SOLUTION to shaking described below: Front driveshaft, at 135,000 miles, was failing at one of the U-Joints. By failing, i mean a part was bent and dried out. Replaced it with a new one from Lucky8, $208 including shipping, pregreased and new bolts, and the scary shuddering on acceleration is completely gone.

SOLUTION to hole in plug: It’s not actually a hole after all, that’s just how the plug came from AB. I got two more, paid for one and was given one free by AB, and they both have chunks out of the center but they’re still solid.

https://cimg9.ibsrv.net/gimg/landrov...d2c5902ba7.jpg

Guys. Do you see the hole in the center of this drain plug? This can't have just spontaneously happened, can it? There is clearly transfer case oil that has drained out, because I see drips around the transfer case and on other parts nearby, nowhere close to the oil pan or oil filter. I'm completely at a loss.

Two weeks ago, I changed the transfer case oil and fitted a brand new fill plug and drain plug right before a 2,000 mile roadtrip to Colorado with my wife and daughter. Rover ran beautifully the whole trip, I was proud. I had also changed the out dif oils and engine oil and some other small things. So the one sticky point with the transfer case was, the fill plug was so tightly stuck in there that, despite lots of PB blaster, I rounded it out using a massive wrench and lots of torque. It was the original fill plug I believe, this was my first time changing the transfer case fluid. This was the plug Drain Plug For Axle/Differential/Transfer Case On Land Rover - 608246, and I replaced it and the drain plug with the same one, as AB sent it to me as part of their transfer case drain and refill kit (which I will never get again; way overpriced). So I rounded the fill plug out, after I had drained the transfer case oil, so I then sadly had to tow it to a shop to have them remove the stripped out fill plug so I could refill the transfer case oil. I haven't taken my Rover to the shop once in three years and 30,000 miles of ownership and hundreds of hours of work. I would have tried to do it myself but we were leaving in two days for our trip. So this shop, with an ex-Land Rover mechanic from the UK who owns multiple Rovers himself including Discos, removed the stripped fill plug and replaced it with my new one, and topped off the fluid.

The reason I checked underneath the Rover tonight, randomly you might say, is because I was trying to diagnose a new onset shaking that started happening yesterday during acceleration. Then I was at work today and my wife was driving and she said the shaking was even worse. I had a little bit of down time at work and did a lot of research, and I came to the conclusion that it was likely either my front driveshaft or the tie rods. So I was under the Rover to briefly check those (which appear fine, but I'll check them more in-depth later), and realized this hole was there, apparently through the center of the drain plug, and random drops of oil were around the transfer case and on nearby things.

How could this hole develop?

Is there a replacement fill plug I could use from a local auto parts store or can I only get compatible ones from AB or similar online sources?

Also, if I refill the T-case and find the shaking is still there, would that possibly indicate a failing output shaft bearing? Based on some stuff I read as well as this: https://www.yourmechanic.com/article...-shaft-bearing

Can I replace an output shaft bearing myself? I see some stuff online on doing it... ugh.

I just can't believe this happened. Unbelievable. Seriously, every single time I work on the Rover to do some maintenance, something else gets screwed up. Every time.

Wow, can’t believe a hole appeared in your drain plug too!

So I had been wondering if it was 1. A rock flying up on the highway and amazingly hitting that small target 2. It disintegrated over time, as I’ve had that plug sitting waiting to be installed for 2 years or 3. The guys that extracted the filler plug STARTED to extract the drain plug and busted a hole in it, then stopped when they realized what they’d done, and didn’t tell me.

My plan is to check the transfer case oil today, see how much is left by draining it, then refill it. Then watch and see if it’s leaking from the same spot or elsewhere. I have a new plug on the way but it’ll be a week till it gets here. If the car still shakes with a full transfer case of oil, AND I find that it was low or out of oil, I guess I may have to assume the front output shaft bearing went bad?

So it is definitely the front driveshaft, which I’m really glad about. I’ve put a dipstick in every oil case and there’s oil in all of them, and plenty. That transfer case bolt—I bought a replacement from Atlantic British and brand new its got a crack and a chunk out of the center!
https://cimg2.ibsrv.net/gimg/landrov...ddd439c70.jpeg



This is definitely a used plug they sent me, it’s clearly had a socket wrench in it. What a joke for $15.

Anyway, here’s what I discovered in the driveshaft today as I was working on getting the frozen bolts off:


Bought Lucky8’s serviceable driveshaft dor $208 and have been working on getting the 8 bolts off. Got two bolts with PB blaster and a lot of effort, one off cutting it with a dremel tool and diamond blade I bought this morning which I’m going to return for some other tool (it broke the ez fit stem in ten minutes). I’m in limbo now till I go to Lowe’s and return the dremel and get another tool. These bolts just strip even with the perfect 9/16 fit.

Question: How do the back bolts come off, given that the flange is blocking the head from backing out? The nut I cut off released the bolt but it’s still held in by the flange coming from the transfer case.