wagon leafs

[mike2]

i picked an 1980 aspen wagon 8.25 rear, and took the iso leaf springs as well, can the leafs be used in a coupe to stiffen and raise ride height, or is it just a wash for ride height, and just stiffen springing, 4 leafs with a "W" shaped spring bolted to bottom , should i use the old style shock plates,or work with the iso stuff

 

[F body Deconstructor Jim]

Wagon shoud be 5 leafs. Should be...

 

[mike2]

Maybe these were add on helper springs then. Guess i could bolt the W. springs on volare coupe see what happens.

 

[F body Deconstructor Jim]

I've had 5 wagons, all 76-79's, and every one had 5 segment leaf springs, 8.25 rears and HD finned rear drums.
225, 318 or 360 made no difference.
Springs should bolt on your coupe.

 

[mike2]

Do these leafs look like they are factory setup? I haven't seen a wagon leaf before. Thought these were helper leaf bolted on to bottom of spring. My coupe doesn't have the bottom curvy leaf on it . Thanks for the info. Couldn't find any pics of wagon leafs.

 

[Aspen500]

Yes, those are aftermarket "helper springs" that were added at some point.

Here's what's listed in the '79 parts catalog for springs:
4026817 Model: All Std (4-leaf)
4131332 Model: H,N H.D. Police cars only (5-leaf)
4186001 Model: 22,29,41 H.D. (5-leaf) (coupe and sedan)
4186002 Model:45 H.D. (5-leaf) (wagon)

It appears that coupe, sedan and wagon all came with 4-leaf as standard. Optional was the heavy duty suspension with 5-leafs but different springs in Police cars, coupes and sedans, and then wagons had a different spring again.

Oddly though, if you look at the spring "box" there's 3 different ones.
3815206 for coupe/sedan with std suspension
3815309 for wagon with std AND heavy duty suspension
3815309 for coupe/sedan with H.D. suspension.
Doesn't make sense why the wagon would have the same p/n for both suspensions yet the coupe and sedan have 2 different parts. Hmmmmmmmmm. Guess it possible it's an error in the catalog(?)

 

[BudW]

For "most years" All station wagons, Police cars and cars with “some” towing packages are supposed to come with 5-leaf rear springs.
Some exceptions exist – either by accident or by part shortage at the time of build.

I only count 4-leaves, plus an aftermarket helper spring, on yours.

The aftermarket helper spring can be unbolted and reused on your existing car – if U-bolts are still good. Personally, I wouldn’t re-use the U-bolts – for too much is riding on them (literally).

5-leaf springs also have a different lower Iso-Clamp part – to accommodate the taller spring.


These pictures were taken from my ‘77 Wagon (with 41k miles) earlier this evening. The pictures were taken from right rear corner of car, first picture from ahead of R/R tire and remaining pictures taken from behind the R/R tire.

I modified one of your pictures. The lower half of the Iso-Clamp is a (no, the) weak link on our cars, The yellow line shows you the warpage you have on your existing lower clamp and the blue circle shows where bolt holes tear out on. The red arrow shows where the lower clamp is different between 4-leaf and 5-leaf springs. Other than the spring and that lower clamp (U-shaped part) – there is no other difference between the 4 to 5-leaf spring setups.

Personally, I would get either get some older shock plates or aftermarket shock plates and do away with those Iso-clamps.
Doing so will raise rear of car about ½”, you will be rid of that problem area, it will be stronger and car will ride much better.

Either way, you can use that helper spring – if wanted.

If it was my car, I would remove your old differential with both (old) leaf springs and tires still attached to it. Roll old differential out from under your car. Then roll new differential back under car with springs attached (but not tight). So much easier and faster than other methods I have done.
Also, I would get one (of the two sets) set of springs re-arched, before hand and not mess with the helper springs.

