W124 Gearbox Probs....

[MangoMan]

W124 Gearbox Probs....UPDATE....

Quick Update..... Just thought I would add this Info quickly, just in case there are further ideas about the problem.
Let the car cool down, for about 7 hours, just gone down the road a couple of miles, and now it's not doing it, changing normally.
Any comments....?
First of all 'Hi' to everyone that knows me, have been away for a few weeks, but now back.....yey!!!

Anyway, back to the story. As said got back the other day and decided to give the 'beast' a run. It's a 1990 w124 300ce 12v. Everything was fine, then on the way back home, after about only 12 miles, half motorway, half town, I noticed that it wasn't changing into 4th gear as normal, it would stay in 3rd right up to 60/70mph. Only after I sort of blimped the throttle whilst going along did it decide to change into 4th. But after about a mile or so down the motorway, cruising at a steady 70 odd mph it decided to go back into 3rd again. Never done this before. I thought maybe the fluid was low or something, so checked this at home, all ok.

All other gears change ok, just wont go into 4th unless I excelerate hard for a second, then release, then it goes into 4th, but of course as soon as I slow or stop, it's back again.

Any ideas? is it electrical, or mechanical?

Any input would be much appreciated.

Thanks, Bill.

 

[Ian B Walker]

when you accelerate hard in 4th are there any strange noises comming out of the box? It sounds as if the clutch pack for 4th gear is on its way out. Or, another thought. Is the filter clogged in the box/

 

[MangoMan]

Hi Ian, no, there aren't any strange noises at all, well not that I can hear. I did try that, window open, radio off, but all sounds ok to me.

Sorry, don't know anything about a filter ???

Cheers, Bill.

 

[Ian B Walker]

Ok, to check this I am afraid that you are going to have to do a fluid change because the filter is inside the gearbox sump. Costs about a fiver for a new filter. Easy job, taking about an hour to do in your local drive If you want me to talk you through it then just holler.

 

[MangoMan]

Ian, do think that this is the problem? Excuse my ignorance, but how will this effect only 4th gear? Have you had the same problem?

And yes, please, I haven't got a clue even where the filter is.

Thanks, Bill.

 

[Ian B Walker]

I had a 201 that had similar symptoms. The filter was clogged and it restricted the fluid going into the clutch pack. I had 3 1/2 gears untill I changed it.

How to change a Gearbox Filter.
Tools required :-
10mm socket
Philips screwdriver
8mm Allen key (not quite sure 8mm is right )
Lint Free Cloth or Hydraulic Wipes
Jack 2 x Axle stands.
Plug Spanner
32mm socket to turn engine with.

Proceedure.

Remove spark plugs (might as well clean them while they are out)
Jack up left hand side of car and place axle stands under it.
Using either a drip tray or something that will hold 7lts of fluid, place under Gearbox sump.
Undo the drain plug that is on the right hand side of the sump and allow fluid to drain.
Once drained remove 10mm bolts (8) from sump
Lower sump and remove from under car.
Locate filter (front of box) and undo 3 phillips screws.
Remove filter and throw away.
Take new filter and fit.
Get friend to turn engine BY HAND till Torque Convertor drain plug reaches the bottom.
Remove plug and drain into tray.
Clean the inside of the sump with wipes or lint free cloth.
Replace sump. (using new gasket, rubber, costs a couple of quid)
lower car and allow Convertor to drain completely.
When drained re fit plug in Convertor (may require front of car jacking up)
Replace Spark Plugs
Fill gearbox, through filler at back of engine using 4 ltrs of New ATF.
Start car and holding foot on brake go through the gears.
Take for very short trip and top up another couple of ltrs of ATF.
Get oil hot by second trip, slightly longer and then check the levels of the oil. Leave engine running while doing second check.
Progressivly do the same again till ATF is at the correct mark on the dip stick.

Job Done, saved yourself Big dosh from stealers.

