axle wrap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

swamphunter · 08-29-2007, 09:00 AM

I'm new to this site. Great to find others who have/appreciate good trucks! I have a 69 chev K20 4x4; 350 vortec heads, RPM air gap manifold, Quick Fuel Holley 650, unknown cam with Comp aluminum rockers, Corvette Ram Horn manifolds, 2.5" exhaust with dual Flowmaster 70 Series mufflers, TH350, NP205, Eaton diff. with factory Detroit Locker, Dana 44 front diff. both with 4.10 gears, MT Classic 2 wheels with 33x12.5 BFG Mud T/A's. Also has a 3 inch body lift and approx 2inch blocks under leaves and extra leaves in the front.
Went to a truck pull at a local fair and was very embarassed in the 3/4 ton gas class when after about 100 feet the truck started to buck so badly I had to get out of it. The other trucks were pulling over 250 feet. Axle wrap is the culprit. Am researching ladder bars, pinion snubbers etc. to control axle wrap.
Any suggestions or advice appreciated.
Thanks,
Swamp

67_C-30 · 08-29-2007, 10:31 AM

On my brother's drag truck we built tubular lift bars to keep from wrapping the leafs up in the rear. They work well, and were pretty simple to build.

shifty · 08-29-2007, 11:01 AM

You might want to ask a moderator to move this into the main 67-72 forum, you will probably get more responses.

This subforum is for 'project' threads, to document truck buildups from start to finish.

swamphunter · 08-30-2007, 09:00 AM

Thanks, no wonder I couldn't find my post. I am fairly new to "forums" and don't know all the ropes. Thanks for the reply and the advice. I would like a moderator to move my post. Will this serve as a request or is there another procedure? If so, please advise.
Thanks again,
Swamp
By the way C-30, beautiful job on that frame!

Rod · 08-30-2007, 12:45 PM

Done

Longhorn Man · 08-30-2007, 01:26 PM

You'll need to start with a real close inspection of the bushings in the eyelets of the leaf springs, also look at every leaf in the packs, and see if there are any cracked or broken.

Blazer1970 · 08-30-2007, 05:35 PM

Four link it

Ackattack · 08-30-2007, 05:41 PM

the first thing I would do is get rid of the lift blocks. Basically they give the axle extra leverage to work against the springs. Going with propper lift springs that are taller and stiffer will definalty help alleviate axle wrap.

JAKES 68GMC · 08-31-2007, 06:38 PM

I read in Petersons 4-Wheel and Off-Road mag to put some clamps on the front side uf the spring to stop wheelhop. it makes the spring harder to twist, so it won't wheelhop as easy, or at all for that matter.

swamphunter · 09-18-2007, 08:04 PM

Everything was re-bushed when we did the overhaul, about 30,000 miles ago. I would like to keep the blocks if possible, although I do realize that they are at least part of the problem. How did the factories get away with lift blocks? Must have been quite a set on the 70's Ford "high boys".
thanks for the opinions,
Swamp

jeffspower · 09-18-2007, 08:48 PM

Here's what I ran back when I was pulling- ZERO hop. i used bushing stock on the ends, and leaf spring bushings that pressed in. Block your rear suspension if rules allow- squat will cut your pull distance down. With no blocks, wheel hop can be a problem unless you clamp the leafs and/ or run 8-12 leafs in a stack. Mine was a daily driver at the time too, so I made my anti- squat blocks slide out in "receiver hitch" fashion.

BTW- I wasn't pulling with the 38" swampers. Those were put on when I went thru my mudding phase

jeffspower · 09-18-2007, 08:57 PM

Here it is today, getting back into its pulling clothes

Gotta keep midlife from sucking me down the toobs

08-29-2007, 09:00 AM	#1
swamphunter Registered User Join Date: Aug 2007 Location: Merrickville ON Canada Posts: 14	axle wrap I'm new to this site. Great to find others who have/appreciate good trucks! I have a 69 chev K20 4x4; 350 vortec heads, RPM air gap manifold, Quick Fuel Holley 650, unknown cam with Comp aluminum rockers, Corvette Ram Horn manifolds, 2.5" exhaust with dual Flowmaster 70 Series mufflers, TH350, NP205, Eaton diff. with factory Detroit Locker, Dana 44 front diff. both with 4.10 gears, MT Classic 2 wheels with 33x12.5 BFG Mud T/A's. Also has a 3 inch body lift and approx 2inch blocks under leaves and extra leaves in the front. Went to a truck pull at a local fair and was very embarassed in the 3/4 ton gas class when after about 100 feet the truck started to buck so badly I had to get out of it. The other trucks were pulling over 250 feet. Axle wrap is the culprit. Am researching ladder bars, pinion snubbers etc. to control axle wrap. Any suggestions or advice appreciated. Thanks, Swamp

