Auto Gearbox Woe - Where's my reverse???

[Stimpy]

Ok - this forum has proven invaluable in sorting techie issues up to now - I just wish I was so tech-savvy to be able to answer other people's issues - however, lets see where this one goes.

I posted an item about 4-speed auto boxes and my totally reliable BW 3-speed obviously found out.

Today - on a nice sunny warm day - the wife and I went out for a drive with the 1 year-old in the back. We were 'testing out the new supergill and bright blue silicon pipes that we had fitted the night before. And the night before that'. Any excuse.

We stopped somewhere and I put it into reverse. It faithfully made the soft badump of engagement. Then (for whatever reason) I decided to make a sharp quick reverse move back. As it took off - within less than a second and probably less than half a yard it made a big clunk (not loud or anything but definitely unusual). Reverse had disappeared. Try as I might there was no reverse gear. So the wife and I jumped out and pushed the thing backwards to realign ourselves. Then we made our way home (along far too many single track roads for our own good!).

I've tried rocking the car in Park and it seems to make what used to be reverse do slightly different things (I can hear a slight noise and I think on one occasion it made it so the car would not roll down the slight decline.

Driving again this evening I was hoping it would somehow 'fix itself'. However - with the radio off and no passengers I noticed that within an echoey bit of road coasting down in top makes a slight chattering noise. Very subtle but not there before.

So - any clues to what I might have done to the old beast.

Or is this something more spiritual telling me to go for that ZF 4-speed box?

Thanks in advance,

Steve

[Guest]

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Hi Steve, it might sound obvious, but is your transmission fluid up to level ? if not, it can lead to all sorts of interesting symptoms ! Another possibility is that the selector change rod has altered length for whatever reason. Worth a look before approaching the bank manager. Martin.

[Stimpy]

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Funnily enough my wife's father told me to check the fluid out.
Originally I wrote that idea off since I knew my auto box dip stick read more than max very recently. However with two people saying the same thing and a healthy dose of paranoia I'll check the oil level first thing tomorrow!

[Stimpy]

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One thing to note - every other gear works fine - from Park down to '1'

[Mpower738]

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I've got the same at the moment, completely lost reverse the other day. It will go back if you rev hard enough, but judders and sounds nasty.

ZF conversion time

[Stimpy]

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Mpower738 wrote:

I've got the same at the moment, completely lost reverse the other day. It will go back if you rev hard enough, but judders and sounds nasty.

ZF conversion time

Join the club. It's not a very popular club though - seems you'e the second member. You can be secretary if you like.

[Stimpy]

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Stimpy wrote:

One thing to note - every other gear works fine - from Park down to '1'

Bit of an update here - in context to the above.

We went to watch a match (public big-screen) involving some excellent individuals who couldn't work together* and on the way back it gained a few more symptoms (on top of the 'no reverse').

These are (in no order at all):

-First lasting ages before going into second (low frequency)
-First ok to second then second taking ages till it engaged 3rd. (medium frequency)
-One occasion where at 20mph it dropped back to first making me look like an amateur in a geared car. (Once only)
- Second (gear) lasting less than a second (time) between normal acceleration (like a hop thru second gear) (high frequency)

A note on box oil - it's well over max. Has been for a long time. To do with when I took the readings (my driveway is very slightly on a hill so it looked very very low when I topped it up, consequentially now that its parked the opposite way around (I have to drift on to my driveway so I can drive out!) it looks quite high. As far as I can tell there is no pressure involved so overfilling is just a waste. Well - it's been that way for a while so I doubt it has an effect.

So - question now is - is my gearbox dying of old age?

[Stimpy]

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Incidentally - I know this veers off topic a tiny bit but when driving today I had quite a high temp reading.

now I realise that ambient temps were mid-80's F (which I actually thought felt more like 90F at least) but bear in mind I have replaced all the pipes with silicon blue ones and installed a new Tony Hart supergill rad (which I have an electric fan connected to [the right way on!] which comes on at half way on the temp gauge).

