Budget Suspension Rebuild

I'm gonna bring this back up as I've yet to see (or at least recognize) the answer to my newest issue.

I've got the axle back, just need to put the drums on and can start the swap. My question is I've got the factory sway bar, meaning I have the wider shackles. If push comes to shove, where can I pick a set of wider ones up or can I use the narrow shackles for the same result.

The cars with rear sway bars (ie: police cars) have a unique shaped rear leaf spring shackles (trapezoid).


The other 99% of us have straight shackles.


The difference is (I don’t have exact measurements on me, at this time), the frame attachment (rear shackle) tube is about 1 inch wider (1/2” per side) and both shackles are bent roughly into the shape of a trapezoid. The rubber bushings (and nuts) are the same.

If I understand your question, the AHB (trapezoid) rear spring hanger is stronger and will hold up to hard cornering a lot better (side motion) than the straight rear spring hangers will. Therefore, the AHB (trapezoid) rear spring hangers are more desirable, to some of us.

If a person can find a pair of these (off any FMJ body (only)) then you can remove/replace your existing rear spring hangers (to AHB (trapezoid) or vice-versa).


On a different note, S-body (Minivans) made from ’83 to ’95 use the AHB (trapezoid) rear spring shackles – but their rear frame mount bracket is different. If a person can find an older minivan you can get the shackles. Then get some tubing and weld up your non-AHB rear frame hanger and you can get a better rear shackle assembly for your car.

The AHB/’83-95 minivan shackle part number(s) are:
4094060 (both halves) 2x needed

Rear spring frame bracket (all FMJ with rear sway bar (trapezoid shaped)):
Right 4014704
Left 4014705

Note: the ’96-07 minivan shackles look the same as the ’83-95 minivans do, but the both studs are smaller diameter and nuts are metric. A person might be able to get the newer ones adapted to fit - but around here, there is still plenty of the older minivans available to get the correct parts from (a lot more minivans were made than FMJ’s).

I think it might be possible to take the rear spring hanger from the minivan, and cut away the weld from tube to bracket and transfer tube over – or maybe cut tubes off (about ½” per side) and weld onto existing frame brackets – so if you are getting a pair of rear shackles, grab the rear frame brackets as well. If the minivan is on stands, and you are a Pull-A-Part, it is about a 10-minute job to remove both sides. If rear shocks are still attached, then shocks will hold springs up (mostly), so no abrupt changes when shackle or hanger brackets are removed (some, but nothing major).

Currently, I have 3 spare trapezoid shackles (no FMJ frame brackets) in my garage (1 and ½ cars worth) – but I wasn’t planning on selling any, until I get more in hand, first.

If this is not your question, can yo re-state your question?
BudW

Well, initially the question was directed to what the difference was regarding handling since I have a sway bar/AHB.

Now, the question is..if the vans have the same (AHB style shackle) can I just pick one of those up and it mount right up to my AHB hanger?

The rubber biscuit design is what makes FMJ’s handle poorly over bumps and other road defects. Compound that with decades old rubber, makes it even worse. My experience is the lower half of ISO-clamp (U-Shape bracket) is a weak spot and does break often, leaving car disabled when it occurs, which is another reason for conversion.

For minivans, the ’83-95 version does not have an ISO-clamp. It does have a leaf spring rear suspension but uses a solid axle (drag axle).

This design can be easily modified to be used for trailer service (if one wanted to).

This is the ’96-07 minivan version and it does use an ISO-clamp.


The full-size vans (B-vans) and pickups share a lot of parts and neither of them use the ISO-clamp system. Also, the parts (like shackles) for B-vans are about twice the (physical) size of what is used on FMJ’s.

Now, in my opinion, why I feel the ISO-clamp design rides worse than older cars (before the ISO-clamp system) is because of a combination of the rubber biscuits and the axle being powered. The axle being powered is a key word, in this case. The minivans (except for some 4*4 versions) are all front wheel drive, so the axle being powered is not an issue.


