Series gearbox, grinding and leaking

[mcook94]

Hello everyone, I think that I have a problem with my gearbox. I am a novice mechanic, so please excuse the ignorance of my descriptions. The oil is leaking from the front of the gearbox, and is quite clean and light brown in colour. Also, there is a leakage from the round bit which the handbrake goes into. I wonder if this might be relatively normal.

Also, when I put the gear lever into neutral and then lift my foot off the clutch pedal there a grinding noise comes from the transmission area. Its not horrifically loud, but wasn't there before the oil leak started.

Finally, when I lay under the LR and look up at the gear box there is a part of it immediately rear of the sump which is round and has fins protruding from it. The bit with the fins protruding has a threaded bolt hole right in the middle at the bottom. This hole doesn't have a bolt in it, even though it is threaded. Should it have a bolt in it?

I have a photo of the hole, but only on my phone.

Any help would be appreciated. My thoughts are that a seal or bearing has gone somewhere, or there is a bolt missing which has lead to the oil leak and the noise is the consequence of there being no oil in the gear box. Funny thing is, that fresh oil seems to be appearing and if that bolt hole was the culprit then surely it would have all leaked out by now?

It looks increasingly likely that I will need to do some work to the gearbox, but Haynes states that it can only be removed through the cab and out the passenger door. And, I'm a novice mechanic ... although with the advice from everyone here I have done some things that seemed miraculous to me! Anyway, is anyone else doing work to a gearbox and would mind me coming to have a look at how its done, before I reduce my LR to its component parts on my drive rendering it unuseable?

Regards, Mike

[Rich_P]

The gearbox is made up of two separate components. The main gearbox and a transfer box. The latter provides low and high ratios, and also neutral should you desire to run any equipment off the PTO (Power Take Off).

I'm not sure what you're talking of when you describe a round section with fins. If it is towards the back of the vehicle, then the chances are it is an overdrive. If it is an overdrive (probably Toro), and there is a bolt missing then you might find that it's the drain plug that is missing! This would go in hand with the fact that if you get the noise mostly when the transfer box is in neutral, all the backlash in the overdrive will become apparent. This is what mine sounds like when there's no load on it and it was low on oil. After removing it I found the big O-ring had popped out from around the output shaft. Also please take note that my Toro is getting on a bit too!

Having said all of this, the bell housing also features a threaded hole. This is a much-needed drain hole for any oil to exit the bell housing without contaminating the clutch. There should be a plug fitted to a plate near it that can be screwed in to stop water ingress while wading.

I hope this gives some pointers.

[bill van snorkle]

That round thing with the threaded hole is called the bell housing. The threaded hole in the bell housing is to allow any engine or gearbox oil that leaks past the seals to drain out and not contaminate the clutch plate.If the vehicle is to do any wading in water over the height of the drain hole a plug should be fitted to the hole to prevent water entry.Remove plug after wading. Clean oil leaking from this hole indicates the front gearbox oil seal has failed. If the gearbox is noisey in 1st 2nd and 3rd gear probably the bearings on the input shaft and the front of layshaft are worn. The gearbox can be removed without removing the seat box assembly but the process is complicated to explain and requires a bit of previous experience.

Bill.

[bill van snorkle]

Correction. The round thing with fins, to be more accurate is called the flywheel housing.

Bill.