The Ford Barn

Art Bjornestad · 03-10-2012, 11:41 AM

My Volvo overdrive fails to downshift out of OD quite often. It will also start in OD rather than standard and lugs the engine. I have the J unit and the oil level looks OK. I am running 30 weight ND and hope that this is correct.

Brian T · 03-10-2012, 12:22 PM

Hello Art,
I would start by removing the little oil pan on the bottom of the overdrive, if you find lots of metal particles then the unit will have to be removed, there were some problems with the pressure regulator valves sticking causing other damage, keep us posted.

takomaned · 03-10-2012, 01:45 PM

Hi Art,the overdrive is engaged with oil pressure.The solonoid opens the passage to the pistons(2).This forces a cone clutch to turn the planetary gears.If it's sticking in overdrive,I suspect the cone clutch is not sliding on the shaft.One trick we used on Volvos was to get the drive wheels off the ground and run in up to a decent speed (40 or 50 in top gear).Then disengage the clutch and quickly reengage it.The jolt would free the cone.As far as lubrication,Volvo always runs type F ATF in their man.trans.but most of the British cars ran 30wt nd.in the gearbox.I'm not framiliar with the Model A set up.The Volvos share lube with the transmission,and drive the oil pump for the Laycock off the connecting shaft between the trans and overdrive.Ned in Md.

BILL WILLIAMSON · 03-10-2012, 02:03 PM

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The valve on the solenoid can be problematic. If you could borrow another to try, just screws in, no adjusting. Bill W.

03-10-2012, 11:41 AM	#1
Art Bjornestad Senior Member Join Date: May 2010 Location: Westlake Village, CA Posts: 477	Volvo overdrive problem My Volvo overdrive fails to downshift out of OD quite often. It will also start in OD rather than standard and lugs the engine. I have the J unit and the oil level looks OK. I am running 30 weight ND and hope that this is correct.

03-10-2012, 12:22 PM	#2
Brian T Senior Member Join Date: May 2010 Location: San Diego,Ca Posts: 1,377	Re: Volvo overdrive problem Hello Art, I would start by removing the little oil pan on the bottom of the overdrive, if you find lots of metal particles then the unit will have to be removed, there were some problems with the pressure regulator valves sticking causing other damage, keep us posted.

03-10-2012, 01:45 PM	#3
takomaned Senior Member Join Date: Jan 2011 Location: Near D.C. in Maryland Posts: 106	Re: Volvo overdrive problem Hi Art,the overdrive is engaged with oil pressure.The solonoid opens the passage to the pistons(2).This forces a cone clutch to turn the planetary gears.If it's sticking in overdrive,I suspect the cone clutch is not sliding on the shaft.One trick we used on Volvos was to get the drive wheels off the ground and run in up to a decent speed (40 or 50 in top gear).Then disengage the clutch and quickly reengage it.The jolt would free the cone.As far as lubrication,Volvo always runs type F ATF in their man.trans.but most of the British cars ran 30wt nd.in the gearbox.I'm not framiliar with the Model A set up.The Volvos share lube with the transmission,and drive the oil pump for the Laycock off the connecting shaft between the trans and overdrive.Ned in Md. Last edited by takomaned; 03-10-2012 at 01:52 PM.

03-10-2012, 02:03 PM	#4
BILL WILLIAMSON Senior Member Join Date: Dec 2010 Location: FRESNO, CA Posts: 12,560	Re: Volvo overdrive problem Sponsored Links (Register now to hide all advertisements) The valve on the solenoid can be problematic. If you could borrow another to try, just screws in, no adjusting. Bill W. __________________ "THE ASSISTANT GURU OF STUFF"