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73-87 Chevy _ GMC Trucks => Brakes, Frame, Steering & Suspension => The Highs (Raising/Lifts) => Topic started by: michaelgtrx on August 08, 2016, 09:56:49 PM

Title: What's causing this?!?!
Post by: michaelgtrx on August 08, 2016, 09:56:49 PM
(http://uploads.tapatalk-cdn.com/20160809/11511bc3a032d82477e3daf877219581.jpg)(http://uploads.tapatalk-cdn.com/20160809/ec5f9204039262fce998ea901b04e523.jpg)


Title: Re: What's causing this?!?!
Post by: michaelgtrx on August 08, 2016, 09:57:23 PM
This on an 84 k30

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Title: Re: What's causing this?!?!
Post by: zieg85 on August 08, 2016, 10:09:30 PM
You are lucky you caught it.  There should be a pin that probably got sheared off on the leaf springs, the bolt that holds the stack together.  Re-using or not re-tightening the u-bolts cause that..
Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 08, 2016, 10:38:02 PM
That would have been VERY ugly and possibly DEADLY. Do not drive that truck untill you fix it properly.
Title: Re: What's causing this?!?!
Post by: 1967KaiserM715 on August 09, 2016, 06:07:30 AM
You are lucky you caught it.  There should be a pin that probably got sheared off on the leaf springs, the bolt that holds the stack together.  Re-using or not re-tightening the u-bolts cause that..
More likely the pin holes in the block got destroyed-also caused by improperly torqued u-bolts

Either way it needs to be fixed- new blocks or/and new leaf spring bolt and new u-bolts


IMO I would opt for full leafsprings or shackle flip over using blocks. I would only use at the most a 2 inch block- anything else I feel causes too much stress on the u-bolts and failure in the rear suspension will occur.

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Title: Re: What's causing this?!?!
Post by: 1967KaiserM715 on August 09, 2016, 06:11:53 AM
Ummm? Is one of the blocks facing the wrong way?

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Title: Re: What's causing this?!?!
Post by: Irish_Alley on August 09, 2016, 06:56:05 AM
there should be a bolt going threw the springs and a pin on the bottom of the block, it doesnt look like anything is there. ive never see a block thats angled like that they all have 90° on them. but yeah good thing you did catch it, at the very least you would of binded up the u-joint causing it to break then the driveshaft would of smacked everything else. do you know where those blocks came from? but i think the blocks are your problem, i would replace them with a straight one. you dont have lift blocks upfront do you?
Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 09, 2016, 08:49:01 AM
there should be a bolt going threw the springs and a pin on the bottom of the block, it doesnt look like anything is there. ive never see a block thats angled like that they all have 90° on them. but yeah good thing you did catch it, at the very least you would of binded up the u-joint causing it to break then the driveshaft would of smacked everything else. do you know where those blocks came from? but i think the blocks are your problem, i would replace them with a straight one. you dont have lift blocks upfront do you?
The blocks are tapered. When you buy a lift you can get tapered and non tapered blocks. The taper is to help correct pinion angle on trucks with large lifts. Usually the larger side is installed facing the rear, this forces the input shaft of the axle to rotate up vertically, decreasing extreme pinion angles.

That block appears to have been installed in reverse, that's why it looks like it is "wedged" between the spring perch and leaf pack. I'm guessing that reverse instalation, improper spring torqueing during installation, not retorqueing after a short period after install (usually 50-100 miles of driving) probably all created stress on the pins, possibly shearing them off and the block starting to slip out.

Regardless, you just have to get it fixed up and you should be fine.
Title: Re: What's causing this?!?!
Post by: michaelgtrx on August 10, 2016, 04:01:03 AM
1st  pic is driver side, second is passenger. First noticed a slight vibration, then the truck seemed to be driving crooked, the back end of the truck being closer to the yellow line. I stopped and crawled underneath to inspect and found this...the truck had also been pulling to the left on acceleration, to the right on deceleration. ...I'm running 6" springs in the front that installed about 3 years ago. Previously had 4" springs that were sagging. I haven't touched the rear end (yet), these blocks were in when I got the truck. I think they're 3.5" or 4", I'll be measuring soon. What would be the best fix to avoid this again,  and make it stronger?

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Title: Re: What's causing this?!?!
Post by: michaelgtrx on August 10, 2016, 04:02:18 AM
And thanks all for the responses

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Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 10, 2016, 09:30:09 AM
New blocks, new U bolts, proper installation method.
Title: Re: What's causing this?!?!
Post by: hatzie on August 10, 2016, 09:40:42 AM
You can use "no-block" "Spring only" lift springs with extended shackles.
Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 10, 2016, 12:19:10 PM
You can use no block lift springs with extended shackles.
This would be better.
Title: Re: What's causing this?!?!
Post by: hatzie on August 10, 2016, 01:08:56 PM
When I bought my 76 I was surprised there's no Iron extending between the U-Bolts on the block of Cast Iron they expect you to stuff under the springs.  I replaced the setup that was already Bubba installed and approved with blocks under the front springs :o :o :o .  If they had locator wings that ran between the U-Bolts it would be much more difficult for them to slide out from under the springs when the pins sheared off.
 
