Rebuilt LT77 now whining/squeaking and horrible overrun noise

[jayso81]

Hi All,

I am hoping someone can help give me an idea of what's up with my Defender before I take it to the specialist Land Rover shop.

I've got a horrible whine/squeak which I'm pretty sure is coming from the transmission (been driving around without the transmission tunnel to find the source) and a really loud overrun when I take my foot off the accelerator quickly.

The squeaking only happens in 2nd to 5th gears and especially when I'm accelerating, no sound when in neutral and idling. If I depress the clutch it goes away immediately, even if I keep my foot down on the accelerator. It started out a few weeks ago and was only intermittent but lately it's gotten worse and louder.

As for the loud overrun, this only happens when I take my foot off the accelerator quickly and it's been very loud the last week or so. Before this there was little to no overrun sound (I think overrun is the right term to use).

I've uploaded a video to youtube which does a pretty good job of letting you hear the two noises (the squeaking is a little more difficult to hear over the 200tdi), Defender Noise - transmission? clutch? transfer box? front diff? - YouTube . The first noise you'll hear is the squeaking (a little faint at first) the second is the much louder overrun.

The transmission is a reconditioned unit from British Offroad, installed just over a year ago. A few months ago I changed the transmission fluid from a Castrol fluid (not an ATF) to Royal Purple Syncrhomax to aid with the cold winters we have here in Canada.

I've spent the last few weeks scouring the web and forums to find some info and many of the posts seemed a little vague, so I thought I'd post something myself.

Any help is greatly appreciated, thank you kindly!

[slug_burner]

You might have a dry spigot bush

https://www.aulro.com/afvb/images/imported/2013/02/979.jpg

although I suspect that you have some bearings that have too much wear and are allowing the input shaft and lay shaft to move away from each other and aggravating the situation by allowing a small amount of movement in the input shaft.

Could be the clutch release bearing?

Either way it sounds like you will have to drop the gearbox and possibly service it while you have it out.

I'd wait for an opinion from a real mechanic before committing to any expenditure on a repair.

[strangy]

I dont think that is from the gearbox.

Obviously its difficult from a short vid, but i would be checking Ujoints first.

cheers

[PhilipA]

I agree with UJs but will add exhaust manifold gasket,turbo gaskets if any.
Regards Philip A

[bee utey]

I don't trust recorded noises but my guess is a ready-to-explode universal joint. Do not drive it anywhere without checking all the u-joints for slop and rust dust from around the cups.

[jayso81]

Thank you slug_burner, strangy, PhilipA and bee_utey for all of your replies :). I know it can be pretty difficult hearing anything from the microphone of a point and shoot camera but thanks for giving it a shot.

I live a two and a half hour drive from the nearest specialist Land Rover shop (a pain to get to) and you've all helped me quite a bit in focusing in on where I should start.

I figure I'll start with the less expensive parts and repairs first and then, if needed, work up to the gearbox and gaskets.

The UJ's are looking a bit old and I have been noticing that when greasing them it's almost impossible to get any grease into them at all. And yes, there is a lot of rust dust. Thankfully, there is no slop in the driveline at all. Nevertheless, the Landy can sit in the driveway for a week while she awaits parts.

I've just placed an order for all new UJ's, as well as wheel bearings (never been done) and a new CV (to accompany another new one I replaced a couple months ago on the other side)...hopefully arriving by the end of this week. I know no one has suggested bearings or CV's but I thought I'm going to be under the car anyways, might as well get them done.

Hopefully, this will take care of the noise and I won't have to look further at work on the gearbox or clutch.

Thank you again.

[AndrewGJones]

as well as wheel bearings (never been done)

that was my first impression, that it was bearing noise and it could well be the wheel bearing opposite your driving position. From where you sit, it would seem to be the transmission.