Rough change down in auto

[bear2020]

I have had a search but can't find anything

Change up is absolutely fine and changing down ok until the car goes into 2nd and then 1st. Also the same if I manually shift down.
It is a new problem and not one I have had before with the car. (2000 3.0)

When it changes down into 2nd and 1st it feels like the brakes have briefly been touched (I know they haven't) and there is a little jolt/thump but no noise. Very hard to explain unless you have experienced it before but very different from the feel when the cars shifts down in other gears.

Can anyone point me in the right direction? I also noted this morning a MAF sensor fault (the only code on the car now and again a new one which when cleared comes back but I may have broken it how many times I've removed everything but car is running fine and performing well)

Any ideas?
TIA

 

[hard top]

I am not sure if this comment is of any help but it could be that the transmission gears and bushings are starting to wear out ?

I would think that someone like @t-tony will probably be able to point you in the right direction ....

 

[Iamjonw]

Not sure if this is relevant or not, but I had an ML280 Auto a few years back. On changing down, particularly into 1st the box would jolt. Local independent Merc "specialist" told me it needed a new torque converter, about £1300 fix. I took it elsewhere and they recommended a change of transmission fluid, said it had probably never been changed. Booked it in and they did their stuff, £113 later and it was a totally different car with smooth changes. If you have not changed the transmission fluid, may be worth a think?

 

[t-tony]

My old boss had this issue with his 740 and it cured his problem. That prompted me to change the Auto Box fluid on my 2000 Z3 2.0 which had at the time 65,000 miles (ish). I didn’t have that issue and but the gearbox operated much more smoothly afterwards without doubt.

Tony.

 

[bear2020]

Thanks I will try changing the oils out as I bet they have never been done
Going to order these


Motul Multi ATF Fully Synthetic Car Automatic Transmission & Power Steering Fluid
£10.99
IN STOCK
1 Litre

Motul Gear 300 LS 75w-90 Fully Synthetic Racing Limited Slip Differential Oil
£21.95
IN STOCK
1 Litre

 

[Iamjonw]

Hope it works mate!

 

[t-tony]

IIRC the box holds around 7 litres.

Tony.

 

[bear2020]

IIRC the box holds around 7 litres.

Tony.

Thanks Tony what oil would you recommend? I've seen all different sorts or just a case of having a look on the label when it comes back?

 

[t-tony]

As long as it’s the correct grade I have no preferences. I would contact Opie Oils on here.

Tony.

 

[t-tony]

By the way, if you have a look under the "Articles" section I posted a "How to" on changing Z3 Auto Box oil.

Tony.

 

[bear2020]

By the way, if you have a look under the "Articles" section I posted a "How to" on changing Z3 Auto Box oil.

Tony.

Already got it saved

 

[Nodzed]

Change the filter as well or the oil change is a bit pointless. Gasket and filter set (good one) around the £60 mark. You will have to drop the pan off the box.

 

[t-tony]

My guide tells you all that and how to refill the oil.

Tony.

 

[Dakar Z3]

Hello,

in response to your notchy gear change,
often Auto boxes are seriously neglected and not serviced as often as they should be,

Modern transmissions are very reliable economical and efficient if treat with a little bit of love, as Tony and others have pointed out a transmission service will breathe new life into your Z, do not change the oil without changing the filter this would be a pointless exercise.
MEYLE do a full transmission service kit for the Z, this includes oil, the correct amount and the correct specification, the filter, new filler and drain plugs where necessary the sump gasket and also a new set of stretch bolts for the sump pan, the part number you need should be 300 135 0402, if your location is Norwich, Motormec based in Lowestoft should have a kit on the shelf. Give them your reg number and they will double check to ensure this is the kit you need.

hope this helps

**One point of note the box may hold 7 litres but you can’t drain the torque converter which will hold at least 1ltr, this differs on different applications/vehicles, however on your box the service kit has 6 litres as this is all you can drain from the box In your car.

Dakar

 

[bear2020]

Hello,

in response to your notchy gear change,
often Auto boxes are seriously neglected and not serviced as often as they should be,

Modern transmissions are very reliable economical and efficient if treat with a little bit of love, as Tony and others have pointed out a transmission service will breathe new life into your Z, do not change the oil without changing the filter this would be a pointless exercise.
MEYLE do a full transmission service kit for the Z, this includes oil, the correct amount and the correct specification, the filter, new filler and drain plugs where necessary the sump gasket and also a new set of stretch bolts for the sump pan, the part number you need should be 300 135 0402, if your location is Norwich, Motormec based in Lowestoft should have a kit on the shelf. Give them your reg number and they will double check to ensure this is the kit you need.

hope this helps

**One point of note the box may hold 7 litres but you can’t drain the torque converter which will hold at least 1ltr, this differs on different applications/vehicles, however on your box the service kit has 6 litres as this is all you can drain from the box In your car.

Dakar

Thanks Dakar I am going to wait until I get the car back from the bodyshop and check the label and then give it a go and will post if it made any difference!

 

[bear2020]

Just an update on this
Changed the gearbox oil & filter and the transmission fluid using Tony's write up. I thought it had made a difference sadly it hasn't.

The change down from 3rd to 2nd and then 2nd to first is rough. Feels like you are hitting the brakes. Change up is smooth

In manual mode the change down is the same as the auto mode however from 1st to 2nd when I shift the car up it feels like it suddenly gets a shot of nos and the car lurches forward at speed. The rest of the gears are fine.

I have had a look on line and can't find anything or anyone that has ever posted the same problem and a bit stuck on where to even start looking.

Anyone point me in the right direction?

 

[motco]

It's called roll-out clunk. Back in 1980 I had a Leyland Princess 2.2 HLS Auto that did this SO badly that it broke its torque convertor mounting adapter plate in less than 15,000 miles - TWICE! Henlys, the dealer responsible for servicing at the time couldn't fix it so I asked them to get Borg Warner in to look at it. Henlys' "expert" argued with me that the box was made by Automotive Products, not BW. The name Borg Warner was written on the torque converter housing right under his nose! Typical!

I don't know who makes the box (I believe it's GM - model dependent on when in 2000 it was registered) you have but their technical people will know about roll-out clonk/clunk. In the Borg Warner box in my car it was a simple matter of knowing which adjustments to make, and as far as I know it was done from outside the box.

 

[bear2020]

Thanks Motco will have a read up on that!