I have a car here which seems to have a cracked diff housing, and i got to thinking is it time to replace it as when driven the oil will spray onto the floor pans, fuel tank etc.
Can anyone shed some light on these questions.....
Does a lc-lj torana diff suit the trick (of course with mounts reworked) and will the new offset allow bigger rubber if so how wide have people gone with what amount of lowering? Do the uni setup and tailshaft need replacing.
Does a eh-hr diff work nicely? pros and cons?, is the universal joint and tailshaft need also to be replaced?
Or should i be easy and refit a fb/ek housing with an eh centre?
What braking mods are required if any, and will there be significant affects on power/economy of the car?
Please note the car is still fitted with crash box, stock front end and almighty grey motor.
What diff and housing is best.
What diff and housing is best.
master of nothing, leader of nobody.
, Thommo you owe me! 
(just kidding)
diff housing
Hi Retro,
could type a novel here- but don't have the time at present - this little Christmas thing has saved you all.
I have an EH housing in mine.
I believe if you are going to modify the vehicle and not just the housing - between HR and EH, I would now choose HR.
It was pointed out to me for engineering purposes, it is more appropriate to have both HR front and rear ends than a mix.
The union bracket for hydraulic brake lines on EH are opposite side to ours - HR are the same as EK.
The spring mounts on HR are welded plates.
Centres can be interchanged in all applications - I have absolutely no experience with LC/J Torana components.
If you want to drop your revs on the open road with a grey - gearbox won't make much difference, I would suggest 3:55 or even 3:36 diff centre.
We have many members down here who have those fitted and I can tell you that after a recent trip around Tas in March, they were managing quite nicely - even over mountains.
I have a 3:08 diff in mine and makes good use of the 4 sp Aus. - it may be a bit tall for 3 speed applications.
Brakes,,,,,, hmmmmmmmmm - I had to fit the very small (0.5625") wheel cylinders to mine because of the single line system using front disc brakes.
Standard rear wheel cylinder size - for EK is 1" as opposed to 0.8125" on EH and HR.
Standard front wheel cylinders size for EK is 1.1875" opposed to 1" for EH and 1.06" for HR.
I would expect there to be issue here.
You may also run into trouble with other things like handbrake cables etc.
If it were me Retro, I would seek another EK housing and fit a taller centre.
Tailshaft - no idea what has to be done here - think you can use the original but may have to change the rear uni joint - latter centres have something different - can't remember- have to go soon.
Tailshaft length - I had to use one from an LJ auto - it was the shortest I could get at the time - most others have theirs cut and balanced.
Mine has been fine for 25 years.
Don't think there is any difference in length of the diff centre - this is from what I can remember - it may not be exact.
With a 3:08 centre - be careful to get one for "coarse" splined axles = there s also a "fine" spline version.
For a 3:08 you will need to "fit" a bolt from within the housing at the lower driver's side - the centre has a nut at this location.
just my thoughts,
frats,
Rosco
could type a novel here- but don't have the time at present - this little Christmas thing has saved you all.
I have an EH housing in mine.
I believe if you are going to modify the vehicle and not just the housing - between HR and EH, I would now choose HR.
It was pointed out to me for engineering purposes, it is more appropriate to have both HR front and rear ends than a mix.
The union bracket for hydraulic brake lines on EH are opposite side to ours - HR are the same as EK.
The spring mounts on HR are welded plates.
Centres can be interchanged in all applications - I have absolutely no experience with LC/J Torana components.
If you want to drop your revs on the open road with a grey - gearbox won't make much difference, I would suggest 3:55 or even 3:36 diff centre.
We have many members down here who have those fitted and I can tell you that after a recent trip around Tas in March, they were managing quite nicely - even over mountains.
I have a 3:08 diff in mine and makes good use of the 4 sp Aus. - it may be a bit tall for 3 speed applications.
Brakes,,,,,, hmmmmmmmmm - I had to fit the very small (0.5625") wheel cylinders to mine because of the single line system using front disc brakes.
Standard rear wheel cylinder size - for EK is 1" as opposed to 0.8125" on EH and HR.
Standard front wheel cylinders size for EK is 1.1875" opposed to 1" for EH and 1.06" for HR.
I would expect there to be issue here.
You may also run into trouble with other things like handbrake cables etc.
If it were me Retro, I would seek another EK housing and fit a taller centre.
Tailshaft - no idea what has to be done here - think you can use the original but may have to change the rear uni joint - latter centres have something different - can't remember- have to go soon.
