Thread: Gearbox Mainshaft Wear

Hi All,

I have read most of the threads listed over the past year or so concerning spline wear on the gearbox output mainshaft. In particular I have followed the thread at
http://www.aulro.com/modules.php?name=Foru...iewtopic&t=1281

Great stuff.

I think i am happy with the whole issue but have a couple of additional questions. I have a 94 Disco V8 manual (early R380) - first batch of the updates - I have had the car from new and it is just coming up to 100,000 km. The car has done little offroad work and little around town work - mainly high speed expressway work. However due to clutch and engine cutting out problems early in its life the drive train has had a bit of a hammering in its life.

The drive train is starting to get a bit slack which I am assuming is the early stages of the above problem - just noticeable but not a major problem yet. Clearly I can simply get the Transfer Case Input gear drilled as described and that will stabilise the drivetrain slack but I would prefer to remove as much of it as possible without playing around with the gearbox - will do that when the clutch is due.

Questions

1. When the wear takes place, is there equal wear on the mainshaft splines and the splines on the input gear - if not which wears the most or what wear ratios can I expect eg 30% mainshaft/50% input gear.

2. If I put in a new transfer case input gear onto the worn mainshft splines the drive train slack will be reduced but not removed - does anyone have any ideas how I could reduce the slack further eg different transfer case oil, products that are supposed to help slightly worn splines etc

3. If I do nothing, at what sort of KM does the problem become - exactly that - a problem?

I am inclined to put a new new transfer case input gear but if I cannot expect an improvement in the drive train slack then I am inclined to get the gear drilled or not worry about it and do the mainshaft and input gear when the clutch needs to be renewed - but given the type of driving I do this is not likely to happen in the near future.

Answers to the questions and other thoughts would be appreciated.


Thanks

Gazz


94 Disco
98 Freelander TD - currently only Front WD

Originally posted by garrycol
I was quoted the price of the gear at $280 - just need to confirm the number of teeth on the gear (95MY but actually built Jan 94) - guess I will have to check when I pull the old one out - seems like a pretty cheap fix if the problem is identified early - also if identified early, then no other parts should be needed other than the oil you mentioned Mark. I will need to investigate this a little more - winter morning temperatures -4 to -6 sometimes - summer afternoons up around 35 or higher.

We've done some temp tests in the UK and found that operating temperatures tend not to be much of a problem but we have still had failures & excessive wear... (The fitting of an over-temperature sender to the R380 is quite simple and the wiring for the dash warning light is already there on the Defender!)

The key to solving most gearbox problems is the oil. LandRover have used ATF for years, this is completely wrong and is too thin to lubricate properly. Recently, LandRover have changed to MTF which is soooo much better.

HTH

Mark.