2,282
|
This seems to be a common problem..
![]() Last edited by 67Fleetsidedream; 10-01-2003 at 12:24 PM. |
![]() |
![]() |
![]() |
#16 |
THE QUICKER FIXERUPER
Join Date: Jul 2002
Location: Ok
Posts: 615
|
Another board member swervin ervin had one of the studs that holds rhe uper control arms on break its an epidemic
![]() |
![]() |
![]() |
![]() |
#17 |
Senior Member
![]() Join Date: Sep 2001
Location: Seattle, WA, USA
Posts: 5,817
|
It is.
When I rebuilt my front/back suspension last fall I used all new hardware INCLUDING grade 8 A-arm u-bolts in the front and grade 8 U-bolts throught the trailing arms. I didn't even bother to recycle them. I also noticed when I got the front u-bolts out they were deformed - meaning they had been twisted so that the threaded ends didn't even match up. I think the fact that grade 5 bolts as original equipment is the problem. The metal is more ductile, and is allowed to flex (which is not entirely a bad thing), but when combined with continual stress due to cyclic loading the deformation due to torsion can make the lower part of the "U" harder than the rest of the bolt. Ultimately that's where the stress is concentrated. A grade 8 bolt is harder but a bit more brittle, but it will distribute stress more evenly and won't result in one part of the bolt being more ductile than other parts, which is why it breaks. To replace them just put your jack up against the center bar, yank them out, and put new ones back in, and torque to spec. Pretty easy. Recheck their tightness after alignment.
__________________
'69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA. |
![]() |
![]() |
![]() |
#18 |
Registered User
![]() Join Date: Jan 2001
Location: Katy, TX...but the love of my life resides in Dublin,OH.
Posts: 1,408
|
I had one fall off on the freeway.... yes fell off, the nuts were still on top of the control arm... The dealer still stocks them... mine was on a 71 though. I kept hearing something scraping when I hit little bumps ... I thought it was my collectors scraping until I pulled over. I had to tow it home... thank the lord it was the back one and not the front.... that could've made a mess.
|
![]() |
![]() |
![]() |
#19 |
Collector of Projects
Join Date: Apr 2003
Location: Las Vegas
Posts: 3,106
|
COBALT
Do you (or anyone else) have the dimnesions for the lower controal arm bolts? And the dimensions for the rear u/bolts as well ... Another question, are they the same for 67-72? I have a 71 C/10 with power steering. .. .. |
![]() |
![]() |
![]() |
#20 |
Robert Olson Transport
![]() Join Date: Oct 2002
Location: recent transplant to NC USA
Posts: 20,293
|
its a good idea to replace em hell i always check the bolts on the front end every year or thereabouts when i do brakes and front end checks noones safety is worth the cost of a bolt and check the rear too
__________________
Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!! |
![]() |
![]() |
![]() |
Bookmarks |
|
|