Timing Belt Change Procedure

[BluevanACD2005]

Alright, so I have been through the above sticky's and used the search feature as well as google.. And I cannot seem to find a procedure to time these engines. I looked for the D24, D24T and LT35. I found other threads of members asking the same question, with replys stating it is on the forum, but no links.

I rebuilt a D24 about 4 years ago and think I remember how to do it, but I would like to refresh my memory if possible. I'm about to do another rebuild on a D24T now. Last time I looked it up in an old book at the library, so I will check there again too.

Thanks,

Spenser

[BluevanACD2005]

And on another note- I cannot find an oil pump available for these engines... The only place I found it was $500 or better. Is there a place I can find one for a reasonable price?

Plus I need a dipstick.. Also not to be found. Even eBay seems to come up empty. I don't remember having this much trouble finding parts before.

I will probably need the valve shims too. Last time I got them from Napa, but they don't seem to have them anymore. I'm starting to feel like I an rebuilding something that I'd obsolete! (Go figure, its a 30+ year old foreign car haha)

Spenser

[745 TurboGreasel]

I go to the junkyard and rape a couple VWs for a pile of shims every once in a while.

set TDC
lock cam
install belt
tension
roll the motor over 2x by hand
recheck

wonder if an Audi 10 valve pump is the same?

[BluevanACD2005]

Thanks for the heads up! I have never come across a D24 in the scrap yard before though.

Also, that is basically what I remember from timing the last engine. What about the pump though? I line the notch in the pulley on the pump up with the line on the bracket at TDC right?

Spenser

[v8volvo]

Originally Posted by BluevanACD2005

Alright, so I have been through the above sticky's and used the search feature as well as google.. And I cannot seem to find a procedure to time these engines. I looked for the D24, D24T and LT35. I found other threads of members asking the same question, with replys stating it is on the forum, but no links.

I think most of the info that's on here assumes you already have the greenbook and have gotten familiar with the procedure there, so folks mostly are posting tips to add to the regular process and expounding on the finer points... I don't think there's actually an official "D24T.com Timing How-To" guide anywhere though there are many posts that go into good detail on the tricky spots. We have been meaning to make a FAQ here for a long time that organizes some of this information in a place that's easier to find.

Best thing is to start with the greenbook info, which is available in various places online, here is one: http://www.k-jet.org/files/greenbook...24_repairs.pdf (for a D24 but procedure for D24T is identical) then check here if there are any points that need further clarification. The greenbook does a pretty good job.

Some general tips: set the tension on the front timing belt (using the water pump) BEFORE locking the front cam pulley back down, since changing the tension after the cam and pulley are cinched up will change cam timing (and pump timing too, if the rear belt is already on). First set front belt tension, then torque down the cam pulley while making sure crank is still at TDC and using your left hand to keep the slack in the belt (and there should be PLENTY of slack when the engine is cold!) on the side of the belt away from the water pump, otherwise after you roll the motor over a couple of times you'll find that the cam timing is retarded from where you originally put it.

Once the cam is timed to the crank, you'll use the special crank counterhold tool (#5187) to torque the harmonic balancer bolt to spec. Greenbook goes into good detail on how to do all this, how and when to rotate the motor, etc.

After the front is finished up and you are happy with where the belt tension and cam timing landed, do the same for the rear -- first set the pump in position on the bracket (align the marks or clock it with the top leaned away from the head if you want -- don't let it lean too far inwards on a turbo motor or the aneroid will get in your way next time you want to get #5 and #6 injectors out), then set the belt tension (which is done by jacking the pump bracket up and down on the motor), THEN set the pump timing by setting crank at TDC, disconnecting cold start advance linkage, and rotating the rear cam gear to your desired timing setting and torqueing the rear bolt (using the cam counterhold tool 5199 and, if you have it, the special wrench 5201). With the rear belt, as with the front, changing belt tension after fixing the timing gears in position on the cam will affect your timing setting, although the effect is less pronounced on the rear.

