C70 auto gearbox issue ?

[jigly]

Hi guys,

So recently got back into the Volvos and bought a C70 t5 2004 auto, noticed it intermittently clunks/judders not too harshly when slowing down at 10ish mph (down-shifting?), otherwise seems to be fine changing up and down. Does it when being driven from cold within 15-20mins maybe once or twice and then okay after that, I know the upper rear engine mount/bush has pretty much gone and has a lot of play, have been told it could be that but if it was that would this not happen more often..

I am going to replace the mount bush, also have checked the atf oil and it's brown not black but not the red or pink I've read it should be, it's got 135k on the clock. I've had a quote for the gear fluid flush and autobox reset at £210, asked if it would resolve the clunk and was told it may or may not, what do you guys think ?

Anyone had similar probs like this and sorted it with a flush.. In two minds whether to have the box flushed/ reset or just move on to something else as I know autoboxes can be costly.

Any advice would be much appreciated,

Many thanks

[LeeT5]

First things first.....get the fault codes read. Are there any in the Gearbox? If there are, then doing any of the above may be a waste of time (depending on the code and it's interpretation).

Brown fluid can indicate that the box has overheated in it's life.

If there are no codes, then start with replacing the subframe to gearbox lower tranmission bush, the smaller of the two always tear out.
Then, odd as it may seam, remove the MAF sensor and give it a good clean with carb cleaner then contact cleaner to remove the residue. This will improve the engine's idle and general smoothness across the revs and you'll be surprised at what a difference it can make to an auto box when changing gear! They will be smoother.

Gearbox flush and reset is a must but like you've already been told, it's no gaurantee and may only prolong the enevitable.

Secondly, If you do none of the above, then you'll never know, will you!?

[jigly]

First things first.....get the fault codes read. Are there any in the Gearbox? If there are, then doing any of the above may be a waste of time (depending on the code and it's interpretation).

Brown fluid can indicate that the box has overheated in it's life.

If there are no codes, then start with replacing the subframe to gearbox lower tranmission bush, the smaller of the two always tear out.
Then, odd as it may seam, remove the MAF sensor and give it a good clean with carb cleaner then contact cleaner to remove the residue. This will improve the engine's idle and general smoothness across the revs and you'll be surprised at what a difference it can make to an auto box when changing gear! They will be smoother.

Gearbox flush and reset is a must but like you've already been told, it's no gaurantee and may only prolong the enevitable.

Secondly, If you do none of the above, then you'll never know, will you!?



Thanks Lee, there is no gearbox light on (orange arrow) but will try get codes read to see if any.. Will also give the MAF a spray clean, is this the transmission bush you mentioned? http://www.ebay.co.uk/itm/Volvo-Gearbox-Mount-Stabilizer-S60-S70-S80-V70-850-C70-XC70-XC90-30680750-/122166757865?hash=item1c71b4c9e9:g:nmUAAOSwr7ZW7uy J

I also rang the main dealer and they said they could do an update of the TCM for £90 :/ and to try this first before a fluid change, do you think this may help ?

Thanks again.

[LeeT5]

Thanks Lee, there is no gearbox light on (orange arrow) but will try get codes read to see if any.. Will also give the MAF a spray clean, is this the transmission bush you mentioned? http://www.ebay.co.uk/itm/Volvo-Gearbox-Mount-Stabilizer-S60-S70-S80-V70-850-C70-XC70-XC90-30680750-/122166757865?hash=item1c71b4c9e9:g:nmUAAOSwr7ZW7uy J

I also rang the main dealer and they said they could do an update of the TCM for £90 :/ and to try this first before a fluid change, do you think this may help ?

Thanks again.

Yes, the mount in the link is correct but my advise is to buy that then replace the small bush with a poly one from Powerflex.

Regards the TCM update, yes it's definately worth it but the fluid should not be brown! You need a transmission flush also.

[Mike Arnold]

I had a 2002 C70 some years ago which was flaring on gear changes from 2nd to 3rd. Thump! I changed the fluid (blooming expensive) and did an adaption. It didn't work so sold it. Shame as it was such a fun car.