V70 G/box: AWD: tf-80sc gearbox issues.

[Gribb]

Been scrolling through most of the already existing tf-80 related threads on this forum but have not found an answer to my question yet.

Bought a 2007 XC70 D5 with gearbox issues. I checked codes with my Launch tester and found only 1 in the TCU which keeps coming back. TCM-0134 Linear pressure solenoid SLC1. Faulty signal. Deleted it and started driving.

Car jumps a bit rough into drive and i drive for about 5 minutes before the yellow warning followed by the red warning comes up. Gearbox needs service. At this time the car has shifted from 1-2-3-4 no problem. Further down the road i have to slow down a bit and the box goes down into 3th gear and will not shift up or down anymore. Later when i stop the same code is back and after shifting into P it will only go into 3th.

I left the car for about 5 minutes and checked again, this time it will only go into 5th gear.

So thats the problem. Now the solution. I know there is a solenoid inside the valve body named SLC1 and im thinking its stuck and replacing it might solve the problem? If not i have found the list of all the cars fitted with the tf-80sc i am wondering if its possible to swap the whole valve body from one of those gearboxes? i've found boxes from Ford mondeo and Peugeot 307 for about 1/3 of the price for a Volvo box.

Does anyone have experience with any of this or any idea if it would possibly work out?

[bobcat267]

I'm not a pro mech but before you get too far into pulling out the gearbox I would change the ATF. You will need VIDA/DICE or access to it. I just changed the ATF on my V70 2.4D. It had done 138K miles on what certainly looked like the original fluid.

[Gribb]

Thanks for your reply. I will check the oil before anything else. Old owner said he flushed the box 2 times over the last couple years, never used it for towing.

The problems also arose very suddenly and are of a serious nature. This combined with the fact that the error code points to one specific component suggests to me that it is the component itself that has stopped working, i.e. the SLC1 solenoid.

[stuart bowes]

again no expert but from what I've read in passing it's not always necessary to replace the solenoids.. there are videos of people on youtube taking them apart and cleaning them out, smoothing down rough edges and so on

if you've got the point of being able to remove your existing valve body (which I believe involves jacking or winching the engine up slightly) then surely it would be worth giving it a go before spending out out new parts

assuming you have another car to use as a daily while this one is out of action


edit: sorry I just realised you have a different 'box to me but the general principles of my comment may still be valid

[Gribb]

Thanks Stuart.

I think dismantling the entire valve housing is a bit too difficult for my skills, I've seen people doing it on YT thinking "wow they really know what they are doing", but then after putting it back in the car they just made it worse haha. The solenoid itself looks like it is quite easily accessible so it might be worth a try to look at it without tampering too much with anything else.

[FORTYVALVE]

Hi Gribb,

I wonder how you got on last August?

I have just bought a 2007 XC70 with gearbox probs. Following the fantastic directions on here and volvosweden's video I had no problem flushing the box through, just to rule that out. It hasn't helped. So now I wonder about the solenoid, and if this is a job I can do myself. Did you fox yours?

All the best,

Forty

p.s. I make it look as though I knew it had problems when I bought it (private sale). I didn't. Perfect test drive. Immaculate condition. Under 100,000 miles. Lots of bills/receipts.

[FORTYVALVE]

A part conclusion at least....

Turns out that the electronic turbo actuator had failed. Replacing that seems to have improved things a lot, though I've only just had a short drive in it. However there is still a judder between 30 and 40mph once it is warmed up a bit so I suspect there is a gearbox problem just maybe not as severe as it may have seemed...

Thanks to all elsewhere for help with this

[barrybritcher]

you need to put a MINIMUM of 15-20 litres through the gearbox