Front Suspension A Arms

[Alpine Addict]

The bushings in the lower A arms on my series 5 have collapsed. These were rebuilt about 6 years and 10,000 miles ago. My concern is why did these fail so soon and how can I stop this happening again? Also who is rebuilding the "A" arms?

Thanks
Steve

 

[PROCRAFT]

bushings

Do the job yourself! get the urthane bushings fron Sunbeam Specialities,
use a piece of tubing betweem the bushings in the arm to keep the arm from squeezing together when you press the bushings out, also
look at the welds on the on the arms its prudent to reweld a bit more.

 

[Tom H]

Steve, What bushings were used when they were rebuilt? The original type use the flexing rubber as the "pivot". The original type bushings are not designed to slide or rotate on the pivot shaft, but are designed with the rubber adhering to both the inner and outer metal. As the wheels move up and down, the rubber is intended to flex, and it's the actual flexing of the rubber that allows the pivoting of the A frame. I am guessing that this is the kind of bushing used in your rebuild. And I am further guessing that when the A frames were installed, the bushing nuts were tightened with the car off the ground and the wheels and A frame extended downward. This would mean that when the car was then placed on the ground, and the weight of the car on the wheels, the bushings were thus put into an already highly flexed state, with the car at rest. And every time you hit a bump and the wheel moved UP, the rubber in the bushing got flexed (twisted) even further, beyond it's max design point. That woulld cause the rubber to become "unglued" from either the inner or outer metal tube or both, with all further pivot action taking place as a friction pivot , quickly wearing out the rubber.

Make sense?

If you use Urathane bushings, they are dsigned to pivot or slide around the inner metal bush and you do not need to have the A frames in the normal rest postition when you tighten the nuts. If you do use Urethane bushings from SS, be sure to grind a bevel or chamfer on the leading edge before you try pressing them into the A frame.


Tom

 

[Alpine Addict]

Tom,
I think you may be correct. Thanks for the help.

Does anyone know who is still re building these?

Thanks
Steve

 

[Ken Ellis]

I'm kinda thinking about it, either on an exchange basis or the "you get the same one back" basis. Mainly because I'm about to do mine...

I think Ian was going down this path back a few years ago, but life interfered.

Don't know what it should cost, yet, though.

Thoughts?

 

[whoizrob]

urethane...

For those that who have done this mod, have the bushings ever squeaked for you? I am wanting to swap out the old bushings but hesitate to use urethane as my old track car had urethane bushings and squeaked like a hoard of mice being steam rolled each time I hit a bump....

Thanks,

Rob

 

[Tom H]

Rob, My Urethane bushings do not squeek. I don't remember if I put any lube on them. I think some have added zerk grease fittings to their bushings.

The urethane bushings on the sway bar of my Dodge Caravan squeek as you describe whenever the temp is below freezing- but I do not drive my Alpine at those temps so I don't know if the same would happen.

Tom

 

[Bill Blue]

I lubed mine real good with the lube supplied with the bushings. They squeek like crazy.

Bill

 

[George Coleman]

You must use dielectric silicon grease on the urethanes. I had Doug J. put grease points on my Tiger so once a year I could lube them, Axel grease will not work it will weaken the urethane. The nuts on the folcrum pins should not be to tight, the large washer on the underside of the nut should be moveable with your fingers.

 

[Alpine 1789]

I'm kinda thinking about it, either on an exchange basis or the "you get the same one back" basis. Mainly because I'm about to do mine...

I think Ian was going down this path back a few years ago, but life interfered.

Don't know what it should cost, yet, though.

Thoughts?

Rebuilding the front end from my parts car is at the top of my list of winter projects. I haven't decided if I want to do the A arms myself or not, but would definitely be interested in having someone else tackle them for me. So, Ken, please let me know if you head down this path. I'd be happy to send you a set for rebuilding or as a core.

I will say that Randy Willet (Oneoffive) sells rebuilt ones on eBay, but $760 seems pretty pricey to me. At that price, I would definitely do them myself.

 

[Tom H]

Geiorge Coleman said:

I had Doug J. put grease points on my Tiger so once a year I could lube them, Axel grease will not work it will weaken the urethane. The nuts on the folcrum pins should not be to tight, the large washer on the underside of the nut should be moveable with your fingers.

