Greetings,
I've been doing some design work for my Frankenstein (ok sr5). I know on the SR8 the gearbox/inner side of the half shaft uses plunging tripod joints. I was wondering about the outters? Also tripod or the Rzeppa (ball and cage) style? I also assume the outer is fixed more or less?
Thanks in advance!
Joe
Hi Joe, I am not an expert on this, but I understand that the SR8 had two different uprights. Here is a picture of a TJ0016 which the radical parts catalog describes as "C.V. Outer - RPE Ptec Transmission - Big Bearing upright". This part uses a tripod joint.
@charleyhradicalsportscarregistry-com
Thanks Charley!
From what I've seen the gearbox side has the deep plunge on it. On other half shafts I've experienced in the past only one end had a real plunge capability. Sure you may get some movement on the "fixed" end. I'm not sure if you could have plunge on both ends or not. I suppose it's possible but why not put a smaller (lighter) joint on the outside (which is what the picture looks like). Just need to figure out how they limit the tripod travel on the fixed side.
That picture is also interesting because it doesn't have a retaining groove on the end of the splines. Does a bolt thread in and sit against a shoulder?
I'm glad to see they used a big bearing shaft. It confirms my calculations that it would be unlikely an SR3 sized shaft would work (or not for long).
Hi Joe! On Quaife boxes, the inboard tripode "cups" bolt in place, but the Hewland cups are slip-fit. On the outboard side at the wheels, the cups bolt in place. The axles can plunge in either direction on both setups. As far as I can tell, the boots center the axles between the cups -- there is no preset spring in any of the cups. The Hewland cups and tripodes are slightly smaller and the axle is a bit longer, and the outboard cups are the same on both.
One of the most annoying things about the setup is the pucks inside the cups. They prevent metal-to-metal contact between the axle end and the inside of the cup, are glued in place with silicone adhesive and are a real PITA to clean and service. If you want to remove the cups from a Quaife box, you have to pry the pucks out as they've been installed over the retention bolts.
If I were to re-design the axles, I'd put the puck as an insert on the end of the axle, and incorporate a pre-load spring. Or even ditch the whole thing and switch to CV joints.
