Date: Tue, 27 Sep 2011 08:42:14 -0500
Reply-To: mcneely4@COX.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dave Mcneely <mcneely4@COX.NET>
Subject: Re: Timing belt replacement and valve timing in VW gas and Diesel
engines
In-Reply-To: <1a5b01cc7cc7$420bd6b0$6401a8c0@PROSPERITY>
Content-Type: text/plain; charset=utf-8
so, another dumb question: Is replacing the timing belt something that I need to do at some particular mileage on my 2.1 waterboxer? Or are there symptoms that I would notice and go from there? It has about 50K miles on a rebuild according to paperwork the previous owner provided to me.
mcneely
---- Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM> wrote:
> hi..
> you always need to loosen the cam sprocket from the cam ,
> any time you replace the timing belt.
> It 'can not' come out exactly right......
> if you do not release the sprocket from the cam.
>
> ( and do not use the cam lock to hold the cam and sprocket while you torque
> the cam sprocket bolt as a final step in the whole process ! ) To remove
> the cam bolt I either impact it off, or use the procedure for holding the
> cam sprocket further below.
>
> So don't even pay attention to that few degrees off thing at the flywheel.
> Keep that at TDC while you get the belt into place with cam sprocket ,
> tensioner, IP sprocket.
>
> here's a little trick ..
> rather than slide t-belt over the edge of the sprockets..,,do this....
> with cam sprocket in your hand..
> put belt in place ..then put cam sprocket 'into' the belt, and onto the end
> of the cam.
>
> My IP pin is just a tad loose ..which allows me to tweak the IP sprocket
> about 1/3rd of a tooth to the right ..
> which is 'just right' ..
> to get belt in place without crankshaft moving.
> sometimes it takes a few tries.
>
> with cam sprocket bolt mostly tightened ( but sprocket still free to move on
> cam ) .tension up the belt ( cam is locked still of course )..
> as you tension the belt...make sure flywheel marks do not move or change.
> Once you get there..
> tighten cam sprocket more - medium firmly, so sprocket is locked to cam for
> now.
> The remove all locks..
> Turn engine through two complete turns ....check that it all lines up again.
>
> the for final cam bolt tightening ...
> rotate engine so you can put a bar through cam sprocket to hold it against
> the head, while you do final tightening on the cam sprocket bolt. Don't try
> to use the cam lock to hold the cam from turning while you tighten that bolt
> ( ! ).
>
> then set the Injection Timing.
>
> Do it this way, and it'll be exactly right.
> Scott
> www.turbovans.com
>
>
> ----- Original Message -----
> From: "Poppie Jagersand" <poppie.jagersand@YAHOO.CA>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Monday, September 26, 2011 7:39 PM
> Subject: Re: Timing belt replacement and valve timing in VW gas and Diesel
> engines
>
>
> Finally got to put some time into the TD injection pump seal replacement.
> With job, family, inlaws etc the bus isn't receiving the time and attention
> it used to... I prepared the engine a month ago by removing all the
> ancillary parts in the way (my home made air intake for the 1.9TD, the
> timing cover, various hoses etc). Today I finally found my dial gauge so
> felt I could continue the job. Thanks to Mark, Bryan, Scott and others who
> have provided advice along the way.
>
> So on to timing belt removal, p 13.16 and 17 in my VW 1.9TD engine manual.
>
> Got engine aligned at TDC mark on flywheel. Oddly neither the bar on the
> crankshaft, not the injection pump locking pin would go in at this position.
> Had to turn the 5-6mm more clockwise to get the crank and pump locked up.
> More on that later.
>
> Took off tensioner and timing belt.
> Took off injection pump drive pulley.
>
> Tried Bryan's tip of pulling out the injection pump shaft seal using screws
> into the seal, however didn't succeed before it turned dark today. I tried
> to pre-drill holes in the seal metal flange using a regular handheld drill,
> but the drill bit would wander despite I had tapped an indentation in the
> seal with a drift. Remember I'm doing this with the injection pump in the
> van, so I have to drill through the license plate access lid. Not so easy
> with a regular drill. Tomorrow after work I'll see if I can locate some
> drill bits for my dremel. That should be easier to hold.
