Series 2 to Series 3 gearbox change

[peterg1001]

I'm thinking about swapping the Series 2 gearbox out for a Series 3, to get the synchro and diaphragm clutch.

Can anyone out there give me a set of bullet points of things I need to consider, and to buy/acquire in order to do the job?

Thanks, Peter

[JDNSW]

You can fit a diaphragm clutch to the 2a, but it is a special pressure plate with a built in spacer. It is possible you already have one (should be able to see if you take the gearlever assembly off and peer in the hole in the flywheel housing this uncovers).

To change the Series 2a to Series 3, apart from the box with bell housing, you will need the Series 3 clutch, clutch slave cylinder and pushrod, clutch fork, release bearing, pilot bush (same as 2a). clutch hydraulic pipe from the master cylinder to LH side, clutch hydraulic hose.

Points to watch - bell housing is different from six to four - make sure your new box is the same as the one you have. Probably a good idea to change out the master cylinder while you are at it.

Personally I prefer the 2a box to use, and they are generally considered more robust, but I do think that the S3 clutch arrangement is probably more trouble free.

John

[peterg1001]

Thanks John, I don't mind the Series 2 box, but my left knee is getting to a point where I need to take any available precautions available to keep it working.

There's a Series 3 box and 6 cyl engine going on ebay at the moment, but it sounds as if there would be some significant bits to add to get it onto my 4 cylinder.

Experience suggests that the acquisition of a bunch of little bits is an expensive undertaking.

Peter

[JDNSW]

Thanks John, I don't mind the Series 2 box, but my left knee is getting to a point where I need to take any available precautions available to keep it working.

There's a Series 3 box and 6 cyl engine going on ebay at the moment, but it sounds as if there would be some significant bits to add to get it onto my 4 cylinder.

Experience suggests that the acquisition of a bunch of little bits is an expensive undertaking.

Peter

The Series clutch is not that heavy, although the diaphragm clutch is lighter, but you might want to consider a remote brake power assist unit to reduce the clutch effort. They are not common, but they can be found.

John

[peterg1001]

The Series clutch is not that heavy, although the diaphragm clutch is lighter, but you might want to consider a remote brake power assist unit to reduce the clutch effort. They are not common, but they can be found.

John

Thanks John, I'll try a power booster on the clutch circuit. I can get a PBR VH44 for about $300, and that can be my next little project.

Stand by for photos . . .

Peter

[pop058]

Thanks John, I'll try a power booster on the clutch circuit. I can get a PBR VH44 for about $300, and that can be my next little project.

Stand by for photos . . .

Peter


yes please :)

[NiteMare]

i'd also go along with the power assist on the clutch, no more than 1.6:1 ratio in my opinion, probably less...

i drive both the series 3 and series 2a with 9.5" diaphragm clutches and feel there is very little difference in the weight of them, i've not driven one using the 9" three fingered clutch cover (early 2a) so can't comment on that...

i did find recently when i changed my clutch (only changed because i was sick of the shudder spring rattle when idling) in the S3 that there was a significant weight difference with the new one (reclaimed out of my parts bin) even though the cover plates were identical make/appearance, i've no idea why though

[JDNSW]

i'd also go along with the power assist on the clutch, no more than 1.6:1 ratio in my opinion, probably less...

i drive both the series 3 and series 2a with 9.5" diaphragm clutches and feel there is very little difference in the weight of them, i've not driven one using the 9" three fingered clutch cover (early 2a) so can't comment on that...

i did find recently when i changed my clutch (only changed because i was sick of the shudder spring rattle when idling) in the S3 that there was a significant weight difference with the new one (reclaimed out of my parts bin) even though the cover plates were identical make/appearance, i've no idea why though

Pressure to disengage a clutch decreases as the plat (and pressure plate) wear, as the spring(s) (either coil or diaphragm) are not tensioned as much - eventually the pressure of them is not enough to grip the plate and you have slip. This is reflected in the pedal pressure needed. Could this be the reason for the difference?

John

[NiteMare]

Pressure to disengage a clutch decreases as the plat (and pressure plate) wear, as the spring(s) (either coil or diaphragm) are not tensioned as much - eventually the pressure of them is not enough to grip the plate and you have slip. This is reflected in the pedal pressure needed. Could this be the reason for the difference?

John

nope the friction plate i used was of a greater thickness than the old one and the cover plate was almost brand new ...

the only possible thought i have for the old cover plate giving greater weight is that this motor does quite a lot of off roading and there was a fair bit of soil sprayed around in the flywheel housing along with a little showing on the cover plate, maybe it had started to rust in places inside itself and was giving extra load, who knows

[Warb]

The original SII workshop manual lists different springs for the diesel and petrol clutches, the diesel having heavier springs, and also states that the springs from the "Rover 105" can be used with "5% increase in pedal effort". Maybe the two clutches in question had different springs fitted?

