2.6 S2a Gearbox re assembly Part 1

[@SafariLifestyles]

Just about going to rebuild may 2A gearbox myself and am finding this series very useful thank you.... especially like the confidence in just getting on with it.

[@MrRobmellor]

I have never seen a better set of videos than with this gearbox Mike. It has awakened many things that I had forgot. Many thanks, and please keep up with the good work. Yorkshire Rob.

[@BritannicaRestorations]

You're not the only one who has forgotten this stuff! Not done one of these for years! I could not drive a Series truck today

[@GrumpsBarn]

...excellent stuff Mike.....glad to see you've slowed down a bit this time!

[@gonesailing]

Thanks Mike. Much appreciate your helpful rebuild and tips. All the best

[@fredjones7307]

In my experience, and as someone else also pointed out to me, if you don't put some sealant on that rear bearing carrier you'll spend the rest of your life swooping oil from the transfer box back into the main gear box Mike..and it's a right pain in the arse..plus, that bush has probably in the past seized up because all the oil that is supposed to be lubricating it is in the transfer box..

[@warci]

Sometimes the housing that seats the rear bearing will start to rotate slightly, worsening this problem. I peg the two so they can't move and assemble the lot with bearing locktite!

[@karlhrdylicka]

Fred Jones .That is my experience as well , I always use a sealant on the rear housing and not had a problem oil transfer to the transfer case since doing that . I would also point out the small breather hole on top of the main gearbox needs to be clear because it is in a steel plate and often blocks up with crud and rust , best way to overcome this if a lot of off roading is done is to put a fitting in an enlarged hole and run a breather pipe from it up behind the rear seat support .

[@nickboylen6873]

Yep, I found the oil migration stopped completely by doing this, even though I initially did it to stop the motion Warci describes (which causes the big circlip to generate aluminium swarf).

[@simongroot7147]

Open gears work as a pump. The oil is picked up from the sump of the transmission by the layshaft gear teeth and then passed through the contact to the mainshaft. Due to the viscosity of the oil the time to pass from the centre of a tooth to the edge is greater than the time available when the teeth are in mesh. When there is a lubrication hole the oil is pushed under tooth contact pressure through the hole. This is very high, in excess of 20bar (300psi) for a short period of time. This is the way the bush is lubricated. It does not need a constant head of oil (like a crankshaft) because it is not under constant cyclic load. Putting thinner oil in will decrease the shift efforts and increase syncro wear. As the oil ages ands or gets hot, the bushes will start to wear because the oil is thinner and therefore the transition into the bush is lower because the work to express the oil from the teeth is smaller.

[@BritannicaRestorations]

Well judging by how many bushes I have replace ( and main-shafts as you cannot get the location pins out) this does not always work

[@karlhrdylicka]

Simon Groot . Have no argument on what you state in your comment , But and a big BUT. the recomended EP 90 gear oil is much to thick in cold winter conditions .Where Mike is in the winter time EP90 would be like a block of butter and the second or third gear would cease on the bronze bushings doing heavy towing from cold causing the retaining pins in the mainshaft to shear ,this has happend to me so I have used a mixture of EP80 and engine oil for many years with no problems .

[@simongroot7147]

@@BritannicaRestorations The balance to that argument is the ones you tear down have an issue of some sort as you would not tear down a functioning unit. So it would be a relatively safe conclusion that the bush has failed because of some other component failure (oil either at end of service life or contaminated would be the most likely) or another issue. Once the oil degrades or an incorrect type is used, then the bush life will be reduced.

[@simongroot7147]

