22 replies to this topic

[koalasprint]

Hi Folks, I'm trying to get my LX Hatch to handle as well as possible for road use but keeping period correct. Bump steer when cornering hard. On straight roads it has a tendency to pull into wheel ruts. It gets worse at high speed. The car is running standard Torana disc brakes and wheel stud pattern. 15inch wheels with 225 wide tyres.

 

Identifiers on the right hand axle are all on the inside. At the top there are two circles with a C and V inside. Further down there is the part number GM 42926. Next to that there is another circle and the mark is hard to read but looks like NF, then there is a lone 6 next to that.

 

There is only one identifier on the left hand axle and that is on the outside. GM 42927.

 

The car is lowered, probably by swapping springs. My parts book was published in 1976 and it lists the stub axles as 9934548 and 9934547. Visually mine look the same when comparing my stub axles to the pictures of the standard LX axles. Definitely not HZ/A9X.

 

I've been looking at old posts for a few days and found some great stuff. Accolades to ls2lxhatch, rodomo, ozyozyozy, axistr, squarepants and Dr Terry.

 

But I haven't been able to make a positive identification of these stub axles. One thought I have is that the car is an early RTS model(4/77) and GM changed the stub axle part numbers. The parts book was published prior to that so maybe there is a supplement I am missing?

 

 

Does anyone know or have a parts supplement/bulletin, etc?

[Bigfella237]

A quick search located (almost) the same question here:

 

http://www.gmh-toran...130-stub-axles/

 

Except Paul says that he has a pair of "GM 42925/ GM 42926", unfortunately there was no answer there either, at least not that was posted, if Paul is still around maybe PM him and ask?

 

If I had to guess I'd say the part numbers may have changed after the LX Parts Catalog we have, does anyone have a UC catalog?

 

EDIT: Just found the UC stub axle part numbers:

 

92000163 - LH
92000164 - RH

Edited by Bigfella237, 20 September 2016 - 01:15 PM.

[koalasprint]

A quick search located (almost) the same question here:

 

http://www.gmh-toran...130-stub-axles/

 

Except Paul says that he has a pair of "GM 42925/ GM 42926", unfortunately there was no answer there either, at least not that was posted, if Paul is still around maybe PM him and ask?

 

If I had to guess I'd say the part numbers may have changed after the LX Parts Catalog we have, does anyone have a UC catalog?

 

EDIT: Just found the UC stub axle part numbers:

 

92000163 - LH
92000164 - RH

Thanks Andrew, yes I saw that post too. But no definitive answer. I'll try your PM suggestion and post a reply if/when I know more.

[koalasprint]

Hi Folks, I'm trying to get my LX Hatch to handle as well as possible for road use but keeping period correct. Bump steer when cornering hard. On straight roads it has a tendency to pull into wheel ruts. It gets worse at high speed. The car is running standard Torana disc brakes and wheel stud pattern. 15inch wheels with 225 wide tyres.

 

Identifiers on the right hand axle are all on the inside. At the top there are two circles with a C and V inside. Further down there is the part number GM 42926. Next to that there is another circle and the mark is hard to read but looks like NF, then there is a lone 6 next to that.

 

There is only one identifier on the left hand axle and that is on the outside. GM 42927.42925

 

The car is lowered, probably by swapping springs. My parts book was published in 1976 and it lists the stub axles as 9934548 and 9934547. Visually mine look the same when comparing my stub axles to the pictures of the standard LX axles. Definitely not HZ/A9X.

 

I've been looking at old posts for a few days and found some great stuff. Accolades to ls2lxhatch, rodomo, ozyozyozy, axistr, squarepants and Dr Terry.

 

But I haven't been able to make a positive identification of these stub axles. One thought I have is that the car is an early RTS model(4/77) and GM changed the stub axle part numbers. The parts book was published prior to that so maybe there is a supplement I am missing?

 

 

Does anyone know or have a parts supplement/bulletin, etc?

[EunUCh]

Not sure if this is much help?

stripped a 77 hatch a while ago and managed to keep to susp. bits together and the stubs have 42926 & 42927 cast on inside

as mentioned.

As already mentioned about the UC part #'s ending in 163 & 164 respectively but  they are cast into the stub (knuckle) on 

the disc side as HOLDEN 163P & HOLDEN 164P.

 

The LX manual shows the part #'s for these bits in pics below.Location # 2 in first pic , part # in second.....6.020.

