Replacing SFA front leaf springs

[niclemaitre]

Hi there

I'm going to be replacing my front leaf springs with new Mikem springs very soon. How does one make sure that the axle alignment stays the same? Is there some kind of locator for the spring?

[Mud Dog]

There is a locating "pin" on the leaf pack and a locating hole on the axle pedestal. Alignment should not be affected at all.

If you are changing shocks and the new ones extend further than the old ones, just make sure that the flexible brake lines are long enough to handle the extra extension. You nay have a little difficulty getting the torque rod bolts to locate after fitting the new spring packs, but altering the axle extension with the use of a jack should help - otherwise use a large crowbar to carefully "wrap" (twist) the axle a little to achieve location of the bolts.

Check the condition of your hangar pins and bushes as well as your shackle pins and bushes. Some pitting on the pins is still acceptable, but if the diameter has been worn they need to be replaced.

[The Legend]

Nic I replace my front and rear leaf springs with Mikem about 5 years ago and still very happy with it.Replace your shackles with grease able ones.

[niclemaitre]

It's a full replacement, springs, pins, bushes, the works. I just have to see if I can find some new torque rod bushes.

[The Legend]

Nic you will not believe the difference. Your bakkie will drive softer.

[Oppies3800]

Nic, speak to Segal in Stellenbosch. 082 064 8373

He replaced my SFA's old suspension and should be able to assist you.

[niclemaitre]

So we've hit a snag. The springs, bushes, shackles and pins all arrived on Friday and I fitted them with the help of some mates.

However, the springs are too short, too curved or a combination of both and now the bakkie has a definite monster truck attitude in front and a hang-gat at the back...

The steering rod contacts the U-bolt on the spring:



The shock absorber is at least 100-130mm too short:


The splines on the prop shaft are exposed and there is minimal amount of engagement:


The spring hanger has forward rake, rather than the expected rearward rake:


The torque rod is miles too short and the entire axle is tilted so that the spring pedestals are not horizontal.

So I called Darrel yesterday, and he's not sure what's going on either. Either my bakkie has had some kind of modification before I bought it (but the sheer amount of effort required to move the spring mounting points would be insane!) or something else is going on. Currently the plan is to remove the new springs and send one of the old springs (OME Dakar apparently) along with them, back to Darrel so he can have one made up to fit.

If anyone has a similar era SFA with the import front axle can you take some comparative measurements for me please so I can see if mine has been modded? With the new springs mounted things are as follows:

1110mm from the center of the front hanger to a vertical line drawn from the center of the rear hanger mounting point on the chassis
1095mm from eye to eye on the spring
300mm from the top of the spring pedestal on the axle to the bump stop plate on the chassis.
6x6mm blades

The old springs are 5 blades, total thickness 34mm (OME Dakar apparently according to the previous owner.)

1125mm from eye to eye on the spring
With the pack inverted a flat surface, it is approx 170mm (if I recall correctly, didn't write that one down) from the bottom of the pack to the ground.

I'd really like to get to the bottom of this so I can have a drive-able bakkie again!

[Mud Dog]

Hi Nick, a couple of things that I notice.

"However, the springs are too short, too curved or a combination of both and now the bakkie has a definite monster truck attitude in front and a hang-gat at the back..."

This is totally expected. The old springs have sagged over time and the OME units add some ride height above standard, so the front now standing high without the rear being done at the same time, is a given expectation. With the old units having flattened out and the new ones with additional curvature, the difference in straight line distance between the bush eyes of old against new will certainly be more on the old units. If however you measured that distance along the respective curvatures, you would find them to be similar.
I have to wonder why there are so many leaves in those packs - that's for super heavy applications like a heavy after market bumper with winch and diesel motor (cast iron block). It's definitely too hard for your application.
While addressing this aspect of your observations, the rake of the shackle will definitely be more forward with the new units. This is as it should be. The only time this can be a problem is if the shackle (on full extension) gets to the point where it is so close to being in line with the spring that it can invert. Your pics show that the shackles are far from this being able to happen.