[NiteMare]

i've no idea what is written in your manual as all i have are haynes manuals covering the Series models but here is a picture of the two clutch covers that i know are fitted to the 2a as standard

the one on the left is a 9" cover and the one on the right is a 9.5", S3 9.5" doesn't have the centre boss

i never drove my 2a with that 9" cover except into my backyard so can't comment on the weight required to release it

https://www.aulro.com/afvb/images/imported/2011/08/253.jpg

[Warb]

The old LR manual is discussing the "3 finger" clutch, where there are 9 coil springs between the cover and the pressure plate. The springs on the diesel version are heavier than those on the petrol version, and the springs from the Rover 105 are heavier again. Each increases the clamping pressure on the driven plate, but also increases the pedal force required.

The later clutch cover clamps the driven plate in the same way, but uses a flat spring (diaphragm). My "book" is too early to discuss that version, but the same rules may well apply, i.e. different spring rates were available depending on the application?

In the earlier "3 finger" version it would seem that the springs are interchangeable (including the "105" springs) and could be identified by their colour.

Given that aftermarket parts do not always abide by colour coding, do not always relfect the full original specification (why make/stock/sell two different types when one will "more or less" do both jobs?!), and often parts are interchanged without full regard to original specs (for example my petrol SWB has a diesel leaf spring on the front driver side) it is entirely possible that two apparently similar components have different operating parameters. So a change in spring rate on the two clutch covers (3 finger or diaphragm) could result in the change in pedal effort without looking any different.

[peterg1001]

Thanks John, I'll try a power booster on the clutch circuit. I can get a PBR VH44 for about $300, and that can be my next little project.

Stand by for photos . . .

Peter

OK, photos attached.

It turned out to be a very easy install, just draining the clutch fluid, bolting the booster in place, and making a couple of lines.

The difference it has made is profound - the clutch effort is now equivalent to a small saloon. Thanks John, a really good outcome.

The only downside is that the clutch now engages about an inch or two off the floor, instead of halfway (4" ??) through the clutch travel.

Is there an easy way to adjust the engagement point up an inch or two?

Thanks, Peter.

[JDNSW]

Thanks for the pictures.

Unless it is a very early slave cylinder setup, there is no adjustment at the slave cylinder (see manual). There should be no perceptible lost motion in the VH44, and assuming it is a change that was introduced with the booster, I suspect that the hydraulic system is not completely bled. The line from the m/c to booster looks as if it would be a likely place for air to be hard to displace from. One solution would be to cut the pipe at the highest point and insert a tee with a bleeder on it, although this may not be necessary - it may just need more bleeding. Remember it is possible to bleed at any junction by loosening the nut.

I assume that the m/c pushrod is correctly adjusted?

John

[peterg1001]

Thanks for the pictures.

Unless it is a very early slave cylinder setup, there is no adjustment at the slave cylinder (see manual). There should be no perceptible lost motion in the VH44, and assuming it is a change that was introduced with the booster, I suspect that the hydraulic system is not completely bled. The line from the m/c to booster looks as if it would be a likely place for air to be hard to displace from. One solution would be to cut the pipe at the highest point and insert a tee with a bleeder on it, although this may not be necessary - it may just need more bleeding. Remember it is possible to bleed at any junction by loosening the nut.

I assume that the m/c pushrod is correctly adjusted?


Yes, the pushrod was fine before I started. I'll check the bleeding again, but it was looking pretty good by the time I finished, no bubbles at all in the tube to the waste reservoir.

Peter

[JDNSW]

Yes, the pushrod was fine before I started. I'll check the bleeding again, but it was looking pretty good by the time I finished, no bubbles at all in the tube to the waste reservoir.

Peter

That does not necessarily mean there is no air in that upward loop. If the volume displaced by a pedal stroke is not enough to shift everything in the pipe to the bleeder, the air is likely to move back up to the highest point before the next stroke, and you never get it out. I can't think of another explanation for the lost movement.

John

[peterg1001]

That does not necessarily mean there is no air in that upward loop. If the volume displaced by a pedal stroke is not enough to shift everything in the pipe to the bleeder, the air is likely to move back up to the highest point before the next stroke, and you never get it out. I can't think of another explanation for the lost movement.

There's a bleed point at the exit end of the booster cylinder (you can see it in the photo), I'll try bleeding from that point next weekend and let you know how I go.

Peter

[RobHay]

yes please :)
PAUL!!!!!! There is nothing wrong with your left knee......so don't even consider changing any of ya massive amounts of landies:D

[peterg1001]

There's a bleed point at the exit end of the booster cylinder (you can see it in the photo), I'll try bleeding from that point next weekend and let you know how I go.

Peter

I had a go at bleeding from the booster cylinder tonight, and, while there was no discernible air coming out of the nipple, the clutch travel is now much better.

Maybe it was just my imagination, given the new feel of the clutch, or maybe it just took a couple of days to start feeling better after the surgery.

Peter