 LX1.JPG   206.6K   5 downloads

 LX2.JPG   220.7K   5 downloads

Edited by EunUCh, 20 September 2016 - 05:26 PM.

[S pack]

What discs and calipers are mounted to those stubs?

[EunUCh]

^ me or OPer ?

[S pack]

^ me or OPer ?

OPer

[koalasprint]

Thanks All, I've received a reply from Paul and he never found out what they were from but is pretty dure they are Torana. I have the same PDF manual above but the publish date is over a year before RTS. So I'm still thinking they could be LX and we're missing the parts catalogue suppliment.

 

The brakes are, AFAIK standard Torana calipers, solid 260mm discs. They feel like cast iron to me.

 

Disc Pic

 

Caliper pic

 

Oh and I was correct about the left hand part number. It is definatley GM 42927.

[S pack]

Looking at your pics, they are LH/LX discs and Torana calipers so the stubs are not from any of the big Holdens.

811 & 812 are the LC/LJ stubs so not them.

Sounds like LX RTS may be the one.

[TerrA LX]

What tyres and rim offset are you using?
AND
How is tyre wear?

[Toranamat69]

I have an LX RTS front end I pulled apart a few months back and the stubs have the same markings as the UC ones I have here Holden 163P and 164P.

It was out of a 77 LX - Don't remember the month sorry.

[EunUCh]

According to History of Torana the RTS version of LX appeared in Feb.77.

The picture of stubs are are from  the 77 hatch that was  raped for what was worth raping.

The numbers are on the engine side of stubs (knuckles) with the 2 live center holes visible from when they turned the the things 

into shape.Who knows what they did with part #'s back then ?

 KNLX.JPG   159.5K   4 downloads

 

[koalasprint]

What tyres and rim offset are you using?
AND
How is tyre wear?

Hi Dr Terry, the tyres are 225/60/15. Standard Torana PCD. 15x8" rims. I measured the offset as 10.5cm. (Inside wheel rim to the disco mounting face) The tyres have only done a few thousand K's, so no wear is showing. The previous wheels were 14x8" hot wires. Tyres were 235 for memory. There was some wear on them but for memory no severe patterns. (I was able to sell them second hand to an exhaust mechanic that worked on the car and was building his own Torana)

 

From the post by EunUCh I'd be guessing that GM used these stubs on RTS Torana's until they switched to the version they went onto the UC model. We're getting closer.

[S pack]

Hi Dr Terry, the tyres are 225/60/15. Standard Torana PCD. 15x8" rims. I measured the offset as 10.5cm. (Inside wheel rim to the disco mounting face) The tyres have only done a few thousand K's, so no wear is showing. The previous wheels were 14x8" hot wires. Tyres were 235 for memory. There was some wear on them but for memory no severe patterns. (I was able to sell them second hand to an exhaust mechanic that worked on the car and was building his own Torana)

 

From the post by EunUCh I'd be guessing that GM used these stubs on RTS Torana's until they switched to the version they went onto the UC model. We're getting closer.

Mate, TerrA LX isn't Dr Terry.

[TerrA LX]

Mate, TerrA LX isn't Dr Terry.

Yes, altho I do get called Doctor Terry alot, I am not "the" Dr Terry and I do not have a doctorate .

[TerrA LX]

Just for shits and giggles, borrow beg or steal a set of good wheels/tyres and try them, Also check air pressure, some tread patterns and brands of tyre do some weird things to the front end.
 

[koalasprint]

I've just found another clue to the puzzle. It seems like GMH changed brake calipers in 1976 during the LX model. I found this when looking for brake pads. The LX had two pads and therefore two calipers. DB14, same as LH then went to DB1028. My Torana has the later DB1028 Caliper/pads, so it stands to reason that the stub axle was changed to accomodate a change to brake calipers. But the parts catalogue we have pre-dates the change.

 

https://www.bendix.c...&oepart=&part=#

[yel327]

I was just about to type that when Holden and Statesman changed from cast iron calipers to combination cast/alloy calipers during HX the stub axle part numbers changed so Torana probably does the same thing. I don't think the stub axle itself changes in term of geometry just the machined area where the caliper goes (you'd just have to look at them side by side to know for sure). So in a Holden you have stub axles (ignoring drum brake and cab-chassis versions):

 

HK to mid HX.

Mid HX to WB.