"The steering rod contacts the U-bolt on the spring"

This often happens when there are extra leaves in the spring pack. One of the U-bolts supplied should have a small cut-away on the corner and that U-bolt is intended to be fitted where the drag-links otherwise fouls (RHS rear).

"The splines on the prop shaft are exposed and there is minimal amount of engagement"

This is a matter of concern and should not be. Possible reasons for this is that the lift is too high (those extra leaves in the packs could be a contributing factor), a motor / gearbox conversion that has resulted in the X-fer box being positioned further back than standard or that the axle has been shifted forward - the fact that your torque rod is now short and from what I can see on your pics, leads me to think that an axle shift has not been done. With no engine conversion, it leaves the possibility of too much lift.

I would start by removing two blades from each pack - probably the bottom two, but Darrel can advise better on this. Torque rods sometime have to be lengthened with suspension lifts, and this might still become necessary in your case.

Good luck, hope you get sorted.

[niclemaitre]

I have to wonder why there are so many leaves in those packs - that's for super heavy applications like a heavy after market bumper with winch and diesel motor (cast iron block). It's definitely too hard for your application.

Darrel says 6 leaves is standard. It does seem far too hard to me too. With my friend and I (~160kgs) bouncing on the bullbar the leaves hardly compress

"The steering rod contacts the U-bolt on the spring"
This often happens when there are extra leaves in the spring pack. One of the U-bolts supplied should have a small cut-away on the corner and that U-bolt is intended to be fitted where the drag-links otherwise fouls (RHS rear).

There is a unique, thinner profile U-bolt supplied and fitted in the correct position (rear U, driver's side). Still makes contact for any amount of right turn

"The splines on the prop shaft are exposed and there is minimal amount of engagement"

This is a matter of concern and should not be. Possible reasons for this is that the lift is too high (those extra leaves in the packs could be a contributing factor), a motor / gearbox conversion that has resulted in the X-fer box being positioned further back than standard or that the axle has been shifted forward - the fact that your torque rod is now short and from what I can see on your pics, leads me to think that an axle shift has not been done. With no engine conversion, it leaves the possibility of too much lift.

I am worried that the prop shaft will in fact either strip or fail to engage. As far as I know, the bakkie is stock, the only mods are an engine replacement and the replacement of the original springs by the previous owner with OME units that I am now trying to replace. The axle has not been moved as I replaced the original drag link with a stock part. The torque rod is also stock. I've also replaced the previous front prop with a stock unit.

I would start by removing two blades from each pack - probably the bottom two, but Darrel can advise better on this. Torque rods sometime have to be lengthened with suspension lifts, and this might still become necessary in your case.

I'll call him in a bit and see what he's got to say.

[niclemaitre]

So I'm going to send my one of my old springs to Darrel and he'll have two made up to fit

[LouisZ]

Those look if they a bit too short. The shackle position is not right. Ask Darrell for the flat u Bolt in the back that the rod can move past.

[niclemaitre]

Those look if they a bit too short. The shackle position is not right. Ask Darrell for the flat u Bolt in the back that the rod can move past.

We all agree totally! I have a flatter U-bolt in the correct position already but the angle that the drag link is forced to adopt because of the shortness of the springs is so steep that it still fouls the flatter U-bolt

[Mud Dog]

The more I look at the pics of those springs, the more I'm wondering if they're not intended for the back rather than the front.

Those blades are very thick and I don't believe that six blades are standard - the original OEM packs on petrol motor models only had four, and thinner gauge than these. The diesel version may have had a slightly thicker gauge or an extra blade, but these look far too heavy to me.

The thickness of that pack is probably why the drag-link is fouling on the u-bolt.

[niclemaitre]

The more I look at the pics of those springs, the more I'm wondering if they're not intended for the back rather than the front.

Those blades are very thick and I don't believe that six blades are standard - the original OEM packs on petrol motor models only had four, and thinner gauge than these. The diesel version may have had a slightly thicker gauge or an extra blade, but these look far too heavy to me.