Tailshaft length - I had to use one from an LJ auto - it was the shortest I could get at the time - most others have theirs cut and balanced.
Mine has been fine for 25 years.
Don't think there is any difference in length of the diff centre - this is from what I can remember - it may not be exact.
With a 3:08 centre - be careful to get one for "coarse" splined axles = there s also a "fine" spline version.
For a 3:08 you will need to "fit" a bolt from within the housing at the lower driver's side - the centre has a nut at this location.
just my thoughts,
frats,
Rosco
-
mrs ratbox
EH/HR is just about bolt in EH more so, bit of fiddling with brake pipes nothing serious, don't know about uni's cause i've always also had different gearbox, you could put the grey centre in the EH/HR housing
torana housing is 11/2" each side narrower you can't fit any bigger wheels but you can have a much bigger dish
torana housing is 11/2" each side narrower you can't fit any bigger wheels but you can have a much bigger dish
G'day Retro,
I can add to and confirm part of what Rosco has said.
The red motor diff centres will bolt straight into the early diff housings providing the red motor diff centre is a course spline centre that is.From memory Holden went to a fine spline centre around the HX Holden and these won't fit the early axles for obvious reasons.
You can use your original tailshaft however the rear universal joint has to be changed to the red motor uni joint which is still commonly available for around the $30 mark and the red motor uni joint 'U" bolts and nuts are used also.No other mods required unless you fit a 3.08 or 2.78 centre then you will have to get the longer bolt to fit it as well.
From general talk amongst grey motor owners previously on this forum and other forums, it would appear that 3.36 is about as low as a standard grey motor is able to comfortably handle without putting too much on the motor.That said, I do remember someone saying that they were running a 3.08 with a grey motor and it ran fine for them.
I suppose its all down to the condition of the motor ( including performance modified greys ) the driving style of the owner and what sort of performance the driver expects from the car.
You win and lose as well. 3.08 should theoretically give you better economy but you will get less pickup.At the other end the standard 3.89 will give you the best pickup but theoretically less economy.
3.36 and 3.55 are in betweens.I'll leave 2.78 ratio out of this as I don't think any grey would have enough power to comfortably handle this ratio.
Then you've got wheel diametre choices as well.
Doesn't answer all of your questions but answers some of then at least,
Cheers,
Terry.
P.S I have an FB/EK Housing here at home if you want to stick with the original type housing but the problem is getting it to you from where I live.Transport companies don't seem to be interested in servicing low volume customers as I'm finding out.I'm trying to get a red motor centre delivered from Wentworth near Mildura to my place and no transport company could be bothered helping me out.Too heavy for Australia Post as well.
I can add to and confirm part of what Rosco has said.
The red motor diff centres will bolt straight into the early diff housings providing the red motor diff centre is a course spline centre that is.From memory Holden went to a fine spline centre around the HX Holden and these won't fit the early axles for obvious reasons.
You can use your original tailshaft however the rear universal joint has to be changed to the red motor uni joint which is still commonly available for around the $30 mark and the red motor uni joint 'U" bolts and nuts are used also.No other mods required unless you fit a 3.08 or 2.78 centre then you will have to get the longer bolt to fit it as well.
From general talk amongst grey motor owners previously on this forum and other forums, it would appear that 3.36 is about as low as a standard grey motor is able to comfortably handle without putting too much on the motor.That said, I do remember someone saying that they were running a 3.08 with a grey motor and it ran fine for them.
I suppose its all down to the condition of the motor ( including performance modified greys ) the driving style of the owner and what sort of performance the driver expects from the car.
You win and lose as well. 3.08 should theoretically give you better economy but you will get less pickup.At the other end the standard 3.89 will give you the best pickup but theoretically less economy.
3.36 and 3.55 are in betweens.I'll leave 2.78 ratio out of this as I don't think any grey would have enough power to comfortably handle this ratio.
Then you've got wheel diametre choices as well.
Doesn't answer all of your questions but answers some of then at least,
Cheers,
Terry.
P.S I have an FB/EK Housing here at home if you want to stick with the original type housing but the problem is getting it to you from where I live.Transport companies don't seem to be interested in servicing low volume customers as I'm finding out.I'm trying to get a red motor centre delivered from Wentworth near Mildura to my place and no transport company could be bothered helping me out.Too heavy for Australia Post as well.
I can't think what to write here so this will do.
Have you tried http://www.airroaddirect.com.au
I haven't myself, but they do jobs without a business account etc.
I haven't myself, but they do jobs without a business account etc.