Front End Shake

Danr55 · #1 (**permalink**) 10-04-2009, 02:11 AM

For almost a year I've been experiencing a front end shake at exactly 70 mph. I've talked with several of the folks on this web site trying to resolve this issue and everyone had good ideas, but not the right ones. I'd changed everything I could think of in the front end and in the back end to try to eliminate this condition. Nothing worked. After several months of irritation, I'd almost given up when I ran into a guy with an MGB who had experienced the same condition. He solved his by adjusting the tension on the tie rod ends where they hook up with the steering rack. If you read the Jag book, it says to adjust these fittings so that there is 7 lbs. of torque required to move the tie rods up and down. Well, information from the MGB guy as well as a couple of other trusted sources told me that that amount of torque can be insufficient. So I tightened them until the torque required to move the tie rod was about 16 pounds. Guess what? No more shake in the front end at 70 or any other speed up to 125. Just a tip that may help someone else chasing this same issue.

Nick, That's a hint you can ad to your endless list of "what to do if..." information. THanks for all your help with everything else. You are truly an endless source of information.

1985 CCX · #2 (**permalink**) 10-04-2009, 04:51 PM

Nice work Dan!
Keep it up.............Jeff

racco · #3 (**permalink**) 10-04-2009, 07:15 PM

thats one of the advantages of owning a contemporary, they use jag front and rear suspension. Service and parts are readily available.
The front end is fully adjustable, while the rear has partial adjustment during an alignment.

Rick Parker · #4 (**permalink**) 10-04-2009, 08:27 PM

There are short VERY stout springs about 1/2" long that are in a pocket that is drilled in the end of the rack. They exert extreme pressure on the back side of the pivot ball of the tie rod. These are intended to allow a minute amount of shock absorbsion and prevent any severe shock from being transfered directly to the teeth of the rack and pinion but more importantly to keep tension on the back of the pivot ball. The threaded ends allow the necessary adjustment.

It sounds like you had some lateral movement that was eliminated with the adjustment.

But how do you measure the torque to move them up and down?

Danr55 · #5 (**permalink**) 10-04-2009, 08:52 PM

I used a spring gauge. It's the same one I use for setting drag on fishing reels. Made a loop out of safety wire and hooked it over the tie rod end. Adjusted until I had 16 pounds required to pull the rod end down or up or laterally. Then grab the tie rod end and make sure you have a full range of motion in all directions.

mickmate · #6 (**permalink**) 10-05-2009, 04:34 AM

Nice Dan, I hope that doesn't wear the rack excessively. I had a pretty good shake in the one here currently. It had bad universals, a loose spline and really sloppy rubber rack mounts. I just replaced the mounts with urethane ones from SNG Barret. I did have to modify the studs for a CCX as they are too long. Had to thread them down further and cut them off.

mickmate · #7 (**permalink**) 10-05-2009, 05:12 PM

I saw that section in the Jag book Dan, nice work. It doesn't look like that has a lock for the nut once you get the tension you're after?

Danr55 · #8 (**permalink**) 10-06-2009, 09:21 PM

THe nut is locked with a jam nut. You dial in the tension you're looking for then bring the jam nut in tight. There is a tab washer between them the holds them in place. It a really interesting arrangement. But the DAMNED SHAKE IS GONE!!!! YEAH!!!!!

Rick Parker · #9 (**permalink**) 10-06-2009, 09:38 PM

Here you go...this shows exactly what's involved:

http://www.youtube.com/watch?v=zQt-u-frkJs

mickmate · #10 (**permalink**) 10-07-2009, 04:23 AM

I looked in the book and saw it's part 24 a tab washer to lock the position. Good work guys.