Help: Gearbox fluid keeps leaking out

[NC Rover]

So I noticed my shifter would not shift into gear the other day. I checked the fluid and sure enough it was empty. I was thinking maybe it hadn't been checked in a long time. So I filled it up, bled out the air bubbles. It shifted fine for a few days...then I noticed it did it again. This time, I discovered there was fluid leaking from the flywheel housing at the bottom drain. Now I've never noticed before (as I was just under the car bleeding out the air bubbles a few days ago...I would have noticed it dripping on me) but is there suppose to be a plug in there preventing the loss of fluid? This doesn't seem right as the manual only says the plug should be in only if doing hard off-roading...including water and mud. My guess is that somethign has gone bad internally but I'm not familiar with it enough to diagnose the problem. Everything is leaking so bad on the rover that I'm guessing some kind of seal or slave cylinder has gone bad. Can anyone point me to whats going on?

Please note: I have the tranny and transfer case from a D90 (LT77 & LT230). Engine is 2.5L Milspec.

[graniterover]

So I noticed my shifter would not shift into gear the other day. I checked the fluid and sure enough it was empty. I was thinking maybe it hadn't been checked in a long time. So I filled it up, bled out the air bubbles. It shifted fine for a few days...then I noticed it did it again. This time, I discovered there was fluid leaking from the flywheel housing at the bottom drain. Now I've never noticed before (as I was just under the car bleeding out the air bubbles a few days ago...I would have noticed it dripping on me) but is there suppose to be a plug in there preventing the loss of fluid? This doesn't seem right as the manual only says the plug should be in only if doing hard off-roading...including water and mud. My guess is that somethign has gone bad internally but I'm not familiar with it enough to diagnose the problem. Everything is leaking so bad on the rover that I'm guessing some kind of seal or slave cylinder has gone bad. Can anyone point me to whats going on?

Please note: I have the tranny and transfer case from a D90 (LT77 & LT230). Engine is 2.5L Milspec.

The clutch hydraulics are pretty simple. Is there fluid at your feet? If so, the master is leaking. If not, is there fluid leaking out of the clutch master housing? If so, it's the clutch master. Follow the line down to the slave. If there is no fluid coming out there, then it's your slave.

I don't know where the slave is on one of those modern transmissions. On a series, it's outside of the bellhousing, so it's easy to see. Not sure if the slave is within the bellhousing on an LT77.

Purely a guess, but I'd say it's the slave.

Mark

[NC Rover]

The clutch hydraulics are pretty simple. Is there fluid at your feet? If so, the master is leaking. If not, is there fluid leaking out of the clutch master housing? If so, it's the clutch master. Follow the line down to the slave. If there is no fluid coming out there, then it's your slave.

I don't know where the slave is on one of those modern transmissions. On a series, it's outside of the bellhousing, so it's easy to see. Not sure if the slave is within the bellhousing on an LT77.

Purely a guess, but I'd say it's the slave.

Mark

Well I followed the line down from the reservoir. The slave is right next to/outside of the bell housing. This is what I bled the air out through the adjustable nipple. There is nothing leaking from it. There is nothing leaking from the reservoir. There is no fluid at my feet or leaking anywhere else other than coming out of the bottom of the bell housing at that drain plug. So maybe something in the slave took a dump internally and is leaking out through the bottom of the bell housing?

[graniterover]

Whatever is coming out of that hole looks fresh. If everything else is dry and it drained in a short time, the must be the only place it could have gone.

[4flattires]

Your bellhousing will leak either engine oil (from the rear main seal) or gear oil (from the tranny front seal). You are seeing brake fluid (from your clutch hydraulics) drip to the lowest point.

Nice galvy frame though!

Not to hijack the post, but I recalled a service manual talking about the fording drain plug normally mounted to the frame when not in use. I scoured my frame and never saw a place it would be mounted. Anyone have this on their frame?

Jeff

[LaneRover]

Your bellhousing will leak either engine oil (from the rear main seal) or gear oil (from the tranny front seal). You are seeing brake fluid (from your clutch hydraulics) drip to the lowest point.

Nice galvy frame though!

Not to hijack the post, but I recalled a service manual talking about the fording drain plug normally mounted to the frame when not in use. I scoured my frame and never saw a place it would be mounted. Anyone have this on their frame?

Jeff

I have the mount on a couple of my frames.

