Clunking defender 90 axle swap?

Hi guys,

I've got a lovely clunking sound under my 1993 200tdi 90. The props and UJ's are brand new, but there's lots of play in both. (Diff or transfer box?)

I thought it would be cost effective to buy a v8 disco and swap the axles over (disc brakes as a bonus, and then pop the v8 in for some extra bonus).

Will a disco2 axle take much work to fit or should I stick with a D1?

Or can anybody think why I've got the clunking I have? Don't think it's the A frame joint.

Any help is greatly appreciated!! Thanks!!!

Josh999 said:

Hi guys,

I've got a lovely clunking sound under my 1993 200tdi 90. The props and UJ's are brand new, but there's lots of play in both. (Diff or transfer box?)

I thought it would be cost effective to buy a v8 disco and swap the axles over (disc brakes as a bonus, and then pop the v8 in for some extra bonus).

Will a disco2 axle take much work to fit or should I stick with a D1?

Or can anybody think why I've got the clunking I have? Don't think it's the A frame joint.

Any help is greatly appreciated!! Thanks!!!

Click to expand...

The trans has a fair amount of play anyway, it may not be a problem.

Not quite sure why you want to fit Disco axles, is that to try and raise gearing, or is there an issue with existing axles? Drum brakes are just as good as discs, maybe better on a off roader. You will need to fit both axles from the Disco if you want increased gearing. Bigger diameter tyres might be easier.

Have you tested the A frame joint with a small crowbar?

Hi Turbo man,

Thanks for taking the time to reply,

I took a video of the props to a LR specialist and he said there was excessive play and said it could be both diffs.

So I figured I'd like to swap the 200tdi for a v8 anyway, for that nice grawl and 'easier' motorway drive. I stupidly drove mine to Monaco recently and it was a tough drive haha.

So I'm thinking why not just buy a disco and do two jobs at once?

I haven't checked the ball joint with a bar, however, I have jacked the 90 up on 4 axle stands, and started it up to hear the noise. Sounds like it's coming from the front end, maybe transfercase to front diff.

Love off roading it, but a nice auto on the roads would be nice as well. Feel like she needs to be taken care of for the rest of her life now, rather than being trashed.

Josh999 said:

Hi Turbo man,

Thanks for taking the time to reply,

I took a video of the props to a LR specialist and he said there was excessive play and said it could be both diffs.

So I figured I'd like to swap the 200tdi for a v8 anyway, for that nice grawl and 'easier' motorway drive. I stupidly drove mine to Monaco recently and it was a tough drive haha.

So I'm thinking why not just buy a disco and do two jobs at once?

I haven't checked the ball joint with a bar, however, I have jacked the 90 up on 4 axle stands, and started it up to hear the noise. Sounds like it's coming from the front end, maybe transfercase to front diff.

Love off roading it, but a nice auto on the roads would be nice as well. Feel like she needs to be taken care of for the rest of her life now, rather than being trashed.

Click to expand...

Do the diffs howl on the road?

V8 auto is lovely, but a fair amount of work to fit, and fuel economy will not be great.

Check the ball joint with a bar.

You could take either prop off and try with either front or back wheels moving to try and diagnose the cause
Pretty sure you can use disco 2 axel the exact same as disco 1 ones
The v8 swap be fine if doesn't drive much but be killer on wallet for a daily driver. If was me I'd just get 2 axel for disc brakes or just buy new parts for the diffs. Alot of things could cause the knocking though
Also did you try running with no props to make sure it isn't the box?

Do you have an LT77 box (reverse next to first)?, if so it could be worn splines on the gearbox output and/or transfer input gear.

Turboman said:

Do the diffs howl on the road?

V8 auto is lovely, but a fair amount of work to fit, and fuel economy will not be great.

Check the ball joint with a bar.

Click to expand...

I checked the A frame and all seems fine although, I'll add that to the next job on the list as I'd like to swap the bushes out.

There is a howling sound that I'm not sure what's going on, all happened around the time of the clunk. (Same drive back from Monaco-last few hours)

Could it also be the input gear or the transfer box?

