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Category: Myths

  1. Myth 2: Grease versus Gear Oil

    Posted on

     

    Fact or Fiction Sign

    Whether it’s true, good marketing or somewhere in between, we all love a juicy myth. But when it comes down to curing an oil leak we all know what to do..... or do we?


    Myth: I’ve been told or read on the forums that it's bad/good to put new-fangled ‘one-shot’ grease in my old Land-Rovers Swivel Housings, and if I use it, it will cure the oil leaking past the big oil seal. True or False?

    Reality: True and False – The ‘one-shot’ grease was specified by Land-Rover for use on vehicles with Constant Velocity (CV) Joints, irrespective if they had taper bearing or Railko Top Swivel Pins.

    Whats happening?

    On older Land-Rovers, the drive to the front hubs is transmitted through Universal Joints or Hooke’s Joint to give them their correct name.

    Each of these joints comprises of 4 journals, each of which has about 40 small needle rollers. It is these needle rollers that suffer if there is insufficient lubrication.

    With the use of EP90 or 80, the gear oil is quickly agitated and warmed up, turned to a nice mist inside the swivel housing and gets to the parts that are hard to reach, including these vulnerable needle rollers. In addition the gear oil is thrown upwards and gets to the top swivel bearing, whether it is a taper roller bearing or a Railko material bush and housing.

    The top swivel bearings do not actually need much lubrication, as they are not constantly rotating, so the occasional drip of oil should be enough. The Railko bush was introduced because one of its properties was self-lubrication for a short period.

    With the introduction of permanent four wheel drive for the Range-Rover, Land-Rover was forced back to using a constant velocity coupling. (Rover had used constant velocity Tracta joints on the Land-Rover from 1948 to 1953). The 101 Forward Control, Series 3 109 V8, Ninety and One Ten Defender all have CV joints and were specified to use gear oil in the swivel housings.


    Tracta Joint

    For those of you who have never seen a Tracta Joint, (not Tractor Joint!) see the picture above. A beautiful and expensive bit of engineering. First developed for Citroens Traction Avant, the idea was also used on the Willys Jeep, Austin Champ and many other front or four wheel drive vehicles.

     

    Front Axle

    Cross-section showing Universal Joint in Series 1, 2 and early 2a Swivel Housing. The top swivel is the early splined pin type mating in a tapered bush.


    Not until the Discovery is introduced in 1989 is the ‘one-shot’ grease specified, and it could well be this was introduced more to solve customer complaints about oil leaks on to tyres and driveways. A lot of Discovery owners were new to the Land-Rover marque and probably did not appreciate the ‘full –flow’ lubrication system that we are all used to: If it’s stopped dripping – it’s run out of oil.

    Compared to Universal Joints (UJ’s), CV Joints are pretty massive bits of engineering, an outer member, inner member and half a dozen large ball bearings and manufactured to tight tolerances.

    On mere front wheel drive cars, CV joints are usually packed with grease, and this usually keeps them lubricated for a good few years. On a Land-Rover however, with the harsh use, wading etc., the big oil seal that runs on the swivel ball eventually starts to fail, and on older models, the oil leaks out. Using the one-shot grease reduces the leaking.

    But can I use the grease in my old Land-Rover?

    If you don’t do many miles each year, you can probably get away with it. Vehicles doing high mileage will result in the grease being thrown out of the UJ journals under centrifugal force, and if the grease does not liquidise quickly enough and get back into the needle rollers, you may have a problem. Best solution is to fix your leaky oil seal and use gear oil.

    From this chart you can see Land-Rover were happy to use the grease with taper bearing or Railko Top Swivel Pins on Discovery models. Railko pins were re-introduced on Range-Rover ‘Classic’ and Discovery models as they were larger diameter and needed to accommodate the ABS sensor.

