I have new front (both sides) drums for my 39/40 project that I am trying to marry to my old hubs. I'm concerned that my new wheel studs won't fully engage between the knurls and hub.
New drum is 0.25" thick. Stud holes are slightly smaller (0.560") than knurls (0.5685") and smooth.
Old hub is 0.4" thick.
New stud knurl is 0.45" long and 0.5685" diameter.
I will only have about half engagement (less actually 0.20" of total engagement. Now, I'm not running a stroker but that still doesn't seem right. I'm also not including the oil shield shown in the photos that are supposed to go inside the drum. It's approximately .06" thick.
The stud is 1.375" long.
I bought the drums and studs new from Jim Carter. My old drums were not nearly as thick and I got full engagement between the knurls and the hub. I haven't had any luck finding new studs with a longer knurled section. 0.65"+. The knurl diameter is 0.570" diameter.
Has anyone else ran into this problem? What am I missing? Did Jim send me the wrong parts?
If everything else seems to fit OK- - - -like the center hole of the new drum being the proper size to align with the hub, and the depth of the drum fitting the backing plate properly, I'd suggest drilling and tapping for a couple of flat head screws to hold the drum to the hub securely, and just live with the short engagement of the knurl in the drum. Finding a stud with a taller knurled section shouldn't be difficult- - - -find a Dorman products paper catalog and a parts store counter man who knows how to read it, which may be the most difficult part of the project! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
How thick were the old drums? How much of a difference are we talking about? I get that your concerned with the engagement length and agree that it should be the same or close to original. Measure the old drums and contact Jim Carter. One alternative would be to have a machine shop reduce the thickness of your new drums. Hotrods suggestion on the Doorman alternatives is worth looking at.
Ron - - Dusty53 1954 Chevy 3604 In the Gallery Forum "You can't dance with the Devil and then wonder why you're still in Hell." "They will forget what you've said, and they will forget what you have done but they will never forget the way you made them feel."
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Old drum is 0.125" thick. Laying on the ground, the top face of the old drum is 3.530". New drum is 3.570". I think I am going to have a friend of mine with a mill face off 0.04" and on the inside 0.085". That should put the new one in the same position as the old drum. That would also solve the issue with the studs for the most part. 0.125" + 0.4" = 0.525" and knurls are 0.45". Jim carter was of no help and basically said well they haven't had any issues with them.. All but kick rocks. Jerry, I was able to get on the dorman website to see their catalog. I may order one that I found on there that has a longer knurl in conjunction with milling the new drums. Thank you for the link to the ebay listing as well. I need 12 studs total.
Thought I would update with what I ended up doing.
I machined the new drums to match the old ones. I indicated the old drums on my granite surface plate and got the height at 3.535". I faced the new drums to match. I took off about 0.040". Then flipped it over and took off the remaining amount to make the face 0.125". I did this to insure the hub remained in the same place as original instead of just facing off 0.125".
