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Banjo TrueTrac

Started by _74LH_ , Apr 19 2020 11:20 AM

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#26 _74LH_

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Posted 06 July 2020 - 05:11 PM

Thought I would revisit this one to see what everyone's opinion is, if I were to go away from banjo and trutrac (which I am considering given the doubts I have about the crown and pin wheel durability) what would be the best solution into my LH?

Engine is 355 into built trimatic (somewhere around 450hp according to engine builder) so needs to be able to handle that kind of output. I want ratio around 3.08 or similar, LSD, and to retain the current wheels I have (which are torana pattern) brakes I'm not too fussed on.

 

Which way would you all go? 


#27 Ando

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Posted 06 July 2020 - 06:31 PM

Danial, a Borg Warner is probably your best bet if you don't want to go with a 9 inch with your 450 hp output. I have heard of the modified Banjo behind power outputs similar to yours but I reckon you would have to use a sympathetic style of driving for feeding the power on.

 

I just bought the Banjo Truetrac & 28 spline axles from SCW. It's for my 308 trimatic ss hatch. The motor should potentially produce 300-320 hp so the bango diff wont be a problem for my cruiser style driving with this car.

 

My other car, I went with the Truetrac 31 spline 9 inch to handle the 530 hp stroked 308 manual TKO 600. I thought the Borg Warner might of been pushed to it's limit if I gave it a boot-full.

 

Cheers 


#28 yel327

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Posted 06 July 2020 - 06:41 PM

9”, 3.25 gears, Tru trac, 28 or 31 spline axles and HQ-WB backing plates. Just buy new drums and redrill them for your 4.25” PCD. You could use HK-HG backing plates but new drums are scarce, they are the same drums as HQ-WB just with smaller centre bore and different stud pattern. Will be as cheap as most other options using new parts.
The only killer might be the centre bore size on your wheels.

#29 warrenm

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Posted 07 July 2020 - 07:25 AM

BorgWarner they are lighter than a 9".


#30 _74LH_

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Posted 11 July 2020 - 06:13 AM

So I reckon from the research I've done, a r31 skyline diff will be the way to go.
Do have another question out of ignorance (mainly because clearly diffs aren't my area of expertise) I currently have wheels which I love (15 x 7in) which are in torana stud pattern. With the skyline diff, can I buy blank axles that I can change to torana stud pattern? Obviously ill need to account for fitting brakes as the skyline diff will have discs, but I think the 15x7s should have clearance.

Side note, will be doing the skyline brake caliper conversion on the front as well (hq stub axles etc) as I'm confident the wheels have clearance, are there ways to get the fronts to remain torana stud pattern as well?

Basically looking to upgrade brakes and diff and really don't want to spend another $2k in wheels if I dont have to haha

#31 76lxhatch

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Posted 11 July 2020 - 06:43 AM

Plenty of custom axles around, you can weld and re-drill the Skyline ones if done properly but I gather that is frowned upon now. Your biggest concern will be having a small enough centre spigot, you may have to pay a little extra to have it turned down. The Skyline brakes fit under 14" wheels no worries so should be good there.


#32 _74LH_

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Posted 01 August 2020 - 06:47 PM

The more and more I look into this, and the associated costs. It seems a new 9 inch is probably going to cost around the same and last me that much longer. I did find through a bit of a search a group in dandenong called Diff King, anyone used them? They do 9 inch diffs to suit torana that look perfect for what I'm looking to do.

 

Any other diff shops that do similar work people can recommend in melbourne? Key parts are trutrac, 31 spline, billet axles (torana stud pattern), disc brakes. Ratio either 3.08 or 3.55 or similar


#33 GTR272

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Posted 05 February 2022 - 09:20 AM

Sorry to bring up an old thread, I have an LJ with an open center banjo 3.55 and it's started to get noisy. Can anyone tell me if I can convert my open center to truetrac, what parts would I need? Can i buy a Banjo truetrac and 28 spline axles and fit it to my current center? Sorry my diff knowledge is very limited. Thanks in advance.

#34 tsn007

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Posted 05 February 2022 - 10:00 AM

check out Harrops website for pricing of trutrac

#35 RallyRed

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Posted 05 February 2022 - 10:07 AM

Sorry to bring up an old thread, I have an LJ with an open center banjo 3.55 and it's started to get noisy. Can anyone tell me if I can convert my open center to truetrac, what parts would I need? Can i buy a Banjo truetrac and 28 spline axles and fit it to my current center? Sorry my diff knowledge is very limited. Thanks in advance.

Need to be aware that the Tru Track is just the centre, you fit your existing gears to it. Thus, your noisey gears will still be in service. 

The noise may be more or less after the thing is set up again.


Edited by RallyRed, 05 February 2022 - 10:07 AM.

