Date: Fri May 24, 2002 9:25 am
From: Ivan, UK View IP address of poster
Subject: Lower timing chain cover... Edit/Delete this post Delete this post

I'm renewing timing gear on tii soon. Just on looking today I can't quite work out if the injection pump has to come off to remove lower timing chain cover. Anyone know? Otherwise I be finding out (practically) very soon.


Date: Fri May 24, 2002 2:03 pm
From: Paul (at Maximill...) View IP address of poster
Subject: Re: Lower timing chain cover...LONG! Edit/Delete this post Delete this post


Here's my explaination from that "other" board from last autumn:



The following is from a 74 tii - but the general ideas and principles apply to all 02s - and most chain driven 6 cylinder BMW motors as well.

The Job? Timing cover and oil pan seal replacement.
The reason? To eliminate the sneers your neighbors give you from their Lincoln Towncar filled driveways across the street. (ie: staring at your oily puddle gross driveway)
Difficulty? 7 out of 10 due to alot of potential disassembly, cleaning, and reassembly involved.

I chose to do the timing covers first, as it would eliminate the possibilty of damaging the new oil pan seal during removal. Do the pan, too though - it's worth it!

Parts - under $50.00 easily, but consider belt(s) and water pump, too.

wrenches / sockets you'll need:
10, 12, 13, 17, 19, 30


breaker bar with long 4 foot steel pipe for leverage to remove the mac daddy crank pulley nut.

2 or 3 arm puller to remove hub from crank shaft
rubber mallet
4-6 cans of Brakleen or similar nasty solvent
1/2" wide paint brushes with bristles cut to 1/2" long

floor jack
blocks of wood - various sizes
jack stands (naturally)
satin black paint, maybe silver or clear too
gloves
screwdrivers
razor blades (for scraping old gaskets off)
tube of non hardening gasket sealer (formagasket stuff)
tube of hardening gasket sealer (formagasket stuff)
3M scotchpad (one will last forever)
...and your brain, emptied of all non essential clutter and noise

PART ONE: removal of the covers


Remove headlight grilles and drain and remove radiator. You'll be reaching through the nose panel for most of this job.

Remove alternator and bracket held to engine block. If you're doing the pan - wait until the pan is loose before taking out a tii alternator - this saves you from disassembling the swaybar mounts. Regular alternators are a snap though. Removing the oil filter helps on a tii, too!

Remove fan, fan pulley, water pump. Make notes as to the location of the bolts as you remove. The danger of mixing up bolts - is that you'll try to force a bolt that's too long into a tapped hole in the engine - and it will strip the threads as it bottoms out - or worse yet - SNAP OFF! I use ziplock type bags and a "Sharpie" felt pen to label hardware.

Remove valve cover - look for small groove/mark on camshaft where it meets the sprocket. Rotate engine until this groove is in line with the oil supply tube on the very top center, of the head. If you're at TDC - the rocker arms will be OFF the lobes (closed) completely. Pull the distributor cap off, and check to see if the pointy end of the rotor is pointing at the groove on the edge of the distributor housing. If it isn't - rotate engine until both the rotor and cam mark line up to these reference points. At this point - your crank pulley should also be lined up to a reference pointer on the timing cover (driver's side - within 1" of opulley edge). What you have just done - is set the engine to TDC (Top Dead Center) of the piston in the No. 1 cylinder. Setting the engine up like this before disassembly is important so that you maintain correct camshaft to crankshaft timing if you chose to R&R the chains and tensioner. Trust me - stuff IS going to move, no matter how careful you are. If you've set everything before hand - it's an easy thing to re-time the spinning bits.

Once the engine is timed at TDC - you can get into the nitty gritty of disassembly, knowing that you can always get it back together if things rotate in the process.

To remove the front crank hub nut - you'll need to keep the engine from rotating. This can be done in a few ways - I'll describe what I did. I tried putting the car in 4th gear, locking the handbrake, then attacking the nut with a 5' pipe and breaker bar - the car still moved and the engine turned, even with wheels chocked. (I felt like a real man moving the car by hand - but it got old fast). So - here's how I locked the engine still:

Crawling under the car - I removed the crescent shaped metal access cover where the transmission meets the engine. this exposed about 15% of the flywheel. I was able to place a large screwdriver squarely inbetween the teeth of the flywheel, and lodged against the block edge, so that as the engine turned - the screw driver would act as a stop against the engine block. it was crude, but worked like a charm and did no damage whatsoever. The key is to have the right sized blade on the screwdriver and to ensure it sits squarely in between the teeth.

