Bushings too small for rear lower link arms?

[jangell]

So here's a weird one: My more knowledgable friend and I pulled out my rear lower link arms and sent them to Marty Maier to turn them into adjustable ink arms. That parts all set, and they look great.

Once we got them back, we decided to replace the bushings with NOS ones. We pushed out the old bushings without problems, but found that the new bushings don't fit -- I mean, they fit, but they fall right through (as opposed to needing to be pressed in) for three of the four holes (the fourth hole seems fine).

I asked Rob Grady (from whom I got the bushings) and Marty about it, but they've never heard of this happening.

To be specific, the bushings are all a hair over 40mm in diameter. The control arm holes are just under 40mm for the one that the bushing fits properly, and about 40.5mm to 40.6mm for the other three where the bushing falls right through.

One theory is that we used something slightly too large to push out the bushings, scraping half a millimeter off of each control arm hole. We specifically used something slightly smaller This doesn't explain why one of the holes is still the right size, though, since we pushed them all the same way.

Anyone ever have this happen before, or have any ideas about how to resolve it? I toyed with getting some polyurethane bushings from Superflex, but I imagine they're the same size as the stock ones and thus will also be too small.

-- Joe

[Bitsyncmaster]

Do the bushings get compressed when installed in the car? My guess is the holes were manufactured that way.

[jangell]

Do the bushings get compressed when installed in the car? My guess is the holes were manufactured that way.

I haven't tried to install the arms in the car yet -- I got the impression that they must fit tightly, or else the car won't behave properly.

I forgot the old bushings at my friend's place; we're going to grab them on Sunday and see if they fit, which will at least tell us if we accidentally made the holes wider or if something else weird is going on here.

-- Joe

[DMCMW Dave]

The bushings MUST be a tight press fit. I've never heard of this happening either so I think you are correct, somehow you stretched the control arm.

FYI - Poly bushings are available for that, they are the same part as the front lower control arm INNER bushing. They are a very tight fit in the control arms so would probably work in your application.

http://74.86.98.148/dmcmidwest/powerparts.html or directly from DMC Europe. You would need two pair to do the rear lower arms. I have several sets in stock here for immediate shipment.

[jangell]

FYI - Poly bushings are available for that, they are the same part as the front lower control arm INNER bushing. They are a very tight fit in the control arms so would probably work in your application.

http://74.86.98.148/dmcmidwest/powerparts.html or directly from DMC Europe. You would need two pair to do the rear lower arms. I have several sets in stock here for immediate shipment.

Excellent -- I didn't know that the front lower control arm bushings worked for this, and I did want to do poly anyway (I didn't realize they existed until after I got the NOS bushings). I'm willing to give it a shot, at least. Thanks!

-- Joe

[jangell]

Good news -- the poly bushings fit great! Thanks, Dave!

Bad news -- as we were tightening the bolt that holds the link arm to the hub carrier, we heard a loud bang (it wasn't even fully tightened yet). There is a clearly visible crack on the hub carrier. I'm pretty sure it would be unsafe to drive on this, so we're taking the hub carrier off the car today.

Of course, this is the right hub carrier, which Houston doesn't seem to have anymore. (Marty Maier also warned me these weren't available). PJ Grady lists them for $659, while John Hervey shows it as $459. I don't know if they actually have them in stock or not; I just checked their web sites.

I have a friend who does aluminum welding, so we're going to give that a shot. He's pretty confident that it'll be strong enough once welded. I've attached two pictures showing the damage.

-- Joe

6583 6584

[Bitsyncmaster]

You must be missing a bushing or the one you have is to short.

[jangell]

You must be missing a bushing or the one you have is to short.

I'm pretty sure I have all the correct bushings. We followed the parts manual to ensure we had the right number of washers, plus the extra washers between the Eibach shocks and the hub carrier. The other side was no problem -- only the passenger one cracked. It didn't even crack all the way through, but rather just on that one side.

We had to cut out the bolt with a Sawsall when we originally took this thing apart. There are marks from the blade rubbing against the inside of the carrier's arms. It's possible that this introduced some extra space between the link at, bushings and the carrier's arms.

