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    vl diffs numbers



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    vl diffs numbers

    Post by bretto on Sun Aug 22, 2010 1:00 am


    Non-turbo - these diffs have 25 spline axles


    Sedan disc brakes

    Wagon disc brakes

    Sedan LSD

    Wagon LSD

    Sedan disc brakes, LSD

    Wagon disc brakes, LSD

    Sedan V5W suspension

    Wagon V5W suspension

    Sedan disc brakes, V5W suspension

    Wagon disc brakes, V5W suspension

    Sedan disc brakes, V5W suspension, LSD

    Turbo - these diffs have 28 spline axles and disc brakes

    Wagon LSD


    Sedan LSD

    Sedan FE2 or V5W suspension

    Wagon V5W suspension

    Sedan FE2 or V5W suspension, LSD

    V8 - these diffs have 28 spline axles and disc brakes
    This is not an official list from Holden



    Sedan LSD

    Wagon LSD

    Last edited by bretto on Sun Aug 22, 2010 1:05 am; edited 1 time in total


    Posts : 169
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    Re: vl diffs numbers

    Post by bretto on Sun Aug 22, 2010 1:04 am


    Anything you want to know about Borg Warner 78 Series diffs, can be found here.

    VLTs and VL V8s were all built with 4 pinion 28 spline centres, with LSD as an option (noted by a brown filler plug), running single piston disc brakes, upon live axle (semi-floating) differential (non-IRS) housings. Otherwise, naturally aspirated VLs were built with 2 pinion 25 spline open wheel differentials (noted by a black filler plug; unless optioned [with LSD] otherwise), running drum brakes (unless optioned otherwise; see below). The diff housing measures 1400mm in width, axle flange to axle flange (sedan and wagon).

    The type of centre fitted can also be determined by the diff tag (where present), secured under one of the cover bolts. See here.

    Non-lsd (2 pinion):
    LSD (4 pinion):

    Video: How a differential works

    Across the VL range, LSDs and disc brakes were optional (not restricted to being present only on turbo or V8 models).
    For example:
    Originally Posted by Steve
    SL/Exec - 3.45 gears, 2 pinion center, 25 spline axles, drum brakes, possible LSD Optional
    Berlina - 3.45 gears, 2 pinion center, 25 spline axles, drum brakes, LSD Optional, Disc brakes optional
    Calais - 3.45 gears, 2 pinion center, 25 spline axles, disc brakes, LSD Optional
    V8 VL's were able to optioned with the same 4 pinion 28 spline LSD centres, running the same disc brakes, however they were equipped with 3.08 ratio gears to improve fuel economy (it was also possible to option these diffs with the higher ratio 3.45 gears). The handbrake cable differs between disc brake and drum brake diffs.

    Changing internals
    Changing a pinion requires tools to measure backlash and gear clearance - without it, the differential wears excessively, and will shorten the life/performance of your diff. A pinion is removed by unbolting the tail-shaft, leaving the handbrake on/keeping the rear wheels on the ground, and undoing the nut on the front of the diff (previously hidden by the tail-shaft flange). The nut should be marked before it is undone to ensure the correct torque and clearances are maintained (this is not ALL of the necessary measurements/torques required).

    Changing the centre is a simple operation, however sometimes the centre can be difficult to remove from the housing (which is where the chain/bottle jack method comes into play, bending the housing slightly). When re-installing a differential centre, the original shims must be installed them same way, otherwise excessive wear will result.

    It should be noted that 25 spline centres use different bearing cups than the larger 28 spline open wheeler and LSD centres, and you cannot re use your original 25 spline bearing cups when converting to a 28 spline BW78 centre. The part number for a single bearing cup is LM102911; you'll need two (one for each carrier bearing). They are worth $8.80 from a bearing shop last time I bought one.

    Housing/Oil Replacement
    VL diff housings do not have a drain plug. Replacement of the oil is achieved by removing the back cover, draining oil, replacing gasket and refitting cover. Drum brake axles have different seals and bearings to discs brake axles. Diff housings are different between sedans and wagons; being that the wagons have differing mounting points for the extra load a wagon can take. Meaning your wagon must take a wagon diff, and your sedan a sedan diff. The axles are the same between wagon and sedan housings.

