I'm in the process of fitting caltracs to my 66 but i've come across
a fitting problem, i'll try my best to explain,
when i try to fit the complete assembly i find that as i tighten the
centre bolt running through the sleeve i find that due to the concave/taper on the inner side of the leaf perch and the same taper on the washer of the main bolt when the 2 ali washers are fitted the front pivot brackets lock solid and do not rotate freely as they should, however when only 1 ali washer is fitted and bolt tightened it all rotates nicely, has anyone else encountered this problem? Gary.
http://usera.imagecave.com/chevy2/DSC01410-copy.jpg
StoveBolt
8th-February-2007, 06:14 PM
Never installed them but Steve covered pretty good..
http://www.novaresource.org/caltracs.htm
novanut64
8th-February-2007, 06:48 PM
hey gary
you can come and look at mine if need be
uk1966ss
9th-February-2007, 02:23 AM
hey gary
you can come and look at mine if need be
Cheers Paul, have you got a mobile no i can call you on to see how
got on with yours? Gary.
uk1966ss
9th-February-2007, 01:10 PM
Never installed them but Steve covered pretty good..
http://www.novaresource.org/caltracs.htm
thanks for the link, as you say he covered it pretty good but the
problem i have is with the earlier 62/67 front leaf perch which is different to the 3rd gen cars.
72novaproject
9th-February-2007, 03:53 PM
The pech is stamped out of 1/8" mild steel and not very accuratly I might add. But it need'nt be with big soft spongey rubber bushings on each side of it. They did have a steel sleeve the bolt went through and that kept the sides of the perch from over tightening onto the bushing. With the Cal-Tracs the aluminum washers act as a bearing surface and the sides of your perch are not square (parralell) to each other. I built my own perches so I did'nt have this problem but I did study the originals as my first intention was to simply relocate them.
The solution will require a little fabrication. First measure the exact width of the sleeve the bolt runs through in the cal-tracs. Get 2 heavy flat washers with a 1/2" hole (the size of the cross bolt) Cut a piece of black water pipe the length of the sleeve minus the combined washer thickness. Make sure you cut the pipe square or 90 degrees to the length. Weld the washers to each end of the pipe and grind smooth. You now have a buck you can drive up into the perch that is the same dimension as your cal-trac assymbly. It should bind in the same spot as the cal-trac washers but now you have something that will fight through the tight spot. Drive the buck in there until you can drive the cross bolt through it. You may have to C-clamp the bottom side flaps of the perch together to get the bolt in. I would use a different bolt than the ones you intend to keep on the car and preferably a grade 8 bolt, nut and washers. Put washers on the outsides of the perch and tighten the crap out of the bolt. While tightend and in place, hammer around the circumference of the buck on each side of the perch especially the top where it is binding. This will make the steel perch take a set. Remove the bolt, washers and buck and repeat for the other side. The perches should have taken a set to the new proper dimension and not bind the cal-trac washers when installed. The perches just need to be bumped back into alignment. You may even need to heat them to do it but you need the buck as a die for the proper inside dimension of the perch. Don't try this with the cal-trac assymbly in place. It will just mushroom the aluminum.
Hope this helps. In theory it should work. I used a similar approach when I built my perches and my cal-tracs fit flawlessly. Note the paralell sides of the perches. Thats what you are after. I know mine is a 3rd gen but the concept is the same.
The pech is stamped out of 1/8" mild steel and not very accuratly I might add. But it need'nt be with big soft spongey rubber bushings on each side of it. They did have a steel sleeve the bolt went through and that kept the sides of the perch from over tightening onto the bushing. With the Cal-Tracs the aluminum washers act as a bearing surface and the sides of your perch are not square (parralell) to each other. I built my own perches so I did'nt have this problem but I did study the originals as my first intention was to simply relocate them.
The solution will require a little fabrication. First measure the exact width of the sleeve the bolt runs through in the cal-tracs. Get 2 heavy flat washers with a 1/2" hole (the size of the cross bolt) Cut a piece of black water pipe the length of the sleeve minus the combined washer thickness. Make sure you cut the pipe square or 90 degrees to the length. Weld the washers to each end of the pipe and grind smooth. You now have a buck you can drive up into the perch that is the same dimension as your cal-trac assymbly. It should bind in the same spot as the cal-trac washers but now you have something that will fight through the tight spot. Drive the buck in there until you can drive the cross bolt through it. You may have to C-clamp the bottom side flaps of the perch together to get the bolt in. I would use a different bolt than the ones you intend to keep on the car and preferably a grade 8 bolt, nut and washers. Put washers on the outsides of the perch and tighten the crap out of the bolt. While tightend and in place, hammer around the circumference of the buck on each side of the perch especially the top where it is binding. This will make the steel perch take a set. Remove the bolt, washers and buck and repeat for the other side. The perches should have taken a set to the new proper dimension and not bind the cal-trac washers when installed. The perches just need to be bumped back into alignment. You may even need to heat them to do it but you need the buck as a die for the proper inside dimension of the perch. Don't try this with the cal-trac assymbly in place. It will just mushroom the aluminum.
Hope this helps. In theory it should work. I used a similar approach when I built my perches and my cal-tracs fit flawlessly. Note the paralell sides of the perches. Thats what you are after. I know mine is a 3rd gen but the concept is the same.
Hi Steve, thanks for replying, i can see you've taken the time to eliminate
the faults with the factory perches,
not wanting to fabricate new perches i've taken same more measurements
and will probably use the ali caltrac supplied washers, turn a taper on them
on the lathe to the same angle as the recess in the inner spring perch & the large washered bolt, hopefully i will then be able to use both washers & also the front pivot plates will rotate freely with the ali washers acting as thrust surface for the pivot plates, Gary.
Jake
10th-February-2007, 05:40 PM
You may just check that the steel sleeves are in fact longer than the complete assembly. This allows everything to pivot once tightened. Measure that the factory perches are parrallel in the opening. It may just take a few whaps with a hammer to straighten them out if theyre too tight. Alittle too far is ok because once you tighten the thru bolt they will draw back together. It is possible that they shipped too short of inner steel sleeves or too thick of aluminum washers.
uk1966ss
10th-February-2007, 05:54 PM
Hi Jake, i've dry assembled the complete pivot assembly out of the car,
ali bush, pivot plate & washer each side, the steel inner sleeve is about
1/16" longer each side,which seems correct to me, the problem is that the outer edges of the ali washers
touch before the shoulder of the bolt seats on the inner spring perch causing the complete assembly to lock solid, i'm hoping that by taper turning the ali washers they will sit deeper so that the bolt shoulder seats before the washers touch, Gary.
72novaproject
10th-February-2007, 08:44 PM
I don't know why you would pay 365.00 US for a square peg and make it fit a round hole when you can just square up the hole. Figurativly speaking that is. Actually the hole deal I said about making a buck probably is'nt even nessasarry (although thats how I would do it). Go at it with some vice grips, a ball peen and mabey good heavy punch from the inside out up toward the top and it will probably work fine. The perch is just tweeked a bit.
And what Jake said about them drawing back together is correct. Plus, that heavy steel cross pin that the bolt goes through is a much larger diameter than the sleeve that was inside the rubber bushings and it will tend to square up the sides. It just needs a little help at the top.
Good luck...Steve
uk1966ss
11th-February-2007, 07:12 PM
thanks for all the advice guys, i've now sorted the problem, i've started
a new thread on the 1st/2nd gen pages as it's only really relevent to the
earlier models, gary.