With the nut off - I used the 3 arm puller on the hub - it came off easily with no drama or force. As with any fastener or part that's stubborn - try heat before brute force. Your bones, skin, and TENDONS will thank you.

With hub and pulleys off - start to remove the upper cover bolts. These are an odd bag of 10mm and 13mm bolts of varying lengths. Mark them all for simple reassembly. At the bottom of the upper cover is a tiny bit of the head gasket. BE CAREFUL not to tear this - as it is notorious for leaking if damaged. ie: it stays ON the engine! When the lower cover is removed, the head gasket will be left hanging in mid air - and it's delicate! Once the upper cover is off and BEFORE you remove the lower cover - you need to remove tension from the timing chain - as the tensioner piston passes through the side of the lower cover. On the passenger's side of the cover is a 19mm plug - looks like an oil drain pan plug. remove it - but remember there's a 6" long coil spring behind it that will fly out. It's not scary dangerous tension - you won't get hurt - but be ready to catch it - that's all. Once the spring is removed - fish the tensioner piston out. This is about the size of a Maryland monster sized garden slug. Now the timing chain has no added tension, and from here on - it's not a great idea to rotate the crankshaft / engine.

Remove the lower timing cover bolts (10mm and 13mm) and gently pry it off the face of the engine block. DON'T FORGET - a few oil pan bolts go through the bottom front of the lower timing cover - make sure to remove these! If it's too tough to pry off GENTLY - then you have most likely left a bolt in there somewhere. DOUBLE check! Forcing it by prying too hard will distort the cover and it will never ever seal properly again. VERY delicate, easily bent and cracked aluminum here! Even thick aluminum is fragile. Watch that head gasket - remember?

Once the cover is off - inspect the rubberized tension rail for deep grooves - replace if in doubt. Both rails are held on with small circlips, but there's a trick to removing the white nylon one without tearing the head gasket (I'll get to that later).

With the covers and valve cover off - cleanse the wickedness from within with liberal amounts of Brakleen.

How to use and conserve brakleen: Get a good sized oil dran pan, lay the parts in it - spray like mad! Soak them evil grease laden beasts for a few minutes, then use your cut-off paint brush to scrub all the sin from the nooks and crannies. Recycle the solvent from the pan - dipping the brush often. After you're satisfied that you've freed up the major grime - "rinse" with more brakleen. You'll have to repeat the technique 3-4 times to really get things clean. Allow parts to dry and either media blast them, paint them silver with wheel paint, or clear coat them - at your whim. Remember, clean parts make assembly easier - and safer - avoiding damage to related parts, stripped threads, and poor sealing problems. I clean the bolts too.

While we're talking threaded fasteners - I even go as far as to use a tap and die to clean the threads on bolts AND the threads in the block. Takes some of the fear out of torquing things down at the end of the job. Tap and die set is about $30 for basic Metric ones - and worth twice as much!

Here's the part I like least - scraping all the old paper gasket crapola off the engine block and head. You MUST have a spotlessly clean mating surface for those wimpy paper and goofy cork seals - or you will have accomplished nothing from all your toil.

Install the front circular crankshaft seal in the lower cover (you used a gentle tool to pull the old one while you cleaned it - right?) I use a set of aluminum tapered bearing drifts for this - but any round flat device should work. I also apply a thin thin thin film of non-hardening formagasket to the outside edge for extra insurance, and to sort of "lube" the thing for installation. Drive the seal in evenly and slowly with deliberate, smooth mallet blows on the drift. It should sit flush with the cover - or just .50 mm or so inward. If you push it too far in - you will most likely need another seal, so be careful.

Here's my technique for sealing the covers. I imagine there are other ways to do it - but it works well, is neat, clean, and makes any disassembly later on, easier.

Coat a LIGHT skim of the hardening formagasket onto the covers - it dries within a few-teen minutes, but take your time. Once there's a thin film of the hardening stuff on there - place the paper gaskets on them, but DON'T put any formagasket on the other side of the paper! leave it dry, and place the covers gasket side DOWN on a flat surface. Dining room tables are bad for this unless you're a bachelor and like having formagasket stick to your silverware the next day - but find something smooth that won't land you in divorce court. This will keep the paper from shifting while it dries. You might even consider putting something with a few pounds on the cover to weight it down. Do the same with both covers, and let them hang out like this, for an hour or so.

