Final instalment of the gearbox strip with removal of the output shaft and gearing and selector shafts from the output case
Business end of the output case
Split pin, castleated nut and drive flange removed revealing the output bearing. Amazingly, the original LEATHER seal was still in place in the drive flange…. and on inspection still doing a good job
Selector shafts dust cover removed
Ready to separate the output housing from the transfer box
With a tap from the mallet, the box literally springs apart
Both selector shafts. 4WD drive “dog” can be seen below the bronze selector, this mates with the output shaft to engage 4WD (high or low). As mentioned before, older Land Rovers were selectable 4×4 and this is where the front axle is engaged
Next is to remove the output shaft from the transfer box. The first task being to shift this circlip. It put up quite a fight.
In the end, I ended up wearing some eye protection…. so much force was needed to release it I wanted to be prepared…. having had the experience of a ball joint exploding off a steering arm and smacking me hard in the face, a piece of sprung steel travelling at some velocity, maybe, could do some damage
There are two types of gearing designs used in the transfer box: 1) Helical and spur gears and 2) All Helical gears. This one is helical (left hand gear) and spur (right hand gear)… and a lot easier to service
Time for some ingenuity (a useful attribute when working on series land rovers). This bearing is used to drive out the outer bearing race form the case. BUT… by the time the high gear wheel reaches the face of the case, the outer bearing race is still well inside the case. The manual suggests creating a packing piece from an old bearing race of the same size (which I don’t have) with a cut out to fit over bearing. So, with a little fiddling about, I managed to secure a couple of bolts behind the bearing and was able to drive it out sufficiently before the high gear wheel met the face of the case again.
Bearing race driven out as far as possible
A little heat on the case helped me knock out the race with a sharp tap from behind
Job done 🙂
Next, the bearing can be tapped off the shaft with a cold chisel. Once this is off, the small circlip (just visible) at the end of the deep groove needs to be removed. With the bearing off, I propped the case on-end so I could access the circlip from above… released it…. with the result that the shaft (leaving the gears behind in the case) fell out of the other end and onto my foot.
In order of assembly….shaft and gears, thrust washed and circlip. The small gear (helical) is the “high range” gear and is in constant use in normal driving conditions. The larger (spur) gear is “low range” and is employed only in 4WD low range. This is why these older gearboxes are quite noisy in low range. If you are familiar with the sound a manual transmission car makes in reverse… this is the sound accompanying the driver in low range 4×4 in a Series 2a.
Final drive shaft, case and bearing ready for removal…. friendly blow lamp is on hand to “gently” warm things up
No caption required… I guess you can all see what going on.
With a little tap from the inside of the case, the bearing is released. The primitive metal bracket on the shaft is an oil thrower…. as the shaft rotates, it thrashes about in the oil at the bottom of the case and makes sure oil gets chucked around, keeping things lubricated. Im sure there’s some mathematics behind the design, requiring the judicious use of a slide rule and log tables to calculate the spray pattern though 🙂
Bare transfer case…. and I know exactly where all the fixings are to be found
All of the primary gearbox components stripped and ready for the dishwasher….. erm, I mean deep cleaning for hours and hours with a tooth brush… ahem
The bearings have arrived and the replacement gears have slowly started coming in but realistically, its going to be 2 weeks before I have everything assembled in one place.
I’ve decided to buy a press….. a 12 ton press 🙂 and for a very good price. Whilst it’s not good practice to batter dead bearings of shafts with a chisel, lack of the proper equipment makes this a necessity. This approach is certainly not going to work fitting new gearings to shafts / housings without causing damage. Theres’ a tool for everything… and if a jobs worth doing etc…
Now, where’s that cork screw…
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