#36 I'm a Red Motor fiend

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Posted 05 February 2022 - 12:52 PM

Col is right, using the same gears may still produce a whine.
But yes, you can buy a bolt in tru trac centre using your gears and bolt in 28 spline billet axles.

#37 meanmachine72

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Posted 05 February 2022 - 01:46 PM

https://www.harrop.c...banjo-28-spline

 

https://www.ebay.com...E4AAOSwiYlaAoJl

 

 

wheel bearings, seals and heavy duty retainer plates can be added for additional expense

call james on 0427 989037

i used this guy for my axles, if you look around you may get true trac a tad cheaper, bought mine for $1200

 


Edited by meanmachine72, 05 February 2022 - 01:50 PM.

#38 Adz1604

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Posted 05 February 2022 - 02:24 PM

Ordered a trutrac and axles from James SCW just before Christmas there has been a hold up which has been explained to me. I dropped of a centre with good gears and he is fitting the trutrac new bearings and seal. Supplying 28 spline axles with bearings and seals approximately $2500.

Edited by Adz1604, 05 February 2022 - 02:24 PM.

#39 kudu

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Posted 25 March 2022 - 03:11 PM

Hi,

A question for the knowledgeable ones on here. I was looking at A Harrop Trutrac diff centre for my LH. HOWEVER..... I was told that these diff centres on bolt straight into 1 type of Banjo. (As there are the 2.78/3.08 long bolt type and the 3.36/3.90 type.) And I was told that the type that the Harrop centres bolt into was the 3.36 type. Does anyone know if that is actually the case? I rang harrop but the guy there didn't know anything.


#40 RallyRed

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Posted 25 March 2022 - 06:07 PM

Good question.
We had a T/ T with 3.36.
My gut feel is that it is only a Centre.
The thing that requires the long bolt/ short bolt caper is 3.55,3.36 ( short bolt from memory) and 3.08, 2.78 ( long bolt, again , from memory).
My recollection is that the different bolt/ housing is all about crownwheel size and clearance.
Happy to be corrected.

#41 kudu

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Posted 25 March 2022 - 06:10 PM

Good question.
We had a T/ T with 3.36.
My gut feel is that it is only a Centre.
The thing that requires the long bolt/ short bolt caper is 3.55,3.36 ( short bolt from memory) and 3.08, 2.78 ( long bolt, again , from memory).
My recollection is that the different bolt/ housing is all about crownwheel size and clearance.
Happy to be corrected.

 

What I was told...and I'd like to know if it is fact, is the T/T centre was designed to fit in the 3.55/3.36 short bolt carriers. But to fit the 2.78/3.08 long bolt there needs to be a few mm of milling done to get them to fit.


#42 dron

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Posted 25 March 2022 - 07:16 PM

I have never tried to set up a trutrack in a Holden 6cyl diff but have done several ratio changes over the years. The carrier is different between the higher (Lower 1st number) to the lower ratio diff. 3.36 is the highest ratio for 1 carrier and the higher ratio ones mount the crown wheel in a different position to accommodate the larger diameter pinion gear (more teeth) This would have to affect the trutrack as well as it is a replacement for the crown wheel carrier.


#43 RallyRed

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Posted 25 March 2022 - 07:31 PM

May be a generic comment, but seems pretty definate?

Attached Files


#44 76lxhatch

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Posted 25 March 2022 - 07:32 PM

I have a Harrop Truetrac in the Borg Warner and it most definitely interfered with the pinion gear even in ratios where they claimed it wouldn't, so it wouldn't be surprising if it needed work. I opted to machine the end of the pinion down a little.


#45 Adz1604

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Posted 25 March 2022 - 08:50 PM

I was going to fit the trutrac myself and was advised that there is a little clearance issue with the 3.08 banjo and you could either machine a small amount of the head of the bolts on the trutrac or a small amount of the housing. Or for $300 he could fit it, sand blast the centre, shimmed and lapped painted

#46 RallyRed

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Posted 25 March 2022 - 09:12 PM

Search on this Forum for - Dummies guide to Bajos". Some info there.

#47 Shiney005

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Posted 24 October 2023 - 06:44 PM

I was going to fit the trutrac myself and was advised that there is a little clearance issue with the 3.08 banjo and you could either machine a small amount of the head of the bolts on the trutrac or a small amount of the housing. Or for $300 he could fit it, sand blast the centre, shimmed and lapped painted

What part of a 3.08 housing needs machining to fit the Trutrac centre? I am going down this route for a replica diff for the L34.


#48 a9x868

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Posted 24 October 2023 - 07:38 PM

Search on this Forum for - Dummies guide to Bajos". Some info there.

same info should be on the L34 fb page oh! banjo,s


#49 Shiney005

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Posted 25 October 2023 - 09:42 AM

Ha ha ha. I expected that from you Dave!!! :D


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