 

You see the same change I think between LH L34 and LX A9X where the LH uses the earlier HK-HJ stub and the LX uses the later HX-WB stub (but the cab-chassis heat treated versions).

 

Just going from memory you probably can use the later stub with the earlier caliper but maybe not the other way around (again check).

 

As for straight line issues, your car may simply be suffering from the same issue HK and early HT had. I know that the initial RTS on LX introduced with LX Sunbird around 11/76 only really had one thing changed in terms of physical suspension geometry, and that was to lower the upper control arm mounting holes by about 25mm or thereabouts. Going back to HK, and when the HT was first released it suffered from the same straight line wandering as you describe (I think only when fitted with radials). Just before HT GTS350 release they raised the upper control arm mounting locations by enough to correct the straight line wandering tendency of the car. So what the early version of LX RTS has may in fact introduce the tendency for the car to what you are describing, and you have amplified it by using wider tyres and wheels, and possibly other suspension settings/parameters associated with lower springs and wheel alignment? Others here better versed in suspension setups might elaborate more. This may well be one of the reasons the revised LX RTS was used for A9X and then on UC where the upper control arm mounts go back to roughly where they were in LH and the upper control arm changed to move the balljoint backwards just like was done to HX mid 1977 ready for HZ RTS.

[koalasprint]

I was just about to type that when Holden and Statesman changed from cast iron calipers to combination cast/alloy calipers during HX the stub axle part numbers changed so Torana probably does the same thing. I don't think the stub axle itself changes in term of geometry just the machined area where the caliper goes (you'd just have to look at them side by side to know for sure). So in a Holden you have stub axles (ignoring drum brake and cab-chassis versions):

 

HK to mid HX.

Mid HX to WB.

 

You see the same change I think between LH L34 and LX A9X where the LH uses the earlier HK-HJ stub and the LX uses the later HX-WB stub (but the cab-chassis heat treated versions).

 

Just going from memory you probably can use the later stub with the earlier caliper but maybe not the other way around (again check).

 

As for straight line issues, your car may simply be suffering from the same issue HK and early HT had. I know that the initial RTS on LX introduced with LX Sunbird around 11/76 only really had one thing changed in terms of physical suspension geometry, and that was to lower the upper control arm mounting holes by about 25mm or thereabouts. Going back to HK, and when the HT was first released it suffered from the same straight line wandering as you describe (I think only when fitted with radials). Just before HT GTS350 release they raised the upper control arm mounting locations by enough to correct the straight line wandering tendency of the car. So what the early version of LX RTS has may in fact introduce the tendency for the car to what you are describing, and you have amplified it by using wider tyres and wheels, and possibly other suspension settings/parameters associated with lower springs and wheel alignment? Others here better versed in suspension setups might elaborate more. This may well be one of the reasons the revised LX RTS was used for A9X and then on UC where the upper control arm mounts go back to roughly where they were in LH and the upper control arm changed to move the balljoint backwards just like was done to HX mid 1977 ready for HZ RTS.

Thanks, yes I suspect that all of what you/re saying is correct. Other Torana guys mention the desire for their cars to track into ruts when fitted with wider tyres. I have found a few worn items that might also be contributing. The anti-sway bar link holes are badly elongated and one of the top shock absorber mount holes. I'm currently welding washers into place to fix that. The steering rack has very slight play in left hand side. So it is off to get a rebuild. I have also noted that the clown who replaced the control arm bushes didn't use a spacer and the arms distorted a little around the bush housing. But this doen't seem to be effecting anything.

[koalasprint]

The mystery is finally solved! Now that the parts supplement from mid 1996 has been unearthed I can confirm that the LX had a change of stub axles.

9934548 & 9934547 were the first stub axles on earlier LX's.

 

9942926 & 9942927 replaced them when RTS came in.

 

It also looks like RTS changed the lower control arms, K frame and steering racks!

 

Here is a link to the supplement, see page 79.

 

https://www.dropbox....lement.pdf?dl=0

 

Cheers, Steve.

Attached Files

•  Capture.PNG   190.96K   6 downloads

[Bigfella237]

I always get a chuckle out of note 108)...

 

One of the biggest manufacturers in the country and the way they determine whether one of their products has a major upgrade or not is to get you to check the badge on the glove box lid!

 

Wouldn't you think they could organise a specific changeover point?

Edited by Bigfella237, 12 January 2019 - 07:10 AM.