difficulty changing down to 2nd

[Dave3066]

Hi gents

Every now and again I have problems changing down to 2nd gear in my '72 3500S with manual 4 speed box. When it goes in first time the change is very positive and needs definite pressure to engage fully. However, I can tell when it's not going to go in because the gearstick feels very loose and the gears grind. When this happens I have to double declutch and blip the throttle to get it into 2nd. I suspect the synchromesh on 2nd is on the way out, perhaps someone can confirm my suspitions from my description. If this is the case, can it be sorted? I understand parts for these gearboxes are very difficult to get a hold of. Would I be better trying to source another gearbox and face the obvious issues of having similar or other problems with that. I'm not interested in fitting a 5 speed box as I don't have the luxury of taking the car off the road for the conversion. I'm happy to live with this fault for now but some advice would be appreciated.

Cheers

Dave

 

[harveyp6]

Synchro cones are the same as used in the 4 cyl boxes IIRC. Make sure the rear flange isn't loose, although when it is the speedo can tend to fail/read slow/waver. Worn selector striker levers can cause the same problem as well.

 

[Dave3066]

Harvey

Thanks. The speedo does waver a bit. When I do get round to dropping the gearbox for a look, is there anything obvious I need to check for or is it simply a case of checking for excessive movement in moving parts etc?

Also having never removed a gearbox before, how easy/difficult a job is that?

Dave

 

[harveyp6]

If you want to check the synchros (baulk rings) then you'll have to remove and dismantle the mainshaft, which is pretty much dismantling the whole box. As for removing it in the first place the only things I would say are disconnect the top hose, and don't allow the engine to drop too far back as the rocker cover can hit the petrol reserve tap and break it. The rest of it is generally the same as you would do for any other gearbox removal. They are easier to get out than a 4 cyl one, but a bit heavier.

 

[Dave3066]

Gents

Update on my gearbox problem.....

It's developed from an ocassional problem selecting 2nd to not being able to select any gears at all! :evil:

I first noticed it whilst driving the other day and not being able to select 1st at a junction. I tried every other gear and none would engage. With limited access to the selectors, any fault finding has been limited. Symptoms are as follows:

With the car totally stationary and the engine not running there are times when I cannot select any gear...... apart from reverse......which goes in every time. I've noticed that sometimes the gears will select following disengagement of reverse and other times not. If I select reverse and find that I can't select any other gears, a push rearwards on the reversing light striker plate (it will move back slightly) will allow selection of other gears.

With the car being driven, 99 times out of 100 I cannot drop down from 3rd to 2nd or 4th to 2nd and following an attempt to change down I cannot then select any other gear and have to coast to a stop. From then if I select reverse, I may be able to get it into 1st after disengaging reverse, but not always.

Help!

Dave

 

[harveyp6]

The only way to get a better idea of what's happening is to wait until it all jams up again, and then you get under the car and look at the selecrors, while an assistant inside the car moves the lever on your instructions.

My guess at the moment with the limited amount of info so far would be that the selector striker lever is worn out.

 

[quattro]

So the gears will not select with the engine turned off?

If they select with the engine off, but won't with it running, this normally points to the clutch not disengaging properly.

If they will not select with the engine off it could only be the selectors have a major problem, or the mainsaft has become dislodged (mainshaft bearings failed badly).

Can you drain the oil and see if there is anything in it i.e. iron filings or parts of broken up bearing cages?

Personally I would not drive it until I have taken the box out and had it apart, but then I am a bit like that.

 

[Dave3066]

The only way to get a better idea of what's happening is to wait until it all jams up again, and then you get under the car and look at the selecrors, while an assistant inside the car moves the lever on your instructions.

My guess at the moment with the limited amount of info so far would be that the selector striker lever is worn out.

Thanks Harvey

I'll do that first time I get a chance. Probably Weds now as I've a long day at work tomorrow. Not sure I'd know what was right or wrong with the movement though :?

So the gears will not select with the engine turned off?

Yes that's correct, but it doesn't do it all the time. Sometimes it will select and other times it won't select any gear other than reverse.

If they will not select with the engine off it could only be the selectors have a major problem, or the mainsaft has become dislodged (mainshaft bearings failed badly).

I'm hoping it's the former. The car will drive and probably once in every 20 selections it will go into 2nd but I'm getting no worrying noises from the gearbox so I'm hoping nothing is broken.

Personally I would not drive it until I have taken the box out and had it apart, but then I am a bit like that.

I'm a bit like that too so the car is going nowhere until I've had a chance to drop the gearbox and have a good look at it. That's a job for this weekend.

cheers

Dave

 

[Dave3066]

Not sure I'd know what was right or wrong with the movement though :?

Seriously now, I presume I'm looking for where the selector is jamming against during selection of each gear? If it is a worn selector striker lever as Harvey says how easy/difficult a job is that to replace. I presume it still requires the removal of the gearbox. Is there any adjustment I can do with the gearbox in situ that will allow me to drive the car until I can get more time to drop the gearbox? Can the selectors be moved in and out manually from underneath to check if the problem is internal to the box?

Lots of questions I know but I like to prepare before I go diving in.