[BackInA88]

I believe the LT77 slave mounts right to the bellhousing casting.
If it starts leaking the fluid will run out the wading plug.
I thing it's time for a new slave cylinder.

Steve

[NC Rover]

I believe the LT77 slave mounts right to the bellhousing casting.
If it starts leaking the fluid will run out the wading plug.
I thing it's time for a new slave cylinder.

Steve

I believe you are correct. Do our sponsors have a slave for an LT77 tranny?

Also, is there anything special required for replacing the slave cylinder? Does someone have to have the clutch pushed in or anything special like that before I unbolt it and remove it? Anything I should watch out for? Special instructions?

[JackIIA]

Don't know if your LT77 fits the following specs, but here's what I've found:

Land Rover Part number: 591231
Applicable Models:
Land Rover Series 1971 on (Not V8)
Defender to LA939975

Product Description:
Land Rover Series 3 and early LT77 5 sped manual, gearbox models clutch slave cylinder.

RN Part number is RNC535, $106.41

* * * * * *
Continuation of THREAD HIJACK. Lane - where would that stow point be on the frame for the plug? I want to see if my old junker of a frame might actually have one (with a plug in it!). Fat chance I know.

* * * * * *

[57109]

wading plug bracket location

On the Series trucks it's on an L shaped bracket secured under one of the Engine to Trans Nuts. Often lost when removing either the engine or trans.
Regards
Gord'n Perrott
Lamorna Garage
Seattle

[NC Rover]

Don't know if your LT77 fits the following specs, but here's what I've found:

Land Rover Part number: 591231
Applicable Models:
Land Rover Series 1971 on (Not V8)
Defender to LA939975

Product Description:
Land Rover Series 3 and early LT77 5 sped manual, gearbox models clutch slave cylinder.

RN Part number is RNC535, $106.41

* * * * * *
Continuation of THREAD HIJACK. Lane - where would that stow point be on the frame for the plug? I want to see if my old junker of a frame might actually have one (with a plug in it!). Fat chance I know.

* * * * * *

Thanks so much for the information. Very helpful as always from the members of Rovers North...

[JackIIA]

NP. And thanks 57, I'll take a look tomorrow.

[NC Rover]

Your bellhousing will leak either engine oil (from the rear main seal) or gear oil (from the tranny front seal). You are seeing brake fluid (from your clutch hydraulics) drip to the lowest point.

So obviously the Slave is the issue. It is outside of the bellhousing just like the series.

**Is there anything complicated to switching out the slave? Anything special that needs to be done? Is it as easy as unbolting/removing/replacing?

[siiirhd88]

It should be as easy are unbolting the old slave cylinder and line, and bolting the new one in place.

There are two 5/16-18 coarse thread (1/2" wrench) sized bolts securing the slave to the bell housing. The steel line fitting threads into the slave, and this can corrode in place preventing easy removal. This fitting should use a 1/2 inch wrench also. You will want to loosen this fitting before you unbolt the slave..... This is a British type fitting, and won't interchange with a U.S. fitting. Any fluid left in the master cylinder will leak out when this line is loosened.

There is a rod mounted to the release bearing fork that can be felt inside the bell housing when the slave is removed. This rod will need to go into the the opening in the end of the replacement slave cylinder when installed. The old slave cylinder's rubber dust cover might be loose enough to come off the slave when it is removed. If so, remove it from the bell housing opening.

The slave cylinder will need to be bled of air after installation. You can bleed the slave single handed by slightly loosening the bleeder screw on the slave cylinder, covering the open end of the bleeder screw with a tight fitting length of rubber tubing, and leading the other end of the tubing into a jar with about 1/2 inch of brake fluid in it. Ensure the end of the rubber tubing is submerged. When the clutch pedal is depressed, you should see bubbles come out of the end of the rubber tubing. (With the end of the rubber tubing submerged, no air will be pulled back into the line when the clutch pedal is released.) Depress and release the clutch pedal until no bubbles come from the rubber tubing, but make sure you frequently top up the clutch master cylinder or you will have to bleed more air..... When no bubbles are seen, tighten the slave cylinder bleed screw. It might be adequately bled just by this method, but I usually finish using a second person to the depress the clutch pedal and hold, while I open and then close the bleed screw, repeating until all air is removed.

Hope this helps,
Bob