Shackle question

[enovey]

Can someone tell me if the front and rear spring shackles for a 109" are longer than an 88"?
Thanks in advance
Ernie

[greenmeanie]

From the parts book the answer is they are the same for both trucks. Some things to note, however, are:
1. There are two different shackle bolt sizes. 1/2 BSF for suffix A and then 9/16 UNF for Suffix B on.

2. If you have an Ex MOD 109 then it will have come with the extended military shackles. You can identify these easily by looking for a bolt mounted midway down that holds the two halves together. THese may have been used on 1 tonnes too.

Some people have retrofittted the military shackles to civilian trucks but thta oipens a whole other can of worms.

Cheers
Gregor

[enovey]

Thanks for the info. Please explain some potentials from opening up the military shackle can of worms.

[daveb]

rear is easy and no problem. in the front though it causes increased propshaft angles and the driveshaft starts hitting the frame.

Thanks for the info. Please explain some potentials from opening up the military shackle can of worms.

[siiirhd88]

The rear shackles on my 109 three door are about 1/2 inch longer than on my 88. The 109 shackle is still shorter than the military shackle. I ended up using a shorter 88 shackle on one side on my 109 to help eliminate some parabolic "lean".

Bob
'96 Disco SE7
'80 SIII 109
'75 SIII 88 V8
'68 SIIA 109 V8
'6? SIIA 109

[TeriAnn]

rear is easy and no problem. in the front though it causes increased propshaft angles and the driveshaft starts hitting the frame.

It can also cause U joint binding at full down articulation and changes the king pin angle.

I have extended shackles, a custom front prop shaft with high angle yolks (and longer slip joint), a divot cut out of the top front of the under bulkhead cross member directly below the front prop shaft, and a 6 degree wedge located between the leaf spring and axle to correct the king pin angle.

[greenmeanie]

TeriAnn,
AS a matter of interest where did you get the wedges? The rest is all fairly standard and I'm actually at a stage of having my 109 project stripped that it makes sense to add the divot to the cross member just incase. The only thing I have never seen for sale is the wedge.

Cheers
Gregor

[meatblanket]

The best degree shims are made of steel. Avoid the aluminum ones.

www.bluetorchfab.com

I used a 4 degree shim and found that it was too much (caused the steering to wander quite a bit) so I am using a 2.5 degree shim. I have no issues with the driveshaft, but that is likely because my RM parabolic springs had nearly sagged flat before I installed the military shackles.

[TeriAnn]

TeriAnn,
AS a matter of interest where did you get the wedges? The rest is all fairly standard and I'm actually at a stage of having my 109 project stripped that it makes sense to add the divot to the cross member just incase. The only thing I have never seen for sale is the wedge.

I picked them up at a chain 4X4 store. I don't remember the name. After I installed the shims & installed all new tie rod ends, I had the steering professionally aligned. The alignment specs of a Series rig are tighter than those of most modern cars. The shimmed steering was adjusted to within one half of one degree of the factory manual spec using a laser alignment set up.

So a 6 degree wedge is really close for compensating for military shackles on a civilian frame and LR semi elliptical springs.