Sense this has been brought up, I’m wondering about the rubber biscuits used for the ’96-07 minivans and will look into if compatible for use in FMJ’s. After I've owned a '96, '98, '00 and '02 minivans . . . I finally get a chance look into this.
The FMJ rubber biscuits hasn't been available for decades. Aftermarket urethane ones are available, though.
BudW

I have used the std. mounts with aftermarket HD std shackles and bushing inserts with no issues.

Bud, whats up with that tail pipe mount/with rubber in your one pic? I could use that thing that weighting your car down.

XfbodyX said:

Bud, whats up with that tail pipe mount/with rubber in your one pic? I could use that thing that weighting your car down.

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Um, that.
That is, um, from my putting my car on a diet, from when, um, the muffler fell off (and tailpipe dragging was irritating me).

That picture is from 3 years ago, and there is a forum post about it . . . somewhere around here.
BudW

So, can I use the shackles from the 96-07s? I think Im kinda lost.

I've got the axle rebuilt, the parts for the iso delete, but Im not sure I can get the current shackles off without causing an issue with them, and if I can get new ones..thats even better.

I was talking with my 84 year old neighbor who is a great, life-long mechanic and mentioned that I wanted to either replace or re-arch my leaf springs on OY as it looks kind of droopy in the rear.

He suggested having them re-arched and offered to do the work and use a spring company that he has worked with for years to re-arch them if I supply the parts. OY has it's original rear diff (8.25 for wagons I think), five leaf springs, and the original (completely shot) shocks on it. I would appreciate some advice on replacement bushings, shocks, and anything else that might need to be addressed while he is doing it. OY is strictly a street cruiser, but I would like to raise up the rear end just a few inches to make it have a better stance, although I don't want air shocks or anything like that. I don't think I need to go the Firm-Feel route, but probably should upgrade from OEM rubber bushings. Any ideas? Thanks in advance!
P.S. Don't mean to hijack this thread, but thought my question might fit in here well and might also answer some other members questions also.

Shocks and a re-arch will go a long way. The ISO delete will add another half inch or so from what I've gathered. It's a lot more straightforward if you dont have the factory rear sway bar and are trying to keep it.

If you go the route of ISO delete, B body shocks are what I used. I just grabbed a set of monroes from Amazon to have so I can switch them. I figure down the road when all suspension is rebuilt front to back, I can get particular on shocks. I'm going with rubber bushings on everything but the sway bar. Sure, poly is better..but anything is better than 35 year old bushings. I'm sure others with more experience will have varying opinions, that's just where I'm at.

Heres a shackle from an 03 grand caravan (rockauto)

Underneath is what's under my car. Without doing any sort of measuring, they look pretty close..maybe the caravan is a bit wider though.

Would someone explain "iso-delete" and how, why, and when this should or should not be done? Thanks.

old yellow 78 said:

Would someone explain "iso-delete" and how, why, and when this should or should not be done? Thanks.

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There are other threads here dealing the specifics. All it is is doing away with the rubber isolation of the rear axle from the springs and mounting it solid like the old A/B/C/E cars. Better handling, but takes a little of the cushy ride these cars are known for.

Brother, my Dad has new factory style shackles that'll fit. I'm sure he'd just give them to you. All you would need is bushings. Don't fret about about the difference between the AHB and regular styles too much.

If you want beef then look at the Firm Feel hangers. I put them on my car this year.

Duke5A said:

Brother, my Dad has new factory style shackles that'll fit. I'm sure he'd just give them to you. All you would need is bushings. Don't fret about about the difference between the AHB and regular styles too much.

If you want beef then look at the Firm Feel hangers. I put them on my car this year.

View attachment 35382

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I can source new straight shackles for cheap, I just didnt necessarily want to go that route if itd create an issue. There had to be a reason behind the factory using separate shackles, I just didnt know if there was enough of a difference to justify the hassle.

brotherGood said:

I can source new straight shackles for cheap, I just didnt necessarily want to go that route if itd create an issue. There had to be a reason behind the factory using separate shackles, I just didnt know if there was enough of a difference to justify the hassle.