Note: the driveshaft is shorter – if you are planning on replacing your existing 7¼” differential with the 8¼” version.
Also, you might have a gear ratio difference between new and old differential – so speedometer gear might be different,

If still available, I would grab the speedometer gear and driveshaft from that donor wagon, if at all possible.
BudW

 

[mike2]

thanks Bud, Aspen500, i was unsure of leafs at the yard when taking the rear out, and decided to take them , $50 mistake but now i know,the drive shaft was bent ,8.25 is good so $70 spent right , i am going to get 8.75 shock plates and bolts , grab a dakota rear with a sure gripp 355 gear and rebuild rear, did this on an A body before, will the big holes on the 8.25 spring perch be a problem with shock plates ? just checking before i make another purchase, Thanks a lot for all the help ,very much appreciated, pictures were great for understanding differences of leafs

 

[mike2]

Anybody need some 4 leaf wagon springs , with helper springs lol

 

[Aspen500]

If you go to regular springs without iso-clamp, you need to make the holes in the spring perches that are welded to the axle housing smaller, so the centering bolts fit tight.
I've still got iso-clamps and used poly insulators (have an 8.75" rear). With a 500" big block, there is no wheel hop or other problems. What I mean is, the iso-clamp isn't really that terrible, it's mainly the stock mushy rubber insulators.(JMO).

 

[F body Deconstructor Jim]

Oddly though, if you look at the spring "box" there's 3 different ones.
3815206 for coupe/sedan with std suspension
3815309 for wagon with std AND heavy duty suspension
3815309 for coupe/sedan with H.D. suspension.
Doesn't make sense why the wagon would have the same p/n for both suspensions yet the coupe and sedan have 2 different parts. Hmmmmmmmmm. Guess it possible it's an error in the catalog(?)

The difference in the "spring box" is to accomodate the extra leaf that all wagons had, as well as the HD coupe/sedan had.
The five leaf box is one leaf thickness deeper than the 4 leaf box. About 1/4".
I'd be willing to bet good money you couldnt get the HD suspension with the 7.25 rear end.

 

[BudW]

$70 for an 8¼” – outstanding job!
The last one I bought, was 3 times that amount.

Salvage yards love to “kill” driveshafts – and I don’t know why. It is not necessary.
You can take existing driveshaft to driveshaft shop and get 1.6 inch removed and it should work fine – other than it's one more thing to do.

There is rumor that some years Dakota rear leaf springs will fit FMJ’s – but I don’t have any measurements to know for sure – but getting one set of yours re-arched will do the trick.
That way, when you remove old differential, you could leave leaf springs attached to it


I agree with Aspen500 about the poly inserts – but the weak link is still the part in my picture (above) – so ride will be improved – but I still don’t trust the lower Iso-Clamp shell (seen too many of them fail/break).

Note: Dakota differentials are mounted underneath the leaf springs, not on top of the leaf springs – so Dakota/Pickup/Van spring plates will not work – made way different.


The big hole can be filled in with a steel washer – that can be found in the same diameter as the hole (which is 1-9/16”). Two different methods to do it. One is to weld the washer onto the differential perch. Others have reported to finding large shoulder nuts from salvage yard that fit fine, instead of washers.
The other method – (which only works if re-arching your leaf springs) is to place the washer on top of leaf spring when installing the new spring center bolt.

BudW

 

[Aspen500]

Not meaning to contradict you Bud but, here's a pic of the axle in my '96 Dakota (4x2) and it's on top of the spring like a car. Never paid any attention if 4x4 is under the spring or not OR '97 and newer.

On the Aspen, I have hardened washers under the u-bolt nuts to spread the load on the spring box, plus I started with rust free desert pieces. Even the original rusted ones showed no sign of impending failure. However, now that I know they do fail, I'll be sure to have a look at them every so often,,,,,,,,,,,,,,,,just in case.

 

[BudW]

Aspen500, we both are correct on the Dakota’s (yes, I’m somewhat wrong)

In these parts, there are not many 2*4 versions out there.

All of the ones I remember working on are 4*4 versions – which do have the differential mounting under the rear leaf springs.
I don’t think I have even been underneath a 2*4 version before – so I looked it up and it looks just your picture (above).

'94-96 2x4 version

'94-96 4x4 version

The shock plates (2*4 and 4*4 versions) are (still) not compatible (without a lot of modification) with FMJ’s

BudW

Edit:
If you notice in the pictures, the rear spring hanger is different (I just now noticed it).
The shackle is mounted the opposite direction, as well.

Why go through so much trouble for the same truck – but between 2*4 and 4*4?

 

[Aspen500]

Ride height. 4x2 sits quite a bit lower than 4x4 and, there are very few 2 wheel drive trucks around here also.