AW55-50SN attempt at repair (with pics)

Post by **precopster** » 04 Feb 2014, 03:53

I took some pics today of the disassembly procedure of a AW55-50SN as fitted to most of the P2 series cars including S60, S60AWD, V70, V70XC, XC90(2.5T) and 2000 model non-turbo S70s and V70s from the P80 series. I believe 2000 model V70 & S70 Rs also had them.

Symptoms my '01 XC70 has are: no reverse, engine loading in P & R and perfect forward motion in D

Early serial numbers almost always have a unattached B4 piston washer

: The casing after a pressure wash; 20140203_114608 (Custom).jpg (153.07 KiB) Viewed 16318 times

The washer was unattached however it wasn't very bent unlike others I'd seen.

: The serial number is an early one denoting B4 cover problems; 20140203_114639 (Custom).jpg (157.26 KiB) Viewed 16317 times

Replacing the piston seal which is provided in the B4 kit

: The B4 cover; 20140204_111839 (Custom).jpg (142.81 KiB) Viewed 16317 times

Much easier when you can get a clamp on it to overcome the piston spring; you can't do this when it's fitted to the car

: The seal being lifted with a jeweller's screwdriver; 20140204_112105 (Custom).jpg (138.58 KiB) Viewed 16317 times

The new B4 piston cover looks so shiny!!

: Using a clamp to compress the piston spring; 20140204_112605 (Custom).jpg (142.88 KiB) Viewed 16317 times

Removing the dipstick and oil line return

: New B4 piston cover; 20140204_112821 (Custom).jpg (119.24 KiB) Viewed 16317 times

Removing the 9 torx 40 bolts on the valve body pan. I had the pressure on the compressor turned right down as I didn't want to damage the heads on the torx screws.

: Oil line/dipstick removal; 20140204_114903 (Custom).jpg (123.76 KiB) Viewed 16317 times

I have an "A" series valve body. These were the second ones produced. Earlier ones had no marking.
So far SS1 through SS5 have passed the ohm tests and are between 11 and 16 ohms (@70deg F or 21degC)

: Rattle gun removal; 20140204_115541 (Custom).jpg (124.08 KiB) Viewed 16316 times

Rear cover removed exposing the Forward (C1) and direct (C2) clutch assembly (left) and reverse gear carrier assembly (right)

: Rear cover removed; 20140204_121717 (Custom).jpg (163.88 KiB) Viewed 16316 times

I removed the casing which houses the reverse gear clutch assembly and checked the 1-2 reverse gear clutch facings for wear; nothing dramatic

: The reverse gear clutch assembly is captive on the rear case; 20140204_121722 (Custom).jpg (150.35 KiB) Viewed 16297 times

SLT, SLU & SLS solenoids were checked for electrical tolerance and are all within 5-7 ohms between the pins. However this doesn't mean they are mechanically OK. They could be so packed with foreign matter that they don't operate at all.

: SLT, SLS & SLU solenoids are within spec; 20140205_115722 (Custom).jpg (195.01 KiB) Viewed 16289 times

The valve body will be disassembled and new gaskets fitted as well as the Transgo kit items fitted.

: Valve body (yes the fluid was really THAT black!! ); 20140205_115733 (Custom).jpg (169.36 KiB) Viewed 16288 times

Post by **vtl** » 04 Feb 2014, 20:20

Nice!

Look at the color! That box was running on transmission dirt!

Next time use chisel to get that stubborn left CV axle out

Post by **precopster** » 05 Feb 2014, 13:43

The darn images were mixed up from the captions since I tried to edit with Tapatalk. It seems Tapatalk and the standard web interface don't mix well if Inline photos are used. Can't make sense of it now; I give up

Moderators please help

Post by **precopster** » 06 Feb 2014, 04:14

I'm going to risk a valve body repair and just last night ordered a Transgo repair kit with valve body gaskets. I know I should probably just order a reman valve body for this '01 XC but as I just purchased another XC, this time an '02 that has flaring/banging problems I can use the valve body parts for that car if I find excessive scuffing in the piston bores of this one. Yeah I know I'm a sucker for punishment but it keeps me off the streets

Thanks for the hint VTL I'm gonna get that sucker off just to lubricate the spline but as I like to regrease the CV boot grease it doesn't really bother me.

Post by **jimmy57** » 06 Feb 2014, 11:03

The way a lot of these tough LH shafts come out is by prying with gentle force and if it doesn't move then push in on the shaft, turn 1/4 turn then pull out and then pry. The circlip gets out of the beveled area on axle gear and doesn't want to compress. IF you can coax it to move then it can center itself and it comes out without too much force. The risk of excessive force is breaking the case or breaking a piece of circlip and leaving it where it can come out of diff ang get between final drive gears.

Post by **precopster** » 06 Feb 2014, 20:10

Thanks jimmy. I tried a gentle pry while rotating but got nowhere.

I may just leave it in as it will be mated with the same shaft it came with.

Did some more testing today on the SS1 through SS5 solenoids. I get no actuation of solenoid 4. It draws current and has the usual ohm reading.

See what you think:

Post by **DGM** » 07 Feb 2014, 09:10

Mike, it is always of interest to follow what you do. I stay tune to see what else you will find. I found these documents on file. You may have them already but in any events I include them.

aw55-50 trans sonnax.pdf: (4.83 MiB) Downloaded 2424 times

AW55-50 SN valve body fix.doc: (4.18 MiB) Downloaded 1796 times

AW55-51 troubleshooting .pdf: (505.67 KiB) Downloaded 2573 times

Post by **precopster** » 08 Feb 2014, 05:04

Thanks DGM I had one of them. I use the ATSG service manual which I paid for to download

and it's pretty similar to these docs.

I believe that S4 is stuck on. This would explain no reverse. I'm going to run some solvent through them tomorrow evening and see if S4 begins to actuate.

Also I'm going to use Vida on another car in TCM Activations to see if S4 makes a loud actuation noise.

Post by **mikealder** » 08 Feb 2014, 05:44

Mike, A small ultrasonic cleaning tank to pop the solenoids in one at a time to agitate the solvent is a great way to clean these out, the small tanks can be bought from the bay for little money usually used for jewellery cleaning.
BTW Great video showing it comes to bits - Mike

Post by **precopster** » 09 Feb 2014, 13:27

I cleaned up S4 only to find that the spring return has failed on it.......when the solenoid is shaken by hand the armature rattles inside. If it lands in the right position, applying voltage creates the right noise however it only happens once, then you have to shake it and reapply voltage.

I don't know if that functions list is correct DGM. S4 has function for reverse If I recall correctly all solenoids are off for reverse according to ATSG. There are several functions lists depending on valve body model. Perhaps that one is for another car or simply incorrect.

The oil pressure forces S4 into an unnatural ON position because of the failed return spring.