Gearbox oil leak - Calling Gearbox heros

SteveR · Post by **SteveR** » Sat Aug 05, 2006 2:25 pm

I have a persistent oil leak from the gearbox.
It is not due to the drive shaft cos that has been done.
I have examined the underside closely but to identify where the oil originates is not easy as there is oil all over the place. I do not think it is the drain plug because oil is further forward.
There is a circlip with a black rod located just above it and the casting around the circlip is not complete but cannot identify if it is broken or meant to be there see below:

Also I would like to know if there is a seal on the shaft that protrudes vertically below the gearbox with a bellow on it and if that seal is replaceable without taking the box apart.

pol · Post by **pol** » Sat Aug 05, 2006 2:55 pm

I suggest first off go buy a can of 'Gunk' and have a good old clean up. Makes things easier to spot.

pol

pol · Post by **pol** » Sat Aug 05, 2006 2:56 pm

My last leak turned out to be a split gaitor but looked like it was coming from the drain... Guess that's the lowest point...

pol

SteveR · Post by **SteveR** » Sat Aug 05, 2006 6:23 pm

Yes - I know Gunk well but figured it was not nice to use upside down etc...
So I wiped clean with Mrs R.s kitchen roll and took phot and then changed front disc and took a photo 3 hrs later (disc was right b - well the caliper bolts anyway).

In 3 hrs I got a drip so that has narrowed it down - ie no airflow to scatter it around.

3.45 and 6.45

Mr Greedy · Post by **Mr Greedy** » Sun Sep 21, 2008 12:31 pm

A bit of an old thread revival

After recently changing my gearbox oil, I am now dropping gearbox oil and I am not certain where it is coming from. The output seal has been changed and confirmed to not be leaking. The gaitor/boot on the passenger side doesn't seem to be leaking. The oil itself is gathering in the little plastic clip on tray that sits below the gearbox linkage in to the bottom of the box.
After taking the box off and getting it upside down on a bench, it would appear to be leaking from the same area as shown in this thread. The little black arm in the picture connects to the coupler for the gear selection linkage. Either something is leaking around this circliped item, or the seal between the two halves of the gearbox is actually leaking, because there is a lot of oily residue going upwards following the joint. However, this could just be because once oil is present at the circliped item, it tends to creep everywhere with a little bit of heat and motion, hence making leaks particularly difficult to identify.

SteveR, did you manage to get this leak sorted?

The other seal in this area is detailed in this thread as No. 11.
click here. Sorry, this is linking to another forum, but I can't seem to get images to link properly

.

This is the part of the selector linkage that goes straight up in to the box, but there is no oily residue in this specific area under the box, even though it is very close to the circlip item. This is good news, because I might need to split the box to get at this seal.

In the book of lies, it just skirts around manual gearbox overhaul by saying it is far too complicated for mere mortals, but the automatic transmission section details replacing the input driveshaft (torque convertor) oil seal. The shaft coming out of the gearbox in the bell housing has the same splines, and I suspect the seal is replaced in a similar manner. If there is a replaceable seal at all in this location. Does any one know?

I am at a loss.

Iroll480 · Post by **Iroll480** » Sun Sep 21, 2008 5:16 pm

Behind this nylon lager, as Volvo calls it, there's just the hole in which the circliped lager is fitted. So no oilseal around/behind it.

This is the part of the selector linkage that goes straight up in to the box, but there is no oily residue in this specific area under the box, even though it is very close to the circlip item. This is good news, because I might need to split the box to get at this seal.

No need to split the box to replace this seal. Just pull out the old oilseal with a screwdriver. Do this carefully as not to damage the box's housing. Offcourse first you have to remove the gearbox linkage. You can drift in a new seal with the right size piece of pipe or socket. Don't forget to lube the oilseal with grease/oil before you do this.

Mr Greedy · Post by **Mr Greedy** » Sun Sep 21, 2008 7:43 pm

The now obvious question is how do you remove the gearbox selector linkage, or is it likely to be the joint between the two gearbox halves?

Is the linkage held in place with some sort of roll pin once the boot is removed/pulled down and out of the way?

I might be better dropping the box off at a Renault specialists. Should be fairly cheap for them to do the work if all the have is the detached gearbox.

eEm · Post by **eEm** » Sun Sep 21, 2008 9:26 pm

Mr Greedy wrote:The now obvious question is how do you remove the gearbox selector linkage, or is it likely to be the joint between the two gearbox halves?

Is the linkage held in place with some sort of roll pin once the boot is removed/pulled down and out of the way?

I might be better dropping the box off at a Renault specialists. Should be fairly cheap for them to do the work if all the have is the detached gearbox.

Nutter!!!!!

Spend a tenner on a Haynes manual and probably another fiver on a new seal and get your hands dirty. Renault will charge you a minimum fee (probably Ã‚Â£50+) just to look at the box and thats after you've spent 4-5hrs removing the ting! Then you have to replace the differential seals too as the driveshafts have to be removed to get the box off, not to mention the gearbox oil, which you'll have to do anyway.

Mr Greedy · Post by **Mr Greedy** » Mon Sep 22, 2008 11:21 am

eEm wrote:
Nutter!!!!!

Spend a tenner on a Haynes manual and probably another fiver on a new seal and get your hands dirty. Renault will charge you a minimum fee (probably Ã‚Â£50+) just to look at the box and thats after you've spent 4-5hrs removing the ting! Then you have to replace the differential seals too as the driveshafts have to be removed to get the box off, not to mention the gearbox oil, which you'll have to do anyway.

