Hello everyone,
last night I was going out to diagnose a separate problem when I see a stain on the driveway and sure enough it’s transmission fluid and oil
(i think oil at least and not just super dirty trans fluid).

I noticed the leak last night coming from transmission(smaller red circle) but when I took photos today I saw some orange/red fluid on the shock absorber but that may be coolant.


it left a pretty good size stain from just sitting overnight but seems to be more oil then tranny fluid as I’m only getting a small hint of red when I wipe it off.


How big of a job is the rear main seal? And are there any any threads on how to go about it for a 1998 XJR?

I have also seen threads talking about a plug that’s at the top of the transmission that is also prone to leaking. Could someone please show me exactly what plug that is?

 

The part with the larger circle is the bottom of the steering rack.

To replace the rear main seal requires removing the propeller shaft and gearbox. There is also an oil galley plug with a hex pattern at the back of the engine just above the rear main crankshaft seal that is prone to leak as well.

 

I'd guess it's power steering fluid due to the wet bit in your larger circle being the steering rack. PS fluid looks & feels similar to ATF so hard to tell apart.

I had what looked like a leak in the same area & it turned out to be a hose in the back of the power steering pump weeping & getting blown back as I was driving. Nipping the nut up on the back of the pump fixed mine which was a surprisingly easy fix.

 

I was able to get under the car and cleaned up all of that area with brake cleaner. I’m going to drive on it a little bit and see if I see any transmission fluid or hopefully power steering fluid.

The RED circle is where I found oil coming from, it had no smell though so it’s my best guess until I can see the transmission fluid.

The BLUE circle is where I think the torque converter is at and it has some noticeable pieces of metal missing all over as shown in the video below.



This photo is of my transmission pan. I noticed some orange substance coming from it. When I felt it was like a gel texture.
There were also drops off this gel like stuff on my engine oil pan.(video down below)

 

Engine coolant (DEXCOOL) is ORANGE so it could be the heater feed/return hoses on top of the engine block or the heater (octopus) hose on top of the gearbox.
Also, the PAS fluid IS ATF. Jaguar filled the system with Dexron III initially.

 

Would coolant gel up like that?
Id like to say it isn’t my coolant because the 2 places you mentioned, I have replaced and made sure there were no leaks.
The only leak I know I have is the 2 piece hard plastic line that runs from overflow tank to intercooler AT the connection to the 2 pieces. And that rests on top of my valve cover at the front of my engine, although it is on the same side.

I never thought to ask about how the steering in these cars should feel, but it’s definitely stiffer than any car I’ve driven. Is that normal?
And I’ll have to check which one I have in my system it seems like.

 

I had a slight coolant leak on those hard line joins, I did occasionally get coolant dripping down the back of the block when parked.

 

So I’ve been looking into what it would take to complete this job and have a few questions about the procedure as this will my very first time doing anything transmission related.
Can I Expect this to be completed in a days time as a rookie?

Since the transmission will be off the car, is there any way to fully drain the transmission oil? It’s got 180k miles and it’s unknown if oil was ever changed. When I checked oil level it was pretty brown but didn’t feel any metal in it.

Is there anything special when putting on the Rear Main Seal? Will it just slip on or will I need a rubber mallet?
When it says “If the transmission is to be refitted, mark the position of the coupling relative to the drive flange.” What exactly am I marking?

And where it says CAUTION, what is the Flexible Coupling Fittings?

When replacing the Oil Galley Plug that’s above the rear main seal, is there a o-ring I should put on it or can I throw silicone around it and call it a day?

While the transmission is out, is there anything I should check, clean, replace etc.?(transmission filter, oil pan gasket electrical connections etc.)

 

Without knowing your skill level and equipment/tools available, it's difficult to say how long it's going to take to replace the rear main seal.

The gearbox can be drained and the filter replaced whilst the unit is removed from the car, but the correct fill level must be achieved following the procedure outlined in the Workshop Manual.

Marking the flange simply means marking the position of the propeller shaft flange relative to the flange at the rear of the gearbox so it's reassembled in the same position. A line of yellow paint across the flange joint is a good method to make sure the parts are replaced in the same position. The flexible coupling does not need to be disturbed as it comes off with the propeller shaft.

Remove the plug to the oil galley and renew the o-ring seal. There is no need to slather the fitting with silicone sealant.

Check the cooler lines and other fittings for the gearbox making sure everything is clean and undamaged for refitting. Note the correct coolant is DexCool, which should not be mixed with other types of coolant.

A best practice for this type of operation if you haven't done it before is to take photos of each area prior to disassembly, and keep the bolts and other fittings together to avoid confusion.