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I remember when you bought this Shark, sure doesn't seem like it was 8 years ago, wow time flys. I was the one who recommended you have Steve at Omega do the ppi on it & I happened to go by when your car was there. It was a nice 928, dark green with a full black leather interior. IIRC, I think the previous owner was an airplane mechanic, maybe in the Navy here. Looked like it had been well cared for. Good luck with your TB/WP success.
Yes it's hard to believe it's been that long. I remember your PM (with pics even!) and Steve calling me to say "If you don't buy it I will." It's been mostly a good experience, although I've gotten a hell of a lot of practice troubleshooting the belt warning circuit and dropping the transmission (in and out 3 times) over that time.
I'm probably a year late on this job but life has been interfering, I really haven't had as much time to spend on the car as I'd hoped, but work and family life have settled down quite a lot recently and hopefully I can get her buttoned up and drive her for a bit before I dive into my intake job (already having fever dreams about snapping the valve cover bolts.)
Water pump bolts were a b!tch for me. Broke on off, then things got worse from there. Chalkboss broke off 10 of 13 when he did it, but miraculously was able to get the broken studs out without too much trouble. Here are a couple more write ups involving this in case you haven't seen them:
None of those bolts look like they were treated with anti-seize. Be sure to use some on installation. The water pump bolt that enters the water jacket gets Hylomar when I do them, keeps the coolant out of the threads. I think Stan recommends Hondabond which is similar.
New bolts for the water pump, of course. I'm not sure that new cad-plated bolts are the right thing for this, as it adds a 'sacrificial' layer that grows as it reacts, plus another dielectric layer in the sandwich by the aluminum block. Others might want to chime in on this. Do we go back with plain steel, black oxide, cad, zinc, or stainless on these? Maybe a poll...
I'll also second Stan's recommendation on using STP in the tensioner; it can be a chore to get in but seems to stay longer. On the tensioner boot, I have yet to open one that isn't hard and crispy. At some point we'll be able to identify a brake wheel cylinder boot from a truck that will do the duty there, something that's better suited to the heat and the oil exposure.
I've been using a dab of Sta-Lube brake caliper slide grease on the pivot bolt where the bushing sits. It's a thick long-fiber grease suitable for high-pressure applications with dirt and moisture present. Seems a perfect description of what that bolt sees. Comes in a tube at the parts place for a few dollars. Handy for lots of things like this. Next choice might be a good wheel bearing grease. Unfortunately there's no room for o-rings to keep it all clean.
It's been a year since I did this job on m car, and I'm suffereing withdrawal just alittle. Niv=ce to live vicariously through your pictures and decriptions.
Belt off this morning, Conti in very good shape at 53k. Crank was locked at TDC and I knew to expect the cams the snap when the belt came off but it startled me nonetheless.
Does anybody else see anything wrong with this? The procedure I followed was to set crank at 45 BTDC so that the cams may move safely without causing valve damage. Also, my cams did not move once I removed the belt. I assume yours is a 32-valve...or that was a typo?
Btw, your cam gears look much better than mine! Since your belt change interval seems to be based on mileage, yours may not last another 50k miles. My interval OTOH is time based as I only do about 3k miles per year.
Originally Posted by dr bob
...On the tensioner boot, I have yet to open one that isn't hard and crispy.
That's interesting, mine was very pliable and not cracked, but the tensioner inside was bone dry and the bi-metallic washers were mostly stuck together. They have what looks like burn marks on the surface...still trying to clean them all off! (Hoping they will be ok.)
Cheers,
Brian
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85' 928s 5-spd. (32v)
I typically advocate leaving the crank at TDC. The procedure to move the crank to 45deg confuses people, and can lead to the cams being out of time when the belt it put on, leading to a valve-piston contact. You can move the cams by wrench 4-5 or even more teeth without damage.
Just double check the marks before you button things up, and turn it two revs by hand first.
Does anybody else see anything wrong with this? The procedure I followed was to set crank at 45 BTDC so that the cams may move safely without causing valve damage. Also, my cams did not move once I removed the belt. I assume yours is a 32-valve...or that was a typo?
Btw, your cam gears look much better than mine! Since your belt change interval seems to be based on mileage, yours may not last another 50k miles. My interval OTOH is time based as I only do about 3k miles per year.