George, I am curious about your comments. First, I assume the grease points allow you to pump grease into the space between the urethane material and the outer metal. But it seems to me that the inner metal bush is more likely to turn inside the urethane than the urethane to turn inside the outer bush. Second, It seems to me you want the nut tight. If I reacall the assembly correctly, you should tighten the nut so the inner bush is fixed firmly to the Fulcrum Pin, and the A frame and urethane rotate about the inner bush. With the nut loose, you may have the inner bush rotating on the fulcrum pin - metal on metal with no lube. Note that when fitting original type bushings, with flexing rubber bushes, you must leave those nuts untightened until after the weight of the car is on the wheels and suspension- but then they are tightened - after the weight is on the wheels. But uretahne bushes do not need this step and the nut should be tightened when convenient.

Tom

 

[Jay Laifman]

I did the urethane ones from Sunbeam Specialties. They don't squeak yet. But, I will repeat to get someone who knows how to do it right - by using the tube Tom mentioned. And that tube has to be cut/sized appropriately. If the guy isn't going to take the time to do it right, walk away. Wouldn't want to be trying to buy replacement A arms.

Dan Walters in San Bernardino area helped me.

 

[AutoX47]

The nuts on the folcrum pins should not be to tight, the large washer on the underside of the nut should be moveable with your fingers.

Hmmm ... I believe that's the case if you have bushings without a steel inner sleeve, so that they ride directly on the fulcrum pin.

When I made the delrin bushings I made the inner sleeve slightly longer than the bushing so that the washer would not come in contact with the bushing unless it managed to begin to back out. I don't see a reason not to tighten the nuts for the A-arm bushings unless as I mentioned the bushings ride directly on the fulcrum pins. In such a case I imagine you would have to use thread sealant or double-nuts to keep the nuts from walking off!

The hard part for me wasn't putting them in ... it was taking the old ones off! That took two people and 4-6 hours - one with an acetylene torch and the other with welding gloves and channel locks. My apologies to his wife, whose house we stunk up of burnt rubber.

 

[George Coleman]

Tom, the big problem with the urethane is thay are hard and if not lubed and keep clean they will size to the pin and cause the pins to break. I have seenthis first hand on other cars, Doug J. raced his Tiger with this setup and found out the hard way, the old rubber units are flexable the urethane is not!

 

[socorob]

I have poly bushings on my 4 link and they are just starting to squeak after a year or so. I relubed them and now 1 squeaks just a little. You have to use moly grease on poly, at least that's what the 2 different manufacturers of the different bushings I have both told me.

 

[PROCRAFT]

poly bush

As Zizzo said their needs to be an inner sleve that is slightly longer than the
bushing so the nut can be tightened,this allows the bush to run on the inner tube and not the fulcrum pin,we have used both urethane and delrin bushes
and have never had a squeek, the 4 link on the Alpine used urethane bushes
and never had problems other than not enough movement(we've now gone to heim joints) also the first generation of bushings did not have an inner tube hense the problem of locking the bushing up which causes problems as George said. the old metalastic bush might be flexable but it fails under constant up and movement, adds to the spring rate,and a pain in the ass to
replace, try Nylon MD the next time you make bushings (like delrin with moly impregnated)

 

[bashby]

Doug J. in Ohio rebuilt my A-arms and did a great job (reasonable too).

 

[Tom H]

Gearge said:

Tom, the big problem with the urethane is thay are hard and if not lubed and keep clean they will size to the pin and cause the pins to break. I have seenthis first hand on other cars, Doug J. raced his Tiger with this setup and found out the hard way, the old rubber units are flexable the urethane is not

Are you saying that the urethane ones you used do not have an inner bush and that the Urethane is in direct contact with the fulcrum pin? If so that is different than the ones SS sold me 7 years ago. They have an inner and outer sleeve. The Urethane rotates around the inner sleeve, and that inner sleeve is held tight to the fulcrum pin by the nut, tightened against the washer and sleeve.

And my real question to you is how/ where is the grease fitting placed that allows forcing grease into the area around the fulcrum pin? I had assumed you were describing a fitting on the "barrel" of the A frame , and probably thru the outer bushing sleeve , that would put grease between the urethane and the outer sleeve. But maybe you are describing a fitting that protrudes all the way thru the barrel of the A frame, thru the outer sleeve, and thru the urethane piece to deliver grease into the area surrounding the pin itself.

Tom

 

[whoizrob]

Delrin...

How does it ride? Is it harsh? How is the wear over time? Do you prefer delrin over urethane? Do you still have the measurements you used for the delrin bushes? Thanks!

Rob

PS. Interesting hybrid:
http://www.cheperformance.com/Tech/CHE_Poly_Delrin_Bushing.html

 

[tigretr]

Rob,
I just finished making my upper delrin bushings and all new washers. Hopefully next week I can get going on the lower bushings. Once I get things installed and decide I am happy with them, I will be more than happy to get you dims. Now, if only I could get those damn rubber bushings out. What a PITA!

Brian