>
> Another "tool" that might work to pull the seal if it existed would be a
> very small diametre inside pulley puller, that is something with outward
> pointing jaws that would grip the inside flange of the seal.
>
> Note on the apparent misalignment of the engine between the flywheel TDC
> mark and the valve and injection pump lock positions:
>
> 6mm off on the flywheel diametre of 210mm is 6/(210*pi) = 0.009 or 0.9% of a
> revolution, 3.3degrees.
>
> I counted 22 teeth on the crank pulley. If I were to move the belt 1 tooth
> forward to would mean a 16 degree change. That is way too much.
>
> By leaving it as is, if the flywheel mark is indeed correct I would be
> running with injection pump reference and valve timing is 3.5 degrees
> retarded compared to flywheel (and presumably cylinders).
>
> So I wonder if anyone else have seen this difference on a VW factory
> assembled engine? (This is a 1.9TD AAZ engine with the std Vanagon Diesel
> flywheel bolted on. I haven't note/thought about it before as I recall, but
> I haven't worked much on the Diesels in the past decade.
>
> I can of course change the valve timing by adjusting the valve pulley. I
> didn't loosen it now assuming I would get the belt on with Mark Drillock's
> "counter rotating injection pulley" technique, but could do the valve timing
> separately afterwards.
>
> Injection pump lock pin and flywheel TDC would remain misaligned though if
> I'm not mistaken. That shouldn't affect timing since it is done w.r.t. the
> TDC mark, but If I change the valve timing belt changes would be difficult
> since I couldn't get the injection pump and valves locked up in the same
> position anymore.
>
> It is still odd that valve lock and the injection pump lock lined up
> perfectly, but not TDC mark. So the two locks are consistent against the one
> TDC mark.
>
> 3.5 degrees off is I believe not a huge deal in terms of timing. Maybe
> affects starting a bit, but when running the pump varies timing with RPM 20
> or more degrees anyway through the advance mechanism. The 1.9TD pump also
> has a load dependent timing circuit that I haven't even hooked up in my
> vanagon install.
>
> So I'm inclined to leave it as is unless people have good reasons to do
> otherwise.
>
> Martin (and '82 Westy 1.9TD "Poppie")
>
>
>
> ----- Original Message -----
> From: mark drillock <mdrillock@cox.net>
> To: Poppie Jagersand <poppie.jagersand@YAHOO.CA>
> Cc: vanagon@GERRY.VANAGON.COM
> Sent: Monday, August 22, 2011 4:30:24 PM
> Subject: Re: Timing belt replacement and valve timing in VW gas and Diesel
> engines
>
> Having the cam gear loose on the shaft does simplify the belt installation
> since then there are only 2 fixed gears to get the teeth count positioned
> exactly on. Also the gear will move out slightly on the taper and give more
> slack to the belt while you fully position it. I still avoid doing it that
> way since disturbing the cam gear just to make the belt go on easier is not
> worth it to me. However it can be quite a struggle to get the 1.9 belt on
> all 3 fixed gears exactly right. There is a trick to it, involving
> preloading the injection pump gear in reverse direction slightly, with the
> locking pin still in place.
>
> Mark
>
> Poppie Jagersand wrote:
> > When replacing the timing belt in a Diesel, the VW instructions say to
> > (first to lock everything up) then *loosen the camshaft nut* (Then put new
> > timing belt, tension, tighten camshaft nut etc). This camshaft nut
> > re-setting seems to be for precisely setting the camshaft angle at TDC.
> > (or is there another reason?)
> >
> > If I remember right (and I may be wrong - it is a long time since), for
> > the similar 70's and 80's 4cyl gas engines instructions were basically
> > lock up cam, replace timing timing belt. No camshaft nut loosening and
> > re-setting of cam timing.
> >
> > Any reason a Diesel would be more sensitive to (very small variations in)
> > cam timing? Anyone skipping the camshaft nut part?
> >
> > Martin (and '82 Westy "Poppie")
> >
> >
--
David McNeely
| 
