Jump to content
tonydrover

Series 2a gearbox problem

Recommended Posts

Hi, I have posted this same question on series 2 forum, but thought I might try here too. Had some good advice from here in the past.

The gearbox appears to be stuck in forth gear.
The clutch disengages, but as soon as you let the clutch up with the engine running it tries to set off (but stalls cos it's in 4th). If you change to low range it will move (not sure how far cos I don't want to have push it back onto the drive).
This all came about whilst up on a greenlane trying to recover another Landy. I was pulling it out backwards when mine got stuck in reverse. Managed to get it out of reverse so I could be recovered, but then it got itself stuck in 4th. Got transfer box into neutral so that we could tow it off the lane and back to tarmac for RAC recovery home.
I'm thinking something may have broken off and got wedged in there. Can the gearbox be dismantled on the car using the car as a stand? I haven't got lifting tackle to take it out.

Share this post


Link to post
Share on other sites

Not really. First thing to come off usually is the bellhousing. You can take the top off and extract the selector shafts with it still in situ, but it doesn't help repair anything.

Have you check the selector slots are clear and the ball on the end of the shaft is still where it's supposed to be? That's a simple fix that often gets overlooked.

Share this post


Link to post
Share on other sites

A long scaffold pole can be used to lift out the box by a couple of strong peeps,out through the passenger door... All nuts and bolts old school spannering.

Share this post


Link to post
Share on other sites

a friend of mine with a series 3 had the same issue (as did i in a discovery) it was a bit of metal broken off in the top of the selector housing, easily fixable in the car.

Share this post


Link to post
Share on other sites

a friend of mine with a series 3 had the same issue (as did i in a discovery) it was a bit of metal broken off in the top of the selector housing, easily fixable in the car.

That is what it seems like......something wedged in it.

As long as it's not a tooth off a gear!!!

Share this post


Link to post
Share on other sites

It'd have to defy gravity as well as transport itself like in star trek to do that :)

Share this post


Link to post
Share on other sites

It's possible that a detent ball , or more likely the interlock slug may be stuck , these are located between the selector rods to stop any risk of another rod getting moved before the one being de-selected is in neutral . I'd start by taking the floor and tunnel out and looking carefully at what is moving when you put pressure on the lever . make sure the socket on 1st/2nd and reverse are in line in the neutral position too .

Another not uncommon thing is failure of one or more of the plate springs in the 3rd/4th synchro hub . With the top off you may be able to see the ring sitting at an angle in the selector fork

cheers

Steveb

Share this post


Link to post
Share on other sites

Borrowed a fancy piece of kit from work to have a look inside with. (A Snap on boroscope)

Share this post


Link to post
Share on other sites

Borrowed a fancy piece of kit from work to have a look inside with. (A Snap on boroscope)

This is what I saw on the boro scope stuck in the 4th gears.

Where would that have come from?

Gearbox was empty of oil by now. Run it for a bit to get it hot, and plastic melted a bit/enough to release it from 4th.

Filled it up again and run/flushed it, then drained it again. Got loads of little bits of plastic out this time.

Rebuilt it and run it but only had enough oil for half full, so couldn't go for a drive. Managed to get in and out of all gears with transfer box in neutral. With transfer on low & high could feel it trying to pull, so will fill with oil (after I have got some more tomorrow) and go for a drive.

That last photo is after all cleared out. What is that smooth white bit between the gears? Is that supposed to be there? Could that be where all that plastic swarf came from?

post-87200-0-61208400-1463253862_thumb.jpg

post-87200-0-76347100-1463253865_thumb.jpg

post-87200-0-68353600-1463253870_thumb.jpg

post-87200-0-05537200-1463253873_thumb.jpg

post-87200-0-86885700-1463253881_thumb.jpg

post-87200-0-59456500-1463253888_thumb.jpg

post-87200-0-33180700-1463253891_thumb.jpg

post-87200-0-69149200-1463253909_thumb.jpg

Share this post


Link to post
Share on other sites

It looks like the cage of the front mainshaft bearing has melted.

This can happen if the oil level is very low.

Edit: In your first post you said that you were recovering a mate.

Did you slip the clutch a lot? That would put a lot of heat in the primary pinion which could melt the bearing cage.

Eric

post-6088-0-76547000-1463255843_thumb.jpg

Share this post


Link to post
Share on other sites

Sounds like that is what has happened.

When we were recovering there was a strong smell of clutch burning, which we thought was the problem initially, until we realised the clutch was still disengaging and re-engaging fine. We were just stuck in gear.

Seems to me that all that melted plastic had effectively glued the 4th synchro into 4th gear.

Hopefully it's fixed now.

Ideally I suppose that should be replaced, but looking at it in the boroscope, it looks OK and probably not worth the hasle of taking the gearbox apart.

Share this post


Link to post
Share on other sites

Sounds like that is what has happened.

... looking at it in the boroscope, it looks OK and probably not worth the hasle of taking the gearbox apart.