    Determining LSD status
    A differential can be tested to determine whether it is an LSD or not in-car by raising the rear end, and rotating one wheel. If they both go in the same direction, it is an LSD. Otherwise, it can be removed from the housing and checked for the presence of a second row of bolts around the ring gear bolts; this indicates it is an LSD centre. This check can also be performed by removing the diff cover and observing the presence of the second row of bolts (without removing the centre from the housing).

    An open wheel centre (non-LSD "Single Spinner" centre) can be modified to dual-wheel spinning status by installing a "spool". This basically locks the centre of the differential to the rotation of the ring gear, and will cause both wheels to always drive. As there is no limited slip action, it will be a rougher ride for street driving on corners and roundabouts, and more stressful to your axles, and wear your rear tyres faster. They are illegal for street use. A tell tale sign is the "scrape-scrape-scrape" sound when a car that has one fitted is performing low speed manoeuvres.

    Borg Warner 78 Series in Other Cars
    Borg Warner 78 Series differential centres are found in VL-VS Commodores, R31 Nissan Skylines and Pintara's, and XC-XG Falcons. LSD centres were found in VLT's/VLCT's/V8 VL's (where optioned), R31 Skyline Silhouettes, VN-VS SS/V8/S-pak's (where optioned), and XC-XG S-pak and XR6 and XR8 Falcons. Their ring gear and pinions are all interchangeable. Brand new BW centres can be bought without gears from eBay for $275, 28 spline spools for $89.99, new billet axles for $660, and gears vary. Ratios include 3.08 (VL V8, VN-VS), 3.45 (VL, VLT, VLCT), 3.7 (R31 manual), 3.89, 3.9 (R31 auto), and 4.11 (Pintara). The higher the gear ratio, the more the wheels will rotate in relation to the tail-shaft. 28 spline axles are present in any BW diff using a 28 spline carrier in the centre (VLT/VLCT with 4 pinion LSD, VN-VS [all centres] ); however 28 spline axles from VN-VS may not be used in a VL diff housing (they are too long). Similarly, a VN-VS diff housing (excluding IRS; see below) cannot be bolted onto a VL chassis (they are too wide).

    Ring gear and pinion:

    Top Speed/RPM Calculators

    To determine the maximum top speed of your car, click on the first link below. You'll need to know your car's maximum rpm (6500rpm for a stock ECU'd VL/VLT), rear tyre width in millimetres (ie: 225, 235, etc), diff gear ratio, and your highest gear's ratio (ie: R33 five speed fifth gear 0.813:1). The second is a similar calculator, with some preset values for different diff gear ratios. It also gives you your results in MPH. I find the first the easiest to use.

    Top speed calculator (Km/h)
    Top speed calculator (MPH)

    Here is another more complicated calculator:
    Tyre size/diameter/speed calculator

    And here are some links to listings of common transmission options final gear ratios.

    MX7 VLT five speed manual
    MF5 VL N/A five speed manual
    M78 VL V8 five speed manual (Walkinshaw only)
    Skyline R32 GTS-t five speed manual (RWD)
    Skyline R32 N/A five speed manual (RWD)
    Skyline R32 GT-R five speed manual (AWD)
    FS5R30A Skyline R33 N/A five speed manual (RWD)
    FS5W7 Skyline R33 GTS-t five speed manual (RWD)
    MS1 VLT four speed auto
    ML4 VLT N/A four speed auto
    M40 Trimatic VL V8 three speed auto
    Skyline R32 RB20E N/A auto
    Skyline R32 RB20DE N/A auto
    Skyline R33 RB25DE N/A auto
    Powerglide two speed auto

    Whilst the BW78 28 spline 4 pinion LSD is a good unit, and has been used reliably to run into the 10s on drag focused cars, there is always something better available. Being a clutch type LSD, it will eventually wear out (especially if you are buying it second hand...making it 22 years old). Your options are varied:

    -Multi plate clutch type LSD (Kaaz 28 spline 2 way [locks both wheels during acceleration and deceleration] LSD; part number DAG3820)

    Best price I have found is from business trader Slide, over on SAU - $1490 delivered with 2L of Kaaz diff oil:
    Slide, of SAU (the original thread is MIA from SAU, so I have redirected you to his personal business page. DAG3820 is not listed, but he can get it for you)

    -Helical gear type LSD (Harrop Detroit TrueTrac 28 spline LSD; part number unavailable, see below)

    Highly recommended, as they do not have wearing clutch/clutch plates like other LSDs. Priced at $1540, directly from Harrop.