@@karlhrdylicka Actually the statement about the grade viscosity of 80 vs 90 weight oil is incorrect. The temperature for a cP of 150,000 for SAE80 is -26C, for SAE 90 it is -20C. (The number is a measure of the ability to pour measured in the Brookfield index). So both will be 'unable to pour' during the winter in Canada at some point. This will only affect primary shift efforts, the oil that is too cold to pour is also too cold to run away from the bush so it is still lubricated, even when cold. The churn of the gears adds significant heat to local areas of the oil very quickly so the lubrication 'loss' of cold oil is insignificant. The best comparator for oils is the Kinematic viscosity measured in cs or mm2/s (the number is the same). For 80 grade oil it is 8 for 90 it is 13.1 and for a 10W 40 engine oil (apparently much thinner to anyone who looks at it) it is 14.4, all measured at 100C. The other thing to bear in mind is the classification of the oil. Land Rover say use an EP90 oil in the 4 speed box. However that needs to be qualified with a DO NOT use a GL5 oil. The reason is GL5 contains certain friction modifiers (which cause pH drop when heated and this attacks Bronze). More modern GL5 oils claim not to do this due to the revision of the friction modifiers, however all the oil specifications I have seen still refer to the problematic additives being present. To counter the effects of extreme cold, substituting an EP85W would lower the cold shift efforts and the power loss. You could go thinner say to an EP75W but then when summer comes, you will need to change it as it will be too thin to work correctly. So I stand by my statements, with the correct oil, uncontaminated, the system will work as designed. Step outside these boundaries and it will fail. How far you step will determine how long that failure takes to occur.

[@philhealey449]

@@simongroot7147 Tribology theory in action! Presumably gear teeth are behaving much like rolling element bearings with elastohydrodynamic lubrication from theoretically tiny point contact , but maybe with some hydrodynamic behaviour due to the sliding contact in helical gears ? I'm assuming there is a compromise on EP additives for avoiding contact versus deliberate friction or viscous drag objectives for synchro cones ? I recall just pouring some EP 90 into my Series One gearbox in 1985 and it's been fine ever since......

[@eliotheasman5378]

Hi Mike very well done as always I call them spring clips jeuas clip because we're did that go very many thanks Eliot

[@chrisgreenwood271]

Looks like he picked up a decent gear box.

[@keithrimmer3]

Nice job mike a copper mallet wouldn't go a miss can you not get new bearings for the 2a now

[@CrtMarko]

Is it better to put new detent springs for 3/4 synchro if old springs are not broken? Can they be too weak?

[@BritannicaRestorations]

Yes - and they do fracture

[@billybunter230]

Any advice please, my series 3 box is jiggered but I have a series 2 box in good condition, is there any way to get it too fit ? I know the clutch will have to be altered.. but I'm sure I read the shaft sticking out the front of the bellhousing is the wrong length.

[@JamesMcArthur1337]

Exploded a lay shaft a few years ago. I think the bearing sized and snapped the shaft. The bearing came out easy as it was cracked. Wish I had known about the punch holes idea before I put it back together. Have an engine main bearing seal issue in a 2a Station Wagon on the go now. Will pull apart the gearbox, redo the syncro. What else should be done when I already have this much pulled apart?

[@BritannicaRestorations]

Not really sure - make sure the rear bearing carrier is tight in the housing, or they can transfer oil out of the main box into the transfer

[@CrtMarko]

On the market are available single bush and split option (main shaft bush for 2nd and 3rd gear). Are both suitable for 2a? Is any better?

[@BritannicaRestorations]

571218 was for the 2a box and FRC4077/6 split bush was for S3

[@CrtMarko]

@@BritannicaRestorations on many web pages it is mentioned that both are suitable for 2a and 3. Did you install split version on 2a? Thank you for your quick response

[@BritannicaRestorations]

I fit the parts as stated in the parts book for that particular gearbox

[@machiningbasics1729]

Very nice work

[@je6017]

Mike, Can you elaborate on your motor oil in a series trans comment? I'm rebuilding a 63 109 with a 2.25l and I have a rebuilt fairey o/d. I've been told that the key to a happy series trans is near constant fuild/oil changes. Im on Van Isl BC and the weather here is rarely under -10 but will get over 40 in the summer. Any further thoughts would be greatly appreciated! Thanks in advance

[@BritannicaRestorations]

Maybe try a synthetic gear oil - check out Lucas oils - maybe they have something

[@nickboylen6873]

LR recommended a 12,000 mile schedule to replace all transmission oils. Hardly anyone ver did it, and then complained about them being unreliable...

