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S80 Transmission Rebuild In-Car DIY

Do you have a “Service Transmission Urgent” message on your Volvo S80? MVS Volvo Forums contributor Oly 850 knocks the ball out of the park with an amazing, well-documented writeup on how he rebuilt his S80 transmission, “in-car”.

2000 S80 DIY 4T65EV-GT rebuild (in car)

After a few nights of reading, I bought a rebuild kit and 4th gear shaft from Dave Norris at Triple Edge Performance. Dave is an excellent resource and happily answered all of my questions. I also bought a wring harness connector repair kit, and a new 2003+ improved 4th gear shaft with hardened splines. Total cost ~$280.

http://shop.tripleedgeperformance.com/4 … K8400R.htm

I just followed the steps in the videos, looked at the manual (pdf version) and hauled the thing apart, rebuilt the clutches, installed all new frictions and bushings from the kit.

Success! It drives like a dream, transmission runs completely silently and shifts beautifully. It’s very, very fast.

Oly

I have a 2000 S80 T-6 with the same P0756 troubles everyone usually runs into, namely no shift into 3rd or 4th. Swapping the whole solenoid set had no effect, so it was time for a complete unit swap or a rebuild. As this is my project car, and I’d done a few VW transmissions before, I decided to do it myself. The idea came from watching this series of videos on YouTube, it’s possible to fix the problem our cars have without actually removing the transmission, so this rebuild just replaces all the clutches and worn bushings and the 4th gear shaft, leaving the torque converter and differential alone.

Oly

I didn’t make any changes to the valve body at all, all of the valves and bores were in good shape, so no Sonnax parts. Didn’t bother with any Transgo items either, just bought a master kit and a new 4th gear shaft. I did replace all the solenoids however. Runs perfectly with that setup.

Oly
s80-new-transmission-parts.jpg
S80 Transmission rebuild parts

How were the 4T65EV-GT’s Valves?

Someone may have worked on mine previously, but I checked for wear marks and axial play in each valves, and found none. Each of the valves was smooth and the bores were clean, no scratches. I expected to find worn or stuck valves. At 152k the bands and hard parts showed very little wear so the ground up 4th gear shaft and burned 3rd gear clutch did no greater damage than making the trans fail to shift into 3rd or 4th gear.

Oly

This has some good background info on the S80 transmission problem.

4T65EV Reassembly Tip

One Note: The re-assembly job with this method is FAR easier if you wind up the engine to completely horizontal so you’re not fighting gravity to insert the clutches, sprags and drums. I would also suggest pre-assembling the driven/3rd clutch shaft, sprag, splined short shaft ( in the sprag ) and the 2nd gear clutch drum with the stove pipe / reverse apply together and installing it all as one unit. It’s heavy but easier than doing them separately and trying to line up friction plates individually.

Oly
4T65E on a domestic (US) GM vehicle

2000 S80 DIY 4T65EV-GT rebuild (in car)