You really believe that?

A bearing comprising steel rollers located securely in a plastic cage has got hot enough to 'destroy' the cage, so the steel rollers are now longer held securely in position, making the bearing unable to do it's job.

Your view is that the bearing was redundant, and hardened steel pins floating loose will be no problem in the future?

Good Luck with that!

  • Like 1

Share this post


Link to post
Share on other sites

You really believe that?

A bearing comprising steel rollers located securely in a plastic cage has got hot enough to 'destroy' the cage, so the steel rollers are now longer held securely in position, making the bearing unable to do it's job.

Your view is that the bearing was redundant, and hardened steel pins floating loose will be no problem in the future?

Good Luck with that!

Quite,I wouldn't do another mile with the box like that,have it apart before any more expensive damage is done.

Share this post


Link to post
Share on other sites

I think maybe you experts are correct.

I tried to take it for a drive today, and straight away something didn't feel right.

Felt like the brakes were binding.

Ruled all brakes out, and it was still the same.

Something in the gearbox is binding, looks like it's gonna have to come out after all !!!!

Share this post


Link to post
Share on other sites

That bearing is almost certainly the culprit. When the rollers skew, they will cause a seizure between the input pinion and the main shaft, which is what selecting fourth gear does. Running the gear box like that has probably damaged the bearing surfaces of both the input pinion and the main shaft, rendering them scrap, but you won't know until you strip it.

No machine should ever be run with a collapsed bearing, nor with low oil levels; the bearings and oil aren't there for the fun of it. I suggest that you get the brakes inspected, since you've had them apart. £20 or so at the local garage is small price for certainty that you rebuilt them correctly, given the consequences of getting that wrong and that, with the best of will, your mechanical diagnosis and evaluation skills need some honing.

Share this post


Link to post
Share on other sites

In some gearboxes these original bearings were of a metal cage construction that did not suffer from melting. These sometimes had less space taken up by roller spacers and hence could employ more rollers and provide greater load bearing area.

Share this post


Link to post
Share on other sites

Don't you just love cost engineers,heskencren? Make it cheap, and sod the reliability and longevity... Welcome to the forum.

  • Like 1

Share this post


Link to post
Share on other sites

Yep , never have liked plastic caged needle rollers , and in this application stuck in a blind hole well above the static oil level , just plain daft . You may find an industrial bearing supplier that can supply steel caged .

Did you know there are needle roller bearings that are made angled to work like a smooth ratchet , free rotation one way and lock up the other , can't remember what they are called .

But yeah pull it apart it's broken :)

cheers

Steveb

Share this post


Link to post
Share on other sites

Yep , never have liked plastic caged needle rollers , and in this application stuck in a blind hole well above the static oil level , just plain daft . You may find an industrial bearing supplier that can supply steel caged .

Did you know there are needle roller bearings that are made angled to work like a smooth ratchet , free rotation one way and lock up the other , can't remember what they are called .

But yeah pull it apart it's broken :)

cheers

Steveb

Years ago in my then s111 swb i managed to melt a clutch release bearing cage when i got stuck in a hole at Castleford yorks so switched to a s11a box and never had the problem again, I hate plastic caged bearings

Share this post


Link to post
Share on other sites

maybe a silly question but can you whip the bellhousing off the front and replace this and the larger input shaft bearing without removing the trans from the vehicle?

obviously the engine would have to be out (I have a slightly grumbly front bearing in my vehicle and engine is being replaced so figured popping a couple of bearings in now might be easy enough)

Share this post


Link to post
Share on other sites

maybe a silly question but can you whip the bellhousing off the front and replace this and the larger input shaft bearing without removing the trans from the vehicle?

obviously the engine would have to be out (I have a slightly grumbly front bearing in my vehicle and engine is being replaced so figured popping a couple of bearings in now might be easy enough)

No. You have to assemble the front of the box vertically to align the shafts and bearings (still fiddly even then), and you wouldn't have enough separation of the units to get the tools in the bell housing in situ anyway.

Share this post


Link to post
Share on other sites

Yep , never have liked plastic caged needle rollers , and in this application stuck in a blind hole well above the static oil level , just plain daft . You may find an industrial bearing supplier that can supply steel caged .

Did you know there are needle roller bearings that are made angled to work like a smooth ratchet , free rotation one way and lock up the other , can't remember what they are called .

But yeah pull it apart it's broken :)

cheers

Steveb

Don't suppose you have any idea where I could get those steel caged bearings from?

Share this post


Link to post
Share on other sites

Right I have both the transfer box and the main gearbox removed from the car and on the bench.

Currently taking the main box apart. I would like to document the strip with photos etc for other people to refer to.

Can't get the photos from my phone onto the laptop, must be a way, just can't find it yet.

Share this post


Link to post
Share on other sites

I'd try a local industrial bearing supplier they will need the diameter's of the shaft and the bore in the first motion shaft and the length , I use Hayley's locally - they are a national company

cheers

Steveb

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy