DIY Urathane

[sbcrockett]

I'm kinda thinking of this as an experimental pair anyway.

Damn, I wish I lived closer to you guys!

[Jester323]

Damn, I wish I lived closer to you guys!

It's only a 3hr drive! what do you need?

[sbcrockett]

I got the 50 mph shimmy and since this is my daily driver, would like to get that taken care of. And, I'd eventually like to put in some new shocks/springs to lower it a bit. The car rides nice but feels a little "floaty" at times. I'm probably going to get an Alpina bar from Ken to see if that helps, but definitely need some strut work. I've just never done it before.

Thanks for posting your progress guys!

[Jester323]

I got the 50 mph shimmy and since this is my daily driver, would like to get that taken care of. And, I'd eventually like to put in some new shocks/springs to lower it a bit. The car rides nice but feels a little "floaty" at times. I'm probably going to get an Alpina bar from Ken to see if that helps, but definitely need some strut work. I've just never done it before.

Thanks for posting your progress guys!

Depending on how this set turns out, if you want to buy a new set of control arms and have me modify & install them for you, I'd be happy to help if you wanna make the drive down sometime this spring. Start buy parts now...

[sbcrockett]

sounds good Jesse! thanks for the help. I'll try to get down even sooner to meet up w/ you guys some Thursday.

[Jester323]

next local PNWBB meet will probably be either March 20th or 27th. we'll post the date on the PNWBB site when the time get's closer.

[Jester323]

John,
I just checked the inner bushings on the old ones & they look pretty good, no dry rot on the inners.

We can still do those in urethane if you want, but I have a feeling that they are already really hard and they will probably live as long as the ball joints in those arms.

[Jester323]

The Urethane showed up yesterday & I started messing around with them this morning. I drilled a bunch of holes in the rubber portion so that the urethane could penetrate all the way through and be one solid cast bushing for both sides. I alsoe tried to remove as much of the rubber as I could, I even cut as much off the top side as I could.





Then I set out to build the forms. I cut up a Coke can and cut out 4ea 10mm wide strips and two 50mm circles. Then using hot glue, I built the forms on the control arms and attempted to seal them up. Next time I'll try harder on this part... Also, one the second one it dawned on me that I should probably try to use some hot glue & seal up the hole in the metal sleve that would be on the bottom so it didn't seep in. Wish I would have thought of that on the first one.






measured out 2 parts urethane polymer & 1 part hardener after setting up an area to work and capture any potential spills. I just so happened to have some disposable cups that were just about the perfect height to set the arms up on so that the top part of the casting would be level, and started pouring urethane down through the holes.




So it's all setting up at the moment, probab;y should have added a tad more hardener as it's setting up pretty slow.



As it turns out, I was right about sealing up the bottom of the metal sleeve, but it worked out okay, I just kept sticking an old pencil down the shaft and wiping off the urethane after I pulled it out.

All in all, pretty easy to do. After it sets up fully, I'll pull the forms off and snap some more pics.

[wayfast]

clay works as a good sealant

[Jester323]

they finally set up enough to pull the forms off. I think they are turning out really well. They still need to cure a while longer, probably a good 24 hrs. Would have been less if I had used more hardener, learned my lesson for next time. They are ready for you to paint them the color of your choice John! Wern't you going to pick up some urethane boot covers too?

[jrcook320]

very nice work. That's exactly what I had in mind if I do this...

this definitely needs added to the FAQ thread, I'll post a link to it in my suspension section.

[waferman]

Jester ROCKS! Some say a judge was going to give him comunity service one time, then laughed and said hell, thats what you do for the bimmer guys anyway! Get outta here and schedule a tee-time with my secratary next week!

Thanks again, Jess. I'm picking these bad boys up today, and putting them on Monday if all goes well. I don't expect a lot of help with my "new" shimmy though- I think the stooge at Les Swab somehow bent my front left inner rim during my last allignment pretty good, which is when it first showed up. But it will be nice to have the popping noises go away! I'll report out on them later since this is also a test of sorts.

[fullswing]

jester 'community service' 323... kinda long for a handle, but i can get used to it...

wafermannnnnnnnnnnnn... what's up?

[Jester323]

I don't expect a lot of help with my "new" shimmy though- I think the stooge at Les Swab somehow bent my front left inner rim during my last allignment pretty good, which is when it first showed up.

PS: that reminds me, I don't know that I ever gave you the contact info for that shop that straightened all of my wheels:

Skip's Wheel Werks
wheelwerks@yahoo.com
503-641-8001
4560 SW 96th
Beaverton, OR 97005

Cost me $35/wheel to be straighened. Let me know if you plan on doing this anytime soon, as you saw yesterday when you came over, my set of wheels/tires is sitting in the garage off of the car, so you are welcome to borrow my set while you are getting yours straightened, so long as we figure out what's going on with your "slotted subframe" that is! I'm also pretty sure that Chris Rich has an extra set laying around that you could probably borrow for a while.

I'm waiting on pins & needles to find out how those arms work out!


PS: I'm happy to report that after an approximate 24hr cure time, the urethane set up as hard as I had expected it should. I have to admit that I was pretty nervous after the first 12hrs or so...

[waferman]

Well, I dont think I will start to put them on today as a good house clean was in order and I needed to take my boy to preschool. Single dad stuff, you know Tomorrow I will try again!

Thanks for the offer to use your wheels, but I don't want to wear them out too much! I still have my 13" white baskets that came with the car. They need new tires also...

