Tension Rod question

[mjyikes]

I have a question regarding tension rod bushing replacement.

I am replacing all of the bushings in the front suspension with new urethane ones from Motorsport. As I'm replacing the tension rod ones, I notice that they are about .100" thicker than stock rubber ones (which may have been compressed since I don't know how old they are), and about 10 times as hard. When I assemble them, the holes to bolt the tension rod to the control arm don't line up any more, they are off about 1/4 inch. I could push the control arm forward to get the bolts in the holes but that seems to put an undesirable torque on the new urethane control arm bushings. Is that the way it is supposed to be ?

One other question while I'm at it, when I put the new ball joint, also from Motorsport,in the holes do not line up with the control arm holes, off by about .050" but enough so that I can't get the bolts in. The old ball joint lined up fine. Should I take off a little material from the ball joint or from the control arm , any thoughts ?

Thanks,

Mike

[2ManyZs]

The control arm is probably moving a bit in its bushing making the alignment seem off. You should bolt the T/C rod to the control arm first, then mount the T/C rod to the frame mount. You should have gotten a U shaped gauge with the bushing kit, this is to preload the bushings while tightening the T/C rod nut. This will put your control arm into proper alignment.

As far as the ball joint goes, I've had a couple that needed just a little filing on the control arm holes to fit the bolts, not a big deal.

Guess there is a bit of a disparity between manufacturers, even though there really shouldn't be.

[mjyikes]

Thanks for that reassurance, 2manyz's

It seemed to work fine, I just don't like to force something if it's not right. There was no measuring guage for the bushings from Motorsport, would you happen to know that dimension, I'm sure I could call them tomorrow and get that info. The tightening of those bushings would seem to affect the caster, so it's probably important. Also, what kind of paint can you use on the brake caliper, and wheel hub, I don't like rust.

[Bambikiller240]

Originally posted by mjyikes

Thanks for that reassurance, 2manyz's

It seemed to work fine, I just don't like to force something if it's not right. There was no measuring guage for the bushings from Motorsport, would you happen to know that dimension, I'm sure I could call them tomorrow and get that info. The tightening of those bushings would seem to affect the caster, so it's probably important. Also, what kind of paint can you use on the brake caliper, and wheel hub, I don't like rust.

The guage 2ManyZ's refers to only comes with the Solid Aluminum/Delin T/C Kit that is sold through companies like Ground Control. It is not provided with the polyurethane bushings sold by MSA. When I bought my P/U bushings from them 3 years ago, they told me to assemble as normal and torque to spec. Then to retorque after 500-1000 miles of normal driving.

[TomoHawk]

How important would it be to get some extra T/C rods? I mean, if I spot some on eBay, should I snap them up?

Also, do you think it would help to put a doubler tube over the outside of the rod, to give it some strength?

thx

[Marty Rogan]

I read recently of a dangerous condition that the PU bushings cause on the tension rod, especially on a lowered car.

The bushings don't have much give to them at all and can cause alot of stress on the tension rod. They have been known to snap in two. The recommended solution is to put a PU bushing toward the front of the car, and put a stock rubber bushing on the back side of the rod mount, to allow for additional flex to the rod. that's what I plan to do.

Marty

[mdbrandy]

Originally posted by Marty Rogan

I read recently of a dangerous condition that the PU bushings cause on the tension rod, especially on a lowered car.

The bushings don't have much give to them at all and can cause alot of stress on the tension rod. They have been known to snap in two. The recommended solution is to put a PU bushing toward the front of the car, and put a stock rubber bushing on the back side of the rod mount, to allow for additional flex to the rod. that's what I plan to do.

Marty

Now THAT would be a very bad thing :dead: ! Do you remember where you read it? I just ordered a Poly bushing kit for my 280Z, and I'm looking for any and all info before I mount it...

Thanks.

[Marty Rogan]

There was a discussion of this on the 240Z mailing list. Someone posted this link for additional info: http://www.hybridz.org/phpBB2/viewtopic.php?t=27871

Apparently this was discussed extensively on a 510 forum also.

Marty

[ChrisA]

I think that hybridZ link is dead. :cry:

[Marty Rogan]

I don't think this is the same link that I had before, which was very in depth and informative, but you can try this one and maybe do a search on the Hybryd site: http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=6616

Marty

[hmsports]

I have raced using the same tension rods for more than eight years with the aluminum/delrin bushings and never had any sign of failure or fatigue. When I smacked the wall hard the tension rod simply bent to about 90 degrees but no 'snap' and no sign of cracks when I inspected it (before tossing it in the trash).

[Bambikiller240]

Originally posted by Marty Rogan

There was a discussion of this on the 240Z mailing list............

There was not any consensus on the validity of the perceived problem, at least on the 240Z.org list discussion. John Coffey, who raced a Z car for quite a long time said that he had never seen, heard, nor experienced any problems in the Compression rods with PU bushings.

I can't find my copy of the 240Z.org discussiion, but I do have a copy of the initial Hybrid Z discussion on this subject that I saved in a WORD document, which I cannot attach here. If anyone wants a copy of that initial Hybrid Z discussion, PM me with your email address and I can forward it to you later today/tonight.