R380 Gearbox

[MRWOO]

Ok I have a vibration within the drivetrain of my 90 300Tdi, originally I have posted symptoms and received responses to check the UJs (replaced) and transfer box front output bearing but I think I have now narrowed it down to the gearbox and more specifically 5th gear i.e. what happens (to note this has a discovery transfer box in)

When it happens-

Step 1. 55 – 60mph in 5th 2400 rpms lots of vibration from somewhere drive train related (only under acceleration) The vibration is worse after everyings warmed up i.e the gearbox oil is thinner etc, the defender is not down on power but almost feels like I have to drive it through a barrier to overcome the vibration which seems to dissappear around 60 - 70 mph.

What I have done to make me think this is the gearbox -

Step 2. 55 – 60mph in 4th 3000 rpm no vibration + same speed

This one rules out transfer box, CV's, UJs and wheel bearings as they are all still turning at the same revolutions as step 1.

Step 3. 45- 50mph in 4th 2400 rpm no vibration + same rpm

This one rules out engine vibration as same RPM's as step 1.

This problem seems to me like a 5th gear problem, if anybody has had any experiences similar please let me know. Is there any other way I could find the problem before ringing up Ashcroft for an new gearbox.

Thanks Richard

[MRWOO]

Since wrting this I have rang L.E.G.S (Land Rover Engine and Gearbox Specialists) whom say that it is likely to be the front differental. They explained to me that it is not likely to be the gearbox as if there was a problem with 5th it would likely to just give up and not vibrate in the mean time. The bit I find hard to understand is how can this be a front differential problem when the vibration is not apparent when travelling the same speed in 4th i.e. same diff, transfer, CV revolutions etc.

Any comments on front diff vibrations please and or 5th Gear problems

Thanks in advance Richard

Edited March 23, 2007 by western
Duplicate of original post removed as it's directly above this post.

[silverwolf]

Since wrting this I have rang L.E.G.S (Land Rover Engine and Gearbox Specialists) whom say that it is likely to be the front differental. They explained to me that it is not likely to be the gearbox as if there was a problem with 5th it would likely to just give up and not vibrate in the mean time. The bit I find hard to understand is how can this be a front differential problem when the vibration is not apparent when travelling the same speed in 4th i.e. same diff, transfer, CV revolutions etc.

Any comments on front diff vibrations please and or 5th Gear problems

Thanks in advance Richard

Check the prop shaft UJs for wear. Diff wear is normally a deep rumble or whine. It should be easy to check if you just crawl under and grab a hold!!

[Douglas]

Richard,

I too have a problem very similar to yours and significantly it manifests itself in 5th gear. Can you tell me what the solution was?

Best Regards

Douglas

Ok I have a vibration within the drivetrain of my 90 300Tdi, originally I have posted symptoms and received responses to check the UJs (replaced) and transfer box front output bearing but I think I have now narrowed it down to the gearbox and more specifically 5th gear i.e. what happens (to note this has a discovery transfer box in)

When it happens-

Step 1. 55 – 60mph in 5th 2400 rpms lots of vibration from somewhere drive train related (only under acceleration) The vibration is worse after everyings warmed up i.e the gearbox oil is thinner etc, the defender is not down on power but almost feels like I have to drive it through a barrier to overcome the vibration which seems to dissappear around 60 - 70 mph.

What I have done to make me think this is the gearbox -

Step 2. 55 – 60mph in 4th 3000 rpm no vibration + same speed

This one rules out transfer box, CV's, UJs and wheel bearings as they are all still turning at the same revolutions as step 1.

Step 3. 45- 50mph in 4th 2400 rpm no vibration + same rpm

This one rules out engine vibration as same RPM's as step 1.

This problem seems to me like a 5th gear problem, if anybody has had any experiences similar please let me know. Is there any other way I could find the problem before ringing up Ashcroft for an new gearbox.

Thanks Richard

[western]

Does reverse give vibrations too, as 5th/reverse are on the layshaft & the bearings can fail.

[kiall]

recently i was working on a discovery 300tdi with a r380 with same problem rumbling in 5 and on a long journey u would struggle to get it out of 5th apparently it was ither balk rings or the layshaft bearing new box sorted it

[JimAttrill]

Does reverse give vibrations too, as 5th/reverse are on the layshaft & the bearings can fail.

You are right, but it is hard to do 60mph backwards

But from the above it looks like a 5th/reverse layshaft problem

[western]

my 5th disappeared at 55mph & I didn't realise I'd lost reverse too, until I tried a 3 point turn at my parents, a fully laden 110 is darn hard to push back on your own, my 380's layshaft bearings had gone on holiday without telling me.

[101sean]

I had a demented budgie trapped in my R380's 5th gear, Ashcroft disgnosed a bearing gone. Fitted new main and tboxes which showed this wasn't the only problem, whole transmission is much quieter

[NicTheOrange90]

After fitting recon R380, then Disco geared recon transfer box, the 'slack' was much more noticable and whole vehicle was sloppy at low speeds (slowing down in gear and then gentle accelerating would sometimes 'rock') also there was a rear end 'slap' when clutch was let out, and finally the traction control would often cut in on acceleration....

New half shafts and driving flanges for front and back (have still got front nearside to do) have cured all of the above, and it drives really well now... Cheap fix (well back one was)...

Also had vibration band on wife's Disco, only in 5th at 70, then at 75ish it was gone, (ahem on a private road for he benefit of the tape) only under load, and could not get it fast enough in 4th.. worn UJ was the cause....

Why not try the old propshaft removal/difflock trick that way your isolating half of the drivetrain...

[Ampo]

MRWOO, sorry to resurrect such an old thread, but I was just wondering if you ever got to the bottom of your 5th gear noise. I have something similar, a kind of grating/ringing noise, only in 5th gear when its under load, which has been going on since I bought my truck nearly 2 years ago. It's not got any worse in that time and has not got any better since changing all the transmission fluids. I want to get it sorted because I don't want it to go bang leaving me miles away from home, but I'm just wondering if there's anything else I can check before I go down the expensive new gearbox route.