308 Winter Maintenance / Cam Seals / Cam Drive Bearing

As far as removing the cam pulley, I would not use a breaker bar. Just pull the cams out and have someone "zap" it with an impact gun.

Good luck

Henry

 

In my opinion, removing the cam pulleys is a waste of time, unless you are going to degree the cams. Just pull both cams out with the backing plate, and the seal housings slip off the cams. It's a little tricky managing both cams and the plate, it saves time. Then if you must, bolts can be zapped out w/impact like hanknum said.

 

Yes, u just slide seals on from rear of cams up to the backing plate. I did this on my 2v 308, much easier than removing pulleys.
Bill

 

Hi Mr jford10014, if you PM me your email address I can send you a word document for changing the cam drive bearings in-situ. It has lots of pictures which unfortunately got zapped in the site melt-down.

Richard

 

Yes, unless you have an air pump pulley on the end of your rear exhaust cam (like on my '78).

 

I'm in the middle of a major on a 328. That fibreglass cam belt cover backing plate on the 328 & 4V engines makes sliding the seal housings back on a challenge that the 2V engines don't have. I agree that on a 2V engine it's easiest to slip the seal over the cams, but not a 4V.

Especially the front bank cams. The plate likes to cock the seal housing just enough so that an edge of the seal slips off over the front of the cam's seal surface, then the spring pops out of the seal. You then get to slide the housing off of the cam, reinsert the #$@ spring & try again.

Took 2 of us 5 tries to get the front exhaust cam seal housing into place w/o cocking the seal & dislodging the blasted spring.

The next night we just happened to discover that somehow in the process the seal for the front intake cam had gotten twisted enough so that the seal's rear lip was sticking out under the front lip. So now we're waiting for a new seal to arrive.

We pulled the cam gears when we discovered the bad seal as we were too fed up with fighting the cams, cam seal housings & belt cover backing plate.


BOTTOM LINE: I'm pulling the cam gears next time I do a 4V major rathar than risking damaging a seal & not noticing it until everythings back together & it leaks.

However, you're right about it sometimes taking an air gun to break the cam gear mounting bolts loose, especially if the bolt head has rusted to a metal cam gear. I've used a long breaker bar, & gotten 3 out of 4 loose, but ended up using the air wrench on the last one.

I used my prototype 4V cam gear locks to keep the gears from turning this time.

However, in the past I've jammed a large screwdriver or pry bar into both rear break rotors, & up aginst the calpers, put the car into 5th gear, & turned the engine over until all the slack was out of the drive train. Then set the parking brake, & had someone depress the clutch until I had the engine on PM1-4 & let the clutch out. Now the engine can't accidently turn. I then broke the front bank cams gear bolts loose with an air gun. (When on PM5-8, the rear bank is on half-stroke, so the cams cams can rotate 369 degrees w/o a valve hitting a piston.)

Next do the front bank: depress the clutch, set the engine on PM1-4, & break the front cam gear bolts loose. Now you're all setup for the rest of the service.

I've never used clups while breaking the bolts loose, but clips certainly won't hurt. Just made sure the belts were fuly tensioned & the tensioner was torqued down to spec.

 

Sorry, didn't pick up on this 1st time I read your post. If you've got any noise from the cam drive bearings, or can feel ANY movement, then it's time to change them. Just changed them on a 328 I'm currently working on. It took longer to work the 2 woodruff keys out of the cam drive shafts than it did to actually pull & replace the 2 outer bearings. (Yes Rifledriver, I finally broke down & went halves on a Sykes tool ;P ).

All in all, it added about about 5 hours to the service. About 1.5 hours of that was hand grinding down some washers so that they could be used with the old ring nut to press the new bearings into place. This way both races were getting pressure at once. This worked out very well.

The inner bearings run in filtered engine oil, so almost never fail.

However, the outer ones only have the factory grease & after 20 years, it's turning into half-cured epoxy. Strongly recommend replacing the outer bearings every 10-15 years. 20 Years is far too long to trust any grease to hold up to the kind of load these bearings are under.

Good Luck!

 

Sorry,
Right now there's only 1. It's a pretty crude 1-off that I hacked out of nylon with a bandsaw & glued strips of innertube to the clamp faces with trim cement.

It isn't a typo, but certainly is very poorly written. If you read carefully, It says the same as your quote.

Since I use an air gun, I just set the engine on PM1-4, but if I were using a breaker bar, would do as you describe.

Yes, have done it several times while re-checking clearances after replacing shims.

No one has ever written up a step by step because it's pretty obvious once you take a look at the FPC to see how everything fits together. However, this thread now has one.

Start a couple of days in advance by soaking the cam drive ringnuts & damper bolt with PB Blaster a couple of times/day.

I prefer to break the damper loose before pulling the cam belts, then torque it up after the new belts are on. Having the damper off makes it easier to install the new belts because you can get a couple of small binder clips on the cam drive gear.

However, you can pull the damper after removing the belts. With an air gun, the parking brakes are enough to keep the engine from turning while breaking the damper bolt loose. (Can use the screwdriver/small pry bar in the rear rotors for add'l safety).

With an impact gun, at most the engine may move 5-10 degrees. That's the nice thing about an impact wrench, it's the impact impulse that generates the short duration torque that breaks the bolt loose instead of sustained torque that you get from a breaker bar.

With the engine on PM1-4, cams on the marks & the belts off, the crank can safely rotate quite a bit before jeopardizing a valve. (I remember reading +/-35 degrees somewhere, but think it may actually be greater) . I've accidently backed the crank up 2 cam belt teeth (24 degrees) & forward 1 belt tooth (12 degrees) many times when doing a belt service w/o tapping a valve.

