5th gear noise

[matthew74]

'99 def 90 td5. I think my gear box is on the way out. It's started making a chirping noise in 5th which I believe is a layshaft bearing. I'm thinking a new recon box from ashcrofts but while its been done I'd like to swap the tbox to a 1.22 ratio as I do a few motorway miles and also get the clutch done.

The questions are:

1. Should i keep driving it until it goes bang?!

2. How long does it normally take before it goes bang?!

3. Would I need to change the ecu for the different tbox as the 99 ecu can't be re-mapped?

4. Which clutch kit to go for?

Thanks in advance.

[Retroanaconda]

Are you 100% sure it's the gearbox? And not something simple like a U/J or the like?

[matthew74]

I'm not 100% sure, but It only makes the noise in 5th.

[101sean]

I had similar a few years ago, sounded like a demented parrot trapped in the box and was told a layshaft bearing. Did around 1000 miles like it before I swapped the box.

Changing your Tbox makes no difference to the ECU, just need to swap the speedo drive over. I have a 1.22 box from a D1 in my Td5 which means the throttle map doesn't switch but I',m not too bothered. If you want to keep that and are fitting a SH Tbox from a D2 make sure it has the difflock.fitted.

[matthew74]

Thanks 101sean.

[Oakmaster]

Might be worth checking the prop UJs I had a 'chirping' noise which was a UJ (on front prop on a 83 stage 1 V8 - list price from LR genuine part was £850 in 1994 - cheaper to buy a new gearbox!)