Can anyone tell me if the housing for the LSD is the same as the non LSD VN diff?
I am getting a complete VN wagon for my conversion im doing. 5lt in the LJ. But im told it is not an LSD diff?
I am looking at shortening the commodore wagon diff to fit my LJ and buying an LSD centre for it..
WILL IT WORK?
Cheers.
VN diffs?
Started by
_barbermi_
, Oct 26 2008 03:56 PM
18 replies to this topic
#2
Evan
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Posted 26 October 2008 - 04:57 PM
The LSD housing's are different.
You can remove the current non open wheeler centre and replace it with a LSD centre.
Evan.
You can remove the current non open wheeler centre and replace it with a LSD centre.
Evan.
Edited by Evan, 26 October 2008 - 04:59 PM.
#3
TerrA LX
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Posted 26 October 2008 - 06:09 PM
Diff housings are same for all holden ford etc, open wheeler and LSD hemisphere's are different.
#4
Posted 26 October 2008 - 08:46 PM
Swapping the LSD centre will work no problems. However as for the housings here's a useless bit of trivia - I bought a late model Falcon Borg Warner to get the LSD for mine, discovered a couple of interesting differences in the housing/gearset. The pinion had a bigger rear bearing, and the crownwheel was approx 1/4" bigger than the Skyline and Commodore ones. A bit of research turned up that there are indeed two different crownwheel sizes for these diffs. Wouldn't be difficult to change one to the other but the housings do differ in the machining for the rear pinion bearing cup in diameter and pinion depth to allow for this. I don't know for sure which models had which but I assume that all the Commodore BW78s were the smaller crownwheel.
#5
_barbermi_
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Posted 27 October 2008 - 10:21 AM
The LSD housing's are different.
You can remove the current non open wheeler centre and replace it with a LSD centre.
Evan.
So i can get a centre from a LSD commodore diff and put it in my non LSD housing?
#6
Posted 27 October 2008 - 10:32 AM
Absolutely, yes. You can get one from a Commodore, Skyline or Falcon. Make sure it is a 28 spline one though otherwise it won't fit your axles.So i can get a centre from a LSD commodore diff and put it in my non LSD housing?
#7
_XU1-043_
_XU1-043_
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Posted 28 October 2008 - 04:16 PM
here's a pic of my diff in my torana out of a VN ute (LSD) does it look the same as yours?
#8
Evan
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Posted 28 October 2008 - 04:41 PM
you cant tell from that picture., you need to look at the centre under the inspection plate or there will be a tag on it.
Evan.
Evan.
#9
Posted 28 October 2008 - 05:14 PM
I'm reasonably certain that if it is definitely from a VN it will be 4 spider centre with 28 spline axles.
#10
_rorym_
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Posted 28 October 2008 - 05:41 PM
The angle on that pinion looks a bit high...??
R
R
#11
_rorym_
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Posted 28 October 2008 - 05:44 PM
Swapping the LSD centre will work no problems. However as for the housings here's a useless bit of trivia - I bought a late model Falcon Borg Warner to get the LSD for mine, discovered a couple of interesting differences in the housing/gearset. The pinion had a bigger rear bearing, and the crownwheel was approx 1/4" bigger than the Skyline and Commodore ones. A bit of research turned up that there are indeed two different crownwheel sizes for these diffs. Wouldn't be difficult to change one to the other but the housings do differ in the machining for the rear pinion bearing cup in diameter and pinion depth to allow for this. I don't know for sure which models had which but I assume that all the Commodore BW78s were the smaller crownwheel.
C/Ws for 3.08/3.27/3.45 and 3.7 are the same...2.73 and 2.92 are a smaller C/W centre.
R
#12
Posted 28 October 2008 - 06:42 PM
Rory I have a 3.45 crownwheel here that is bigger than the 3.08 and 3.91 crownwheels I have. The 3.45 is from a Falcon, 3.08 Commodore and 3.91 Skyline. The docs I have (based on late model BTR version I think) back this up but I don't think they are complete.
edit: centre diameter is the same on all, its the outside diameter that's different
edit: centre diameter is the same on all, its the outside diameter that's different
Edited by 76lxhatch, 28 October 2008 - 06:54 PM.
