HEVAC blunder

Don't do what I just did...
After overhauling blend motors I took off the "magic" wheel there control all the distribution flaps as something was slightly sticking.
Found it to be the facia flap so loosened the two bolts behind the clock/buttons and split opened unit with thick screw which sorted the issue.
BUT I forgot to tighten the two bolts which resulted in breaking the "magic" wheel as it wasn't fully engaged and therefore slipped several teeth going in one direction and upon reversing snapped the "magic":doh:
It only snapped the longest part with teeth, the other was me "snapping" getting it out in frustration over the experience.

Have disconnected blend motor atm. so it doesn't get damaged too
On afterthought I could just have left it maybe just cut off the bit the was broken one end and have no book symbol as there is now.. too late...

Anyone got some spare magic kicking about?


When I thought all was good


Well it wasn't

weld it back on with a soldering iron

Emmotts?

Druim said:

Don't do what I just did...
After overhauling blend motors I took off the "magic" wheel there control all the distribution flaps as something was slightly sticking.
Found it to be the facia flap so loosened the two bolts behind the clock/buttons and split opened unit with thick screw which sorted the issue.
BUT I forgot to tighten the two bolts which resulted in breaking the "magic" wheel as it wasn't fully engaged and therefore slipped several teeth going in one direction and upon reversing snapped the "magic":doh:
It only snapped the longest part with teeth, the other was me "snapping" getting it out in frustration over the experience.

Have disconnected blend motor atm. so it doesn't get damaged too
On afterthought I could just have left it maybe just cut off the bit the was broken one end and have no book symbol as there is now.. too late...

Anyone got some spare magic kicking about?


When I thought all was good

View attachment 53018
Well it wasn't
View attachment 53019

Click to expand...

That is because you have engaged it incorrectly. There are pips on the gears and the quadrant that must be aligned on reassembly. Looking at the heater from the R/H side with the quadrant fully anticlockwise the pip on it MUST align with the pip on the L/H flap gear. Fully clockwise the pip must align with the pip on the R/H flap gear. When you get your new one engage it correctly and move it through fully travel in each direction to ensure correct positioning. The L/H or rearmost as it sits in the car flap, hits stops in both directions if the gear and quadrant are not meshed correctly it will cause what you have.

wammers said:

That is because you have engaged it incorrectly. There are pips on the gears and the quadrant that must be aligned on reassembly. Looking at the heater from the R/H side with the quadrant fully anticlockwise the pip on it MUST align with the pip on the L/H flap gear. Fully clockwise the pip must align with the pip on the R/H flap gear. When you get your new one engage it correctly and move it through fully travel in each direction to ensure correct positioning. The L/H or rearmost as it sits in the car flap, hits stops in both directions if the gear and quadrant are not meshed correctly it will cause what you have.

Click to expand...

I did make sure it traveled freely to full extent in both directions and it worked for a day or so but driving round with the bolts loose must have allowed something to get out of order, I think.
I set the marks to all line up fully anticlockwise, maybe that was wrong but it worked in my eyes at that moment.
Did see your suggestion in another post but couldn't get that to work

Anywhere you can see an exploded view of the unit?

Druim said:

I did make sure it traveled freely to full extent in both directions and it worked for a day or so but driving round with the bolts loose must have allowed something to get out of order, I think.
I set the marks to all line up fully anticlockwise, maybe that was wrong but it worked in my eyes at that moment.
Did see your suggestion in another post but couldn't get that to work

Anywhere you can see an exploded view of the unit?

Click to expand...

Can't see how leaving the two top bolts loose could do that. Maybe the quadrant was cracked. The rear flaps hit their stops before the quadrant reaches it's stops. That way there is always a little more travel to allow the flaps to settle on their foam seals, as they do over time. On calibration the motor is driven until the flaps hit their stops and stall the motor in both directions, the Hevac then remembers those two positions as being 0% and 100%. The forward flaps don't have stops and will rotate 360 degrees but the pip must be aligned correctly or they will be in the wrong relationship to the rear flaps in any given position. Giving incorrect distribution. The only proper way to free the rear flaps is to remove and strip the heater unit. It is usually the bearing on the gear itself that tightens. That gear can be carefully levered off but great care is needed as it is located by a large pip into a hole in the flap shaft. The forward gear cannot be levered off without pushing to the left a square steel shaft that joints the two forward flaps together and locks the pip on that gear in place.