[waferman]

Well, the home-made Urathane control arms are in, and I am way happy. Shimmy is gone! The steering is very light now and I'm happy to report that it still tracks straight, so my last allignment is still good. Couldnt' be happier! Jester came over at noon, and we literaly had them both on by 1:30. The only test now is durabilty, and that of course will take time.

The failure was limited to one control arm, and it wasnt the rubber as I had suspected. The whole large bushing had worked it's way out! It was still fine, new in fact, and stiff, but the pressed in bushing had worked it's way out of the control arm. Not a normal failure mode I suspect. But with these, I am hoping to never replace them again.

John

[Jester323]

Actually John, I was looking at them closely today, and the old rubber bushings were starting to dry rot a bit, not exactly perfect, but the fact that the bushing was working it's way out is in no doubt in my mind the "popping" noise you were hearing. The ball joints in those arms should fail long before the urethane does... I hope...

I like suspensions!

[jjgbmw323]

PS: that reminds me, I don't know that I ever gave you the contact info for that shop that straightened all of my wheels:

Skip's Wheel Werks
wheelwerks@yahoo.com
503-641-8001
4560 SW 96th
Beaverton, OR 97005

Cost me $35/wheel to be straighened. Let me know if you plan on doing this anytime soon, as you saw yesterday when you came over, my set of wheels/tires is sitting in the garage off of the car, so you are welcome to borrow my set while you are getting yours straightened, so long as we figure out what's going on with your "slotted subframe" that is! I'm also pretty sure that Chris Rich has an extra set laying around that you could probably borrow for a while.

I'm waiting on pins & needles to find out how those arms work out!


PS: I'm happy to report that after an approximate 24hr cure time, the urethane set up as hard as I had expected it should. I have to admit that I was pretty nervous after the first 12hrs or so...

Jesse two quick questions: Do the urethane control arms make you less comfortable in the car. Can you feel the bumps more?

Secondly do you like Skip's wheel service. I have a set of BBS marhle rims I need straighted and polished and painted. I was thinking about sending him my set of rims.

[waferman]

Jesse two quick questions: Do the urethane control arms make you less comfortable in the car. Can you feel the bumps more?

Secondly do you like Skip's wheel service. I have a set of BBS marhle rims I need straighted and polished and painted. I was thinking about sending him my set of rims.

Joe, the ride is fine. The steering seems much lighter than ever before, and the shimmy due to a big dent in the inner rim has been taken care of. When you hit things like a manhole cover, or small cracks in the road, it seems to be xmitted to the steering wheel more, but nothing close to dangerous, no jerking or anything like that.

A business like Skips isn't hard to find, and I am sure that you can find one closer! You would have to pay a lot in shipping that would be better spent on your mechanic's shop fees!!

John

[waferman]

but the fact that the bushing was working it's way out is in no doubt in my mind the "popping" noise you were hearing. The ball joints in those arms should fail long before the urethane does... I hope...

I like suspensions!

Yea, I am sure that's what the noise is also. But I think you should pitch that arm. If it was remanufactured, they may have reamed out the control arm too much and the metal sleeve of the bushing wont stay in any longer, or if the arm was manufactured by OCAP then it is out of spec. I don't think urathane will keep it from popping out again, and a new one pressed in may do the same. They are cheap enough to give it a try, though- under $10 IIRC.

[E21Craze]

The failure was limited to one control arm, and it wasnt the rubber as I had suspected. The whole large bushing had worked it's way out! It was still fine, new in fact, and stiff, but the pressed in bushing had worked it's way out of the control arm. Not a normal failure mode I suspect. But with these, I am hoping to never replace them again.

Happened to me once, a perfectly fine bushing popped out. My mechanic spot-welded it into place Worked fine for a couple of years, though!

[Jester323]

Jesse two quick questions: Do the urethane control arms make you less comfortable in the car. Can you feel the bumps more?

Secondly do you like Skip's wheel service. I have a set of BBS marhle rims I need straighted and polished and painted. I was thinking about sending him my set of rims.

Joe, you really won't feel the bumps any more if you think of going over a speed bump in a straight line, but you will feel a bit more if you hit a pot hole. You will be able to feel the road a bit more though, one of the reasons I love this car as opposed to something with power steering where some of that connection is lost. What this should be doing is pulling out some of the "muddiness" or sluggishness respose from the sway bar. With the rubber bushings there is a little more give so the car can roll a bit more from side to side. It should also make the steering a bit more responsive as John was illuding to.

Yea, I am sure that's what the noise is also. But I think you should pitch that arm. If it was remanufactured, they may have reamed out the control arm too much and the metal sleeve of the bushing wont stay in any longer, or if the arm was manufactured by OCAP then it is out of spec. I don't think urathane will keep it from popping out again, and a new one pressed in may do the same. They are cheap enough to give it a try, though- under $10 IIRC.

John, the way I build these, the bushing poppong out really won't be possible any more, as it's all sandwiched in between the two large washers on each end and there is positive contact from the washers to the actual metal of the control arm. This was possible with the design of the rubber bushings because the washers on each side never had 100% positive contact with the actual control arm. Kind of hard to explain, but I wouldn't have any doubt that that would no longer be a problem with the way that I've designed them, I'd even be willing to run them on my car. now I would be concerned about this with the other method of filling the control arm bushings that's shown in the Tricord thread and linked to in the FAQ thread vs my method.

[waferman]

OK, I see what you mean about the washers and the contact. I remember the stock bushings did have some room. Keep em as back ups for when Freds' fail

[E21kiwi]

Hi..how much was the tin of Urethane and hardner. I am thinking of getting some sent out to New Zealand. Cannot find anyone here doing this product.

[Jester323]

shoot me an email & I'll hook you up.

the_nemecs AT verizon DOT net