The thickness of that pack is probably why the drag-link is fouling on the u-bolt.

You and me both. The curvature suggests that as well.

This bakkie was petrol, then converted to diesel by a previous owner. The front leaves I removed had 5 blades for a total thickness of 34mm, the Mikem ones are 6 blades and 36mm total

[niclemaitre]

I'm pretty certain that my bakkie is fairly stock, but I'd like to confirm that. The only feasible mod that would have created this problem is moving the front spring attachment point forward. Can someone please measure from either the rear edge of the front spring mount to the front edge of the bumpstop plate on the chassis in either a direct line (1) or the horizontal distance to a plum line from the front edge of the bumpstop plate (2)?



Also while I'm certain "they" wouldn't have moved the rear spring mount, can someone please confirm that it is positioned in between the two gussets of the body mounting bracket roughly level with the bottom of the A-pillar?

[LouisZ]

Dont move the spring mounts forward. Your Hilux is std.

Those blades should measure about 1100mm in lenght in the front if my memory serve me correct. Looks if you have the rear blades there.

[Mud Dog]

I very much doubt that the rear has been moved - there's no feasible reason on a standard vehicle that I can think of that would provide any benefit.

From your pics I can see that the spring hanger and shackle mounting positions are standard. Shifting the axle forward is done by drilling an additional hole on each of the pedestals (on the axle housing) where the location bolt-end (on the leaf pack) locates. If there was only one hole on each pedestal, yours has not been modified.

I am still suspiciously of the opinion that you have rear leaf packs.

[niclemaitre]

My axle looks exactly like this one:
.

One hole in the driver's side saddle, and three in the passenger side saddle, with the two outer holes being much smaller than the center hole.

Darrel doesn't seem to think that they are rear leaves, I'm not so certain.

[The Legend]

Nic my front Mikem springs measure 1140mm from the grease nipple on to the rear shackle to the grease nipple on the front shackle in a straight line

[Mud Dog]

OK, so there's no axle shift that's been done. Now the big question is why the prop-shaft is extended so far. I lifted both my SFA suspensions (one was OME) and I never had the splines showing.

The torque rod can sometimes be a bugger to re-fit after a suspension change, but with a little help from a jack on the axle, it fits back into place. Something strange going on there.

Dawie. that distance will change as the spring deflects (if you're measuring to the lower shackle pin). However if you look at Dawie's leaves, they look to be of quite a bit thinner gauge than those in your pics.

[niclemaitre]

It's extended so far because of the steep curvature of the springs and their (related) shortness. This pushes the axle lower, increasing the distance between the diff and the transfer case.

I'm very close to removing them, sending them back for a full refund and getting springs from Johan Tyre just down the road, even if he is 4k more expensive

[niclemaitre]

@Dawie, thanks for checking that for me. Your rear shackle on the front spring, is it raked towards the front of the vehicle or towards the rear?

[The Legend]

It is raked towards the rear of the vehicle.My propshaft extended only with 15mm with the Mikem suspensie but I have a suspension lift of 50mm overall towards the old suspensie

[niclemaitre]

So I have to eat MUCH humble pie.

They are the correct springs, we just made a mistake when fitting them:
We fitted the springs to the chassis, torqued the bolts to Toyota spec (90Nm) and then fitted the axle to the springs. What we didn't realise is that you should only torque the bolts once there is load on the springs and not before...
The bolts were so tight, they compressed the bushings until the pins couldn't swivel at all, which is why the springs refused to settle into their proper shape.

I undid everything and then refitted them with the pins just a bit tight and now everything fits. I'll call Darrel on Monday and apologise and get his torque spec for the bolts.

[Froll]

Glad you got it sorted.

[Mud Dog]

These things happen from time to time.

[ismail]

Good to hear. Don't Friday night I removed a egr valve which I calculated 30 min to remove and replace. Dam thing took 3 hrs. ......

[niclemaitre]

I do feel like a total chop though!