I really need to get the car back on the road as I'm using my girlfriend's at the moment and she will want it back for work soon :|

cheers

Dave

 

[harveyp6]

The selector striker lever can be done without removing the box itself, but it does mean removing the exhaust front pipes, gearlever and propshaft, then undoing the rear mounting and dropping the rear of the box. You then have to disconnect the speedo cable and reach over the top of the box to remove the remote. Fit the new selector lever and refit.

But you really need to confirm this as the problem before doing it. The actual selectors themselves can only be accessed with the box out, but once the remote was off you could move each selector rod individually, but you could do the same thing with someone moving the lever while you look from underneath.........

 

[quattro]

Bit of a long shot and please remember that it is 30 years since I worked on a 3500S speed box.

I seem to remember that there are some plungers at the front of the selector shafts that prevent you selecting two gears at once. As you select a gear, the shaft pushes the plunger over to lock the next selector in place.

There are also some springs with balls at their base which click the slector shaft into place when gears are selected. These are held into place by a plate at the front of the box (on top). I seem to remember that this plate can work loose allowing the balls to let the selector shafts drift slightly backwards or forwards. This would lock the next shaft and prevent it from selecting a gear.

This problem can also arise by these plungers just sticking in their tracks, which could explain why selecting reverse can sometimes free it up as you are moving the plunger over towards 1st and 2nd.

As I said - a long shot but worth just seeing if this plate has worked loose.

 

[harveyp6]

If the selector striker lever was worn, and the reverse selector rod wasn't coming all the way back when you come out of reverse, because it was a bit stiff and the smaller (worn selector striker could slip through the gap,) then the interlock plunger could still be held across stopping the other selectors moving. By moving the reverse light plate backwards you are in effect bringing the selector all the way back to the neutral position, so freeing up the interlock plunger and allowing selection of another gear. If the plate on the top of the box is loose then it doesn't affect the interlock mechanism, but it will change the "detent" which will have an effect on how cleanly the gears engage and could make the detent spring pressure weak so that it hasn't got quite enough force to fully bring the reverse selector back to the neutral position.

If you look from underneath the car while someone moves the gearlever inside the car you will see if this is the case!

 

[Dave3066]

Gents

Thanks for all your helpful suggestions and explanations as to how the selectors work. I will be lying under the car tonight checking its operation and checking for any loose bits as best I can whilst my girlfriend moves the gearstick.

I'll let you know how I get on.....I might even post some picks if I think it'll help with diagnostics.

cheers

Dave

 

[Dave3066]

Hi Gents

Well I've been under the car and I have to say that there's not a great deal of visibility of what's going on. What I did see though was this....

Well I would show you a picture of the bottom of the gearstick with no bush in the eye on the end of the remote lever that the bottom of the gearstick sits in. I'm guessing there should be one because at the moment the gearstick has to travel some distance before contacting the eye on the end of the selector remote lever. Would this be the whole problem? Guess I won't know till I get a new bush. I reckon probably not that simple but it does explain why the gearstick rattles so much at high speed.

Perhaps the Webmaster could increase my pic upload quota so I can post a pic but you probably get the idea.

cheers

Dave

 

[harveyp6]

If you mean the plum shaped ball on the bottom of the lever then you need a new lever as it's not a seperate part, but if that is missing then it's worth doing as it could well be the cause of your problems.

 

[Brian-Northampton]

Hi Dave,

I dropped in on Ian Wilson (RoverClassics) last week, and he had a couple of gear levers complete with "plum" on the end sitting on his bench.

Give him a call.

Brian.

 

[Dave3066]

If you mean the plum shaped ball on the bottom of the lever

If I could show you the picture then you would know what I mean. I wouldn't know what shape it is because it's not there.... :shock:

On the parts catalogue exploded view of the gearbox casing it shows the remote lever with what looks like a bush, part no 90622363 above it, presumably designed to fit in the eye of the remote and have the plum shape sit in that. That's definitely not on mine. The end of the gearstick has a small ball shape and a nut (I think) on the end.

Brian, are the gearsticks the short type?

 

[quattro]

The lower part of the gearstick should look like this

It would be very nice if that was the whole problem; lets hope so

 

[Dave3066]

Well I have a new gearstick coming from Wins & Co by special delivery tomorrow so that's my job for the morning. Apparently there are 2 different length short gearsticks so without the luxury of being able to measure mine I've ordered the one they had in stock. 50/50 chance it's the right one.....fingers crossed.

Now that Richard has upped my picture quota (thanks) here is the pic I took last night from underneath the car



You can see the complete lack of bush.

Hopefully a new one will sort my gear selection problems.

Dave

ps I nearly forgot to mention that my reconditioned distributor is waiting for me at the local post office too . So that's another job for tomorrow. £105 from H&H before anyone asks.

 

[Dave3066]

My new gearstick is in and working fine. Picture below shows my old gearstick on the left and the new one on the right. Bizarrely, although my gearstick was a short one, the new one was actually shorter so I had to grind a bit off the bottom of the sleeve to allow reverse. Not ideal but it works. I think I'll still see if I can get a new bush for my old one and refit that if I can.