Major transmission failure. Need help troubleshooting

Hello All and thank you in advance for any advice. I have searched forums but no luck on troubleshooting this issue on my Defender 90 200 tdi. I have had a "clunk of death" since I imported this creampuff to Tampa Florida about 1 year ago. I use the Landy for kiteboarding only which is infrequently and relatively short distances. Today as I was merrily returning home from a decent kiting session, thinking to myself "I really enjoy this vehicle" when all of a sudden after shifting into 3rd and slightly accelerating I heard a loud "clunk" and it was just like being in neutral. I tried to engage transfer case (difficult to shift and couldn't get it in high at all) still no movement. If I put it in 3rd or 4th gear and release the clutch it has a slight grinding sound. Not so much in 1st or 2nd gear. The clutch seems to feel and operate fine but I am not ruling that out as the culprit. My buddy towed me home with a strap and as we reached about 30 miles per hour the transmission started making a clicking or grinding sound which proceeded all the way home at all speeds. I read something about "meshing gears" "side shaft" or "drive flange" . Sorry that these vehicles are very rare here and nobody has much knowledge on working on them. I am a decent shade tree mechanic and apologize if those terms are common knowledge but perhaps we call them something else here. If I could know where to start to evaluate and determine what exactly has failed I would really appreciate it! Thanks again. Cheers!

Hello,
I’ll get @accynina or @accywingy to shift this to the Tratter section as they are a knowledgeable lot in there...
Buccaneers or Chiefs?

Does it drive if you lock the centre diff?

JohnM70 said:

Hello,
I’ll get @accynina or @accywingy to shift this to the Tratter section as they are a knowledgeable lot in there...
Buccaneers or Chiefs?

Click to expand...

Who?

Stripped output shaft on the main gearbox perhaps, if diff lock does not restore drive.

If the noise is coming from the gear-box / transfer-box then the output shaft can strip its splines where it attaches to the transfer-box.
The splines on the drive flanges can also wear where the half-shaft enters them. This is the easiest to fix, just one failed flange will disable the vehicle, but drive will be restored if you lock the diff-lock.

Rowdies was my favourite team. Had Rodney Marsh playing for them for a while. Even stayed in Tampa Florida for R n R when I was in Belize Central America as a Heli-refueller.
That's by the by welcome to Daft Zoo

saxavordian said:

Rowdies was my favourite team. Had Rodney Marsh playing for them for a while. Even stayed in Tampa Florida for R n R when I was in Belize Central America as a Heli-refueller.
That's by the by welcome to Daft Zoo
View attachment 229439

Click to expand...

Is that a talking knob??

Kiteboarder Ken said:

Hello All and thank you in advance for any advice. I have searched forums but no luck on troubleshooting this issue on my Defender 90 200 tdi. I have had a "clunk of death" since I imported this creampuff to Tampa Florida about 1 year ago. I use the Landy for kiteboarding only which is infrequently and relatively short distances. Today as I was merrily returning home from a decent kiting session, thinking to myself "I really enjoy this vehicle" when all of a sudden after shifting into 3rd and slightly accelerating I heard a loud "clunk" and it was just like being in neutral. I tried to engage transfer case (difficult to shift and couldn't get it in high at all) still no movement. If I put it in 3rd or 4th gear and release the clutch it has a slight grinding sound. Not so much in 1st or 2nd gear. The clutch seems to feel and operate fine but I am not ruling that out as the culprit. My buddy towed me home with a strap and as we reached about 30 miles per hour the transmission started making a clicking or grinding sound which proceeded all the way home at all speeds. I read something about "meshing gears" "side shaft" or "drive flange" . Sorry that these vehicles are very rare here and nobody has much knowledge on working on them. I am a decent shade tree mechanic and apologize if those terms are common knowledge but perhaps we call them something else here. If I could know where to start to evaluate and determine what exactly has failed I would really appreciate it! Thanks again. Cheers!

Click to expand...

Think poor old ken from over the pond may need some pics to lay it out for him as the Cousins over the water have different terminology i believe for the drive train ( transmission)

Hope these help

Hopefully these should help a bit @Kiteboarder Ken

JohnM70 said:

Hello,
I’ll get @accynina or @accywingy to shift this to the Tratter section as they are a knowledgeable lot in there...
Buccaneers or Chiefs?

Click to expand...

Bucs for sure. First time ever that a home team has played in a Superbowl. If it wasn't for the 'rona it would be a 2 week, nonstop party! Now just a one weeker--

saxavordian said:

Rowdies was my favourite team. Had Rodney Marsh playing for them for a while. Even stayed in Tampa Florida for R n R when I was in Belize Central America as a Heli-refueller.
That's by the by welcome to Daft Zoo
View attachment 229439

Click to expand...

I knew Rodney. My best friends sister married a Rowdies player and Rodney was his teammate. We had a good time at the reception. Those guys could guzzle some booze fosho.

Cavey_P38 said:

View attachment 229444 View attachment 229445

Hopefully these should help a bit @Kiteboarder Ken

Click to expand...

