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4 Link Suspension for a LJ


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#1 Ricky Bobby

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Posted 16 November 2023 - 10:34 AM

Hi everyone, my LJ has been mini tubed to suit 245 tyres. I'm looking for help and advice on installing a 4 link suspension kit. Is there a kit that has an engineering certificate? What would be the best diff (standard length). I will be running a 202 and a 5 speed top loader. I'm in the early stages of the build, so i'm putting together a wish list. Thanks

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Edited by Ricky Bobby, 16 November 2023 - 10:38 AM.


#2 Dr Terry

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Posted 17 November 2023 - 08:17 AM

5-speed Top Loader ??

 

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#3 claysummers

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Posted 17 November 2023 - 10:53 AM

Pardon my higgorance, but isn’t the factory setup a four link?


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#4 yel327

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Posted 17 November 2023 - 11:31 AM

If you are just fitting a 202 then the banjo you have with a Trutrac centre and better axles might last OK on the street. Will save a few $. Another diff that works but aren't as easy to get hold of today is a HQ-WB Salisbury diff shortened to LJ width. You can get 1-tonner axles resplined to LJ length. This would allow you to run 4.75" PCD and HQ-WB rear drums, then upgrade the fronts to larger rotors with the same stud pattern. Or go the whole hog to a 9" but might be overkill in such a light car with only a 202. Lots of people seem to go for Borg Warner rear ends too and will be easier to get hold of gears and centres



#5 Ricky Bobby

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Posted 17 November 2023 - 01:29 PM

Pardon my higgorance, but isn’t the factory setup a four link?


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Hi mate yes it is. The rear shock absorber points are mounted too far into the rim to be able to use this set up. I need to bring the shocks mounting points in. The "drag car" 4 link set up would allow this to happen, then I could use coil overs ect...



5-speed Top Loader ??

 

Dr Terry

I'm referring to a no linkage gear box, maybe a Supra 5 speed



#6 Ricky Bobby

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Posted 17 November 2023 - 01:37 PM

If you are just fitting a 202 then the banjo you have with a Trutrac centre and better axles might last OK on the street. Will save a few $. Another diff that works but aren't as easy to get hold of today is a HQ-WB Salisbury diff shortened to LJ width. You can get 1-tonner axles resplined to LJ length. This would allow you to run 4.75" PCD and HQ-WB rear drums, then upgrade the fronts to larger rotors with the same stud pattern. Or go the whole hog to a 9" but might be overkill in such a light car with only a 202. Lots of people seem to go for Borg Warner rear ends too and will be easier to get hold of gears and centres

Hi yel327, The car is set up with HQ front rotors and the diff in the pic has the fine spline HQ axles, so as you say get a Trutrack centre and I'm good. I just wasn't sure a banjo would be strong enough. I'm guessing I will have about 150 - 200 kw in the end



#7 yel327

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Posted 17 November 2023 - 01:52 PM

You can buy 28 spline axles for an LJ and a 28 spline Trutrac, but you can also get a 23 spline Trutrac to suit your axles.

 

In the end its a 202. kW doesn't matter anywhere near as much as torque - its torque that kills gearboxes and diffs not power. Torque and vehicle weight are the triggers in GM vehicles to step up in transmission and rear axle strength. It's why any V8 HQ-WB has a large Salisbury, whereas no Torana ever got one except for LX optioned with A9X and that was only for racing durability so the rear axle could be used in race cars. It is also why 4.2L Commodore got the "banjo" salisbury rather than the large salisbury like a Holden or Statesman did.

 

You will still be able to kill a banjo with a 202, just not as easily as you will with a V8. Trutrac will fix your centre issues, but won't make the gears any stronger so with abuse you can break them. Maybe then think about a diff upgrade.



#8 claysummers

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Posted 17 November 2023 - 02:47 PM

You don’t want to do all the work converting a bango only to blow it up I dare say. Just in-boarding the lower shocker perches wouldn’t require too much effort. Then if you blow it you can do the 4 link kit on a shortened Borg Warner.


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#9 Bruiser

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Posted 17 November 2023 - 04:02 PM

Wouldn’t the cost of a trutrac diff centre go a fair way towards having some other diff modded to suit anyway?

#10 gtrboyy

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Posted 17 November 2023 - 05:38 PM

If cant move shocker over enough to clear tyre then move it to inside of rail...I'd avoid coilovers as they take up decent amount of room also factory set is not that bad with some tweaking & more rego friendly.

 

Go adjustable tubular control arms to correct pinion angle...plenty of shops advertise on facebook.

 

You sure wont need to move diff to centre wheel in wheelarch for better tyre clearance?



#11 RallyRed

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Posted 17 November 2023 - 07:04 PM

Not sure about 245's, but some people have success by just cutting the top cover off the shocks and leaving them where they are. Just sayin'.

Edited by RallyRed, 17 November 2023 - 07:04 PM.


#12 Ricky Bobby

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Posted 17 November 2023 - 09:20 PM

If cant move shocker over enough to clear tyre then move it to inside of rail...I'd avoid coilovers as they take up decent amount of room also factory set is not that bad with some tweaking & more rego friendly.

 

Go adjustable tubular control arms to correct pinion angle...plenty of shops advertise on facebook.

 

You sure wont need to move diff to centre wheel in wheelarch for better tyre clearance?

I would like to move the diff forward to center the wheel in the arch for sure, I have seen pics of the 4 link set up where the coil overs are in the boot area mounted to a cross bar that spans the two wheel arches. The boot area is going to be busy anyway with the battery and spare wheel so I don't mind using the space.



#13 Ricky Bobby

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Posted 17 November 2023 - 09:33 PM

You don’t want to do all the work converting a bango only to blow it up I dare say. Just in-boarding the lower shocker perches wouldn’t require too much effort. Then if you blow it you can do the 4 link kit on a shortened Borg Warner.


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I'm heading towards the Borg Warner diff maybe a VL 28 spline, they have a 3.08 and 3.45 ratios. As I'll need new mounting points, I like the 4-link plan.



#14 skap

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Posted 18 November 2023 - 07:48 AM

Shorten the diff for sure. Why add tubs and then not maximise the dish available on the rear wheels?

Change stud pattern to chev while your at it so you have a decent wheel choice :)

Edit: just realised posts are still out of order… come on this can’t that hard to rectify ;)

Edited by skap, 18 November 2023 - 07:49 AM.





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