A tale of three discoveries (4x4 and V8 content)
Discussion
So, onto that drivetrain work.
Those who like the meaty nuts & bolts posts should like this one. It's a bit of a long one.
A little while ago I picked up a new transfer box.
This was another LT230, the same as fitted to the Disco already, but from a Defender. So this new one has a 1.4:1 gear ratio instead of the standard D2 1.2:1 ratio.
The reason for the change is the 33" tyres that I have fitted. The larger circumference had the result of effectivly lengthening the gearing, which meant the Disco was now geared to cruise in top gear at 100mph plus.
The engine could do it, but at anything past 70mph the rest of the Disco (suspension, brakes, steering, aerodynamics etc...) starts to get out of it's comfort zone. So the extra top speed was largely pointless. The new transfer box ratio would cancel out the larger tyres and return the gearing to near standard, meaning the extra V8 grunt could be used for more useful acceleration.
I picked up this box reasonably cheap, because it had a common issue - The splines on the inside that mate with the output shaft from the gearbox were well worn.
That didn't bother me though, as I'm happy to do a quick refurb and swiftly ordered the appropriate bits.
OEM Timkin bearings
And a new input gear with nice straight splines. (Still covered in storage wax)
Got the box into the garage and onto my bench.
God knows why my camera made the next few pictures look really dark, the lighting in my garage is reasonably good.
Rear bearing housing removed and the input gear comes straight out.
Unfortunately the two housing retaining screws were past it. They rounded straight away and needed to be it drilled out.
So I got some stainless allen head replacements.
So on with the rebuild, and the front and rear outer races were removed along with the bearing preload shim
Mating faces of the bearing housing and box casing needed to be cleaned up.
After
The sump plate got the same treatment (no after pic though)
The new input gear was then cleaned of all it's storage wax.
The new inner races were then pressed on at each end.
The front outer race was fitted to the gearbox case.
And the rear one fitted into the bearing housing, WITHOUT the preload shim at first.
The bearings were then given a quick squirt of gear oil.
And fitted to the transfer box.
The bearing housing was then fitted (with the gasket as it's thickness is included in the preload) and the play was measured with a DTI.
Play was measured at 3.65mm, plus 0.05 preload gave a required shim of 3.7mm. Exactly what the existing shim was, so no dramas there.
The housing was removed, race pressed out, shim fitted and then everything put back together and correctly torqued. (Forgot to take a pic again.
)
Lastly a new input seal was fitted to the casing. One of the inner races from the old input gear was just right to press it in. :tup:
Next I wanted to do some preventative maintenance prior to fitting. This is the intermediate shaft, which is a common spot for the LT230 to leak from
The retaining plate was removed and shaft was pushed forward to reveal the two o-rings, which were both replaced.
With that, the new box was pretty much ready to go.
The old one was removed
Before the new one could be refitted, the output flanges had to be swapped over as they are different sizes between the Defender and Discovery.
This gave me a chance to do the output seals too.
Including the little white felt ones which seal the splines
And there we go, ready for fittment. Old (left) and new (right) boxes together
No pics of refittment as it started to get dark quickly and I wanted to get finished.
The new box is lovely to drive with. As expected, it's like having the standars wheels back on. She picks up and accelerates much quicker than before.
An added bonus is also that the shift points on the automatic gearbox are right where they should be - something I hadn't noticed was off before, because I'd fitted the bigger wheels straight away when I bought this Disco. But having driven It now I couldn't go back to how it was before.
For those who made it through to the end of that post. Thanks for reading.
As always, comments welcome.
Those who like the meaty nuts & bolts posts should like this one. It's a bit of a long one.
A little while ago I picked up a new transfer box.
This was another LT230, the same as fitted to the Disco already, but from a Defender. So this new one has a 1.4:1 gear ratio instead of the standard D2 1.2:1 ratio.