That's interesting, mine was very pliable and not cracked, but the tensioner inside was bone dry and the bi-metallic washers were mostly stuck together. They have what looks like burn marks on the surface...still trying to clean them all off! (Hoping they will be ok.)
Cheers,
Brian
------------------------
85' 928s 5-spd. (32v)
Lot's of discussion here about locking at TDC vs 45 BTDC and from my reading the consensus of the people that have changed a LOT of timing belts is that TDC is less error prone. Of course that may just be the consensus of the vocal people here, but they are voices I trust.
That said I'm not that confident that I'm not asking for Bill Ball's help to make sure I get it timed right before I call the job done :-)
If you are careful you can do the job at TDC, but 45 BTDC is safer. If a cam snaps down off a lobe top, you can get valve-piston contact, although generally not hard enough to bend anything. I do it at 45 BTDC just noting the cam gears will be 3 teeth off. Other than the shoulder bolt and distributor parts, and the tensioner boot, of course, things look good. I didn't know any of the water pump bolts penetrate the water jacket, other than the shoulder bolt. I coat that one. Also, there is one of the 4 tensioner bolts that penetrates into the oil galley, as indicated in the WSM which calls for thread sealer on that bolt.
Kevin, I can bring my Porken cam timing tool over and we can check yours and adjust if needed. Leave those gears alone for now. They have only minor dings at most and are good.
Remove and clean the tensioner guts. There is an o-ring on a "valve" at the bottom that should be replaced as well as the boot. The rod and washer assembly should drop out into your hand unless the body is very dry inside. Turn the body over carefully with your hand under the open end so the assembly comes out in one piece and the washers don't fly all over the place. After that you may have to push out the valve from the tensioner adjuster bolt hole. I just wash the washer assembly with brake cleaner unless it is really bad in which case you can disassemble it noting the 7 groups of 5 washers packed in a pattern shown in the WSM. The tensioner body inside is coated with Teflon. Sometimes that deteriorates and flakes off, in which case the tensioner body should be replaced. I've only seen this once.
If you are careful you can do the job at TDC, but 45 BTDC is safer. If a cam snaps down off a lobe top, you can get valve-piston contact, although generally not hard enough to bend anything. I do it at 45 BTDC just noting the cam gears will be 3 teeth off. Other than the shoulder bolt and distributor parts, and the tensioner boot, of course, things look good. I didn't know any of the water pump bolts penetrate the water jacket, other than the shoulder bolt. I coat that one. Also, there is one of the 4 tensioner bolts that penetrates into the oil galley, as indicated in the WSM which calls for thread sealer on that bolt.
Kevin, I can bring my Porken cam timing tool over and we can check yours and adjust if needed. Leave those gears alone for now. They have only minor dings at most and are good.
Remove and clean the tensioner guts. There is an o-ring on a "valve" at the bottom that should be replaced as well as the boot. The rod and washer assembly should drop out into your hand unless the body is very dry inside. Turn the body over carefully with your hand under the open end so the assembly comes out in one piece and the washers don't fly all over the place. After that you may have to push out the valve from the tensioner adjuster bolt hole. I just wash the washer assembly with brake cleaner unless it is really bad in which case you can disassemble it noting the 7 groups of 5 washers packed in a pattern shown in the WSM. The tensioner body inside is coated with Teflon. Sometimes that deteriorates and flakes off, in which case the tensioner body should be replaced. I've only seen this once.
Well I guess I maybe should have asked the guy I was going to ask to help me before I went with TDC.
After consulting with Bill I took another shot at the last five bolts and went with the following strategy - a blast of penetrant for each followed by a sharp hit with a hammer and punch and then using extremely short turns of the ratchet to move the bolt while minimizing the twisting/torquing action applied on any one effort. The first four came out relatively painlessly but the final bolt only moved about a third of a turn in this fashion before obviously binding. I then sprayed the bolt, waited 5 minutes or so and then rotated the bolt clockwise until I met resistance and then repeated in a counterclockwise fashion. Each time I met resistance I stopped and repeated this sequence and very slowly I made progress until after 90 minutes or so the bolt finally made its way clear and I was able to pop the water pump off the block.
Examining the bolts you can see that this was a pretty close call, but patience really paid off. I'm quite sure without this forum I would have snapped at least one of these in the process of removal - so a huge thank you that went through the pain so I could avoid it.