[@jenpeterson3712]

a boiling jug of water is good to tip on that small outer race bearing and tap casing it will drop out

[@spitfiremk1uk]

Given any opportunity I would always replace the bearings as a minimum... But here in the UK Bearings are cheap, even skf and timken Given the choice ensure you use a steel carrier rear layshaft bearing... Much easier to install than the plastic versions. The rear mainshaft bearing carrier is best fitted with some loctite, cases these days are getting old and worn. It prevents chattering and oil passing into the transfer box. You surprise me mate... Drilling out the rear layshaft bearing holes!!! You have all the tools never to need to drill a box or use a punch for that job. Strip the main box, place it front face down onto a block of wood. Use heat to gently warm the area around the rear layshaft bearing (Just a few minutes) Lift the gearbox case and drop onto the block of wood. the weight of the outer bearing race will cause kinetic energy to easily pop out of the warm casing. Worked every single time since my first gearbox back in 1985 sometimes it literally falls out without tapping or banging. No oil leaks or sealant required. PLEASE buy yourself a copper hammer faced hammer! I may be an engineering clean freak, and I accept lesser clean work spaces and practices still work... But a very clean, very non oily, very non dusty, environment works best for assembly to prevent shortened lifespan of components due to contamination A very light oil required only for assembly. Keep up the great filming work.

[@BritannicaRestorations]

This casing was really good and the carrier was tight - the old 2.25 casings have gone in the scrap now so drilling it the layshaft bearing was not a big issue - the 2.6 was already drilled and tapped Bearings were pretty good and I would much rather re use good bearings than fit cheap ones, but they have to be good This box will hardly do 500 km per year if that - no body drives then regularly here and remember I have to work with what customers supply - I no longer supply parts - I strip things, work out what is needed and pass the numbers to the customer - no shipping, responsibility for quality, no tax to calculate, so all in all it works out nice

[@kevinnarine5110]

Can a series 3 bell housing fit a series 2 gearbox? I want to change out the whole clutch system

[@BritannicaRestorations]

I don't think so

[@peterhanson5042]

Mike I have a TD5 attached to an R380 with oil cooling pipe fitted from factory and I want to fit an extra finned oil cooler to this line, firstly will the internal oil pump have enough omph to circulate the oil through an additional cooler and should the additional cooler be mounted at the same level as the gearbox or can it be a little higher near the front radiator? I expect this will give another 1/2 liter of oil for the box which should be good in hot Australia.

[@BritannicaRestorations]

Good question - I would have thought the oil cooler supplied would be adequate - is it built into the radiator or separate? I have not seen one. I could not understand why a cooler was not fitted to the transfer case

[@peterhanson5042]

@@BritannicaRestorations The oil line is just a long loop of metal pipe and I can't see how it would add to much cooling. I am thinking of cutting the loop off end and fitting a finned cooler to add some oil volume and better cooling. It seems the main fault with the R380 while towing in hotter climates is the small oil volume rather than any design deficiency and this is my reason for the mod. Your thoughts would be appreciated Mike. Thanks Peter

[@BritannicaRestorations]

I think that would work - the housing on the side of the R380 that feeds and returns oil has a built in thermostat so you cannot over cool - which can be as bad as over heating!

[@peterhanson5042]

@@BritannicaRestorations Thanks Mike from very hot and smoky Australia.

[@defendermender4959]

Ashcrofts do a kit with a proper cooler for the Defender more like the Disco set up.

[@coyote5735]

Isn't the phosphor bronze bearing self-lubing? The amount of oil required is minimal?

[@BritannicaRestorations]

I do not think it is self lubricating

[@stevep8773]

Any oil is better than no oil. I used to carry spare 5W30 Mobil 1 in my car and it still flows at -50C. Regular motor oil does not as you have shown. So when you start a cold car at low temps, even with "good" non-synthetic oil, it runs without oil pressure for a few seconds or more. GM had a cold-weather research lab in Kapuskasing ON, and they said that 80% of engine wear occurs on cold starts, but also that even at -30C, it took a typical (V6, I believe) three days to completely cool off internally www.nytimes.com/2006/03/06/automobiles/test-cars-keep-returning-to-a-towns-icy-embrace.html

[@BritannicaRestorations]

And that is the beauty of modern oils! I ran a 200Tdi all year on 0w30 Rotella- thrashed the bejesus out of it in summer up and down to Ontario and not a flicker of the oil light

[@philhealey449]

I thought we were supposed to use sawdust and nylon stockings for silent operation? Seriously though, presumably we should just use whatever oil grade Rover said in 1960 for the local ambient operating temperature range. Miracle Slick 50 or Molyslip or other PTFE or molybdenum diisulphide gloop presumably upsets the synchro operation?

[@BritannicaRestorations]

Modern oils are really good now - look at the R380 - runs on ATF which is very light - put gear oil in it and it is like a brick!