The reason for the change is the 33" tyres that I have fitted. The larger circumference had the result of effectivly lengthening the gearing, which meant the Disco was now geared to cruise in top gear at 100mph plus.
The engine could do it, but at anything past 70mph the rest of the Disco (suspension, brakes, steering, aerodynamics etc...) starts to get out of it's comfort zone. So the extra top speed was largely pointless. The new transfer box ratio would cancel out the larger tyres and return the gearing to near standard, meaning the extra V8 grunt could be used for more useful acceleration.
I picked up this box reasonably cheap, because it had a common issue - The splines on the inside that mate with the output shaft from the gearbox were well worn.
That didn't bother me though, as I'm happy to do a quick refurb and swiftly ordered the appropriate bits.
OEM Timkin bearings
And a new input gear with nice straight splines. (Still covered in storage wax)
Got the box into the garage and onto my bench.
God knows why my camera made the next few pictures look really dark, the lighting in my garage is reasonably good.
Rear bearing housing removed and the input gear comes straight out.
Unfortunately the two housing retaining screws were past it. They rounded straight away and needed to be it drilled out.
So I got some stainless allen head replacements.
So on with the rebuild, and the front and rear outer races were removed along with the bearing preload shim
Mating faces of the bearing housing and box casing needed to be cleaned up.
After
The sump plate got the same treatment (no after pic though)
The new input gear was then cleaned of all it's storage wax.
The new inner races were then pressed on at each end.
The front outer race was fitted to the gearbox case.
And the rear one fitted into the bearing housing, WITHOUT the preload shim at first.
The bearings were then given a quick squirt of gear oil.
And fitted to the transfer box.
The bearing housing was then fitted (with the gasket as it's thickness is included in the preload) and the play was measured with a DTI.
Play was measured at 3.65mm, plus 0.05 preload gave a required shim of 3.7mm. Exactly what the existing shim was, so no dramas there.
The housing was removed, race pressed out, shim fitted and then everything put back together and correctly torqued. (Forgot to take a pic again.
)Lastly a new input seal was fitted to the casing. One of the inner races from the old input gear was just right to press it in. :tup:
Next I wanted to do some preventative maintenance prior to fitting. This is the intermediate shaft, which is a common spot for the LT230 to leak from
The retaining plate was removed and shaft was pushed forward to reveal the two o-rings, which were both replaced.
With that, the new box was pretty much ready to go.
The old one was removed
Before the new one could be refitted, the output flanges had to be swapped over as they are different sizes between the Defender and Discovery.
This gave me a chance to do the output seals too.
Including the little white felt ones which seal the splines
And there we go, ready for fittment. Old (left) and new (right) boxes together
No pics of refittment as it started to get dark quickly and I wanted to get finished.
The new box is lovely to drive with. As expected, it's like having the standars wheels back on. She picks up and accelerates much quicker than before.
An added bonus is also that the shift points on the automatic gearbox are right where they should be - something I hadn't noticed was off before, because I'd fitted the bigger wheels straight away when I bought this Disco. But having driven It now I couldn't go back to how it was before.
For those who made it through to the end of that post. Thanks for reading.
As always, comments welcome.
Edited by JordanTurbo on Sunday 25th December 21:25
So next mod.
Back at the start of the thread, you'll see that I fitted a Discovery 1 linkage to my old TD5, to activate the Diff lock internals in the transfer box.
I always thought that having the use of the traction control and the diff lock at the same time was one of the best modifications I ever did to that D2, but I hadn't yet sorted out similar for this one.
With the change of transfer box I thought I better pull my finger out and fit something, but I wanted wanted to do something a bit more than my previous effort.
I decided I wanted it to be switched electronically on the dash instead of using the tranfer lever. So sourced an electronic actuator.
The actuator is fully environmentally sealed so should be fine living under the Disco and has a strong 100kg pull rating which is more than enough for engaging the CDL.
The only problem I found after some playing about in the garage, was that the 2" stroke length was a bit longer than I required. So I took the actuator apart to look at moving the internal micro switches to reduce the travel.