Does this picture rank as 'rather too high' with readers here? Technically the gauge is still pointing to the 'normal' black however it would be nice to know what others think. Also when would you pull over? If it *just* touches the red or before/after that?

Cheers

[Guest]

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Temp in your pic looks highish but OK, bearing in mind you have the most useless monitoring instrument in the universe ! What fluid are you using ? - not Dexron I hope ! You haven't told us which gearbox you have or the year of your car. Your symptoms still sound like low fluid, there are two dipsticks, does yours have a curly steel top or a yellow plastic one ? Are you checking the level exactly as per the book ? Sorry to go on, but it does matter. If all the answers to the above are correct, get the extra fluid out and try again. Keep us up to speed. Martin.

[Stimpy]

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The temp got very very slightly higher on an earlier trip on the motorway - but still enough black to call it 'normal' if that's what black is (it usually is). re= 'useless' I read somewhere that the reading is taken from the second bank - meaning that the other bank is slightly hotter r something. Anyhow....

The dipstick has a curled steel top - which always burns your fingers if you try to do a reading after a good drive. Not sure about colour - looks like 'used car black' to me! Haynes tells me to take the reading while in Park after a good drive with the engine ticking over.

I got the fluid from Halfords - I chose 'ATF' (I think it was called) - basically the label with the widest compatibility. Since then I've bought a gallon of (unused yet) Comma AQF from one of the stag specialists.

The car is M-reg, 1974 - making it a MkII.

I will get to a dead level surface and take another reading. I presume from your concern that overfilling CAN be detrimental. If that's the case I will take the U-bend (dipstick tube) off to drain and re-fill (I have some new special washers to put on the connection anyway).

Much appreciated for your help - btw

[DJT]

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Stimpy wrote:

The temp got very very slightly higher on an earlier trip on the motorway - but still enough black to call it 'normal' if that's what black is (it usually is). re= 'useless' I read somewhere that the reading is taken from the second bank - meaning that the other bank is slightly hotter r something. Anyhow....

The dipstick has a curled steel top - which always burns your fingers if you try to do a reading after a good drive. Not sure about colour - looks like 'used car black' to me! Haynes tells me to take the reading while in Park after a good drive with the engine ticking over.

I got the fluid from Halfords - I chose 'ATF' (I think it was called) - basically the label with the widest compatibility. Since then I've bought a gallon of (unused yet) Comma AQF from one of the stag specialists.

The car is M-reg, 1974 - making it a MkII.

I will get to a dead level surface and take another reading. I presume from your concern that overfilling CAN be detrimental. If that's the case I will take the U-bend (dipstick tube) off to drain and re-fill (I have some new special washers to put on the connection anyway).

Much appreciated for your help - btw

Hi. You should have a BW35. The BW65 wasn't fitted until the last year or so of production.

If draining the 'box, I would go one stage further and drop the sump. Very straightforward, you just need a sump gasket which should be available from any local g/box specialist. Also get new washers for the banjo joint, or anneal the ones you have and re-use. Even better get 'dowty' washers.

You will probably find sludge in the sump to clean out. It will also give you the opportunity to see if there is anything untoward inside. Download the Stag Repair Manual (http://www.donkennedy.co.uk/StagManual.htm) and it may help.

Sorry, I am not an auto g/box expert but I also have a BW35 and dropping the sump is easy. Just keep everything very clean.

Dave

[GDPR]

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Unless you want to rebuild the box don't waste your time removing the sump.

You have torn the friction lining off the rear brake band or bust the rear clutch frictions, both of which are a major stripdown/rebuild. You are not going to be able to fix this with the box in.

The debris from the failure is now all through the valve block, the governor (hence the very late shift), the converter is full of detritus and the pickup strainer is now well blocked reducing overall box pressures to add insult to the injury.

Time to give it a decent burial..