    Harrop Detroit TrueTrac

    When removing a ring gear from a centre, the bolts are left hand thread.

    IRS setups cannot be directly bolted onto a VL chassis (without custom work). There were a handful (and I do mean handful, probably less than five) of Directors that were fitted with IRS. The only mention I have seen of IRS on a VL is as hybrid R32/Z32 IRS, found here. Thanks to 87calais for the reference.

    A picture of an R33 Skyline IRS differential set up. Notice the completey different structure and flexible driveshafts, not present in the VL BW78 diff:

    Watts Linkages, invented by James Watts, are a live axle set up used by the V8 Supercars. It does away with the panhard rod, and makes use of a central bell crank, mounted on the diff housing, and two (adjustable) arms off the bell crank to the chassis. This can also be reversed, where the bell crank is mounted to the chassis, and the two bell crank arms are attached to the diff (as opposed to the chassis). This type of differential set up allows the diff to stay centered below the chassis, despite a change in ride hide due to motion of cornering or bumps. This is great for maintaining tyre/rim to wheel arch clearances in very low track cars. An excellent example of the first type (diff mounted bell crank) is found here.

    Here is a visual representation of the basic principle of a Watts Link. The red dot is the centre of the rotating bell crank, and the diff would sit horizontally through it.

    And, more realistically:


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    Join date : 2010-03-27

    Re: vl diffs numbers

    Post by bretto on Sun Aug 22, 2010 1:06 am


    Diff information thread - The basics... (Salisbury, BorgWarner BW78, Ford 9")
    Rightio - I have raided sources all over the interwebs to try and provide a guide to "the basics" of a few of common options for diff upgrades or conversions. Hopefully this provide a good source of information for those just starting out. (Excuse the information in this post being in a rather hap-hazard order. I patched it together as I found different bits of information) Anyway...

    Holden Large Salisbury "10-Bolt" Diff.

    A Salisbury diff is called a 10 bolt because it has 10 bolts holding the crownwheel and the fact there are 10 bolts holding the cover on is just a coincidence. The Salisbury 10 Bolt came out in Holden HQ - WB V8 Sedans, Wagons, Ute, Panel vans, 1 Tonners, Statesman's, VB - VL Commodore, and A9x Torana.

    Salisbury 10-Bolts were available in Open Centre Hemisphere or Limited-Slip (LSD) Hemisphere configurations, all of which used 28 Spline Axles.

    Salisbury crown & pinion gear-sets were available in a variety of different ratios including 2.60:1, 2.78:1, 3.08:1, 3.36:1, 3.55:1, and 4.44:1. (It is worth noting that the 2.60:1 and 2.78:1 ratio gear-sets use a slightly different housing to the other ratios, so 3.08:1 and up cannot be swapped into the 2.xx:1 housings) There was theoretically a 3.9:1 ratio that was optional on the A9X Toranas, but none are known to actually exist.

    Upgrade options:

    The weak point in the Salisbury is the 2-pinion spider gear arrangement. The spider-gears are prone to breakage in higher-horsepower applications.
    Unfortunately the Salisbury diffs are somewhat lacking in availability of spares and upgrade parts due to being an Australian-only diff - but there are still options to strengthen the diff over standard.
    While the factory LSD can be rebuilt - If strength is the order of the day, something a little tougher will be needed.

    A Salisbury Diff can be converted to a 4-pinion center, but it is not common, so will be more-or-less a "one-off" custom job and price will likely be quite high. However, there is even a conversion centre available (from G&J Diffs) which uses the (much stronger) LSD internals of the 4-Pinion BW78 Borg-Warner Diff centres.

