Member Since: 06 Mar 2017
Location: Lost
Posts: 5180
Rear differential seals replacement.
To do the seals proceed as follows.
1. Pop out the rear wheel centre cap of the intended side and break the torque
on the drive shaft retaining nut as well as both sets of rear wheel nuts.
2. Deflate the air suspension or place it is "access mode" Chock the front wheels
and raise the vehicle making certain it is supported correctly,
and remove the rear road wheel.
(If you don't have the aid of a lift, you will need to remove the opposite road wheel as well)
3. Remove the brake caliper and tie it above the upper susp arm out of the way.
4. Mark carefully the position of the upper knuckle to susp arm bolt
(camber) in relation to the arm and remove the nut.
5. Pop off the susp levelling sensor rod from it's position on the upper arm,
and remove the ABS sensor from the hub housing.
6. Undo and remove the ARB drop link from both sides of the ARB,
as well as the toe link retaining bolt and move them both out of the way
7. Drive out the bolt from the upper knuckle.
(be prepared for the heavy hub falling toward you)
8. Remove the drive shaft retaining nut, and using a suitable drift
in the centre recess of the half shaft, shock it loose with the aid
of a hammer. Do not strike the threads! As the shaft slides
back the hub will fall further towards you, but it will be retained
by the bottom knuckle! (see pic below)
9. Working from beneath the vehicle use a suitable combination of wood and
a pry bar, or length of wood and heavy hammer to shock the inner shaft out
of the diff. For later reference, note the seated position of the old seal in
relation to the diff housing!
10. Clean thoroughly the external surface of the diff tubes, and Remove the
drive shaft keeping the splines clean. Then remove the seal from the diff
using a seal puller or other suitable implement.
11. Place the new seal carefully into the housing tube, and with a few gentle
taps ensure it is seated evenly in the diff.
12. Using the special tool (or a home made recessed tool, see below) gently
tap the seal and check it's progress is even as you go. If it is going in even tap
it fully home until fully seated in the housing tube.
Replace the retaining clip on the diff end of the shaft, a thin smear of grease
will help keep the clip centered.
13. Apply a thin film of oil to the new seal and carefully slide the shaft
back into the diff making sure to locate the shaft splines correctly.
An assistant with this is helpful.
14. If the shaft does not slide fully home, make sure the splines are
engaged and try again. Thread the old shaft nut back on to outer
CV and using a heavy hammer and wood block drive the shaft
fully home, so that the retaining clip is now seated inside the diff.
Insert the outer CV back into the hub and retain it there
with a few turns the new nut.
Prise down the upper arm as far as you can, and place a block of wood
between the arm and body to keep it there.
Using a Jack carefully and slowly raise the hub and bottom arm
so that the upper knuckle can once again be located in the upper arm.
Insert the camber adjusting bolt. (from the front side of the arm)
15. Reconnect the height level sensor, ARB links, caliper etc and clean the ABS
sensor with brake cleaner before reinserting.
Tighten everything as per below and Re-inflate the suspension.
TIGHTENING TORQUES
DRIVE SHAFT RETAINING NUT 230Nm
(for an older bearing you may need to increase this if there is any "Play" afterwards)
UPPER KNUCKLE CAMBER ADJUSTER 133Nm
TOE LINK TO HUB BOLT 175Nm
(Use a centre punch to make a mark on the head of this bolt indicating it has been retorqued,
once 4 punch marks are present the bolt must be replaced)
If you do not have a socket or suitable drift to drive home the seal, a quick and easy DIY option can be fashioned from approx 5"x 5" square (or round) piece of 3/4" plywood. Then, using a 70mm hole saw make a cut into the plywood to around 10mm depth. Now place the plywood in a vice and using a wood chisel remove the centre layers until you are down to 10mm.
This recess will now sit over the outer lip of the seal and protect it as it sits
in the diff! A longer piece of wood or pipe can be used to tap the seal in,
but check it's going in evenly and adjust the point where you are striking the
plywood to ensure it's even travel home
Click image to enlarge
yµ (idµ - eAµ) ψ=mψ
3rd Jan 2025 12:10 pm
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
Much appreciated, really. I'll order the seals and a few other bits that could do with being done while I'm in there, should be able to attempt it in the next few weeks.
3rd Jan 2025 1:38 pm
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
Checked the old oil today, it had been sitting since I drained it, no water contamination...
12th Jan 2025 9:57 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5180
In that case it's possible whoever last changed the oils used an incorrect grade which might account for it's poor condition.
Overfill might account for the rear seal leaks and if they're holding now that's at least one possible problem mitigated against.yµ (idµ - eAµ) ψ=mψ
12th Jan 2025 10:03 pm
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
The wrong oil would surprise me as it was done by a very well-known and respected transmission specialist, but not impossible I suppose. But the overfill on both diffs also surprised me so anything is possible, no one had touched the diffs since them.
The NR seal is still leaking, it's only a very slight weep making the shaft look a bit damp but with no drips. I've got that to do in a few weeks.
13th Jan 2025 8:08 am
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
At the same time as changing the diff oil the transmission specialist also did a running flush of the autobox and changed the transfer case oil too... I changed the transfer case oil yesterday (was curious of the condition given what I found in the diffs) but it still looked quite healthy. Relatively transparent, not too dark. But would like to get the autobox fluid changed again just to have peace of mind that the fluids are all the correct ones at the correct levels given the state of the diffs. Another job to add to the list...
13th Jan 2025 8:13 am
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
Would the early 6 speed D4 rear diff (3.54) work on my 05 D3 TDV6 auto? Doesn't seem to be a terrible price for a punt, when recon diffs are going for around a grand plus VAT these days.
Member Since: 19 Jul 2015
Location: Fife
Posts: 1056
@ disco chris,
See my earlier post, that's what I did. Sourced a rear diff from A damaged D4, same ratios.
17th Mar 2025 7:50 am
disco chris
Member Since: 25 Apr 2022
Location: London
Posts: 331
Ah yeah, apologies, I'd forgotten that you'd said that. Great news. I think I'll investigate that option as the the grumbling is getting louder recently. For some reason the D4 diffs seem cheaper from the breakers than the D3 diffs.
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