View Full Version : tranny out fix'n leaks

02-19-2007, 10:48 AM
hello all. i got my tranny, trnsfr & o/d unit out to replace the clutch. notice a bit oil inside of the bell housing. engine rear seal looks good. what else should be r/r while is all apart? what seals should i be looking at? thanks

02-19-2007, 02:53 PM
If its a SIIa box then inside the bell housing the two openings to seal are the main input shaft wind back seal and the clutch selector fork seal.

The wind back seal is a groove on the input shaft so shouldn't really wear. If you take the release bearing housing off you can check for any wear/damage and replace the shaft and sleeve accordingly. Under normal conditions this is not a wear item. This thing is the source of many oil drips under SIIA Landies as it is not a positive seal but merely encourages any oil that gets into the gap to return to the box. Any overfilling etc. of oil will come out this hole. When the shaft stops turning there is nothing to stop any oil already in the gap between the shaft and sleeve from dribbling out the front of the box.

The clutch selctor fork seal is the usual type of o-ring or lip seal (Its been a while) and is often overlooked when it comes to oil leaks. Check you green bible to see if you have to remove the release bearing housing to access it.

That's all. Everything else can be accessed with the box attached to the engine.


02-19-2007, 04:21 PM
thanks, it's just that the entire unit is coated in oil soaked dirt. this might be because the previous owner thought oil was cheaper than a lifter cover cork. if it is leaking it'd be hard to see from where. i just thought the out put seals might be easier replaced while it's out and i couldn't see (in the green bible as you put it) where the input had a seal. i was also wonder if it was worth seperating the transfer case from the tranny and the o/d unit to replace the seals between these components. i will do that seal or o ring on the clutch selector fork

02-19-2007, 04:54 PM
My advice would be to remove the transfer case from the transmission and replace the seal that separates the two. I have found this is usually leaking on units that have never seen a service. The transmission oil level will slowly go down and the transfer box gradually fills up. This fluid transfer can be annoying and cause leakage due to excess filling of T/C.

I have tried both o-rings and genuine landrover selector fork seals. Either set up will weep a bit.

One area that also leaks is the output shaft seals. There is a groove that wears into the pinion with age/time/grit. A speedi-sleeve can give a new seal a smooth surface to seal upon.

Hope this helps

Jon M

02-20-2007, 08:30 PM
Not to hijack the thread, but can a rear main seal be replaced without lifting out the motor. I assume you can lift the motor a bit (after separating the gearbox) then get to it. I guess my question is; what is the easiest(ha) way to replace the rear main seal?

02-21-2007, 08:32 PM
I presume the seal could be replaced with the motor in place, although I've never done it this way. With trans. out, remove the flywheel, flywheel housing, oilpan, and remove the rear main bearing journal. Then you could remove the seal retainers halves. The last thing might have to be removed before the journal (its been awhile). Then install the seal (as per the green bible) and the "T" seals for the rear main bearing journal.

Hope this helps

Jon M

02-21-2007, 09:27 PM
some else told me that could be done but fortunant fo me all seal are working. i'm just clean'n slipping in the new clutch and pp and out to the dirt i go. my bud reminding me that we're not restoring our trucks just playing with 'em