Jag Rear End Questions

[Hot Rod Todd]

George/Ted/Gerry,

George did some drawings a while back of a rear upper bracket that was bolt in with rubber bushes. Very clever as it allows for some movement.

Would you achieve the same thing by solid mounting the upper location pad (like almost everyone does) and then putting a rubber pad between the upper location pad and the top mount on the rear end?

Thanks
Todd

 

[GAB]

Todd,

I don't think that I would use that method of getting some rubber insulation for the rear end. With the small coupling area, any movement or flex would likely get magnified at the wheels. Too much leverage on a rubber mounting. The rear end is a awfully large unit to try to maintain it's location through 4 bolts through a rubber pad. Those bolts would either need something in the way of a different design to keep them tight and be inspected very often.

The crossmember with the bushings on the end would be a much easier and reliable method...IMHO.

 

[Youngster]

As I respect George's opinion, I'm asking him to give his honest opinion of this crossmember.

I would especially be interested in any improvments you might express.

Ron

 

[GAB]

Ron,

IMHO, you have created a mounting unit that is functionally and esthetically outstanding. I really like what you have fabricated ! The only change that I might entertain, and it's not a change so much as a different approach, would be to make patterns and cast it in aluminum. It already has that look. Of course, then everyone would want to give you piles of money for them and you would kill the uniqueness of your design. Forget that idea!

The wide stance of the urethane (or rubber) bushings minimizes the controlled movement of the whole unit in all directions, fore and aft and side to side. With the radius rods to control the rotation of the rear axle unit about the center of the bushing, you will have the bases covered. What kind of unique ideas for them do you have?

George

 

[Youngster]

This one is acually a sort of prototype. The car it's in is coming along nicely. He hopes to have it on the road late this summer. The pinion struts are 7/8" DOM with a clevis on the trunion tie bar and a bushed end at the frame. The radius rods are 30" long 1" DOM with a Krugle adjustable bushed end at the trunion end and a bushed end at the center cross member. He is using a single QA-1 coilover one each side mounted to the front side of the trunion to the outside of the frame.

The builder lives a little over 400 miles away so there might be a road trip in the near future. I will be taking my camera!!

Ron

 

[Ted Brown]

Just me here with my take on that cross member, I believe it should be wide enough to mount shock/coils units to that same member, and when the Jag rear third member has the bottom plate and the two Dog bone connector bars in place... there is absolutely no need for any tube connectors to the frame, as that whole unit needs to be able to move a tiny bit, to keep from binding the lower main control arms, the radius rods hold the wheels in place, just like the stock Jag units lower flapper arms (radius rods, but ugly for sure) and with longer length radius rods, the movement is also less than with the shorter factory RRs... By trying to hold the third member from moving, you are creating two problems, one is noise and vibes, and two is binding of the bearings in the lower main control arms... My 2 cents worth and I am sticking to it