All done and shortened to about 1" stroke.
Next up was making a support bracket to mount it to the gearbox. This was reasonably easy using the end brackets supplied with the actuator, and some suitable angle steel I already had.
The diff lever end had some steel welded on to allow it to correctly engage with the spigot on top of the transfer box.
And here it is all fitted for testing on the old Disco box.
CLICK ME FOR VIDEO
I then sorted out the wiring to switch it between locked and unlocked positions from an OEM switch on the dash.
CLICK ME FOR VIDEO
The factory tell tale LED in the switch shows the current selection of the actuator but not the CDL lock/unlock status - the factory dash symbol is still used for that and lights up as normal.
I'll sort out changing the fog light symbol on the switch for the correct CDL picture at a later date, just currently working out the best way to do it.
For now just I got everything fitted up properly so it can be used, but first the bracket needed a lick of paint.
And then onto the Disco
I used a factory plug for the actuator wiring so that it could be cliped in neatly with the rest of the Transfer box wiring.
And that's that. It all works as it should, can't wait to get off road again and test it out.
Thanks for reading.
Back at the start of the thread, you'll see that I fitted a Discovery 1 linkage to my old TD5, to activate the Diff lock internals in the transfer box.
I always thought that having the use of the traction control and the diff lock at the same time was one of the best modifications I ever did to that D2, but I hadn't yet sorted out similar for this one.
With the change of transfer box I thought I better pull my finger out and fit something, but I wanted wanted to do something a bit more than my previous effort.
I decided I wanted it to be switched electronically on the dash instead of using the tranfer lever. So sourced an electronic actuator.
The actuator is fully environmentally sealed so should be fine living under the Disco and has a strong 100kg pull rating which is more than enough for engaging the CDL.
The only problem I found after some playing about in the garage, was that the 2" stroke length was a bit longer than I required. So I took the actuator apart to look at moving the internal micro switches to reduce the travel.
All done and shortened to about 1" stroke.
Next up was making a support bracket to mount it to the gearbox. This was reasonably easy using the end brackets supplied with the actuator, and some suitable angle steel I already had.
The diff lever end had some steel welded on to allow it to correctly engage with the spigot on top of the transfer box.
And here it is all fitted for testing on the old Disco box.
CLICK ME FOR VIDEO
I then sorted out the wiring to switch it between locked and unlocked positions from an OEM switch on the dash.
CLICK ME FOR VIDEO
The factory tell tale LED in the switch shows the current selection of the actuator but not the CDL lock/unlock status - the factory dash symbol is still used for that and lights up as normal.
I'll sort out changing the fog light symbol on the switch for the correct CDL picture at a later date, just currently working out the best way to do it.
For now just I got everything fitted up properly so it can be used, but first the bracket needed a lick of paint.
And then onto the Disco
I used a factory plug for the actuator wiring so that it could be cliped in neatly with the rest of the Transfer box wiring.
And that's that. It all works as it should, can't wait to get off road again and test it out.
Thanks for reading.
Edited by JordanTurbo on Tuesday 27th December 20:09
JordanTurbo said:
Thanks guys, just got to decide how to best get a factory look on the custom switch front now.
the only thing i can think of is buy a spare switch from a wrecked disco and put it in a blank location , and get a custom sticker made up to make it look factory ( or wipe the factory icon off with some acetone and then stencil a new icon on with some white airfix paint)Tinkshusband said:
the only thing i can think of is buy a spare switch from a wrecked disco and put it in a blank location , and get a custom sticker made up to make it look factory ( or wipe the factory icon off with some acetone and then stencil a new icon on with some white airfix paint)
I have plenty of spare switches to experiment with.The issue is that the factory switches illuminate at night, and I want to keep that when I relabel this one.
The switch front is actually translucent and then covered in black leaving the icon showing. I need to get the black off, then work out how to make a tidy stencil to redo it.
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