argh...gearbox problems! :-(

[dave1814]

Hi Guys,

I have an oil leak for what i think has been a while now, just been to the garage who state that its coming from the gearbox but doesnt know exactly where. He suggests my options are to either...

Live with it
Try replacing drive shaft oil seal first
Replace the whole gearbox

tbh i think the gearbox is knackered, its never been that easy to get into gear, an 80 something man owned the car before me and apparently has gone through more clutches than hes had hot meals at the time of owning so i dont really expect the gearbox to have been shown much love!

On thing i do find strange is that I have only noticed the leak since changing the gear box oil. so mu questions are....

1. Could i have overfilled the gearbox oil, as I think oil was still coming out of the filler plug when i put the plug back?

2 . How hard is it to replace the drive shaft oil seal?

3. Worst case senario - replace the gear box - its this a big job and does the clutch need to be replaced at the same time?

cheers for any input!

Dave

 

[MarkGSi]

Trace the oil leak and see where it's coming from. You'll probably trace it back to one of the oil seals on the diff. There less than a tenner from the dealer and are quickly replaced in a garage. If youre ever in doubt then change the cheapest thing first.
Clutches on these cars are pretty weak anyway so i'm sure a bad driver will kill one pretty quickly.
I wouldnt write the gearbox off too quickly. Is it noisy in any gear, jump out of gear hard to get in any gear, or does it crunch? Maybe get a garage to check the linkage if your having trouble getting in into gear?
If you do change the gearbox at any time then make sure you change the clutch and the release bearing. You dont want your replacement gearbox off again after a short while to change the clutch.
As a thought check to see if the clutch has an inspection cover? If it does, take a look and make sure its nice and dry?

 

[dave1814]

thanks mark,

yeh i think the first step is maybe to pressure wash and clean all the oil off and trace the leak.

its pretty hard to get into 3rd from 2nd and from 5th, it doesnt crunch. I have just fixed the return spring on the box but it still doesnt seem to want to 'spring' into the middle when in neutral!

Im not sure what a clutch inspection cover is?!

cheers!
Dave

 

[MarkGSi]

Hi mate, sorry to swear but i've got a vauxhall mind going here but your problem has the symptoms of gear linkages being worn. I had similar selection problems on my Astra, a £2 part later and it was changing gear 100%
The spring on our Micra gearbox has never worked and we haven't had any problems with gear selection.
Again on the Vaux, there is a clutch inspection plate on the bellhousing that you can remove to check the clutch and flywheel. I was thinking that it you've got an internal gearbox oil leak you'll most likely see it here. I do think that the clutch would slip badly though if you had any oil here.
If i were to place a bet i'd say you have a diff oil seal gone and a lot of play in the gear linkages.

Hope this helps
Mark

 

[dave1814]

Thanks a lot for all your help so far mark!

right im going to clean the gearbox up and try and find out where the leak is coming from. If the diff seal has gone, should i be able to see the leak coming from there then? Do you know roughly how much these are usually to replace at a garage?

cheers!
Dave

 

[MarkGSi]

You should be able to follow the leak without cleaning it up, just follow the mess upwards! On my vaux the diff seal is simply a case of: Hun hub off, ball joint seperated and pinch the drive shaft out of the diff. Then you can butcher the old seal out and tap the new-one in. I'm sure the Nissan is just as easy so a garage should do it in half an hour. May be worth putting a new drive-shaft gaiter on whilst it's all apart. Just need to make sure the gearbox oil is topped back up at the end.

 

[davsl]

I used to have a Primera eGT that had a sh*t gear change into second gear, pretty common. I tried additives and it did sod all. Then I tried some fairly expensive fully synthetic gearbox oil and it went, not straight away but after a 100 miles or so. Well worth trying. My second car is a K11 and it is leaking from a driveshaft seal. I am going to change the oil and seal this weekend. The thing is that the guy at the motor factors gave me the wrong oil, and his computer recommended it. He gave me a GL5 spec oil. The K11 uses GL4. I am returning it today for some correct spec GL4. Could you possibly have put the wrong oil in. As looking on the internet, GL5 oils can damage certain types of metals used in boxes due to it's high sulphur content. I guess it's ok if it is an oil for GL4 and GL5 applications. But the one I was given was just for GL5 :doh:

 

[sjohnston]

hey Mark, you seem to know alot about the nissan Micra and would like to know if ya could help a young lad out like me?

I've recently found out by my mechanic that i need a replacment gearbox but unsure what gearbox it is as there were 2 specifications for my 2002 micra S. I have specified to breaker yards that it is cable clutch 5 speed reverse but they keep saying which type? well am new to the micra so not up on my specifications. Any idea?

cheers Sean