[AutoGeek]

So my 2005 V50 T5 M66 FWD developed transmission noise at around 140K miles. I had it to Volvo service and a local transmission shop to diagnose but neither could determine if it was the clutch kit or the transmission itself with out dropping the transmission at the cost of around $1200 just to diagnose. Both said it was not worth fixing. I fellow member here offered to do the job for a much more favorable rate. I ordered a Valeo SMF conversion clutch kit (which I highly recommend). We installed it only to find out that the problem was in the transmission itself.

I ordered a low mileage used transmission from a 2008 C30 to swap with mine.

In my old tranny, we found a bad shaft bearing and the differential had an assembly error. One of the spider gears had 2 bearing plates and the other had none. The one with 2 plates showed signs of excess heating as the plate was discolored blue.

Well we made a mistake of not making sure that the differential spider gears were in place for the drive shafts to enter the splines properly. We didn't realize this until the attempted test drive. Oops!. The spider gear was now jammed out of place and messed up one of the bearing plates. This resulted in having to drop the tranny again and disassemble to put the spider gear in place.

If anyone is interested I have photo-documentation of a disassembled M66 FWD transmission to share.

Bottom line, after getting past the aggravations, this was the most fun I've had with my car and now my V50 T5 M66 is running great again. I still can't explain the assembly error or the rather odd bearing anomaly. It does not fit a normal wear pattern as it looks more like pitting of the metal.

Some lessons learned:

When the axle shafts are removed, make sure the spider splines are aligned prior to reinstalling the shafts. Do not run the transmission with the axle shafts removed (ref S80 EV Conversion Blog).

The transmission is more easily removed by dropping the sub-frame. When reinstalling the sub-frame do not over torque the bolts. Torque to the Volvo spec. The subframe is supposed to have some give and over torquing can cause a stick-slip clunking in the suspension. If you want it stiffer, replace bushings with poly.

I highly recommend the Valeo SMF clutch conversion kit so far. It engages smoothly with no added noise and feels more positive.

I also recommend the Ford e-Focus torque mount. In tracking down my stick-slip clunk I changed the torque mount and love it. There is no added noise or vibration and it takes out the slop.

 

[Facusan]

Nice job!

Did you had to remove the steering rack to remove the subframe or can be left in place?

It engages smoothly with no added noise and feels more positive.

That part made me remember when I checked out a S40 M66 FWD that was for sale. The transmission had a rattling sound at idle, and the guy said it was because it had the Viva performance SMF installed. He also warmed up the car before I arrived (a car that was parked for sale, not in use) and had mayonnaise under the oil cap. I walked away from that car.

Sent from my iPhone using Tapatalk

 

[AutoGeek]

Nice job!

Did you had to remove the steering rack to remove the subframe or can be left in place?

That part made me remember when I checked out a S40 M66 FWD that was for sale. The transmission had a rattling sound at idle, and the guy said it was because it had the Viva performance SMF installed. He also warmed up the car before I arrived (a car that was parked for sale, not in use) and had mayonnaise under the oil cap. I walked away from that car.

Sent from my iPhone using Tapatalk

We disconnected the tie-rod ends from the knuckles and unbolted the steering rack from the sub-frame and tied it up with bungy cords. We did not have to disconnect the hosed or the steering column.

Apparently some of the higher performance SMF clutch kits can chatter. The Valeo kit is tame but does feel more sporty than the factory clutch. It does rev a little quicker and seems to rev-match between shifts better. It was also quite a bit cheaper than a new DMF and clutch.

With 160K miles, my old DMF was still good but had a little burnishing on the surface. The clutch was not slipping yet and had a little more life but probably would have been slipping before long.

 

[Facusan]

Thanks for the explanation!

 

[muppetman342]

Good to hear your positive experience with the Valeo SMF. I've always felt the DMF in these cars were too heavy, making it slow to rev match. Where did you buy yours?

 

[AutoGeek]

And now the sequel to M66 Woes

So that replacement transmission (actually the old housing with newer shafts... long story) developed a whine about a year and a half ago. Considering the mismatch of worn-in bearing races from 2005 vs the newer shaft bearings maybe this can be expected. Like I said, long story. The noise would occasionally go away for several weeks during the summer. However, it had been getting worse all winter long and now I'm getting nervous driving it. It still shifts well and the oil is very dark but NOT metallic looking. I guess the $1800 I paid for the replacement donor tranny and labor was worth 26K miles of driving that I got out of it.

Faced with the decision to replace the tranny again or replace the car, I decided the car is otherwise in great and it is worth doing another swap. So an M66 arrived today from Used OEM Volvo Parts | Used Volvo Parts Experts | ErieVoVo.Com today. I have a cousin who is a very experienced euro car mechanic and has owned several Volvos who is going to help me out this time. I'll keep you all posted.

 

[avenger09123]

How much does an M66 weigh?

 

[AutoGeek]

The shipping weight with the tire and pallet was 185lbs. I guess the tranny itself is ~130lbs.