What is the correct number of leafs for the rear springs on a v8 10 bolt diff. The original springs in the car sagged and remember sending them away to be "reset" as well as adding an extra leaf added. Now not sure if this leaf replaced an original leaf or is four leaves standard? No sign of any wear marks on the main leaf from the insulators (as seen on the other original leafs). There is about 10 mm of thread visible on the centre bolt with the four leafs assembled. Phots attached - Will try again later
Also wondering if the spring insulators for these springs are common to all HK - HT - HG, or is there only one kit available anyway?

Edited by user Monday, 20 July 2015 8:57:36 AM(UTC)  | Reason: Not specified

Good memory Byron.
The standard rear spring assembly for all HK GTS, 6 and V8 and shared with all V8 manual HT GTS is 7449998.
It is 4 leaf. The upper 2 leaves are about 8.9mm thick and the lower two about 6.9mm thick. The total compressed spring stack at the centre bolt is about 31.4mm thick.
The round plastic liners are the same for all springs and are 7429208. The Rare Spares ones are very close to original.

There are of two types of spring to spring pad insulators , a thicker one for 4 leaf springs and one thinner type.
The one for 4 leaf springs is 7427212, is about 18mm thick overall, and 15.3mm thick to the main compression face.

Byron, I was hoping you wouldn't ask that, as HT is far more complicated!

-The HT GTS350 manual, 81837, and the HT GTS V8 manual, 80837, use the 7449998 4 leaf spring with a 1" front eye.

-The HT GTS 6 cylinder models, 80737, all use the 2808059 spring which is 4 leaf, exactly the same rates, spring arch and thicknesses as the 80837/81837 manual spring, but with a 2" front eye. The bottom 3 leaves of this spring are identical to those of the 80837/81837 manual spring. The top leaf differs due to the larger spring eye.

-The HT GTS350 Auto 81837, and HT GTS V8 auto, 80837, use a 3 leaf spring, 2808063, with a 2" front eye. This same spring is used on all base model 80337 and 80437 Monaros, as well as most of the sedans, and shares nothing with the two 4 leaf springs mentioned above.
There was also a 4 leaf heavy duty version of the 2808063 (the 2808064), but none of its leaves are shared with any other spring.

The HT GTS manual springs should be quite distinctive, as they have the highest spring arch (camber height) of any of the springs used on HT, so that alone should help identify them.

Gerard, the measurements I provided for the 7427212 are from a set of NOS GMH insulators I have. I have a few used ones too, and they are about the same as yours.

I don't speak for Rare Spares, but they do have the SPK5 set of rubbers, which have part number 7427212 moulded into them and they list them as suitable for everything except ute and van. I agree with that part number for those applications.

The Rare Spares part SPK6 is moulded with part number 2805573, which is the thinner insulator and the correct part for Ute and panel van.

There are two sizes of radius rod rubbers, 1" and 1-1/4". These two sizes were used on HT.
For the 1" type the rubber bush part number is 7410362, which is readily available as the step bush for up to HD shock absorbers. It is also similar to the stabiliser bar end bushing.
Your HK should have the 1-1/4" type, which is 7437489.
Mackay rubber make an identical part as their number A1169, also sold as a top shock absorber rubber. You can get them from Blackwoods, Total Fasteners or from Ebay.

As a quid pro quo, I'm interested in a couple of things on your car:

1/ What thickness is the spacer plate between the upper and lower spring plates?
2/ What is the length and type of the bolts which pass through the spring plates, the spacer, the radius rod and its spacer?

I'm interested to know if it is an Ajax SAE Grade 5 bolt (3 lines), or a plain Jane type, and what its length is under the head.
(The reason for this question is that I've seen a few cars now where this bolt is an Ajax Grade nothing bolt, and has been stretched beyond its elastic limit when torqued to the numbers in the Shop manual. - I believe this may have been a manufacturing defect. And I bet Byron jumps in here and says they must have all been Dandenong cars.)

Thanks Gerard.
The shorter bolts on mine are 3 line Nettlefolds ("N" head) and the longer ones are Ajax Grade nothing. I've seen the same on some other cars.

