

| Subject: | Re: Timing belt replacement and valve timing in VW gas and Diesel engines |
| From: | Dave Mcneely |
| Date: | Tue, 27 Sep 2011 08:42:14 -0500 |
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
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