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I don't think it is. I ran the factory shackles on my car until just this year with lots of spirited driving. I would certainly replace yours with new though as those look pretty rotten.

The rear shackles on ’83-95 minivans are the same as AHB (yours).
The ’96-07 minivan rear shackles are close, but not quite (as you have pictured in post # 30). The newer ones are metric and studs are smaller diameter. A person would need to find a way to sleeve the difference on stud diameters and inner rubber bushings. I hadn’t looked at the newer shackle for width or tallness but would expect them to be about the same.

I have three good used ’83-95 minivan shackles, if you experience a broken stud or yours is too rusty.

The important part is to get under car, maybe a couple of times with a liberal dosage of penetrating oil at these locations, before disassembly (will make the job a lot smoother) at yellow arrows.


Fasteners at white and red circles (not visible) need to be gotten, as well.

Another item that helps is if your existing fasteners are rusty (like yours are) is to clean what you can using a thread cleaner. These look a lot like taps/dies, but these to not make new threads, but to clean existing threads (a big difference). You do not want to create new threads out of your existing threads – which can happen if using taps/dies (I’ve done it and have ruined a few fasteners that way).
They go by several names: thread cleaner, thread restorer, thread chaser (and maybe a few others). I have a metric and SAE sets at home and sets are about $35 each. I “believe” a person can rent a set from the local parts store from me. Well worth the money if you work on old cars.

In this case, I would use a thread cleaning die on each of the fasteners after they been sprayed (a few times). The thread cleaning tools can’t do anything for the rust between stud and nuts, until the nuts get removed – so that part will still need to be man-handled (carefully).

Not often do I see rust inside of the rear frame rail affecting the rear spring hanger bracket to frame bolts (white arrows, below) – so in most cases, those should be ok to remove. If they don’t come out easy, you might have to drill a small hole in frame rails to get the rust penetrating oil tube inserted, for soaking.

Note: the rear spring hanger is wider at the blue arrows, for the AHB (trapezoid) hangers. This rear spring hanger fits FMJ cars only. You can see the difference in width between the straight and your (AHB) bracket.

The aftermarket does make a very stiff (but straight) shackle, as seen in post #33 – but they don’t work on your brackets.

I agree with others; your parts do appear to be rustier than I’d like. I understand the appearance of rust and being rusty are two very different things, so I can’t tell if that will be an issue for you or not (based off picture on post # 30). For what I can see, if the nuts come off, I would say you are fine with your existing shackles.
The rear frame bracket – might a bigger concern.

If both items ae serviceable, I would definitely clean the items and give ‘em a good coat of paint before reinstall.
BudW

Managed to get out and work a bit on this, and put myself in a bit of a dilemma. 3 of the 4 nuts came off of the shackles okay, the 4th ended up snapping the bolt.

So, is there a way I can pull the old "bolt" out and put a new one in? Alternatively, it looks like at most (so far) I'd need is just 1 shackle

Went back out today and managed to see how screwed I really was.

After breaking a shackle stud on the driver's side, i managed to get the shackle off on the passenger's side and realized it's pretty bent up. On top of that, the hangers are worse than I had thought.

That being said, where can I pick up non sway bar hangers? Since they need replaced, I'd might as well go with what's more common.

Also realized how bad I need a cutting tool, as I we get through half of a container of Kroil and nothing budged

..I guess I never updated this when it was finished.

Everything was swapped over and finished mid July last summer-just in time for the rear end to go out in Dads truck. I got one day of driving it before he took it over as his daily while his truck was down and was blown away by how much the suspension/SG/3.55s woke up the car. One thing we didnt give the appropriate attention to was the pinion angle due to the change in suspension geometry. I ended up putting a 6 degree shim in the leaf springs this weekend to correct the driveline shake. The non-HD shackles don't seem to make a difference one way or the other, but we'll see many years down the road if they hold up to the pressure from the sway bar.

Can i ask you where about did you place the shims? Im having a driveline issues after installing 5 leaf springs in my car. Still has the stock iso blocks. Thinking my angle is off. Thanks