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Massive gearbox rattle M66-AWD V70R

Ingo-960SE

New member
Joined
Mar 1, 2006
Location
southern Germany
Hello,

a few years ago I converted my 2005 V70R to single mass flwheel (http://kalmar-union.com/parts/volvo-transmission/) with standard clutch. No increased power.

That worked fine since 2013 with a steady gearbox rattle only when the oil is really hot. Only hearable outside. No rattle with cold oil.
But since a few weeks I hear massive louder gearbox rattle which has now some "irregular" metallic beats in between. Doesn't sound like a can of marbles anymore. More as if you throw some metal into a shredder.
When I depress the clutch pedal the noise completely disapprers. Formerly it also disappeared when the car was slowly rolling down the road (pedal depressed, gear engaged) but since a few weeks I also hear those irregular metallic beats during this condition.
The sound during acceleration when the oil is warm in the 1st-3rd gear is horrible. Sounds like if the gerabox will break into pieces within the next few meters.

I have uploaded a mp3 file I recorded yesterday after driving approx 150km (=almost 100mls): http://volvo-turbo.de/V70R/gearboxrattle.mp3
Engine idling. Sounds from gearbox are like an old diesel tractor.


Is that sound still coming from loose teeth (=not a "mechanical" sound) or do I have to expect an upcoming major gerabox damage?


Kind regards
Ingo
 
A friend gave me his 245 which has a similar rattle in the M47. Goes away when the clutch is depressed but is there all the time if the clutch is out or you are in gear driving. I'm pretty sure it is the input shaft bearing in that trans. So that would be my guess about yours. The only other things I could think of are the pilot bearing and the throwout bearing. But all of those require trans removal in any case.
 
Sounds as if I have to take the gearbox apart. Never did that on a M56/58/59/66 before.
Is the main input bearing a taper roller bearing which needs to be adjusted or a cylinder roller bearing? Anyone has a SKF part no?
 
The mainshaft is supported by two taper roller bearings.

IMG-8862.jpg


IMG-7346.jpg


It is normal for these to rattle at idle with SM flywheel. I drove my old V70 AWD M66 for years that way with no harm to the transmission, it does sound like **** though. Hopefully you kept the OEM gear oil in there. Redline etc., can damage the synchros.

If you are going to strip the trans, you might as well change all the bearings. None are listed. I don't have the numbers off mine to hand.

See this SwedeSpeed Thread for bearing kit source, if you don't want to dismantle yours & wait while you order bearings based on what you find.

Be aware the torx screws on the end caps on the shafts was are LH thread.

M66-Wreverse-Shaft4.jpg


My FWD M66 trans (I removed it when I did the M66 AWD conversion on my C30) has a balky reverse, so I will be dismantling that at some point if you aren't in a hurry for the bearing numbers

M66-Wreverse-Shaft5.jpg
 
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Okay I will install a used M66 until I find the time to change bearings on my current M66. So .. no hurry.

I guess the bearings are pressed onto the shafts?! Can the be removed with some standard pullers (have also some Volvo tools for the old M4x)? Are any special tools needed?
And what about adjustment? I remember some shims on the M4x gearboxes when I repaired one last time. Does the M66 also have those?

Synchros should be okay as it shifts very smooth. I used 75W140 GL5 hypoid synthetic oil for better durability (temp and load).

Can the damaged bearing on my M66 suddenly fail leading to a major/complete damage of the gearbox? Or is it just making noise due to increased tolerances? I'm asking because I won't have the time to change it before the end of month and usually make 300km (almost 200mls) a week...
 
Okay I will install a used M66 until I find the time to change bearings on my current M66. So .. no hurry.

I guess the bearings are pressed onto the shafts?! Can the be removed with some standard pullers (have also some Volvo tools for the old M4x)? Are any special tools needed?
And what about adjustment? I remember some shims on the M4x gearboxes when I repaired one last time. Does the M66 also have those?

Synchros should be okay as it shifts very smooth. I used 75W140 GL5 hypoid synthetic oil for better durability (temp and load).

Can the damaged bearing on my M66 suddenly fail leading to a major/complete damage of the gearbox? Or is it just making noise due to increased tolerances? I'm asking because I won't have the time to change it before the end of month and usually make 300km (almost 200mls) a week...

No special tools to remove the bearings. The only shim(s) are for the differential, located behind the inner race

IMG-7413.jpg


The differential carrier (stock) bearings have plastic cages. If those break up, you will be ****ed.

Make sure you get metal cage bearings for those 32008xq outer, 32010xq AWD inner

Get a Quaife 14j while you're in there, its much better than one driven wheel up front.
 
Any updates to this? I have an '05 M66 V70R now with a single mass flywheel and it rattles slightly especially with the AC on. I know this is normal, but I also get a slight clunk from 1st to 2nd only if you aren't careful. I would love to know for future reference. These are great cars and the trans are interesting.
 
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