    Paul


    www.pegasusparts.co.uk




  2. Myth: Jumping Out Of Gear

    Posted on

    A reality check on Land-Rover myths

    To paraphrase Mark Twain, it's not what you don't know that can come back to bite you; it's what you know for sure that isn't true. When it comes to maintaining your Land-Rover, misconceptions abound. And even the best intentions can lead you to spend more money than necessary or even compromise your safety.

    In this section we talk about Land-Rover myths that can do more harm than good!

     

    Myth: My Series 1, 2,2a or 3 gearbox keeps jumping out of gear. If I replace the little springs that push against the detent balls in the selector mechanism, that will cure it. True or False?

    Reality: False - It might stop it jumping out of gear for a short period, but eventually as your gearbox continues to wear,  the worlds strongest springs in those holes will not stop your gearbox jumping out of gear.

    Main Gearbox

    Why not?

    Firstly, the detent springs and balls serve 2 purposes, they provide a positive location and ‘feel’ that the gear is engaged and secondly and more importantly they all interact to form an interlock system so it is impossible to select 2 gears at the same time.

    What’s happening?

    If its jumping out of 3rd and or 4th, the cause is either worn synchromesh teeth or the main shaft bush is starting to break up, as it does so the gears and synchromesh on the mainshaft can move backwards and forwards as the geartrain is put under load. This back and forth loading gets worse and worse, initial symptom being the jumping out of gear. Eventually bits of the bush disintegrate and if you are unlucky they get fouled up in the gear teeth.

    If you drain the gear oil you may see it has brass coloured flecks, this is the mainshaft bush slowly disintegrating. The bush itself, on a Series 1, 2 or 2a gearbox is a one piece bush with a integral thrust washer machined as part of the bush. As it wears, one or both of the ‘collars’ become detached.

    Mainshaft Bush

    This became such a common occurance that for the Series 3 gearbox, Rover redesigned the bush so that one of the ‘collars’ was a separate item, effectively building the gearbox with a pre-broken mainshaft bush!

    Mainshaft Bush Series 3

    All the forward gears are permanently in mesh with each other. As you start to select a gear the synchromesh unit slows the mainshaft gear to the same speed as the mainshaft itself, then as you fully engage the gear, a set of small teeth on the synchromesh engage with a matching set of teeth on the gear, locking them all together. It is these small teeth that wear.

    Synchromesh teeth

    On early gearboxes they have parallel sides, and as they wear they develop tapered sides, which is not good if you want them to stay engaged. Later Series 3 gearboxes had these teeth machined as ‘arrowhead’ shapes, so they tended to stay locked together longer, but even  these will eventually wear away to a tapered shape.

    Series 3 gearboxes of course have a 1st and 2nd speed synchromesh, which makes things even worse.

    Think about it, in the space originally taken up by 2 gears on the mainshaft, Rover had to introduce a third component that had to do the complex job just described above. This compromise led to the 1st/2nd synchromesh unit being an inherently weak unit, as it also has its own set of detent springs, balls and spacer blocks.

    Whilst the Series 3 gearbox had a nice strong  one piece layshaft, this was offset by the weak 1st/2nd synchromesh unit.

    If you drain the gear oil, you may find lots of little teeth that seem to be too small to be gear teeth, these are the synchromesh teeth that have broken off.

    1 and 2 Synchromesh Unit

    What’s the cure?

    Whilst the new springs in the detent mechanism trick will work in some cases, unfortunately the only permanent cure is to overhaul the gearbox and replace all the worn and damaged components.

    We offer several different kits depending upon the gearbox serial number and in 2 flavours, a budget version (REP suffix on the part number) or an OEM version.

    For Series 1 from 1955 onwards and all Series 2 gearboxes, use PSK 1134 or PSK 1134 REP.

    For Series 2a, Suffix A gearboxes use PSK 1189 or PSK 1189 REP.

    For Series 2a, Suffix B, C or D use PSK 1142 or PSK 1142 REP.

    For Series 2a, Suffix E use PSK 1188 or PSK 1188 REP.

    For Series 3 gearboxes use PSK 1024 or PSK 1024 REP.

    Paul