This picture is misleading, in reality the bare threads of this bolt are down to bare clean steel, I assume I should chase this bolt hole carefully prior to re-assembly.
One interesting thing is that it looks like Omega replaced at least a couple of the bolts with some sort of plated ones (or at least if they did replace the set they mixed plated and unplated), they also didn't appear to use anti-seize anywhere.
On the plus side the gasket was sealed on the waterpump side only so I have a minimal amount of cleanup to do on the mounting surface.
The pump bearing is still tight however it's making a squeaking noise when rotated, I assume this is not normal. Again I am glad I did this job now, thanks for all the feedback so far.
Didn't I read on here somewhere that getting the water pump bolts out intact was much easier with an impact driver? Did I just make that up, or is there a good reason not to do it that way?
I'm a fan of using the hammer-type impact driver on bolts that might be stubborn due to corrosion. The sharp rap combined with the twist is usually enough to convince the bond to break. To get that effect though, you need to stuff a nut into the socket first so it just fits over the bolt head.
Sean R turned me on to the benefits of the cordless impact driver several years ago, and I've been a fan since. I have compressed air plumbed in the workbay and a nice assortment of pneumatic tools. Still the little cordless unit gets the bulk of the impact-driving duty since it's so convenient. It might be OK to use tha on water pump bolts to break them free, but use care. The 18V Makita unit has enough zip to remove lugnuts on my car, so it likely has enough to break a 6mm water pump bolt without breaking a sweat.
I'm a fan of using the hammer-type impact driver on bolts that might be stubborn due to corrosion. The sharp rap combined with the twist is usually enough to convince the bond to break. To get that effect though, you need to stuff a nut into the socket first so it just fits over the bolt head.
Sean R turned me on to the benefits of the cordless impact driver several years ago, and I've been a fan since. I have compressed air plumbed in the workbay and a nice assortment of pneumatic tools. Still the little cordless unit gets the bulk of the impact-driving duty since it's so convenient. It might be OK to use tha on water pump bolts to break them free, but use care. The 18V Makita unit has enough zip to remove lugnuts on my car, so it likely has enough to break a 6mm water pump bolt without breaking a sweat.
Knowing how that last bolt felt coming out, the thought of an impact driver on it makes me nervous - it very well could be that the driver doesn't apply the constant torque that causes bolts to twist and snap but I'm not sure that I'd want to try to prove that hypothesis on my car.
There is no way in hell an impact driver would have worked on most of the ten I snapped off. I know people with more experience on these cars than me do it but not for me.They were necked down due to corrosion from a long standing leak. Corroded along the threads too. I used new bolts and coated them with ptfe.
Good job getting them out!
Had a bad night tonight. Was just wanting to get the rear cover off, get everything cleaned up and ready to pull the oil pump. Tried every which way to get the crank gear off and it won't budge. Looked at sacrificing the rear washer to a puller but there isn't any space to get behind it. Worse yet is that I was hitting it with my mallet I dinged the two teeth on the edge of the gear. Do I need to replace it now? Need to try heat next I guess but it's late and no propane at the moment so nothing else to do really until my next Roger order arrives.
the crank gear can be dressed with a small file or stone otherwise it looks to be in good enough condition to continue its use.
I would suggest to use some PB blaster on the gear and let it sit for a while,
then get some wet towels and place them behind the rear thrust washer so you dont melt the rear cover add the torck and then quickly install the puller.
NOTE you will sacrifice the rear thrust washer doing this. new ones are available.
NOTE The tensioner pivot bolt should also be replaced . as well as new pivot bushings installed
A two jaw puller will get behind that washer. May have to grind the back of one of the fingers just a bit to have it fit behind the driver side, but it'll go in. You will likely sacrifice the rear washer. I would do this before heat. Gear isn't a gonner, just take off the sharp edge if any.
If you are doing the front seal, there's a recess on the pax side for you to get in and lever the old seal out. Be careful with this recess as it doesn't leave much meat to lever on. When you stick the small driver in there and pound it in to the seal, don't mar the recess area. Put the new seal in with a cutoff piece of PVC, I forget the size. Use a little gasket sealer and make sure the new seal is flush to the crankcase all around. It's kind of a kludge down there, and there's a beveled/lip machined surface area to confuse you as well. See that it's all the way in flush, or it will leak a lot.
03-09-2015, 02:35 AM
