Prothane Transverse Link (aka control arm ) Bushings

[headrush]

My car was starting to drive really bad. I drive on grooved cement freeways and it follows the grooves and wanders all over. It is also is very susceptible to seams or ridges in the road, wind, and the crown of the road. I have a lot of steering feedback - the car wants to drive me instead of me driving it. It drives better on pavement, in fact I hardly notice any problems on pavement. But on grooved cement this car is hell on wheels. It turns out I had one rear transverse link bushing with a crack and it was leaking fluid (yes, the crazy things are filled with what appears to be a high viscosity silicone fluid). It didn't look very bad when I removed it (only one crack), but it was very soft. When they lose fluid it appears to have a profound effect on stiffness. Until I removed it I thought it was wet with engine oil.

 

I have spent a fair amount of time on suspension diagnosis over the past few months and if new bushings don't solve the problem I will be at wits end. The only other possibility is a bad steering gear, but the steering gear feels tight.

 

I am in the process of installing the Prothane 16-201 on my 95 Legacy with 160k miles. I wasn't looking for performance in new bushings, I was looking for something inexpensive, easy, and available. Prothane seemed to fit the bill, but I judged poorly. Getting the old bushings out is a major pain in the butt.

 

The problems are:

 

1) The stock rear bushing is pressed into an aluminum bracket. You're supposed to press out the old bushing from the bracket and install the Prothane bushing into the bracket. The stock bushing has an outer steel sleeve approximately .030" thick (it looks thicker because it has a flange on each end). The chances of you finding something the right size to press such a thin sleeve out is about 1 in 100. I pushed the rubber out and then carefully cut the sleeve with a hacksaw and then carefully tore the sleeve where I cut it and pulled it out. This was more difficult than I anticipated. It's easy to damage the ID of this bracket and it becomes a bearing surface for the Prothane bushings, so you don't want to damage it. Although I can see how the Prothane bushing should be much beefier than the stock bushing, the process of removing the old bushing is a significant P.I.T.A, The stock rear transverse link control arm bushing is overly complex. Why did Subaru make a contraption with silicone oil inside when a simple bushing should suffice?

 

2) You are not going to get the stock front bushings out unless you are very dedicated. You can't fit a control arm in a standard hydraulic press. I tried a ball joint press, but it didn't have the right size arbors. Yes, if you really want to you could probably succeed. A machine shop could likely do it but I think this would be expensive. Maybe a Subaru dealer will do it? You really need a special tool to remove the stock front bushing and this isn’t worth the hassle in my opinion. Maybe two sockets of the right sizes on either end with some all thread through the two sockets to press the bushings out? I doubt it, but it might work. You can buy a whole new control arm with a front bushing for $65 from Rock Auto. That’s the way to go if you need new front bushings. I am putting my arms back on with the old stock busihings. I think they are OK. I’m not looking for performance, I just want my old beater to be drivable.

 

3) My kit is missing two parts - the big thrust washers. It’s Saturday night and my front end is torn down. These washers are 5/8 ID x 2-1/2 OD. They are custom. You can’t find these washers at Home Depot or Lowes. I have wasted 2 hours of my time driving around and looking for some viable replacements with no luck. The only other place on earth I could find them is McMaster Carr (which means if I order them on Monday they will be here on Wednesday). SO WHAT THE HELL AM I GOING TO DO?

 

I bought this kit from an ebay seller called Autowearhouse (and yes, that's how they spell it). I have contacted Autowearhouse and he says his other 16-201 kits are missing the washers too. I can only assume Auto Wearhouse purchased directly from Prothane.

 

4) Prothane’s instructions are confusing.

 

Prothane claims urethane is impervious to everything. That's a bit of an overstatement. Urethane is an impressive material, but it isn’t impervious to everything.