The spacers can be confusing. The rectangular spacers, with a notch in one corner are 7427210, and are 0.180" (4.57mm) thick.
There are several different thicknesses available, depending on the insulator pad used and the spring stack thickness.
80837 and 81837 manual are specified as using 2 per spring. These go between the spring clamp plates.

The radius rod bracket spacers are also confusing. The isometric assembly drawing in the parts manuals, both HK and HT, show 1 spacer, and the position is not all that clear. The spacer appears to be quite thick, with rounded ends. The same picture appears in the HK Monaro + Brougham supplement.
The parts books specify 4 of these spacers, and that's what the cars end up with.
I think what probably happened was that the part was originally designed and drawn as 1/2" (12.7 mm) thick, and when it went into production it became apparent that it could not be punched and needed to me machined, which would have made it expensive. At some point it seems to have been replaced by two punched 1/4" (6.35mm) spacers, part no 7448372, and these are stacked to produce the necessary spacing between the radius rod diff bracket and the lower spring clamp plate.
The photo below shows what I believe to be the correct assembly.


[/URL]

Edited by user Sunday, 26 July 2015 8:37:14 AM(UTC)  | Reason: Not specified

Geoff, checked the thicknesses of the tramp rod spacers (round end pieces) they are 6.5 mm each, not 4.5mm as I posted before and the rectangular spacers are 4.5mm each as per your details. Thanks for the photo of the complete assembly.
You also mentioned that there are short bolts on this assembly on your car, I am missing two bolts washers and nuts, but the other 6 I have are all identical and the length as noted before. Any thoughts on whether I should be looking for 2 short bolts for a HK and if so what length would they be? Thanks Gerard

quote:

---

Originally posted by gm5735
Provided it's in good condition, I would personally rather use an original Ajax, Nettlefolds, Spurway, or FGS bolt in preference to a brand new threaded cheese bolt that comes from a certain country to our North and purports to be a quality fastener.

---

How true ! How many pieces of an old Holden could that be applied to.

Dr Terry

Just about everything Terry, in my opinion. It's often harder and requires
more skill, tools and time to refurbish old parts but, done correctly, I reckon the
end result is mostly better. The temptation for a quick fix and a nice shiny new thing is often overwhelming. In the case of threaded fasteners, by the time you find the right ones, clean them, strip the old plating, replate them and bake them out after plating there is a lot of time invested. Personally, I find the result more satisfying, the car more like it was built and the lack of concerns about fastener failure make it worthwhile.
Have a look at some of the reproduction fender washers for example - they look, feel and are thin, cheap, nasty and bend when used. GMH used 15 gauge for a reason, and not 1.5mm. Such a visible thing, and so easy to get right.

Gerard, I seem to remember your car was used for towing a van by the previous owner. Are they helper springs that were fitted? That may explain the bolts, which look more like upper control arm pivot pin retaining bolts. The nuts look correct. You said you only had 6 sets - did a couple break when you removed them? Those bolts have a high torque spec, which is why they have the heavy nuts and why I will not use junk bolts in that application. (or any other application..)
Also, the spring stack centre bolt seems to have a lot of excess thread. You might want consider if that will chew up the insulator pads.

Gerard, as requested.

I had the ute leaf springs fitted to my HG Premier, as the reason why, the dude before towed a van he said.
I always thought it fine handling in the rear for a leaf sprung car, much better than any Falcon up to XD by far. not to mention the HQ-WB leaf was a good set up as well.

I am interested in the geometry of the leaf springs, the Falcon ute and p van rear end behaves much better than the sedan and the wagon Fairlane LTD are totally hopeless coming into big sweepers hard around say 180KM/H as the springs flex to much side to side allowing the diff housing to move about to much. this Is one thing I look at and the Falcon spring has to much of a bend in it, as the Holden is more flat.

The front of the spring to the diff is interesting to me, I don't remember what the difference is between the 1 inch and the 2 inch in how it looks, but there must be a good reason for it.

I Remember the HQ WB rear spring has a thick spring running past the rear axel with a U shape bracket right at the rear that acts like a anti twist that holds the axel housing more solid I believe.