Drum or Axle? Getting beat dahn
Drum or Axle? Getting beat dahn
Out of all fo the years of owning Vee's I have never had as much trouble as I am having now. I made an exchange of a short box for a long box and everything at first went ok but the the axles on the exhange seemed to be worn out after trying to run a double regional at Nashville - I didn't go out for the second race since the the drums (new and old) would not keep from the wobbles after torqued to the proper ft lb. I have replaced those axles with another set of used ones and measured at least a .005 diffrenece of a larger O.D. I had been given a new Italian drum set and looked forward to getting those on the car and being ready for Barber, alas I didn't get a warm fuzzy when the drums somewhat easily slide down the spines. I have torqued them down and also am using the thicker washer the is betwwn the bearing and drum but I am not confident that this will hold up. How do you tell your axles are good, is there some OD measurement or something on the width of the spline? I had put drums on amny a time on my old Caldwell and never remembered drums going on so easy. Are the Italian drums crap? Running out of time and need a solution before Labor Day weekend and help is appreciated.
Re: Drum or Axle? Getting beat dahn
FV 90:
To be very honest I have not seen Italian REAR drums in years- fronts yes, rears no. Do they say : Italian inside ? Are you sure they are not Brazilian?
Yes, there are different axle diameters in the 1200 series (plus the axles from the split case) but diameter should not matter in your situation. Splines should all be the same unless someone has done something to try to make it easier to install drums!
Also not sure which THICKER WASHER you are referring to between the bearing and the drum. Hardness of the washer might be different from one set to another, but not the thickness (to notice).
I would try a set of German drums and see if this solves the problem.
Hope this helps
Dietmar
Quixote Racing
To be very honest I have not seen Italian REAR drums in years- fronts yes, rears no. Do they say : Italian inside ? Are you sure they are not Brazilian?
Yes, there are different axle diameters in the 1200 series (plus the axles from the split case) but diameter should not matter in your situation. Splines should all be the same unless someone has done something to try to make it easier to install drums!
Also not sure which THICKER WASHER you are referring to between the bearing and the drum. Hardness of the washer might be different from one set to another, but not the thickness (to notice).
I would try a set of German drums and see if this solves the problem.
Hope this helps
Dietmar
Quixote Racing
Re: Drum or Axle? Getting beat dahn
Mark,
The first thing I would suspect is the WASHER that you referred to. When you removed the 'bad' drums, was that washer trashed? If the washer is not HARDENED, then it will crush - thereby loosening the drum on the splines and cause a problem as you describe it. I have not used a washer in YEARS and my drums generally slide right on with (mostly) no problem. If the axle or tube has been removed, then the drum nut will "pull" the axle bearing onto the axle (light press fit) as you tighten the nut.
You mention 'specified torque' also - WHAT specified torque and how are you determining it? VERY few racers actually have a torque wrench that will indicate 240 ft lbs. I use a socket with a 3 foot bar and tighten until "tight", then tighter to get to the next cotter pin slot ... but I have a pretty good feel for it after 30 years
. I used to tighten about as tight as I could get it, but found that I was overtightening and rolling the threads on the axles themselves. Made the nut VERY hard to get off and on, so I reduced my torque somewhat to avoid that.
Also - you might want to take the time to make CERTAIN that the 'shaped' spacer is behind the axle bearing. If that washer is not there, then you can pull the axle right out of the side gear (through the snap ring and spacers in the center section). That is not likely, if you've been pulling over about 150 # of torque or you would already know it
.
Hope you can make it to Barber (with the car).
Steve
The first thing I would suspect is the WASHER that you referred to. When you removed the 'bad' drums, was that washer trashed? If the washer is not HARDENED, then it will crush - thereby loosening the drum on the splines and cause a problem as you describe it. I have not used a washer in YEARS and my drums generally slide right on with (mostly) no problem. If the axle or tube has been removed, then the drum nut will "pull" the axle bearing onto the axle (light press fit) as you tighten the nut.
You mention 'specified torque' also - WHAT specified torque and how are you determining it? VERY few racers actually have a torque wrench that will indicate 240 ft lbs. I use a socket with a 3 foot bar and tighten until "tight", then tighter to get to the next cotter pin slot ... but I have a pretty good feel for it after 30 years
. I used to tighten about as tight as I could get it, but found that I was overtightening and rolling the threads on the axles themselves. Made the nut VERY hard to get off and on, so I reduced my torque somewhat to avoid that.Also - you might want to take the time to make CERTAIN that the 'shaped' spacer is behind the axle bearing. If that washer is not there, then you can pull the axle right out of the side gear (through the snap ring and spacers in the center section). That is not likely, if you've been pulling over about 150 # of torque or you would already know it
.Hope you can make it to Barber (with the car).
Steve
The Racer's Wedge and now a Vortech, FV80
Re: Drum or Axle? Getting beat dahn
On some new drums the splines are too tight and the drum wont go on all the way. After a session or so, the drum does loosen some and create end play. Assemble the spacers, bearing drum and nut on an axle that's not on a tranny and make sure that everything seats up. Try sliding a thin feeler gauge between the components and see if there's any space.
The above post is for reference only and your results may vary. This post is not intended to reflect the views or opinions of SCCA and should not be considered an analysis or opinion of the rules written in the GCR.
Re: Drum or Axle? Getting beat dahn
Well, thanks to Mike Chandler things may be looking up with the German drums. I took a some quick measurements and found the Italian drums I have to be about .10 wider than the German ones, but the fit on the splines seem to be better. I am not using the soft thin washer supplied in the kits, so all in all it seems to be in good shape. I will check it after a few laps around Barber.
Yo Steve looks like the Sherm has entered.
Yo Steve looks like the Sherm has entered.