My Speedo and Auto box is going CRAZY!! HELP!!!!

[GRIFFO69 0]

Hi 2 anyone that can HELP!!

My speedo goes a bit crazy usually when engine is warm, the speedo clocks 170mph and cuts out or just flicks back to 10pmh when i slow down and usually is ok then. But sometimes the speedo doesnt work at all and then it would continue as if nothing had happened lol.. Also id like to add my mk3 vr6 is automatic and when this speedo problem begain another fault also accured! I dont seem to have 2nd or 3rd on the box and will only kick down wiv the throttle!

And today i seem to be gettin little power when selecting gears.. Its takes 3000rpm to even start a crawl..

This car was a project! and after my engine rebuild and all other parts i have replaced this seems to be it for me wiv my vr6.. Its $hit or Bust ive had enough Grrrrrr!

[GRIFFO69 0]

an update..

Had my car put on a diagnostics test today and no electrical faults have shown up, everythin is sweet!

But this guy seems to think my gearbox has had it

Im thinking mayb torque converter but im unsure..

I would just like some feedback PLEASE?????

Cheers

[Ben Seabrook 4]

After looking on some other forums I found this :-

"from what you are describing, three things come to mind, either the speedo has died/or is dying,... the speed sensor is on its way out, or the transmission is having a problem. honestly, I would take it in to the shop and have them test the speed sensor first. this is the cheapest fix first of off, secondly the next area to look at is the speedometer. VW offers remanufactured speedometers now, so the prices have dropped a bit"

[GRIFFO69 0]

Speedo was sorted today..

There was a bit of swarf on the speed sensor! cleaned up like new..

The only thing that comes to mind about the gearbox is, When we removed the box to change the crankshaft, the torque converter leaked some oil but we just generally thought it was gearbox fluid..

But from reading forum posts im led to believe there is 2 types of fluid in a automatic box??

1 oil and 1 fluid.. the oil is stored inside the torque converter is in a closed unit so theres no need to check the level..

So... what im thinking is... The torque converter has burnt out because of lack of oil??

But i would like someone to confirm this first..

Also apon reading up.. you have to have the engine running to top up the level of fluid in the gearbox.. As when cold it does not give a good reading on the dip stick..

We did not do this.. filled fluid up from cold start.. not good?

Any thoughts??

New gearbox im trying to get hold of

[GRIFFO69 0]

Today i spoke to a Auto Box specialist and he said with my current symtoms, he seems to think when i disturbed the box while removing it, i may have blocked the oil filter behind the sump. Therefor not enough oil getting to gearbox.

So i removed the sump and oil filter to attempt to 'clean it up'.. But looking closer this filter seems tobe a sealed unit... Phoned the stealership and the guy give me a quote of £400 for the new filter!! Shocking!! When a new box is £1200 supplied by them.. Crazy!!

So im gonna atempt to clean this filter up as best i can..

Some pictures attached showing filter and gearbox

[lightbox=../../e107_files/public/1192893965_4240_FT200721_oil_filter.jpg][/lightbox]

[lightbox=../../e107_files/public/1192893965_4240_FT200721_front_view_gearbox.jpg][/lightbox]

[lightbox=../../e107_files/public/1192893965_4240_FT200721_side_view.jpg][/lightbox]

[lightbox=../../e107_files/public/1192893965_4240_FT200721_bottom_view.jpg][/lightbox]

[GRIFFO69 0]

Still waiting on some replies lol im basically on my own here! I have 1 Haynes manual but that can only take me so far........

Today i cleaned up the old oil filter with some petrolium.. Left it inside a tin overnight to soak up. And a good idea it was.. its looking 2nd to brand new!.. Cleaned out the sump and was suprised to find 2 magnets inside.. Obviously this must be standard practice on the Autos.. Its job must be to attract any loose fileings from the gearbox to stop them from re-entering the gearbox..

Also something else to add from scouring the forums... If your stearing wheel vibrates or shakes above 70mph and all tracking and balancing is correct, then your gearbox mounting has gone or hopefully loose so no trip to the stealership

Write back someone lol running out of ideas here!

[Ben Seabrook 4]

Take a look at this - seems to have the same sort of problem as you !!!!

http://www.vwaudiforum.co.uk/forum/showthread.php?t=3725

[GRIFFO69 0]

Cheers Ben for your HELP!

Looking through forums i found this...

1st stop is to check your fluid level; also, when was it last changed? Brakebands and clutches can fail, but most problems are caused by low or contaminated fluid.

Here goes with a brief outline of how auto boxes work...

[Others please comment if this isn't 100%, it's been a while since I played with any auto boxes]

There's a torque converter on the flywheel; this is essentially two discs with vanes that pass close to each other, the whole thing is filled with transmission fluid. One half is bolted to the flywheel, the other is mechanically coupled to the input shaft of the gearbox.

Power transfer to the driven plate occurs courtesy of the viscosity of the transmission fluid and the proximity and design of the vanes.

When you go to pull away, the design allows for a certain amount of slip, as the differential in speed between drive and driven plates, the combination of viscosity and turbulence caused by the design of the vanes causes the friction between the two to increase dramatically as revs rise and thus more torque is transferred to the gearbox.

At standby in idle, you can normally detect some 'creep' but as the revs rise you will feel more 'pull' as the upper differential speed is reached. This is why they’re nicknamed ‘slush boxes’. This differential speed under load also wastes power and creates a lot of heat, so most modern implementations have oil coolers and a clutch that will lock up the torque converter once the car is underway.

If you tow with an autobox, you should have an oil cooler fitted of your car doesn’t already have one, as towing puts a real load on the torque converter. It is possible to overheat the both the torque converter and oil which can lead to further problems.

Meanwhile, inside the box itself, there are sets of 'planetary' gears [one inside the other] these are arranged in ratios and are all attached to the same output. The outer gear has to be stationary for power to be transferred, so they can all be mechanically engaged at the same time as long as the outer rings are allowed to 'spin'. Ratio selection is carried out by braking [stopping] the outer planetary gear from the chosen ratio set by using hydraulically operated brake bands around the outside of the gearset.

Often, a set of planetary gears is used more than once [e.g 1st and 3rd] by having another set of gears on the input or output that changes the overall ratio [like an overdrive]. These are usually operated by a hydraulic clutch in conjunction with the brake bands to select gears. You normally won’t know anything about this as the box just works it’s way through all the ratios as needed.

In older designs, all the decision making regarding speed, clutches and brake bands [and ultimately which gear ratio] were carried out with lots of hydraulic sensors and valves based on fluid pressure. This was known as the valve body and reliable operation relied on clear, clean fluid.

Although much of the decision making is now electronic via the ECU, there are still sensors and actuators that are hydraulic in operation. Any debris of any kind in the ATF fluid can screw up the logic and cause mayhem - if the wrong combination of brakes or clutches are engaged simultaneously, disaster can follow.

If anything starts to break up the debris can cause further problems. There is some sludge in the sump which can mix with the fluid if disturbed and every so often it can block the pump inlet, pressure drops and the drive would disappear. A thorough flushing of the box and valve body can cure the problem

[GRIFFO69 0]

Just been quoted £350 for a recon box delivered and everything awwwwsum!!

I hoping though that when i flush out the system and then finally put sump back on and fill up fluid and give her a try she'l be fine.. Hopefully lol but if not im going for the recon!