Another possibility is that the sleeve in the carrier was so rusted that it caused too much friction, keeping the bolt from sliding smoothly (we had to hammer the bolt out when we took the hub carrier off just now; going to have to clean that up before we put it back together), which in turn lead to the force that caused it to break.

Or something like that. I really don't know what I'm talking about. :)

-- Joe

[DMCMW Dave]

We had to cut out the bolt with a Sawsall when we originally took this thing apart. There are marks from the blade rubbing against the inside of the carrier's arms. It's possible that this introduced some extra space between the link at, bushings and the carrier's arms.

Another possibility is that the sleeve in the carrier was so rusted .


-- Joe

Without seeing it I'm guessing but I think you are close in your diagnostics. The sleeve in the hub carrier is supposed to slide the tiniest amount when you tighten the bolt to make sure that the lower shock mount sleeve, and control arm sleeve, are all locked in place when tight. This happens once, during installation. It's now probably rusted in place. If any of the new parts (shock or bushing center sleeve) are at all different in dimension from the original, or you altered the dimension with the saw, (normally acceptable with the sleeve's ability to slide a bit) you have a problem if the sleeve would not move.

I'm not sure but I had heard that Ed Uding has reproduced that hub carrier out of billet (i.e. solid block) aluminum. Might ask there. I'm sure it would not be cheap. Otherwise you are looking for someone with a parts car if your welding does not work.

[Delorean Industries]

We have a bunch of used rear hubs in stock ready to go.

[jangell]

Without seeing it I'm guessing but I think you are close in your diagnostics. The sleeve in the hub carrier is supposed to slide the tiniest amount when you tighten the bolt to make sure that the lower shock mount sleeve, and control arm sleeve, are all locked in place when tight. This happens once, during installation. It's now probably rusted in place.

It is rusted solid -- won't move at all. I've been considering pressing it out (since I had to take the carrier off the car anyway), but I'm not sure it's worth trying to do, given the how hard it might be to get a press in that space.


If any of the new parts (shock or bushing center sleeve) are at all different in dimension from the original, or you altered the dimension with the saw, (normally acceptable with the sleeve's ability to slide a bit) you have a problem if the sleeve would not move.

Ah. It was also brought to my attention that aluminum doesn't flex in the way that steel does, which is something I was not aware of. It now makes more sense to me why it is so important to have the proper clearance.

The driver's side hub carrier tightened up with no problems, but I believe that the saw didn't damage the carrier as much as it did on the other side.

Thanks for the info

-- Joe

[jangell]

We have a bunch of used rear hubs in stock ready to go.

Great -- if my welding patch doesn't work, I'll be giving you a call. :)

-- Joe

[dmc6960]

When I did my suspension a year and a half ago, I had to push these sleeves "outward" to get the links with the new bushings installed. I used a socket and a large C-Clamp to do it. When reinstalling the sleeves popped back into their proper tight position when tightening the pivot bolts. Considering I had to use a saw to cut off the old bolts/link bushings (the bolt was seized to the inner bushing race), I can consider myself lucky these sleeves weren't also seized to the hub.
6683

[Delorean Industries]

Great -- if my welding patch doesn't work, I'll be giving you a call. :)

-- Joe

How did the engine upgrades turn out?

[jangell]

How did the engine upgrades turn out?

We (me, and my friend who actually knows what he's doing :) ) got stuck in the "while we're in here..." trap, so while we had the car up we did the adjustable lower control arms and are replacing the lip seals on the transmission -- all of which seemed like nice, simple repairs until 30 years of rust and not quite having the right parts on hand tripped us up. The engine has been completely re-assembled for about a month now, and we've turned it over enough times to prove it can run, but we haven't yet had a chance to get the distributor properly timed (right now it only runs cleanly if you give it throttle, and stalls when you let up). We may not have aligned the distributor properly, and may have to pull it out and rotate it one notch, but I think otherwise we'll be good to go soon. Hopefully this weekend, although I've been saying that for a few months now... :)

-- Joe

[jangell]

Quick update: I got the welded hub carrier back (with a very nice weld). With the carrier already out of the car, we were able to get the sleeve out and put in a new one. We bolted everything back up, and were quite relieved that nothing broke this time.

Thanks again everyone for all the assistance!

-- Joe