I agree, will it be sub 20mpg on a disco v8?

Kwakerman said:

Do you have an LT77 box (reverse next to first)?, if so it could be worn splines on the gearbox output and/or transfer input gear.

Click to expand...

It is an LT77, and I think you might be onto something as well. Could be the input gear, is there a way to check without removing anything yet?

alexc2701 said:

You could take either prop off and try with either front or back wheels moving to try and diagnose the cause
Pretty sure you can use disco 2 axel the exact same as disco 1 ones
The v8 swap be fine if doesn't drive much but be killer on wallet for a daily driver. If was me I'd just get 2 axel for disc brakes or just buy new parts for the diffs. Alot of things could cause the knocking though
Also did you try running with no props to make sure it isn't the box?

Click to expand...

Very good points, I'll do exactly what you said tomorrow and report back! Thanks for the d1/d2 info, wasn't sure if the aframe was the same.

Fuel would be a nightmare, would it be sub 20mpg?

Josh999 said:

It is an LT77, and I think you might be onto something as well. Could be the input gear, is there a way to check without removing anything yet?

Click to expand...

Not really, however if you take the PTO cover off of the transfer box (the round cover with about 7 bolts) then you will be able to see the splines. Should be plenty of threads on here if you do a search.

Josh999 said:

Very good points, I'll do exactly what you said tomorrow and report back! Thanks for the d1/d2 info, wasn't sure if the aframe was the same.

Fuel would be a nightmare, would it be sub 20mpg?

Click to expand...

I'd try with individual props off in diff lock so it drives the wheels moving or jacked up then try with none to check box is okay while stationary see if you can diagnose noise from that. That's if it is in fact diff or boxes could be lots more things

Josh999 said:

I checked the A frame and all seems fine although, I'll add that to the next job on the list as I'd like to swap the bushes out.

There is a howling sound that I'm not sure what's going on, all happened around the time of the clunk. (Same drive back from Monaco-last few hours)

Could it also be the input gear or the transfer box?

I agree, will it be sub 20mpg on a disco v8?

Click to expand...

Howling is more likely to be diff. T box usually knocks when it lets go.

Spline wear in the T box is a good shout on the clunk on take off.

This is me ingaging and releasing the clutch in the first part of the video, then in the later part, I'm pressing on a off the accelerator.

Transfer box?

alexc2701 said:

I'd try with individual props off in diff lock so it drives the wheels moving or jacked up then try with none to check box is okay while stationary see if you can diagnose noise from that. That's if it is in fact diff or boxes could be lots more things

Click to expand...

Just uploaded a video with the props on, I'll try what you said now

Turboman said:

Howling is more likely to be diff. T box usually knocks when it lets go.

Spline wear in the T box is a good shout on the clunk on take off.

Click to expand...

Good info, thanks! I think it could be the transfer box, I've uploaded a video

Send video of props

Josh999 said:

Send video of props

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I don't think that is anything unusual, others may differ. If those don't have any play, the whole thing would seize.

A sound recording of when you pull away might be better.

Another video of the transfer box

Josh999 said:

Send video of props

Click to expand...

There's supposed to be alittle play in them like that, when you moved rear prop in that video it sounds like the handbrake is catching though
mine doesn't make any noise
Did you try with no props on? That'll be a good indicator of if box is okay, though some sounds only come out under load
Also is that oil on your handbrake drum? Might be rear seal on tbox and low oil

Mine has some play in it, at very low speeds in traffic it sounds like yours when I slow and then move on, clunk. I got under it and twisted and played around with it but concluded there is some play anyway. However, when my rear diff started to play up it got very noisy so it was obvious there way and issue, easily replaced. Changing all the diffs over seems a little extreme, the only think I was worried about with mine was the input shafts to the transfer box, when I replaced the 1.4 ratio one to 1.2 disco box I checked them and they were ok. So I guess what I'm saying is unless its noisy don't be too worried about it. I like the clunk in town anyway.