BAUM TOOLS Ring nut tool FR104 ~$100
http://tools.baumtools.com/index.jsp?index=2&newIndex=1&menu=ferr
- Remove the cam drive gears (bottom pulleys). You have to pry them off because they're a light press fit on the woodruff key. I've never found a puller that will reach behind the cam gears & yet not bend up the flange. So I use small/medium sized pry bars & wood blocks. The gears are snug, but not super tight.

The woodruff key is a very tight fit. I used a brass drift to drive it toward the bearing & it rolled out. This was after after trying to grab each side of it with a pair of alligator pliers, then a pair of large dykes, this didn't do the job. Be prepared to re-face the drift a couple of times as it really gets chewed up. However, try the pliars & dykes 1st as

- Remove the circlip that keeps the bearing in. Need a strong circlip tool for this.

-Remove the bearing: You pry the outer plastic seal off of the bearing, then use a cobolt drill to drill out the rivits between the bearings so you can pry the outer metal separator strip off. You then insert the Sykes tool ($200) tips into the races & turn the pry screw.

- Remove the cone washer that's behind the bearing(inner edge of cone goes against outer bearing race.)

-Clean out the bearing mountingn area & inspect the seal that's behind the bearing to make sure it's not leaking. Clear any burrs out of the circlip groove.
-Reinstall the cone washer

- Use the old ring nuts & large thick washers (~3/32" or 1/8" thick, w/ID & OD ~= bearing so both inner & outer races get pressure) to press the new bearing into place.

Early on, one bearing got cocked & I had to tap on high section of the outer race to straighten it out.

It takes a fair amount of torque. After the bearing was about 1/3 in, I had to use a butterfly wrench set on 8 to drive it. Be careful not to run the ringnut past the end of the threads in the shaft.

Once the bearing's about half-way in, you can use the cam drive gear under the old ringnut to press on a couple of washers to drive it the rest of the way in. Just seat the bearing enough so the circlip goes in. (I slip the circlip into place, then use the washers to press it in until it clicks into the groove.

Rest is reverse of removal.
[/QUOTE]

 

The 98000 is the one I have. The #2 fitting fits the cam drive bearing.

Or trade time for $$ & just grind the heads of a pair of 5mm socket head cap screws down to flat sided balls 6.5mm in diameter & adapt a steering wheel puller to yank on them.

www.EssexParts.com in NC is where we got the one we used. There are only 1 or 2 places in the US that carry the Sykes-Pickavant line. Price was $199 +shipping.

You shouldn't need a puller for the damper. Just a pry bar & a 6" piece of 1x2 to rest it against & spread the load over the timing cover. The damper usually comes off pretty easily.

 

After you pull the cam drive pulley off, just straighten the lip, it's fairly thin mild steel. When you're pulling the pulleys off to change the bearings, it's very hard to not bend at least one lip on 1 of the pulleys. A few taps with a hammer & it'll be straight again.

TIP: Find a large socket that the cam drive pulley just fits inside, then just gently tap on the bent area until the lip is flush with the outside of the socket, now you can see that the lip is flat again.


Have never run into a damper (knock on wood) that a little prying didn't coax off. Never really had to use much force. However, sounds like you need to find a large size puller. AutoZone & some other parts stores loan/rent tools. Maybe they have something large enough.

 

An air impact gun will get those cam drive nuts off- just give it a little time and some penetrant. I find PB Blaster works a little better that WD40. Check the pressure of the gun, maybe a larger one is needed. The gun is safer than the breaker bar also- because it won't spin the motor. Also- rotating the motor without cams is fine.

Those nuts also have a locking feature in the inside lip that grips the threads- so new ones should be installed.

I would also replace the main seal. Did you take any photos before you sprayed WD40 on the end of the crankshaft/damper. Was it dry but dirty, or oily like in the photo?

Just scotch-brite pad the end of the crank shaft, and the mating surface in the damper before trying to assemble. It will go on without a special tool, and the damper nut will do the rest.

 

This is about the best thread I can imagine for a 308 QV wanna be. I stopped in at the local independent today and he quoted $5000 for this service w/o the bearing replacement. I had labored under the impression this service called for an engine removal. Keep up the good work Jason, and let us know the parts total when you're done.

Thanks in advance

Dan

 

To remove seals like the main seal with the shaft in place:
- drill a couple of small (1/16" or 3/32") holes thru the body of the seal near the outer edge (Want to avoid nicking either the shaft or the mounting hole).

Then put a pair of about 3/4" or 1" long sheet metal type screws (#6 I think) into the holes & use them to pull the seal out. I use an auto body slide hammer on the screws, It's quick, but really overkill.

Seals work by the surface tension of oil under the seal lip(s), so a slight surface roughness is needed to maintain the oil film. The seal will have polished the shaft surface, so scuff the area the seal lip mates with with 600 grit sandpaper(wet sand), or green scotch brite. All you need to do is slightly dull the finish on the surface.

Most likely ring nuts were used because they were about half the thiskness of std nuts, & are self-locking. Ring nuts are fairly commonly used in European mfg.

 

If you are still having trouble getting the cam gear drive nuts off, i would try a little heat from a blow torch as this helps the penetrating oil penetrate. And then use the air gun.

You are replacing the outer bearings anyway so any damage from the heat, say to the seal, will not matter.

good luck

 

On the newer engines (all 4Vs fer sure, don't have my 2V injected manual here at work, but think they're like the 4V engines), the seals are BEHIND the outer bearings, so you don't want to risk cooking them, unless they're already failing & you're replacing them.

Replacing the 4V timing drive seals is fairly tricky as it's pretty easy to push them all the way thru the housing & then getting them out is a real PITA.