Timing chain removal - Cam drift pins - what happens?

[MongoMcG]

I'm replacing the valve stem seals, thus pulling the cams. There is a step in the FSM where drift pins are inserted into 4 of the 8 spots for the actuators that change the exhaust cam timing, then the engine is rotated twice, back to TDC. My drift pins mostly did not feel seated in anything, and those that did feel like they might do something just pop out a little bit. Not much else happens. It seems they served little or no purpose, and their action is not explained in the manual. The tool is T40196.

So can someone let me know what should be happening? Thanks.


– Only insert the tools in the positions shown.
– Install the Camshaft Pins -T40196- as shown.
– Turn the crankshaft two complete turns in the direction of engine rotation.
• The engine must be back at “TDC”.
– Remove the Camshaft Pins -T40196-.

[Smac770]

The point of them is to transition the sliding cams on the exhaust cam shaft into the appropriate position for the task.

[MongoMcG]

I know those sliding bits on the cam need to be in certain spots for removal/installation, and I figured the drift pins were supposed to do just that. My drift pins don't seem to be doing anything at all, nor seated in any of the cam adjustment grooves. I guess what is unclear to me is, how do I know when the pins have done their job?

[RPMtech147]

I know those sliding bits on the cam need to be in certain spots for removal/installation, and I figured the drift pins were supposed to do just that. My drift pins don't seem to be doing anything at all, nor seated in any of the cam adjustment grooves. I guess what is unclear to me is, how do I know when the pins have done their job?

When I apply slight pressure to the pins, I feel it cam the sliders more. I've never tried it without using them so I couldn't tell you what, if anything, happens if you don't use them.

[MongoMcG]

Okay. I went with what I had, in which I, too, put some pressure on the pins and they felt like they popped into something (one at a time), but as I turned the motor the pins are simply pushed back out - i.e. it doesn't feel like anything on the camshaft is moving. If it's wrong, well, I guess that will be revealed when the valve cover comes off. I have those t-handle spacer things that are supposed to make everything on the cam just peachy for removal, so I still don't understand the need for this step.

[Smac770]

The T-handles are used for installation, not removal. As such, they'll confirm the slider positioning. Most likely the removal drift step is there to set the sliders in the correct place so you don't have to manually mess with the positioning during installation. Since doing it wrong will end up with a ball bearing who knows where.

Surprised the drifts should be backing out. Based on the pics, the drifts are moving the sliders for cyl 1 and 3 to the high lift position, leaving the sliders for cyl 2 and 4 in the low lift position.
https://www.audizine.com/forum/showt...1#post13793925

[MongoMcG]

I can confirm the slider bits on the camshaft were perfectly allocated, setting up perfect gap widths for the t-handled spacers. The drift pins did their job or I just got lucky. I actually did get lucky...when I stripped out the Torx head on the 22nd (and last) valve cover bolt. Well, that wasn't so lucky, but a few light taps with a hammer on the T-30 bit gave me just enough bite to back out the bolt, which was lucky. This was the first stripped bolt in 6 months of heavy duty work on this car - a streak I hate to see come to and end.