What is the "reset" procedure for timing the CVVT hub

edbrig · Post by **edbrig** » 21 May 2011, 05:20

My mechanic and I replaced the timing belt on my 2000 Volvo Xc 70. Everything went fine except that we were not aware of that when removing the ltiming belt we screwed up the CVVt hub spring position (?) . We were not aware of a removal procedure. Anyway now the car is not running well and we need to re-time the CVVT hub. Does anyone know the "reset" procedure to dpo this. Any help would be greatly appreciated. Thanks, Ed

Post by **jimmy57** » 21 May 2011, 09:42

first procedure is to check to see if the cam timing is off.
Pull rubber plug out of end of intake cam on rear of head. Remove the engine torque support/upper engine mount from head and remove the cam position sensor and then the CPS reluctor from end of cam. Now the slots on end of cams are visible.
Rotate the crank until the mark on oil pump is between the two marked belt drive teeth, the other indicator is the mark on forward end of crank t belt gear. The mark on oil pump will align with the "valley" between two teeth. For a visual check the cam gear marks can be aligned or 180 degrees off. If the cam locking tool is used then the marks on cam gears must be up to align with the marks on belt top cover.
The crank needs to be easily turned the last bit to align the marks. You can't go past and back it up for this check.
Once crank is set to position look at the slots on rear of cams, if the cam positioning is correct the slots on the two cams will be parallel to each other( --- __ or __ --- ) with one slot offset up and the other offset down as shown in my crude illustration. Not the engine is mounting leaned back so the slots are also parallel to the break line between cyl head top and cyl head, not the ground.
If the CVVT hub TX55 plug was not removed and the TX55 bolt under it not loosened then the CVVT should not have moved relative to cam but this check could reveal the belt is off a tooth so repositioning the belt and repeating the check by rotating engine around to bring marks up again and rechecking the slots to be sure.
To do a complete cam gear and CVVT hub proper reset relative to cams will require the locking tool that bolts onto rear of cams to hold them in the proper position. Visual is not good enough for anything other than verifying whether something is off.
The plug on rear of head over intake cam will have to be replaced or the hole used for removal will have to be sealed if it is re-used. I responded with all of this in a PM but I do not see it in my sent items......

Post by **JDS60R** » 21 May 2011, 10:14

Here are the Volvo procedures for the timing belt ( if center VVT bolt was not touched) and the VVT replacement procedure if it was.

beoutside · Post by **beoutside** » 02 Feb 2015, 11:19

For those of us that are visual learners this really helped me.

SCP74 · Post by **SCP74** » 12 May 2020, 14:42

I'm having a beginner's trial here with my 2002 v70. I did not make sure that the crank mark was on the money before removing the belt.

I want to just ask one question, that's WHY is it so important that the crank lands on the oil pump mark going clockwise? What is the risk if I get close going CW and then adjusting the crank having gone past the mark?

Post by **bmdubya1198** » 12 May 2020, 23:16

SCP74 wrote: ↑12 May 2020, 14:42 I'm having a beginner's trial here with my 2002 v70. I did not make sure that the crank mark was on the money before removing the belt.

I want to just ask one question, that's WHY is it so important that the crank lands on the oil pump mark going clockwise? What is the risk if I get close going CW and then adjusting the crank having gone past the mark?

If the belt is off, it really doesn’t matter which way you turn it. The purpose of turning it clockwise is to prevent the VVT hub from unloading.
Just make sure the crank isn’t 180 degrees out of alignment.