Final drives, diffs and all that stuff.
Discussion
Got a few questions for a really knowelgeable person to answer (aint me obviously! 
)
Suppose you have a differential that sits in its casing, and the application you wish to use it for wont allow it to be used due to space constraints, namely the diff is too large in diameter along with its casing to fit into a particular space that it *must* be fitted into.
Thats the scenario.
The question is: Is it possible to reduce the crownwheel diameter and maintain the same final drive ratio to allow a diff casing to be modified in order to allow fitment of the aforementioned differential into the space available??????
If the answer is yes/maybe, can anyone recommend a company that could supply me with the modified componentry or maybe modify the existing parts to acheieve this difficult solution???
Im thinking quaife engineering but im also thinking "expensive"!!
Any help as ever gratefully appreciated.
Ps, the diff is approx 20mm in diameter larger than the space will allow it to go into.
) Suppose you have a differential that sits in its casing, and the application you wish to use it for wont allow it to be used due to space constraints, namely the diff is too large in diameter along with its casing to fit into a particular space that it *must* be fitted into.
Thats the scenario.
The question is: Is it possible to reduce the crownwheel diameter and maintain the same final drive ratio to allow a diff casing to be modified in order to allow fitment of the aforementioned differential into the space available??????
If the answer is yes/maybe, can anyone recommend a company that could supply me with the modified componentry or maybe modify the existing parts to acheieve this difficult solution???
Im thinking quaife engineering but im also thinking "expensive"!!
Any help as ever gratefully appreciated.
Ps, the diff is approx 20mm in diameter larger than the space will allow it to go into.
I have done exactly what you have just said, fitting an 8.5" Salisbury 4HU Pow-R-Lok diff into a Salisbury 14HU 8" XK8 open diff. I used 15HU side shafts to suit the spline of the 4HU which I had ground to suit the package, then had a custom diff carrier machined from solid EN8.
That is probably the best way of going about it.
If you want a very big diff in a very tight space on a transverse gearbox you can get one half of the diff machined from gear steel and have the teeth cut into the casing, and then brace the casing with extra webs tig welded along the major stress lines to help the casing withstand gear separation forces (low grip tyres and an open diff are the safety mechanism in many cars for the transaxle).
A custom case is well within the abilities of any competent machine shop who can turn and drill.
That is probably the best way of going about it.
If you want a very big diff in a very tight space on a transverse gearbox you can get one half of the diff machined from gear steel and have the teeth cut into the casing, and then brace the casing with extra webs tig welded along the major stress lines to help the casing withstand gear separation forces (low grip tyres and an open diff are the safety mechanism in many cars for the transaxle).
A custom case is well within the abilities of any competent machine shop who can turn and drill.
GavinPearson said:
I have done exactly what you have just said, fitting an 8.5" Salisbury 4HU Pow-R-Lok diff into a Salisbury 14HU 8" XK8 open diff. I used 15HU side shafts to suit the spline of the 4HU which I had ground to suit the package, then had a custom diff carrier machined from solid EN8.
That is probably the best way of going about it.
If you want a very big diff in a very tight space on a transverse gearbox you can get one half of the diff machined from gear steel and have the teeth cut into the casing, and then brace the casing with extra webs tig welded along the major stress lines to help the casing withstand gear separation forces (low grip tyres and an open diff are the safety mechanism in many cars for the transaxle).
A custom case is well within the abilities of any competent machine shop who can turn and drill.
Speaking as someone who is currently up to his arms in 4HA and 4HU bits, why did you want to do this? Wouldn't it have been easier to get limited slip unit that fitted the 14HU from the outset?
The 14HU is the centreline diff fitted to the XK8 and XJ8. The 15HU is the XJ40 / X300 axle from 1986 to 1997 model years.
There was no limited slip differential for the 14HU (and I suspect there still isn't), and as the XK180 project needed a limited slip diff I had to design one. Hope that explains adequately....
There was no limited slip differential for the 14HU (and I suspect there still isn't), and as the XK180 project needed a limited slip diff I had to design one. Hope that explains adequately....
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