Sorry

Russ

[richardthestag]

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Easy one first – if the gearbox fluid is anything other than a nice clean looking pink colour that doesn’t smell like satan’s underpants, the gearbox will require some expensive attention. Drop the whole car to a local autobox specialist to confirm...

Onto the temp. Really depends on what it does in the minutes / miles before and after the reading.

Firstly the cheap and easy fixes. Do you have the rad brimmed. You are running a mk2 so hopefully will have the filler on the top n/s of the rad (just above the top hose).

Is the fan working? If you have lost the viscous fan and now only have an electric fan make sure that blow or suck is working the right way...

Is the voltage stabiliser earth lead still connected to the back of the speedo. If not it will cause both fuel and temp gauges to over read.

Do you have the correct sender installed to the rear of the n/s head? There are a couple of types and the one with white insulation around the spade terminal gives the wrong reading back to the gauge – the resistance curve is all wrong or something like that. Looks the same as the proper item (with black insulation) and has the same thread but in makes the gauge read too high.

Do you have the correct thermostat fitted – i.e. the one with the second plunger on the end – they don’t look like normal thermostats!!

Now onto the more expensive stuff

Are the head gaskets ok – dives for cover

My car also used to run hot on hot days. I also had a BW35 and TV8. My BW35 was also on its last legs except that my fluid was ok but the front pump was growling like a drunk tiger. My symptoms were;

Drive it around town all day long and the gauge would sit around the ½ mark. Get it on a motorway and after a few miles the gauge would start to rise and sit about where yours does in the pic. Come to a stop after a spirited run and in would launch closer to the red sector. On one day it sailed through so I lifted the bonnet and took a ½ hour break.

All fixed now. I removed the bw35 and the mashed up cooler that sits under the radiator and fitted a Man o/d. Since then the car rarely goes over the ½ way mark and last week (in 25+ ambient) after a good but not efficient run the gauge went up to the ¾ mark BUT only after I had stopped. Within a couple of minutes getting underway the gauge was back to just above ½ and after 5 miles was back below half.

I reckon that a knackered autopox coupled with an inefficient autofluid cooler tipped the marginal cooling system. My car never actually boiled over but it never made for a relaxing drive on very hot days. It is just about perfect now – on the cooling system front that is.

[Stimpy]

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kryten wrote:

Unless you want to rebuild the box don't waste your time removing the sump.

You have torn the friction lining off the rear brake band or bust the rear clutch frictions, both of which are a major stripdown/rebuild. You are not going to be able to fix this with the box in.

The debris from the failure is now all through the valve block, the governor (hence the very late shift), the converter is full of detritus and the pickup strainer is now well blocked reducing overall box pressures to add insult to the injury.

Time to give it a decent burial..

Sorry

Russ

What you say makes a lot of sense - it did feel like a 'snap' type break when I engaged Reverse on that fateful day. And the chattering you can sometimes hear when cruising down in speed could well sound like bits 'n' pieces swimming around. The erratic symptoms could point to bumpf in the box too. Bugger. Well sort of. It might push me towards the ZF conversion. I just wish it could have waited to see if I had a job in a couple of months (my job might disappear due to govt cuts).

What's the worse thing that could happen if I keep driving it? That's apart from parking it close to a cliff edge front forward with a 1:3 hill behind me.
For the moment I have to keep reminding myself - NO REVERSE NO REVERSE!
Well it's knackered so I can't make it worse - broke is broke? ;-)

Having said all that the dipstick showed a nice pink odourless liquid (higher on the stick due to extra objects in the box?).

Might well at least drain and refit to see what dribbles out. I've got the right dowty washers to hand.


To the temp answer in detail:

"depends on what it does in the minutes / miles before and after the reading." - stays the same. very very slow movement either way. Oddly sometimes it drops a bit (very visibly) then climbs back to where it was. That's rare though.