    Realistically though, the most common upgrade for drag or burn-out vehicles using a Salisbury diff is the installation of a "spool". (Note: It is illegal to have a spool fitted to any road-going vehicle, as the vehicle's handling can become unpredictable in adverse conditions).
    The are both Mini-spools and Full-spools available to suit the Large Salisbury diffs. (Generally however, it is accepted that the mini-spool can only be fitted to an LSD Hemisphere on the Salisbury Diffs)
    Billet axles can also be ordered from companys like Moser or Strange, but again are likely to be a custom or low-volume item and priced accordingly.

    Borg-Warner BW78 Diff.

    Better known as the VL Turbo Diff, or VN-VS Commodore Live-Axle Diff, and were call the "BTR 78" by Holden. For reference, the diff housing on a VL measures 1400mm in width, axle flange to axle flange, whereas VN-on is approx. 1440mm.

    OK, a HUGE thanks to 76lxhatch for the information provided here...

    The information in this post refers to BW78 Diffs/Centres, So anything post-10-bolt Salisbury and pre Commodore M80 (IRS diff used from mid VT I believe but could be wrong on the exact timing). That is, the M80 is a Borg Warner based diff too but not the same - the easiest way to pick them apart is by ratio, e.g. 3.08:1 becomes 3.07:1 in the M80. Also the VR/VS HSV Hydrotraks are another animal entirely.

    The 25 spline 2 spider versions of the Borg Warner use the same housings and same crownwheel/pinion gearsets so they are interchangeable. This is why the Pintara (4 cylinder Skyline) ones are popular because although the axles and centres are no good, the 4.11:1 gears are. The 25 spline/2 spider versions are available in VK 1/2, most VLs, many Valiants and heaps of Falcons (Ford did a similar thing to Holden and decided the larger 4 spider/28 spline would be a good idea and swapped it over somewhere in the EA-EF range).

    The LSDs are a cone type like the Salisbury (except with the centres being smaller in size they unfortunately seem to be a little shorter lived).

    BTR took over making the diffs (as opposed to Borg Warner themselves) at some stage, hence some commodores having the BTR tag.

    R31 Skyline diff housings are a handy conversion for LH/LX/UC Torana as you only need to change the mounts and alter the axle stud pattern. They are around 20mm wider overall than standard LH/LX/UC and run a similar brake caliper to the Commodore but fitted with a built-in handbrake instead of the drum and mounted on a different angle. The discs are also slightly smaller at around 260mm.

    Another little secret is that while the VK 1/2 Borg Warner is the same width as VL, it has a different centre offset. This means that a VN short side axle will bolt straight in (may require minor trimming on the end, I've measured it but haven't actually built it yet). End result is a 28 spline (and disc brake) conversion using this housing only requires one axle to be shortened.

    Ratios that I am aware of and easy places to get them:
    2.77:1 some Falcons (possibly Fairlanes), I have heard that these may require a different housing
    2.92:1 also Ford stuff
    3.08:1 standard on VN-VS V6 and V8
    3.23:1 VK 1/2 injected six
    3.45:1 VL
    3.7:1 R31 Skyline manual
    3.89:1 R31 Skyline auto - dodgy according to most people, noisy and possibly failure prone
    3.91:1 R31 Skyline auto supersedes above
    4.11:1 R31 Pintara
    (Other vehicles use some of these ratios, these are just the easiest sources)

    I've fitted 3.91:1 and 3.08:1 into the same housing no worries. There's a list of Fords here, but not sure how reliable it is - I don't know much about Fords but I'm pretty sure there is no such thing as a 2 spider 28 spline version.
    All VN onwards BW diffs are 28 spline/4 spider, as are R31 Skyline but not Pintara. Regardless of the centres though, all of the Commodore and Skyline diffs have 7.5" crownwheels which are completely interchangeable. The 7.8" crownwheels used in some Fords of the same era use the same centres but have different main housings due to differences in the pinion bearings and crownwheel/pinion sizes

    It is also worth noting also that the pinion housing of the BW78 is made of cast steel (not cast iron) so mounts can be safely welded to the cast pinion housing for easy conversion into HQ-WB (where the upper trailing arms pick-ups on the diff are positioned quite far inboard on the coil-spring models).