When installing the lower cover - I apply a thin dab of grease on the inner ring of the crank seal - this allows the crank hub to slip in later on, without grabbing or tearing the new seal. Tighten the bolts evenly - working around different parts of the cover, just snugging them up - then tighten down the rest of the way. Since most of these fasteners are small - and a few go into soft aluminum - you don't need alot of torque on them at all. Just snug with firm wrist pressure on a small 1/4" drive ratchet seems to work.

Install the crank hub - and make sure the crank is still - or once again at TDC. then slide the chain tensioner piston back in, spring and 19mm hex plug. The tensioner relies on oil pressure to work - so you can pour a little oil into the top of the tensioner chamber, and work the rubberized rail back and forth with a long screwdriver to "bleed" the piston. these units will bleed themselves within a few engine rotations anyway - but why take chances?

If you're doing chain or tension rail R&R, remove the small circlips from the pins that retain them. On the white nylon guide rail, use a wrench to remove the pin from the engine block, then slide it over to the passenger's side and pull off. - THIS will allow you to remove the rail without tearing the head gasket.

Assemble the hoses, etc. And you're done with the upper half of things.

As for the oil pan seal, first - drain all the oil out! - Here's how I raised the motor without the use of a hoist. I loosened the motor mounts, removed the distributor cap (you'll need to, to avoid damage as the engine tilts BACK toward the firewall) , and used a floor jack under the oil pan - protected by flat wood piece, to raise the engine up enough to reach the pan bolts, and insert wood blocks under the passenger side motor mount. This will buy you about one inch or so. Once the pan bolts are all removed (use of a swivel socket on a small 1/4" drive ratchet makes life simpler by the right mount area) you should be able to gently pry the pan from the block mating surface. At this point - you'll no doubt find that the pan will not come completely free from the car because it gets hung up on the oil pump pickup "foot" against a baffle wall inside the pan. Since I was not able to raise the motor up enough with the wood blocks - I carefully placed my floor jack on the exposed front corner edge of the block on the passenger side on a portion NOT involved with mating the oil pan gasket. This bought me about another inch - and just enough to slide the pan free and clear from the car.

Here's the warning part - BE VERY careful as you work under the motor - as I don't trust little wooden blocks under a 350 pound engine - NOR do I trust my floor jack holding up a small edge of the motor. Keep your fingers clear of any bracket that might squish 'em should the temporary engine supports fail! It could take yer finger tip clean off - those are SHARP edges there!!!

Cleaning the oil pan mating face is crucial, as is ensuring that all the bolts and bolt holes are clean. (use a tap on the ones you can reach to make 'em clean) it takes very little to strip out an oil pan bolt, or threaded hole. Clean clean clean every mating surface you can see. For reinstallation with the new seal - I used the hardening formagasket on the pan - and installed the seal for a few hours while the pan sat upside down with a few pounds of weight on it. This ensured that the gasket wouldn't slide off like the upper half of a peanut butter sandwitch, as I slid the pan back on the block underside. I used non-hardening formagasket on the engine BLOCK surface. At this point you might notice a pattern of gasket goo usage: I use hardening stuff on the parts that are cleanable OFF the car in the comfort of the garage - and NON-hardening formagasket on the parts not easily cleaned IN the car. Reinsert the oil pan in the reverse order of disassembly (you'll need the floor jack under that front corner again) and go to town on those little pan bolts. They do NOT need to be super tight - or they'll distort and crush that soft cork seal! remove wooden blocks, lower motor onto mounts, and assemble the rest of the parts.

A very satisfying repair - solves 99% of an engine's oil leaks, and now you can justify using that hot rod synthetic oil you've been considering. I run Mobil 1 in mine (I'm a believer!!!) - but there are considerations in an older motor that have been discussed before, making it perhaps NOT the best choice for everyone.

Change oil and filter again after a hundred miles to make sure you've flushed out all the dust that may have settled on the internals.

Have a terriffic Weekend!


Paul
Maximillian Importing Co


Date: Fri May 24, 2002 5:05 pm
From: Ivan, UK View IP address of poster
Subject: Many thanks, but... Edit/Delete this post Delete this post

That's very helpful. Is the lower timing chain cover also the bracket for the tii injection pump - ie does the pump have to unbolted,too?


Date: Tue May 28, 2002 11:47 am
From: Paul (at Maximill...) View IP address of poster
Subject: yes - .... Edit/Delete this post Delete this post

You will need to gently remove the k'fischer pulley from the pump - revealing the 2 17mm or 19mm bolts that hold the pump to the timing cover. Sorry for the oversight - good Luck!

Paul
MAximill...
_________________
-Rob S.

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