Gearbox woes

[DesM]

I have a 94 Disco 3.9 auto. It has the dreaded clunking transmission, now not only when engaging reverse, but pretty much any throttle action like deceleration or sudden acceleration etc etc. I understand this to be the notorious "input shaft" to the transfer case, (my terminolog and probably wrong) that by some lack of wisdom, LandRover decided to design with no useful way to obtain a steady oil supply - another story I guess.
My questions are - has anyone had this fixed - what was actually done and did it cost a fortune? Any advice is gratefully received....tremble!

[chard]

You would probably be better off investigating other bits of your transmission first as AFAIK the auto does not suffer in the same way as the manual. (Input shaft is different)

Check all your UJ's, sliding joints and that funny dougnut thing on the rear prop. Also check your A frame ball joint as this can produce similar knocking noises.

HTH

[DesM]

Thanks for the feedback. I have replaced the flexible drive coupling and had a new rear A Frame balljoint recently.
Am having an inspection of the gearbox and transfer box this week. Will let you know what I find for others reference.

[DesM]

Well folks - I've been to see my transfer box in a 1000 pieces (actually less but my eyes were blurred with tears) and the input shaft and several gears were in poor states of health. It was pretty much as I feard.
FYI - the input shaft to the transfer case on a Disco auto is approx 7 - 8 " in length. It has 12 splines and inserts into a gear in the transfer box which in turn mates with 4 small gears on a cross arm, which then inserts into a primary gear within the transfer box. Basically Rover decided not to provide an oil pathway (eg drill a couple of holes guys) to the input shaft - and 12 splines is not many anyway and with time and use a certain amount of "play" occurs in the gears and snatch and backlash produce accelerated wear. I haven't got a car yet and we are 3 days into it - cost? well who knows yet, but suffice to say it will not be cheap. All for the sake of some oil holes.
The replacement here in OZ is for a re-machined and case hardened replacement shaft (LandRover gear hardening is a joke over here) which is 22 splines going into a modified gear. Drilled and with proven oil delivery pathways, the 22 splines means a loss of the dreaded 'bang' when shifting into reverse and a certain anount of harshness in upshifts gone as well.
My advice is listen to a few Disco's go crunch and if yours is the worst - get it fixed early - you may just get away with the half shaft only. By the way - manuals are not exempt from this - the shaft in question is just longer, more expensive and just as poorly supplied with oil.
I have some photos of the bits - both ******ed and replacement, if anyone would like to see them..just email me and I'll fwd to you.
cheers
Des

[darrenptalbot]

Hi

I have a clunking gearbox in a 1990 S1 Disco.

Being ex-military, I thought it sounded like most of the SIII's and Ltwts that i had driven in the past - but then I hadn't really heard it too much on a Wolf.

How serious is this - what can I do before it becomes terminal - how much is this likely to cost me?

Help!!!

[Tusk]

Hi Darren
just lettin u know that I had the dredded same problem of the clunky gearbox.It turns out that the S1 Disco has a bad wear problem on the gearbox mainshaft and its transfer gear eg: no oil hole for lubrication (but the new parts have) .When the splines wear on the main shaft you get alot of play in the mating of the transfer gear and its shaft in its twist motion.So what this all means is slack in taking up drive or backlash Hence the clonk.Since I sorted mine out with a new recon gearbox,(£390) transfer gear (£95) and put a new clutch in at (£80) even tho the old clutch was fine it has totally transformed the vehicle.Hope this helps you.I would have lost drive pretty soon if I hadnt of sorted it had I of set off too sharpish

Silver V8 Discovery S1 3 door 1990..mint condition
Bilstien shocks
Full waxoil injection every two years
New gearbox, transfergear and clutch.
164 000 miles mostly trouble free.
Climeair windows with tints.Apart from that truly standard but still gets very dirty on muddy lanes

[Langley]

DesM: Tried to send you a personal message but not enough privelages (whatever that means).

I need to speak to you about gearboxes (manual). My tail of woe is in a post "Looking for a link between Centre DiffLock and Gearbox Problems".
I am wondering whether the insufficient drill holes is the reason I have a (suspected) overheating of the case hardening in 5th and subsequent wear when the dealer we bought it from (non LandRover) reassembled the transfer case and not only left it in diff Lock but unplugged the dashboard warning light!

Who is rebuilding your gearbox and are they Land Rover specialists who can give advice?

Please email direct to langley@studiobaker.com.au (03 9751 2898)

I am in Olinda, Victoria

[Langley]

DesM: Sorry to be a pest (and having to send this as a post).

You will have to phone - I will call you straight back.

You e-mail address did not work and I cannot receive messages via hotmail accounts (banned by my ISP for excess spam)

Please contact me soon about your gearbox

Rod Baker
ph: 03 9751 2898