Series 2A Landrover Gearbox/Transfer Case Assembly

Firstly, consider how much you really need to prevent oil flow between gb & tc.

No, it might be possible , but it is certainly not practical to do it without removing the gear box assy. But this whole job is far easier than many others on the 2a, and far easier than on many other vehicles, so as long as you can get the seal, what is the fuss?

To be quite honest, I don't know if I need to or not, but if I don't do it, will it not interfere with the oil levels, in that is it a possibility for the GB to drain into the TC....? I prefer not to do it, the thought of having to drag the gear box out is a tad depressing but if it has to done, so be it. Thank you, Norm.

Are you losing oil from the gearbox? ..that should tell the tale....

What's it say in the "Green Bible"?

Series II & IIa Workshop Manual (part 1, engine), AKM8159
Series II & IIa Workshop Manual (part 2, chassis), AKM8159
Series II/IIa Bonneted Control Parts Catalogue, 605957
Series IIa Parts Catalogue, RTC9840CC
Series IIa/IIb Instruction Manual, LSM641M

http://www.landroveraddict.com/forums/thread.cfm?threadID=3770

Thing is with Ser2 a you need to apply the age old formula "if you don't put any in -nothing will drip out "Leakage between the two is not uncommon. I remember taking out the seal on the output shaft, washing it off to find a part number I found it was made of leather, when I presented it to the stores guy at the local LRD he said "humph you just cant get the quality any more", gave me the replacement which he said would wear out in a few years.

Hi lads This query goes to the everlasting problem of oil migration between gear box and transfer case. I have my gear box in bits at present and am rectifying the traditional causes, vis. Mainshaft oil seal, seepage past bearing insert, plus, in my case leakage past one of the internal studs which mount the G/B to T/C. A guy I've been in contact with, tells me that he installed a virginal box to his L/R and he advises that the problem of oil migration soon became apparent. The fact that this box was brand new, would  seem to indicate that this problem may be a design fault.....!! Apparently there are stories circulating in Europe that it is due to the fact that the drain from the rear end of the gear selector shafts, is taken via a channel in the casting at the gear-T/case interface directly into the transfer case..! So my question is, does anyone have any info regarding the reason why it was designed this way and would the amount of oil which in time, appears in the compartment at the end of the selector shafts, be of any consequence..? The fact remains that this channel is a direct, unimpeded connection between the two. Anyway Fellahs, thinking caps on. Norm.

After further deliberation I believe that what is happening with reference to oil migration is that the gear selector rods, act as pumps, transferring oil every time a gear is selected, to the chamber at the rear end of the selector rods, which of course is then drained into the transfer case...! I think I am on the right track in drilling a drain into the gear box and blocking off the channel drain into the transfer case. Further I cannot see any ramifications in doing so, it isnt as though the flow from this drain is meant to lubricate anything within the transfer case. (or is it....??) I've been racking my brains, trying to work out why rover would provide this channel, could it be that it was meant to be simply a means to relieve any pressure which may build up, due to the action of the selector rods....??? Anyway, for me my mind is made up, I intend to go ahead with the mod. I will advise in due course, unless lads, any of you, can see any reason why I shouldn't proceed. Norm.

Oil Migration gearbox to transfer case. Ive been giving the matter of oil migration between gearbox to transfer/case in series Land Rovers a great deal of thought and have concluded as follows. I am well aware of the widely held conception that They all do that mate but there has to be a reason..! The popular opinion is that oil tends to leak around the insert at the G/Box to insert interface which carries the main output bearing, assuming of course that the oil seal is in good condition. I have recently become aware that oil may also be leaking to the transfer case at the rear end of the gear selection rods, where there is a chamber which drains directly into the T/Case via a channel in the casting at the G/Box -T/Case interface. Apparently this channels primary purpose is to provide a breather to the transfer case. I believe that for oil flow to occur past the insert and past the gear selection rods, something must be driving it. The manufacturers have provided a small hole, approx. 3mm in diameter in the top of the gearbox, and again in the inspection plate at the top of the T/Case, to serve as breathers to relieve any pressure, I contend that this is inadequate! When one considers a chamber, where pressure exists, for it to dissipate in a timely manner, provision must be made to relieve any pressure. It then follows that the larger the breather, the faster pressure relief will occur. If of course pressure isnt relieved, then it will blow oil past the output shaft oil seal, past the bearing insert, past the gear control rods, and also that maybe thats the reason that very often, the oil seals at the forward end of the of the control rods leak. In my own gearbox, which is presently undergoing overhaul, Ive taken steps to address these issues. Ive mounted the bearing insert with Loctite 680, at the insert/Gbox interface, also the bearing mounting into the insert. The output bearing was changed to a 2RS, the seal removed on the inboard side and new oil seal fitted. A hole was drilled from the chamber at the rear end of the gear selection rods into the gear box and the channel in the casting, which had served as a T/Case breather, was blocked off, thus ensuring any gearbox oil appearing in the chamber, would drain back into the gear box. An 8mm banjo was installed to the top of the gearbox and an 8mm ID. nylon pipe connected, and run to the engine bay and terminated to the top of the firewall. An 8mm banjo was installed to the top of the transfer case and again, an 8mm ID. nylon pipe connected, and run to the engine bay and terminated to the top of the firewall. The G/Box oil filler was modified to allow oil replenishment to be carried out from the cab, a dipstick has been installed to the oil filler cap, to allow monitoring of level. The T/Box was modified by the installation of a dipstick and a new oil filler plug was installed to the top inspection plate, so the oil level, and replenishment of oil can again be carried out from the cab. If after all that, oil migration still occurs, then I will join the They All do that Brigade The only problem is, is that it will be some time before the vehicle is ready for the road, so I wont know for a for a while whether Ive been successful. Norm.