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#1
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Leaf Spring Question
How many of you racers out there are running leaf springs without using perch pads? The reason I ask is I have a problem with my right rear slipping out of the spring tab. It slips backward. Thanks Andy
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#2
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Sounds like maybe your center bolt is broke..
Check some of the links for "Cal-Tracs"...
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ECM member. 2008 Outlaw Pontiac Drag Series Champion MANDRA Do it now fool! Life is short. 69 Grand Prix/3163lbs / IAII 535 w/ Tiger heads by Gaydosh....9.35@ 144 so far.. through mufflers. 1.26 60'. Going back to track with pump gas engine.... My 60 Ventura retired to street/strip duty.. |
#3
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Hmmm,without using spring pads and it's slipping...
If the locating pin is still intact and it's still slipping back it must not be clamping to the spring sufficiently to keep the rear in place. What kind of hardware back there? Tell us all about the rear suspension and what is like,or better yet a picture would be a real plus at spotting possible culprits,if you need help posting pics somebody here will always help out. They do make taller locating pins,but this does'nt always help,as the pin hole in the perch is'nt really that deep to use the taller pins. And often when mounting these solidly,there is a difference between the inside diameter of the hole in the perch,and the outside diameter of the pin (the hole is bigger than the pin),this is to accomodate the OE isolator pads thickness,but when the pads are'nt used,a gap exists,when this is the case a bushing needs to be used to take up that gap. Let us know more about what's back there,should be able to figure it out. HTH. Bret. |
#4
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Is it an F body? I've seen a number of rear perches that are a kind of 'V', and not actually have a hole at all. If your trying to locate it by just letting the pin ride in that valley in the perch, it isn't going to work. In that case, you'd be better off using the pad.
ScreamingChief- When not using the pad, in the scenario you described, where the hole is larger then the pin, how have you seen that dealt with? Reason I ask, that's my situation, and I used grade 8 flat washers that fit perfectly. Think that's acceptable? If not, what's the source for those bushings?
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#5
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The second gen rears use the "V" deal,not the first gens,I agree with the "V" deal you are pretty much stuck with the pads,either that or cutting the stock perch off altogether and using another style spring perch.
The bushing I used for the locator on cal-tracs for my '74 ventura was sourced from a local HD truck and spring company,they build custom springs and such for cars and HD trucks,I get all my hardware from them,they custom build my 1/2" U-bolts and such too. Always helps to find local sources for this stuff,that way you can go there in person and show them exactly what you need,as a mechanic I always had a pretty good idea what local shops could handle my needs. Basically it's just a simple bushing,not 100% sure the exact sizes off-hand,determined the size by measuring the hole in the perch/housing,and the diameter of the locating pin,had to grind the height just a bit to get it to fit "just right" in the housing,but once it was all together,no way that thing was gonna move unless the locating pin sheared it's head off! I wish I had a digital camera when I had put that together,would have been a lot easier to post pics,but I just did'nt get any pics of that deal,I do have some of it all assembled,but you cant really see that much anyways,and the pics I have were of the first attempt when I had the isolators in place,became real obvious that was'nt gonna work,had to go back and re-do all that. Not sure this helped,sorry 'bout that,Bret. |
#6
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Don't know if this helps. but............
Quote:
I had to make my spacers out of solid aluminum as the one's currently made out there would rip the pin alignment boss out of the right pad and the rear would move back. The block is not solid and cracks apart into the open area. I also use U bolts. Also if ya take the rubber pads out, ya need to make spacers and use solid stock with a thru bolt. |
#7
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Yeah, I was talking about a 2nd gen, went through that recently. I purchased a 9" moser housing, and after a thread here, and talking to a few people, suggested I use a single leaf perch on a multi-leaf spring, deleting the pads. I might have pics, would have to look, but think I used rod nut flat washers. 2 stacked came right to the surface of the perch' hole, and fit the pin perfectly. The pads were butted against the housing on the other side of the hole, so they aren't going anywhere.
PDude- What I mentioned above is the solution to your problem, and what I was trying to avoid. I've heard the same, with guys trying to use the drop spacers, and they do break up in higher HP applications. The perch moser uses is thicker steel then the factory. Maybe get a set of those and change the perches? I too use 1/2 u bolts, but to get them to fit the bottom plate, you kind of have to bend them a little, in like a shape of a hairpin. That I believe could be because the tubes are bigger too.
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#8
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I removed the rubber all together.Welded a plate in the 'V' with a hole in the center to locate the rear and traction bar pad. The bolts I'm using are allen socket head cap screws with a nut that is round with internal splines that go into the hole in the plate ,clamp the spring leafs together and locate in a hole in the traction bars.I have wrapped the springs with rubber inner tube for some insulation from squeaks. Mine is all 'backyard' stuff.It is a low 12 sec car.I had trouble finding spring shims to keep the pinion down so I used steel plates made for approx 5 degree down.Pete Mc told me that there should be some for and aft movement mine is solid.I haven't figured out how yet as the slapper is not a locater so the rear wouldn't at times come back to center line(wheel base).Others have tried different manufactured traction devices I don't know about them.As i said I try to do it myself to save $.
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#9
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When using leaf springs in a race application you really should be using housing floaters. Otherwise when the housing tries to rotate it tries to bind up the springs.
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#10
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Yes,I did what I did to keep it relatively stock as thats what I built the car for,NHRA stock.
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#11
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Hey,
Sorry about the wait, i have been out of town. Pontiac Dude it is the right side like you said in your case. Have not had time to look at it, I just took it off the trailer and saw tha the right tire was moved back. I have mulit leafs and a new 9 inch ford rear. i will try to look at it this coming weekend and let yall know what i found. Thanks |
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