G/box: AW50151AWD: How to repair/replace the linear solenoids on aw55-50/51sn

[timh30]

I've made this guide in case anyone else wishes to try repairing/replacing their linear solenoids, rather than replacing the whole valve body or complete gearbox (at just the cost of a gallon of gearbox oil).

Normal symptoms caused by 'gummed' up linear solenoids are bumps on down changes (in my case 3-2) and slipping on upchanges.

I mainly followed this excellent guide written for the xc70 (http://www.v70xc.com/resources/how-t...ment-Notes.pdf), but most of it is relevant to the xc90 (and in fact slightly easier as I didn't need to perform some steps - i.e. draining coolant).

I'd estimate the whole job took about 8 hours, but obviously if you are replacing the linear solenoids (available on ebay in the states - rostra linear solenoids) then it should take a couple of hours less as you don't need to open up and clean your existing solenoids.

Basically you need to raise the engine and lower the subframe to make space to remove the valve body cover plate, once this is done you then have access to the linear solenoids (either to repair/replace). PLEASE TAKE a PHOTO OF THE ORIENTATION OF THE SOLENOIDS, AS IT VARIES ACROSS GEARBOXES.

These are the steps on an 04 XC90 D5:

0. remove front skid plate
1. Drain gearbox oil (drain plug at bottom)
2. Remove air filter box and pipes etc
3. remove turbo pipe
4. unbolt front engine mount (unbolt from bottom through subframe)
5. loosen off the rear engine mount bolt (from bottom) - leave bolt in place
6. unbolt the gearbox steady bar - which mounts from bottom of gearbox to subframe
7. unbolt earth strap on front subrame
8. remove engine cross brace at top of engine
9. remove gearbox oil pipe (on top of valve body cover) (2x22mm spanners needed)
10.remove gearbox oil pipe at bottom of gearbox 10mm bolt (and bracket securing pipe at dipstick tube) - some oil will come out
11.unscrew a few turns the front right subframe bolt, and the rear left, then the front left (passenger side) subframe bolt as far as possible
12.place a jack under where the gearbox/engine mate and using a block of wood to protect the engine/gearbox, lift the engine as far as possible.
13.you should now have access to the 9 torx bolts holding the cover plate on, remove those and carefully remove the cover plate (some oil will come out) pulling it up through the engine bay. You may need to slip a flat blade in between the coverplate and gearbox to break the seal.


At this point take a photo for later reference. Also ensure no grit/debris gets into the valve body (I used a platic carrier bag to cover it and keep clean).


14. Using a small screwdriver, push this into the top gap between the connector plug/socket and lever down while pulling on the connector plug. Do for all 3 linear solenoids.
15. The top (black) solenoid is held by a single bolt and bracket (which also has a little cable bracket as well) remove the bracket(s) and slide the solenoid out.
16. The blue and green solenoids are held by a single bracket - note the orientation and remove the bracket and then the solenoids.

If you are fitting replacement solenoids, then skip this next part.

Refurbishing solenoids:

17. As per the photo, hacksaw slots into the crimped end, then use a flat bladed screw driver and hammer to gently bend these back.
18. Carefully remove the round end cap, the pintle and small washer (keep parts with corresponding soleniod)
19. repeat for the other solenoids.
20. remove the clip from the snout of the solendoid, then using allen key (2.5mm I think) unscrew the end fitting, noting how many turns it took.
21. Remove the spring and valve (note orientation).
22. using a 4mm drill bit, insert this into the bushings (from the bottom) and turn back and forth for 15secs to remove any debris (see this youtube video http://www.youtube.com/watch?v=rB5Mw8lGh7A)
23.clean the parts and soleniod in a solvent (I used white spirit) and allow to dry.
24. check that the pintle drops under its own weight when inserted
25. once cleaned, put the end cap back in place and knock back over the crimping using a drift of some sort.
26. gently shake the solenoid up/down and make sure the pintle moves freely (you should hear it clearly)
27. reinsert the valve and spring
28. insert the screw cap the number of turns noted previously (4.5 turns for blue/green, 8 turns for black are recommended)
29. replace the clip on the snout end
30. Repeat cleaning process for other solenoids, note that the black solenoid has a smaller spring and valve and finer thread on screw cap.
31. Finally - if you have a multimeter, check the resistance across the connector terminals on each solenoid, it should read 5-7ohms.


Re-installing:

31. re-install the solenoids and brackets, into the orientation noted previously
32. plug the connectors back in
33. clean any gasket sealant from the gearbox face (make sure no debris falls onto the valve body!)
34. clean the valve body cover thoroughly - removing any sealant.
35. Put a bead of new sealant on the cover and refit - be careful to avoid getting sealant on the valve body when guiding through the gap.
36. reinstall the torx bolts, dont overtighten.
37. reinstall everything in reverse (as detailed above)
38. Finally top up the gearbox oil - you need about 4 litres, but follow the guides to check the levels.
39. Test drive. If you have someone with vida - get them to put the gearbox back into learn mode.

I'd recommend doing a flush (gibbons method?) of the gearbox oil once you are happy there are no leaks and its all working correctly.


I did this at the weekend and so far neither I nor my wife have experienced the bumps on downchange or slipping going up gears.

[timh30]

Gearbox still running fine - about 1500 miles on it since the fix.

I also added a magnefine filter on the return line from the cooler - this should pick up any sludge and keep the oil clean.

[Steve1564]

Excellent write up.... "Good Skills"

- I noticed that some aftermarket solenoids have holes in the end cap to allow the crud to get out - any point in modding the existing ones ?


Steve

[timh30]

Yes the Rostra solenoids have some little drain holes in the end cap. As this could affect the dampening of the pintle I didn't risk it, but I have put a filter on the return line to catch any sludge.

[Steve1564]

Originally Posted by timh30

As this could affect the dampening of the pintle I didn't risk it.

Good point... Now i just need to get a clear day - or tidy the unit so i can get a car in!

Did you have the software updated ? - My T5 is 2002 so i don't know if it has the stop N or not -

Steve

[timh30]

Originally Posted by Steve1564

Good point... Now i just need to get a clear day - or tidy the unit so i can get a car in!

Did you have the software updated ? - My T5 is 2002 so i don't know if it has the stop N or not -

Steve

We'd previously had the latest s/w updates for the gearbox, which didn't make a great deal of difference. If you can get hold of someone with vida dice it is worth putting the gearbox back into learn mode - although I didn't have access to that, but overtime it will re-adapt itself.

[mrc1501]

Originally Posted by timh30

I have put a filter on the return line to catch any sludge.

Have you any info on how you did this, and what parts (filter) did you use.

[timh30]

I bought one of the magnefine 3/8th inch filters (from ebay in the states). You cut the return line from the oil cooler in a suitable place to install the filter, I took about an inch or so out of the pipe (you would need to check if this is necessary on other models) and then insert the filter with jubilee clips (direction arrow pointing from the cooler to the gearbox.

Some picture here (not mine) http://www.matthewsvolvosite.com/for...hp?f=9&t=24805

Tim.

[mrc1501]

Originally Posted by timh30

I bought one of the magnefine 3/8th inch filters

How often would this be replaced

[timh30]

Originally Posted by mrc1501

How often would this be replaced

http://www.magnefine.com/html/faq.html