" Do you have the rad brimmed."
Yep - on a mk2 with the no air betwixt bolt and top. The wife and I replaced all the pipes and the rad (supergill by T Hart) prior to the 'gearbox death run'. I was really expecting dramatic drop from the 'heavy with silt' old rad I took out! If anything it's gone up! eh?

"Is the fan working?"
Viscous fan operating well - electric fan pushing from the front of the rad

"Is the voltage stabiliser earth lead still connected to the back of the speedo. If not it will cause both fuel and temp gauges to over read."

The fuel gauge is remarkably spot on - I can take it to empty and I nearly have to fill it with the gallons quoted in the book! Life on the edge and all that. After which FULL really means full. Does this facttette dispel the stabiliser thing?

"Do you have the correct sender installed to the rear of the n/s head? There are a couple of types and the one with white insulation around the spade terminal gives the wrong reading back to the gauge – the resistance curve is all wrong or something like that. Looks the same as the proper item (with black insulation) and has the same thread but in makes the gauge read too high."

Will have to check that later!

"Do you have the correct thermostat fitted – i.e. the one with the second plunger on the end – they don’t look like normal thermostats!!"

I haven't checked that but until this heatwave it only slightly got above the centre - so I guess that's right (and the water heated up nice and quick 'proving' the stat is closed to start with).

"Are the head gaskets ok – dives for cover"

I think so - just done the water change and oil change and both came out with the right liquid for each! The water had the pretty oil look on the very surface but this would have been the oil collected from the engine casing on the way into the bowl. You can only see it against the sunlight.

"Drive it around town all day long and the gauge would sit around the ½ mark. Get it on a motorway and after a few miles the gauge would start to rise and sit about where yours does in the pic. Come to a stop after a spirited run and in would launch closer to the red sector"

All the same until the last bit! Coming off the fast motorway run to a stop shows the reading going down again. To just over half way.
Thinking back to my school days I remember the 'hot air rises' stuff and pulled the bonnet release whilst on the motorway (DO NOT DO THIS on a front lifting bonnet unless you like to inspect the finer details of your bonnet paintwork!). Didn't seem to make much difference though.

"Since then the car rarely goes over the ½ way mark and last week (in 25+ ambient) after a good but not efficient run the gauge went up to the ¾ mark BUT only after I had stopped."

I'm a bit of a fahrenheit fan when it's hot - so my guess is that 25 is less than 80 so cooler than Sunday. Maybe I should just stop worrying so much!! So long as the tip does not touch the red then we're ok - right? If it does happen I guess it means pulling over and switching off (the pain being that stationary hot water can't be a good thing!!)

"I reckon that a knackered autopox coupled with an inefficient autofluid cooler tipped the marginal cooling system. "

That's a thought - but the temp was that way prior to the snap noise in the box - ie when everything was a-ok. New rad, new pipes new higher temp on the gauge *BUT* ambient temps of well more than 80 - which I have not driven it in before.

Well I'm forced to do something so whatever I do will probably mean a new box of sorts so a more efficient box might lead to lower temps.

I have finger/keyboard ache now so just to say - thanks to everyone for their help and if I've mentioned an 'ah! that's it' moment in my chatting above then please let on!!

In the meanwhile I still love the beast and intend to go out for a reverseless run in a mo - no narrow back lanes then (shame!)

[richardthestag]

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Stimpy wrote:

All the same until the last bit! Coming off the fast motorway run to a stop shows the reading going down again. To just over half way.

That might make me check the ignition timing :?Is the vacuum advance connected to the dizzy and does the baseplate move when you suck on the vacuum pipe?

What is the ignition timing set to? And when you rev the engine does the timing advance?

I ran my gearbox with growling pump for ages, the problem is that whenan autoboxlets go you loose drive. and you can bet your arse that should you find yourself near Hyde Park Corner on a sunny day during rush hour then that will be the moment that it all goes wrong.

Must admit that I sort of wish that I went ZF rather than Man o/d but the manual box still has those moments of fun:dude: