Gearbox help and advice needed

[snailracer]

My gearbox got stuck in 4th last week. Thankfully not too far from home but it was still recovery truck time.

As the day was written off I stripped the cab out to get to the top of the box hoping it was something simple. It wasn't.

Local mechanic has advised that it's got to come out to be fixed so the question is what to do?

It's a standard 4 speed series box and transfer box with overdrive behind a 200tdi discovery engine in a '79 109.

Options seem to be:

Fix it £?

Replace with recon £700 ish or £1500 ish if I do transfer as well

Upgrade to lt77 or r380 using Ashcroft mating kit £1000ish plus some other mods

Upgrade transfer box as well so no need for Ashcroft mating kit £? 

I've been considering selling the landy so also the possibility of selling it broken but how much does that wipe off the value. 

And if I do fix it, and im spending money, should I go for maximum upgrade/comfort and keep it.

Really stuck on this one.

Thanks for reading and any opinions

Matt

 

 

[steve b]

It's most likely to be broken detent spring plates in the 3rd/4th synchro- hub . accessible once out of vehicle without fully stripping it .  

If it was otherwise ok I'd do that - simplest and cheapest if you are thinking of selling it anyway ?

cheers

Steve b

[jordan_meakin]

If you are thinking of selling, whole heartedly agree with the above.  If you want to keep, go for longevity considering your engine and fit lt77.

[snailracer]

Cheers guys. 

It's the first gearbox issue I've had in 16 years so bit worried that other bits might decide to give up once it's messed with.

Does the lt77 make a big difference?

[Snagger]

LT77 will be a fair bit quieter, a lot stronger and will weep less than a perfectly rebuilt Series unit.  But you can't add an overdrive and 5th gear is a fair bit lower than Series 4th with overdrive.

You could add the LT230, but would need to change the diffs to get it all to drive at reasonable speeds and mpg, and would need the speedo recalibrating.  Theoretically, you'd be wanting a CV joint upgrade to the front axle if running full time 4wd, too - the kick back at the steering wheel in 4wd on a solid surface is significant at high steering angles, but I haven't tried it with an open centre diff like the LT230 has.  Not difficult, but more cost and hassle to consider before deciding.  So, removing the existing transmission is an opportunity to fit the more modern transmission, but not an actual reason to do so.

I think Steve is probably correct in diagnosing the 3rd/4th synchro leaf spring failure being the cause - they are a common failure point and very cheap to replace (do all three).  I consider them an essential replacement any time the gear box is opened up, as they're cheap, cause such trouble, are so prone to failure when old, and are such a pig to do (needing the box to be removed and opened).  What else you find when the box is open depends on how well it was looked after, but I'd recommend replacing all the bearings (ideally Timken, but SKF or NSK will do) and Angus or Corteco seals.  Do not use Britpart components unless you want to do it all again in a month.  Dunsfold Land Rover will stock the springs and other parts, but bearings may be cheapest from you local bearings specialist.  If you take the old ones with you, they'll read the numbers from the races to get the right ones.

[Snagger]

If you do rebuild the existing unit, then make sure you use bearing seating compound (a bit like thread lock) between the main shaft rear bearing carrier and the main casing; that's where the leak into the transfer box is, and why the gear box needs such frequent refilling.

[Bowie69]

16 minutes ago, Snagger said:

Theoretically, you'd be wanting a CV joint upgrade to the front axle if running full time 4wd, too, but haven't tried it with an open centre diff. 

The other way to do this is a selectable 2WD conversion for the LT230 from Ashcroft.