Yes helpful. Thank you very much for the effort. It doesn't move with the differential locked either. I guess I will tear it apart and take a peek. Just hoping there were some tests that I could perform to isolate the problem. I am sure that shaft must be stripped. Now to run down to the parts store at the corner and pick up everything I need to do the necessary repairs. Oh wait----I am in the States, let me order some parts, pay five times the price and wait a week or two to get them.

When I had this problem it turned out to be the clutch. The splined boss in the middle of the friction plate had come loose, so the friction plate wasn't transmitting any torque to the gearbox. Also, like the fault described here, it happened on letting the clutch up after a gearchange, and when the engine was run or the vehicle was towed there was a slight clanging clattering noise. Yes of course there are a whole variety of splined joints which can wear out, but don't forget the humble clutch.

Kiteboarder Ken said:

Hello All and thank you in advance for any advice. I have searched forums but no luck on troubleshooting this issue on my Defender 90 200 tdi. I have had a "clunk of death" since I imported this creampuff to Tampa Florida about 1 year ago. I use the Landy for kiteboarding only which is infrequently and relatively short distances. Today as I was merrily returning home from a decent kiting session, thinking to myself "I really enjoy this vehicle" when all of a sudden after shifting into 3rd and slightly accelerating I heard a loud "clunk" and it was just like being in neutral. I tried to engage transfer case (difficult to shift and couldn't get it in high at all) still no movement. If I put it in 3rd or 4th gear and release the clutch it has a slight grinding sound. Not so much in 1st or 2nd gear. The clutch seems to feel and operate fine but I am not ruling that out as the culprit. My buddy towed me home with a strap and as we reached about 30 miles per hour the transmission started making a clicking or grinding sound which proceeded all the way home at all speeds. I read something about "meshing gears" "side shaft" or "drive flange" . Sorry that these vehicles are very rare here and nobody has much knowledge on working on them. I am a decent shade tree mechanic and apologize if those terms are common knowledge but perhaps we call them something else here. If I could know where to start to evaluate and determine what exactly has failed I would really appreciate it! Thanks again. Cheers!

Click to expand...

Does it drive in diff lock (changing hi/low won’t help). If it does then could be drive flange or broken half shaft. Easy fix if you have some spanners. If it doesn’t drive in diff lock then my guess would be worn splines on the gearbox output shaft/ transfer box input gear - the input gear in the LT230 wasn’t cross drilled as standard for some god unknown reason so splines don’t get lube. That’s much more of a hassle.

Def90man said:

Is that a talking knob??

Click to expand...

Brilliant, randomness restored. Simply WTF.

doriz said:

Brilliant, randomness restored. Simply WTF.

Click to expand...

Why, thanks, I think

payydg said:

Does it drive in diff lock (changing hi/low won’t help). If it does then could be drive flange or broken half shaft. Easy fix if you have some spanners. If it doesn’t drive in diff lock then my guess would be worn splines on the gearbox output shaft/ transfer box input gear - the input gear in the LT230 wasn’t cross drilled as standard for some god unknown reason so splines don’t get lube. That’s much more of a hassle.

Click to expand...

This ^^

The first thing to check is to confirm that you are actually selecting and locking the central diff, little gearstick all the way over to the left hand side of the vehicle (which should be the passenger side if you have a proper one rather than a mirror image for the foreign market version!). If it is not something that is used regularly it may be worth getting under the vehicle and looking up at the transfer case to ensure difflock is actually engaging. The blue circle on the pic below is the end of the linkage connecting the the transfer box and can be seen if you look up from the underneath of the vehicle to the righthand side of the gearbox to the rear of the bell housing. it is common for this to become stiff and move to fully engage diff lock.




If it does drive when you select diff lock then the probelm is going to one of the axles. In which case jack up each wheel individually and try and turn it. if the wheel turns that is the wheel which has the problem. Likly to be a broken half shaft or a stripped drive flange as mentioned above.

If it does not drive in diff lock then first make sure diff lock is actually engaged as I mentioned above, if still not driving then the problem is gearbox, transfer box or clutch, all of which will likly requir removal to rectify but there are a couple fo checks which can be made without removal.

You can remove the transfer box input drive with everything fitted to the vehicle and check both it and the gearbox output shaft for wear (link). If these both look to be fine then I would be suspecting the clutch @Brown mentioned. But at this point you will be dropping the boxs anyway to either repair the gearbox faults or replace the clutch.

Another ploy that might tell you something is to see if the vehicle feels like it's trying to move in 4th gear but not the others. 4th gear is a 'straight through' gear and doesn't rely on any of the other cogs in the box. If this happens you might suspect a problem in the primary gearbox.

Just watch that you should remove the prop shafts before towing these. If the broken bit had jammed the transmission during towing....

Similar to others I wouldn’t rule out the clutch but if you’ve succeeded with diff lock and still no movement it has to be in the gear boxes or clutch.

If it still makes the noise when the gearbox is in neutral then the transfer box is probably ok. If pressing the clutch up and down doesn’t change the noise it may be a clutch problem.

As suggested it could be the clutch friction plate, or another common issue on older landies is the pivot could have punched through the clutch fork/arm. Both are easy fixes once you’ve gotten to them.