    Whilst the BW78 28 spline 4 pinion LSD is a decent unit, and has been used reliably to run into the 9s on drag focused cars (VLT's), there is always something better available (particularly if doing circuit/hillclimb/track-work) as being a cone type LSD, it will wear out fairly quickly in performance applications.

    Upgrade options:

    > Multi plate clutch type LSD (Kaaz 28 spline 2 way [locks both wheels during acceleration and deceleration] LSD; part number DAG3820)
    > Harrop sell a Detroit TrueTrac Helical-Gear type LSD in a 28-spline LSD center; part number: 99-TTRC9492-00, see link: http://www.harrop.com.au/products/dr...rc9492-00.html)
    > "Lokka" locking differential, available from 4WDsystems. Link: http://www.4wdsystems.com.au/index.php?id=29
    And again, Mini-spools and Full-spools are available for the BW78 as well.

    Ford 9" Diff.

    Ford used the 9 inch rear from around the 1957 model year right up until the early 1980’s in cars and trucks. Variations in the housings exist in the size of the outer axle bearings and also the carriers bearings, as well as with the spline count on the axle shafts. Generally most cars received the small axle bearings and 28 spline axle shafts, but there were exceptions which received the 31 spline carriers and axle shafts. Some of the heavier cars like the Galaxies also received the larger wheel bearing housings.

    A small bearing housing can be differentiated from a large bearing housing by the size of the nuts and thread used to retain the brake backing plates to the housing, the small bearing housings use 9/16 socket size nuts with 3/8” fine thread, while the larger bearing use 11/16” socket size and 7/16” fine thread.

    For a bunch of information regarding the American uses and variations of the Ford 9", see this link: http://www.maliburacing.com/ford_9_i..._nine_inch.htm

    Available ratios and teeth count (crownwheel-pinion):
    2.8:1 (42-15)
    2.86:1 (40-14)
    2.91:1 (32-11)
    2.94:1 (47-16)
    3:1 (39-13)
    3.07:1 (43-14)
    3.25:1 (39-12)
    3.33:1 (40-12)
    3.4:1 (34-10)
    3.45:1 (38-11)
    3.5:1 (35-10)
    3.55:1 (39-11)
    3.6:1 (36-10)
    3.7:1 (37-10)
    3.75:1 (45-12)
    3.82:1 (42-11)
    3.89:1 (35-9)
    4:1 (36-9)
    4.11:1 (37-9)
    4.22 :1 (38-9)
    4.33:1 (39-9)
    4.44:1 (40-9)
    4.5:1 (36-Cool
    4.56:1 (41-9)
    4.63:1 (37-Cool
    4.71:1 (33-7)
    4.86:1 (34-7)
    5:1 (35-7)
    5.14:1 (36-7)
    5.29:1 (37-7)
    5.43:1 (38-7)
    5.5:1 (33-6)
    5.67:1 (34-6)
    5.83:1 (35-6)
    6:1 (36-6)
    6.2:1 (31-5)
    6.33:1 (38-6)
    6.5:1 (39-6)

    If that's not enough for you, there's some more here:

    Upgrade options:

    The 9" is probably the most commonly used diff in performance rear-wheel-drive applications, and there is a plethora of upgrade options for the 9" Diff available so
    one can be built to meet almost any performance requirement.
    Standard 9" LSD's are either simple clutch-pack or cone-type LSDs, but like all factory LSDs are often prone to excessive wear in performance applications. There are many aftermarket options available for a 9" when a torque-splitting between driven wheels or equal drive between rear wheels is required (too many variations to practically list in reality...).
    Upgrade options for a 9" include aftermarket Clutch-pack style LSD's (Like KAAZ), Detroit Lockers, TrueTrac Helical-Gear LSD's, Posi-LSD's, Air-Lockers, Electronic Lockers, Mini-spools, Full Spools. There is also a few Alloy pinion support housings available, and a bunch of different axle/main housings for the 9" too.

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    Re: vl diffs numbers

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