BTW this is why you NEVER EVER use blocks on the front axle.

I used US DOT compliant ORD long brake hoses (http://www.offroaddesign.com/catalog/braidedbrakelines.htm)  rather than the included hose mount lowering brackets.  ORD are not cheap.  Whatever you buy be double sure they are DOT legal with a real compliance number.  No DOT compliance # means offroad only.  I'm sure the Canadian members have their own DOT compliance for parts like these and USDOT may not be CADOT compliant.  Be sure.  Insurance companies are looking for ways to leave you holding the bag.  Make em work for it.  Don't give em something this easy.
I fabbed my own front swaybar lowering brackets rather than use the fairly anemic pieces with the kit or the really really cheezy ones that were already there.

These guys still sell reasonable quality complete spring-only lift kits for the GM K10-K30 73-91 GM trucks.  This includes important bits like lowered pitman arms, brake line brackets, and front swaybar mounts.
http://www.roughcountry.com/suspension-lift-kits.html (http://www.roughcountry.com/suspension-lift-kits.html)


Since it's lifted you should buy and install the ORD steering box braces and re-enforcing plate (http://www.offroaddesign.com/catalog/steeringkit.htm) before the frame cracks.
Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 10, 2016, 01:53:53 PM
Off Road Design  (ORD) & Rough Country are both great companies that make good quality products. I've bought twice from ORD and both times I was very impressed.
Title: Re: What's causing this?!?!
Post by: blazer74 on August 10, 2016, 06:16:55 PM
Lift springs or a shackle flip is good for about 4 inches of lift with stock springs.
Get rid of the blocks.

I use 4 inch tough country lift springs with a 1 inch zero rate for approx 5 inches.

Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 10, 2016, 11:46:41 PM
I built my own lift blocks out of 1/4 inch steel plate, they are only 1 inch blocks tho, I was just getting a little extra height out of the rear. Plus the springs and bolts were all brand new.
Title: Re: What's causing this?!?!
Post by: blazer74 on August 11, 2016, 12:30:56 AM
I built my own lift blocks out of 1/4 inch steel plate, they are only 1 inch blocks tho, I was just getting a little extra height out of the rear. Plus the springs and bolts were all brand new.

Yes, same purpose as the zero rates, I used them for leveling purposes. 

Zero rates bolt into the spring pack. 

They can also move your springs fwd or aft if you choose.

You can get them machined to an angle also if you need to adjust pinion angle.
Title: Re: What's causing this?!?!
Post by: Blazin on August 18, 2016, 07:34:45 AM
That's sketchy!
I agree lift springs, with shorty blocks if need be.
Title: Re: What's causing this?!?!
Post by: 1967KaiserM715 on August 18, 2016, 06:41:50 PM
That's sketchy!
I agree lift springs, with shorty blocks if need be.

was behind a Ford today, he was lifted probably 8", and obviously had a 4" block, as one came out, I hit it-it went flying into the woods., but it was probably the worst thing I have seen as when the bed came down it punctured the tire, which caused it pop; making for an even worse situation. he was lucky the u bolts at least held or that could have been the last of that truck.

I absolutely will not put anything over 1-1.5 inches as a block-as it is too much leverage for U-bolts-a zero-rate is the best as it is tied directly to the spring pack.
Title: Re: What's causing this?!?!
Post by: LTZ C20 on August 18, 2016, 10:13:45 PM
That's sketchy!
I agree lift springs, with shorty blocks if need be.

was behind a Ford today, he was lifted probably 8", and obviously had a 4" block, as one came out, I hit it-it went flying into the woods., but it was probably the worst thing I have seen as when the bed came down it punctured the tire, which caused it pop; making for an even worse situation. he was lucky the u bolts at least held or that could have been the last of that truck.

I absolutely will not put anything over 1-1.5 inches as a block-as it is too much leverage for U-bolts-a zero-rate is the best as it is tied directly to the spring pack.
Oh freaky! You both got real lucky.
Title: Re: What's causing this?!?!
Post by: chevyk1069 on August 20, 2016, 09:14:08 PM
Having a taller block on the rear is fine as long as the block is solid. The pictures you posted will require new center bolts through the leaf springs to start. Next you will possibly need new blocks. Some you could replace the head on the bottom of the blocks. You can also (to save money) grind the old head off the bottom that sets in the axle flat and drill it for a 3/8 center bolt. Contrary to popular belief all the center bolt is for is holding the spring together and keep it lined up until you get the u-bolts tight. When you replace a spring or work on one, especially modifying one, always replace the u-bolts with the proper size and make sure they are grade 8 if it's modified. Grade 5 is okay for stock. Chevy u-bolts are 5/8. Most people don't know a u-bolt stretches when you tighten it. Once stretched it will never be the same. Just a few tips from an old spring man.