08-29-2007, 10:31 AM	#2
67_C-30 I have a radical idea! Join Date: Jan 2005 Location: Sweet Home Alabama! Posts: 6,513	Re: axle wrap On my brother's drag truck we built tubular lift bars to keep from wrapping the leafs up in the rear. They work well, and were pretty simple to build. Attached Images __________________ '67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club! Last edited by 67_C-30; 08-29-2007 at 10:32 AM.

08-29-2007, 11:01 AM	#3
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: axle wrap You might want to ask a moderator to move this into the main 67-72 forum, you will probably get more responses. This subforum is for 'project' threads, to document truck buildups from start to finish. __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

08-30-2007, 09:00 AM	#4
swamphunter Registered User Join Date: Aug 2007 Location: Merrickville ON Canada Posts: 14	Re: axle wrap Thanks, no wonder I couldn't find my post. I am fairly new to "forums" and don't know all the ropes. Thanks for the reply and the advice. I would like a moderator to move my post. Will this serve as a request or is there another procedure? If so, please advise. Thanks again, Swamp By the way C-30, beautiful job on that frame!

08-30-2007, 12:45 PM	#5
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	Re: axle wrap Done __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

08-30-2007, 01:26 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: axle wrap You'll need to start with a real close inspection of the bushings in the eyelets of the leaf springs, also look at every leaf in the packs, and see if there are any cracked or broken.

08-30-2007, 05:35 PM	#7
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,510	Re: axle wrap Four link it __________________ Tim

08-30-2007, 05:41 PM	#8
Ackattack Senior Member Join Date: Aug 2002 Location: Valley Center KS Posts: 3,525	Re: axle wrap the first thing I would do is get rid of the lift blocks. Basically they give the axle extra leverage to work against the springs. Going with propper lift springs that are taller and stiffer will definalty help alleviate axle wrap. __________________ Project Bruiser: 68 Pro-Touring C-10 5.3L / 4L60E Project Ironhide: 97 GMC Crew Cab 4x4 Cummins SOLD: '69 GMC 1/2T SWB TBI'd: Project No Buck Assembly Manual Index Sign up Thread!!! Factory Service Manual Index

08-31-2007, 06:38 PM	#9
JAKES 68GMC Aluminum slot wheels rule... Join Date: Jan 2006 Location: Maine Posts: 6,212	Re: axle wrap I read in Petersons 4-Wheel and Off-Road mag to put some clamps on the front side uf the spring to stop wheelhop. it makes the spring harder to twist, so it won't wheelhop as easy, or at all for that matter.

09-18-2007, 08:04 PM	#10
swamphunter Registered User Join Date: Aug 2007 Location: Merrickville ON Canada Posts: 14	Re: axle wrap Everything was re-bushed when we did the overhaul, about 30,000 miles ago. I would like to keep the blocks if possible, although I do realize that they are at least part of the problem. How did the factories get away with lift blocks? Must have been quite a set on the 70's Ford "high boys". thanks for the opinions, Swamp

09-18-2007, 08:48 PM	#11
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Re: axle wrap Here's what I ran back when I was pulling- ZERO hop. i used bushing stock on the ends, and leaf spring bushings that pressed in. Block your rear suspension if rules allow- squat will cut your pull distance down. With no blocks, wheel hop can be a problem unless you clamp the leafs and/ or run 8-12 leafs in a stack. Mine was a daily driver at the time too, so I made my anti- squat blocks slide out in "receiver hitch" fashion. BTW- I wasn't pulling with the 38" swampers. Those were put on when I went thru my mudding phase Attached Images __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car

09-18-2007, 08:57 PM	#12
jeffspower Well, Whoop-dee-do! Join Date: Mar 2003 Location: Easton, Mo. pop.- me & scarcely a few others Posts: 2,302	Re: axle wrap Here it is today, getting back into its pulling clothes Gotta keep midlife from sucking me down the toobs Attached Images __________________ '68 GMC shortbox 4x4 350/SM465/T221- bought it in '83 SOLD '72 K20 500 Cad/TH400/NP205 SOLD '92 Chevy 2500 6.5 mech TD 4L80E crusty daily driver '72 Monte Carlo... sweet low mile toy '11 Dodge Challenger IE 392 6spd... midlife car



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