 

The main problem with this kit is the difficulty of removing the stock bushings. If I could do it over I would have bought new controls arms with front bushings installed and the factory rear bushings. I suppose using the rear Prothane is not so bad if you have access to a press and are willing to saw the sleeve out, but from my perspective the front bushings are a no-go. Of course since parts are missing from my kit I am completely screwed. I destroyed my old rear bushings and have nothing to replace them with. I either go to the dealer on Monday and buy stock rear bushings (approx $100 ea) or wait for Prothane or Autowearhouse to ship me some washers or order some from McMaster Carr. Until then I have no transportation.

 

One more note: removing bolts from a car that’s been on the road 15+ years really sucks. Particularly when you can’t get an impact wrench on the nuts due to access problems. When I reinstall, I will put the bolts in the other way so I can access the nuts in the future. And who is the moron who designed the 10 degree ball joint taper? That SOB should be shot!

Edited July 18, 2011 by headrush

[headrush]

I found 2.5 inch OD washers at the hardware store. They have a terrible finish and a 1" ID hole instead of 5/8. I hope they stay centered (I clamped them using the old thrust washers).

 

Replacing the rear transverse link bushings appears to have solved the susceptibility to wind and steps/ridges in the road, but the damn thing still pulls to the right (which could be rear end alignment) and still wanders pretty bad on grooved cement. It's worse than just wandering, it's schizophrenic darting all over the place. I still have some steering feedback, but mostly just the pull to the right. The pull to the right feels worse now which probably means I have changed my caster for the worse. I can feel bumps more now. I'll try to report back after a couple days of commuting. So far the results are disappointing.

 

I had it aligned 6 month ago but I may need to take it in again. Or change the front transverse arm bushings. Or replace some rear end bushings.

Edited July 18, 2011 by headrush

[Fairtax4me]

Good old fashioned aftermarket PITA.

I've found that the hassle of installing some aftermarket parts is not worth the cost savings, at all. And often times the ride quality suffers.

 

The rear bushings are about $70 a side from a dealer if you order online. Some dealers will match online pricing to get a sale, which means you can often get the same price or close to it locally. Takes all of 5 minutes to change it and you're done.

 

The front control arm bushings can be pushed out with a C frame press or a long bolt with some proper size sockets. Or you do it the redneck way and burn them out with a torch.

 

If you haven't done so, I recommend replacing the bushings on the steering rack with poly bushings. I got a set of Whiteline bushings on Ebay for around $35 shipped. They take maybe 30 minutes to install and make a huge difference in the feel of the steering. No noticeable difference in NVH or ride quality. And the Poly is resistant to oil contamination which is what degrades the factory rubber parts so badly.

 

Wandering on grooved cement is usually more of an issue with tires. It's commonly known as Tram-lining. It tends to be worse with higher performance tires, but plenty of other tire types are affected by this as well. It all comes down to tread design. You can search your tire brand and model on Tirerack and read some reviews by people with the same tires to see if others have the same trouble.

[johnceggleston]

Wandering on grooved cement is usually more of an issue with tires. It's commonly known as Tram-lining. It tends to be worse with higher performance tires, but plenty of other tire types are affected by this as well. It all comes down to tread design. You can search your tire brand and model on Tirerack and read some reviews by people with the same tires to see if others have the same trouble.

 

if it is not tire related, what is the most likely cause, steering rack related (bushings, inner or outer tie rods) or control arm bushing related?

 

thanks

Edited July 18, 2011 by johnceggleston

[Fairtax4me]

A bent frame, or severely out of spec camber.

 

In my experience, bad bushings will allow the wheels to "walk around" under the car, when driven on grooved concrete/ steel deck bridges, but not move the whole car around as much, or no more than any other paved surface.

Most of the time you just get a generally unstable feeling at higher speeds, and clunking /wobbling during acceleration or braking, or during harsh maneuvering.

This is just in general. Obviously every car reacts differently to worn suspension parts.

I tend to think the bushings on my 96 sedan are pretty worn out. It feels like it wants to float off the road at anything over 60, but it doesn't feel wobbly or drive any differently on cement than it does on asphalt.

[bheinen74]

There is a reason OEM cost more sometimes. At least it fits, installs with ease, and comes with all washers, bolts to do the job.