#13
_on the limit_
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Posted 30 October 2008 - 09:44 PM
Yes you will find that the inside diameters are the same, the important # is the (0575 part# & 0578 # stamped on the gears. The difference is the 75 stands for 7.5 inch & the 78 =7.8inch. Most late model falcon had the 0578 gears as to the commodores & skyplines had the 0575 gears. Hope that helps.Rory I have a 3.45 crownwheel here that is bigger than the 3.08 and 3.91 crownwheels I have. The 3.45 is from a Falcon, 3.08 Commodore and 3.91 Skyline. The docs I have (based on late model BTR version I think) back this up but I don't think they are complete.
edit: centre diameter is the same on all, its the outside diameter that's different
#14
_rorym_
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Posted 30 October 2008 - 09:51 PM
Thanks Limit...remember now...the cruncher was the "75" in the part number...Sorry for confusion. But I did have a 2.92 that was smaller from a Ford ...it wouldn't fit on the 78 3.45 centre.
R
R
Edited by rorym, 30 October 2008 - 09:53 PM.
#15
Dr Terry
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Posted 31 October 2008 - 07:09 AM
Hi Guys.
The BW diffs in Holdens, Falcons & Pintara/Skylines etc. are listed in the BTR catalogues variously as M75, M76, M78 or M80 depending on the model. So there are a many different gear sizes.
Dr Terry
The BW diffs in Holdens, Falcons & Pintara/Skylines etc. are listed in the BTR catalogues variously as M75, M76, M78 or M80 depending on the model. So there are a many different gear sizes.
Dr Terry
#16
Posted 31 October 2008 - 08:02 AM
So is there a 3.45 available in 7.5 inch crownwheel? Also I noticed that the 78 crownwheel has tapered profile teeth (milled) while both the 75 crownwheels have straight profile teeth (hobbed). I guess the 78 would be slightly stronger due to the extra width, would it be worth setting the housing up to run the 78 gearset? Or a waste of time?
Is the 80 gearset the one used in the later model IRS Commodores where they changed the ratios (e.g. 3.07:1)? Didn't know about the 76...
Is the 80 gearset the one used in the later model IRS Commodores where they changed the ratios (e.g. 3.07:1)? Didn't know about the 76...
#17
_on the limit_
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Posted 31 October 2008 - 09:10 AM
If you want to run 3.45 7.5 inch gears , they will fit a vn housing, 3.45 7.8 inch gears you will need to use a Au Falcon ute/wagon housing. Yes the 7.8 inch gears are stronger, but i would only be marginally. cheersSo is there a 3.45 available in 7.5 inch crownwheel? Also I noticed that the 78 crownwheel has tapered profile teeth (milled) while both the 75 crownwheels have straight profile teeth (hobbed). I guess the 78 would be slightly stronger due to the extra width, would it be worth setting the housing up to run the 78 gearset? Or a waste of time?
Is the 80 gearset the one used in the later model IRS Commodores where they changed the ratios (e.g. 3.07:1)? Didn't know about the 76...
#18
Dr Terry
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Posted 31 October 2008 - 09:12 AM
Basically the M75 is fitted to VK to VS with a live rear axle. The M76 is VQ to VS IRS & the M80 is VT onwards IRS.So is there a 3.45 available in 7.5 inch crownwheel? Also I noticed that the 78 crownwheel has tapered profile teeth (milled) while both the 75 crownwheels have straight profile teeth (hobbed). I guess the 78 would be slightly stronger due to the extra width, would it be worth setting the housing up to run the 78 gearset? Or a waste of time?
Is the 80 gearset the one used in the later model IRS Commodores where they changed the ratios (e.g. 3.07:1)? Didn't know about the 76...
So I guess that means, the 3.45 VL gears are 7.5 inch.
Dr Terry.
#19
Posted 31 October 2008 - 01:04 PM
Thanks guys. The 78 series 3.45 gearset I have here is in really good nick and it does fit in the housing, just needs the pinion 0.15" deeper (already swapped the pinion bearing to suit). I'm hesitant to modify the housing though as I've already spent plenty on making it fit the Torana and don't want to wreck that, plenty of VL 3.45 gearsets around so I'll hunt out one of them.
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