After the pump timing is finalized, roll it over again a few times and make sure everything is happily returning to where you wanted it. Once that's done, if you're satisfied, re-check final torque on all the critical fasteners (front crank bolt ~350#, front cam bolt ~40#, rear cam bolt ~30# with contact surfaces dry and clean). Then re-connect the cold start device, and you're done.

Some more detailed recent discussion of cam bolt torques is here: http://d24t.com/showthread.php?t=1440

Lifter shims are available very cheap from many online sources -- IMO much faster and cheaper in the end to make your measurements and just buy what you need, vs the time/energy/effort/cost to harvest them from the JY, but YMMV there. If you want to go that route, you can steal shims from any gas or diesel watercooled VW or Audi that has mechanical lifters (old 4cyl Golfs/Jettas/etc and 5cyl Audis, mid 80s or earlier). Depending on how worn your valves and seats are though, or whether or not you had the head overhauled, you also may need shim sizes outside the range of what you'll find in junkyard motors, you may need extra thin ones if you ground the valves or are putting in a used high-mile head, or extra thick ones if you had it rebuilt with new valves. The shims are ~$2 apiece, FCP is one of many places that has the whole range of sizes. https://www.fcpeuro.com/Volkswagen-p...3&m=105&page=1 NAPA, CarQuest, etc can also source them easily, as can your friendly local garage with an IMC or WorldPac connection. ..

Or, if you don't have time to measure first and then wait for shims to arrive, rent/borrow a complete set one from a member or an online source, I have loaned out my set before along with adjustment tools, but I require a massive deposit (~$1000+) to ensure return of the stuff, since I really don't have time to put together another set if they don't come back. Or you can buy a whole kit of your own for $200 from the source above... Ultimately unless you're in a time crunch or plan to be doing this pretty frequently, there's really no reason not to just check lash after you get it together and buy the pieces you need a la carte.

[BluevanACD2005]

Thank you very much for the help! That is a very detailed reply.

I have never used the green book, but I look forward to it. I feel a lot more confident about progressing with this rebuild now. I am to the point where I am about to take head off. There is no hurry though, it is only a project vehicle.

Spenser

[BluevanACD2005]

Well after pulling the head on this engine, I don't think I'll be using it after all. The cracks between the valves are beyond specs. There is also another crack on one cylinder that goes from the pre chamber to the intake valve. Pistons don't look the best either. They are what I would describe as eroded on the top and edge by the injectors.

I will have to go to plan B and use another engine I have stored. It was supposed to be good to go but I will tear it down regardless.

Spenser

[745 TurboGreasel]

I've run with cracks between the valves that my key wold fit in, but the other one is doom. (in theory can be welded, but $$$).

[BluevanACD2005]

The head was pretty rough. I will hold onto it for now, but I am basically going to piece one engine together with the best parts from two now.

What is your opinion on injector pumps? Would it be better to use a known good pump with 235K miles on it or a pump that is 'supposed to be good' with 110K on it?

Spenser

[ngoma]

Originally Posted by BluevanACD2005

Would it be better to use a known good pump with 235K miles on it or a pump that is 'supposed to be good' with 110K on it?

What causes problems with these IPs?

1. Overtight belt ruins the input shaft bushing, and hence the seal, causing air ingress which makes for hard or impossible starting.

2. Running with clogged fuel filter or other fuel supply stoppage grenades the lift pump portion and sends shrapnel throughout the rest of the IP.

3. Old age (not necessarily mileage) deteriorates various o-rings, causing leaks.

4. Switching fuel type families (petrodiesel to biodiesel, or vice-versa) causes the o-rings to shrink or swell, causing leaks.

5. Water in fuel (more common with WVO) causes cavitation (erosion) of finely machined surfaces.

Knowing these, choose the IP that has suffered less of these issues.

Me? I would probably choose the known good, higher mileage IP, better yet after refreshing the seals.