 

[MangoMan]

Thanks Ian, will give it a go at the weekend and I'll let you know.

Cheers, Bill.

 

[MangoMan]

Sorry,

one more thing.

I've just spoken to the garage that used to service the car before I owned it, he said he would charge about £50.00 to do the required work, eg. change fluid & filter. What do you think, sounds pretty fair to me?

Thanks again.

p.s. He agrees that this would be the first thing to look at. He also said that the gearbox seemed ok to him when he last saw it in July this year. All he did was to adjust the Kickdown.

 

[andy_k]

p.s. He agrees that this would be the first thing to look at. He also said that the gearbox seemed ok to him when he last saw it in July this year. All he did was to adjust the Kickdown.

the kick down on these can be quite fussy, if it's not adjusted right then it could make the box hold a lower gear.

£50 sounds fair for an ATF change, ask him to drain the torque convertor as well if he can - some (but not all) are fitted with drain plugs accessed from a small plate on the bell housing.

Andy

 

[MangoMan]

Hi Andy,

I must say that did enter my mind, about the kickdown, but that seems to be ok in all the other gears, you have to almost floor-it to drop down a gear, depending on speed of course.

Thanks anyway, Bill.

 

[MangoMan]

Updated, please go to top.
Thanks.

 

[Ian B Walker]

I must say that did enter my mind, about the kickdown, but that seems to be ok in all the other gears, you have to almost floor-it to drop down a gear, depending on speed of course.

Thanks anyway, Bill.

The Kickdown is at the end of the pedal travel, a small switch you can feel when your foot reaches the floor. A further press instantly launches you into warp speed. Give it a try...........loads of fun, but select an empty road to try it on first.

 

[MangoMan]

Hi Ian....

....yeah, I know all about that, I tell you it was real fun in the 560, thank goodness it had ASR !!!! There wasn't much that could keep up !

But tell me, what you think now it's seems to be ok now (4th) ?

Cheers, Bill.

 

[Ian B Walker]

Bill, dont know what to suggest. In your shoes I would change the fluid and filter but there again thats me. At least I would have peace of mind that if the problem occured again it was not the fluid or filter. Anyone else here have a suggestion?

Ian t'orrible

 

[MangoMan]

An Update.......

Right, had the Filter & fluid changed last Saturday. But will you believe it, it did the very same thing again on the way home, bloody thing!!!!

It seems very erratic in it's occurance, sometimes I can drive around all day in usual traffic, and no problems at all. Then on another day I can get a mile down the road and it will do it, and I've noticed that now it can get only as far as 2nd!!!

This causes me to really lose it, and I just 'floor' it! Then it will go back to normal operation, sometimes.

Any Ideas????..........Please.........

 

[Ian B Walker]

I would check your cable adjustments again. If they are right then it sounds to my untrained ear like a pressure loss somewhere within the gubbins of the box. I think in your position I would be considering a box change.

 

[MangoMan]

Thanks Ian.

To be honest, I'm convinced that it is the cable going from the throttle assy to the gearbox. This is because, like just now I drove down the road and it was doing it straight away, so I stopped, then pulled away quite sharply, depressing the throttle enough to make it engage first, it was fine after that.

Now, not that I know too much to be honest, but I presume that by doing this, it makes that cable move to the gearbox, not so? Thereby freeing it up maybe, then the gearbox behaves normally, which is nice because when it is acting normally the gearchanges are almost unperceptable, which also re-inforces my belief that the gearbox is ok really.

Whats your, or anybody elses thoughts?

Thanks, Bill.

p.s. Is there a way of adjusting this cable, I see there is an adjustment knob near the throttle assy? Thanks again.

 

[kth286]

MangoMan

Don't forget the vacuum side of things.

There is normally a vacuum unit bolted to the side of the gearbox (petrol cars), so either the diaphram is slightly perforated or the lines to the unit have a slight leak at times, depending on the strength of the vacumm at those times of greatest engine "pull" .

Hope that may be useful.

Regards