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Good technique for doing a transmission.

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I’m in the middle of replacing an AW50-42 leg in a 99 S70. I have a lift and all the resources a professional garage offers, but I don’t think anything I’ve done is precluded if you are on a driveway.  I thought about lifting the chassis right off the sub-frame/drivetrain, but on thinking through what I needed, I decided that I could could get the engine low enough and get enough stuff out of the way, it should be ok. I did one a couple years ago and it was a sobering 2 days at the end of which I felt drained.

This time I decided to go heavy on the prep and to be efficient at the same time. For starters:

get rid of the sub-frame completely. 

Hang the motor with an ability to tip it and drop it significantly.

Get the entire front suspension out of the picture  

This means:

hang the motor with bracing or an engine hoist that will allow you to dip the motor down 8-10 inches on the driver’s side and a few inches on the passenger side  


clear out all the stuff that goes from body to drivetrain including harnesses, Heater core lines, tranny cooler lines, grounds, evap line et cetera.


Also, separate the sub-frame from drivetrain. Tranny mounts, harness connections, steering rack, all engine mounts. 

A word about steering rack. Undo the steering rack bolts from the subframe and the tie rod ends from the knuckle. Also detach the driver’s sway bar link at the sway bar and detach.  The sway bar goes with the sub-frame and the steering rack will stay and hang off the steering column and the passenger tie rod/knuckle. 

Remove the control arms from the sub-frame on both sides.

remove both axles.

Remove the brake caliper assembly from the rotor, remove the rotor, suspend the brake caliper in the strut tower with a bungee or whatever  

remove the strut nuts on the top of the driver’s strut tower and remove the entire strut/knuckle/control arm.

lower the sub-frame 

Disassemble the rear 2-piece engine mount  and remove. 

Set up a 30 mm with 2’ of extensions on the crank and rotate the crank and remove the 6 T-40 torque converter bolts visible from the passenger side rear of the motor looking toward the driver’s side

Work your way around the tranny to engine bolts. Most are 14 mm.   Get your landing pad for the old tranny ready. Find a good place to start with a screwdriver, chisels, whatever.  Pry off the transmission with special attention to the dowels at 10 O’clock and 4 O’clock I believe.  I recommend a tranny jack on a garage floor, but two guys can do it in the mud if necessary. 

Anyway, this is from my phone so not very slick, but I think the ideas presented are solid and will save many from wanting to put a gun in their mouth after 3 days of hell. 


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Sorry for the delay.  I got it out in about 2 1/2 hrs.  I spent an hour or so replacing solenoids in the valve body and the PNP on the new tranny and put it back in in about another 5 1/2 hours.  I ended up throwing some speed sensor and rpm sensor codes and needed another couple hours after the install to sort it all out, but it runs great with no codes now.

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yo Matt!! long time buddy .. nice work here, nice to see some more useful content appearing.   what did ya use to hang the motor?  I've been looking at maybe getting the harbor freight style support beam for when I eventually do the steering rack in my xc90 .. I have a hoist kicking around but I feel the legs/feet will just get in the way when I'm working under the vehicle ... is that your home garage or are you still using the shop?


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