Mr Greedy wrote: After taking the box off and getting it upside down on a bench, it would appear to be leaking from the same area as shown in this thread.

Mr Greedy wrote: In the book of lies, it just skirts around manual gearbox overhaul by saying it is far too complicated for mere mortals.

From the above posts, we can see that the box is already off, so this is not a problem. After just completing an out-of-car engine overhaul (timing belt, tentioners, every oil seal in the block and head, including valve stem oil seals, water pump, head gasket, regrinding valves, new clutch) I though it would be a good idea to sort out the gearbox leak, whilst the box is off.

Unfortunately, the Haynes manual doesn't detail any information about the manual transmission, except the actual removal of the box and possibly the changing of the clutch. This is why I don't know how to remove the gear selector shaft that goes in to the bottom of the box. It could be possible to remove it by just yanking the cr@p out of it, but I don't know if this is the way to remove the shaft, thereby giving access to the seal. If I take this approach, I could well damage the box. I would have thought it logical that the plate welded on to the end of the shaft should be fasted with a roll pin or similar, but because it is welded (as with all of these boxes) it cannot be removed. It will have to come off with the shaft as well.

I also have the problem that I don't know what the Renault part number for the seal is. Once I have figured out the removal, I can take the seal in to Renault, and they should be able to match it up. Although, this is all academic if the seal between the two halves of the gearbox is the culprit for leaking.

How do you remove the shaft that goes in to the bottom of the gearbox so I can remove the oil seal?

Iroll480 · Post by **Iroll480** » Mon Sep 22, 2008 12:57 pm

I answered your Q here as I find it impossible to post an attachment on this site.

martinholmesuk · Post by **martinholmesuk** » Mon Sep 22, 2008 1:08 pm

Forum does not support attachments. You need to put a picture on a site like photobucket.com then link it back to here.

eEm · Post by **eEm** » Mon Sep 22, 2008 3:05 pm

Mr Greedy wrote:
eEm wrote:

From the above posts, we can see that the box is already off, so this is not a problem. After just completing an out-of-car engine overhaul (timing belt, tentioners, every oil seal in the block and head, including valve stem oil seals, water pump, head gasket, regrinding valves, new clutch) I though it would be a good idea to sort out the gearbox leak, whilst the box is off.

My mistake, jumped the gun a bit there

Mr Greedy · Post by **Mr Greedy** » Tue Sep 23, 2008 2:49 pm

As it turns out, the seal that is around the control shaft entering the gearbox can only be removed once the control shaft is removed from the gearbox.

This, in turn, can only be removed once the box has been split, and involves the driving out of a double roll-pin.

Can anyone provide any advice with regard to the splitting of the gearbox?
Are there any tips or specific problems I might encounter?
Is there a gasket seal between the two halves of the gearbox shell/housing, or would resealing with a universal high temp, oil resistant gasket compound be sufficient once both sides of the housing have been given a good clean back to metal?

SteveR · Post by **SteveR** » Tue Sep 23, 2008 3:43 pm

The picture linked by Iroll480 is vGood.
I never did get rid of the leak, which was minor, and I wish I had had that pic then. I now have a turbo though (that was my previousGT).

pol · Post by **pol** » Tue Sep 23, 2008 3:52 pm

It's pretty much impossible to put back together once separated without special tools. I tried and failed. Big waste of time. There's lots of little spring loaded ball bearings which locate the selector shafts.

pol

Mr Greedy · Post by **Mr Greedy** » Tue Sep 23, 2008 4:53 pm

Looks like I'll be taking the box to a Renault specialist then.

Given the cost of the gearbox oil

, it is probably worth it.

Mr Greedy · Post by **Mr Greedy** » Wed Sep 24, 2008 11:38 am

I have called round a few gearbox specialists, and everytime they pick up the phone, I am sure I can hear the sound of hands rubbing together and the kind gentleman I am speaking to is trying to styfle laughter in the same way that a child who has found his Christmas presents early tries to styfle his excitement.

Anyway, the bottom line is about Ã‚Â£120 plus parts, plus VAT.

Owch

I am faced with three options.

1) Put up with the leaking box, and keep it topped up. Not a problem, but a pain in the backside. I hope that the leak rate is slow and that the spare oil I have will last a while (Millers TRX fully synthetic - bought 5L and should have 1.6 litres left).
2) Take my trousers down in preparation for a gearbox rebuild at a specialists. Whilst I am at it, would it be a good idea to get the syncro replaced? What are the weak spots in this box?
3) Try to find a recon box or replacement box from another vehicle at a good price, and hope that there is nothing wrong with the box and it doesn't leak.

The box I have is the M55. I think this is based on the JC5 Renault box, and according to a PDF manual easily located on the web (via google), I should be able to get a JC5 box from a Laguna, Clio or Megane.

Does anyone have any idea of price for a replacement box? I guess I would go to a breakers and hunt around for a lowish mileage car, and take the box out myself.
Any other boxes that fit that I might hit lucky with? Will any of the JB or JC Renault boxes fit the B18U block?

Iroll480 · Post by **Iroll480** » Wed Sep 24, 2008 7:19 pm

So it's a M50 series gearbox. Check this site for interchangeable boxes.