Cambelt driveshafts and crankshaft seals - how to ?

Hi all,

I've noticed my oil leaks on the belts ends of the engine are getting a bit worse on my GT4 and a bit of investigation would suggest it must be either the crankshaft/balancer pulley seal or the lower cam belt drive pulleys - or all three a bit. They look to be the originals. The leaks aren't too bad, but are definitely getting worse and dropping oil on the exhaust heat shield - urgh. It could also be the gearbox to crank case joint on that end, but I kind of doubt it.

Jimshadow - I know you wrote up all your work on the cam belt pulley bearings can you point me to it please - I just can't find it!

Also can't find any posts on doing the crankshaft seal - e.g. undoing the big nut, removing the pulley, removing and installing a seal...

thanks

Lee

'77 GT4

 

Doh, it looks like the cam belt drive shafts don't have seals when I checked the diagram and I remember a thread on sealed vs unsealed bearings. Or does it ? Superformance quote a "Timing belt pulley oil seal 30816020"

So maybe that just leaves the crankshaft seal, how do you do it?

thanks

Lee

'77 gt4

 

Thanks, that explains it well.

I pulled the balancer pulley off to take a look. It's not gushing out but was clearly wet - I've not cleaned up the area and I'm ready to do the seal but worried about it being tough to get out - I'll be using the sheet metal screw method to start with. Wish me luck

Images show the area all cleaned and ready to extract the old one. The 12v impact wrench that I used to undo the pulley bolt (36mm socket) and a general view of my garage and work area.

Lee

'77 GT4
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Whilst waiting for a new seal (from superformance) I made a nylon tool to push the new one in square It fits smoothly over the crankshaft, has a groove for the key and a recess for the seal collar. I didn't have a piece of nylon long enough to clear the end of the crankshaft so I will use a large socket of piece of wood.

Lee

'77 GT4
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Thanks guys, I hope it will come out easy. Anyone want to borrow the tool ? - only (will be) used once

I have a nice little miller/lathe combo which is great for making stuff like this as well as even some small component parts. I had some sizeable nylon bar lying around so it was £0 to make too.

I pulled the lower A-arm and cleaned it up (de-rust) and painted it as well whilst waiting for the seal to arrive

Lee

'77 GT4

 

Damn, how annoying the post man just dropped off the package and it turned out Superformance sent me distributor seal!

Of course a quick phone call sorted it and the correct seal should be with me tomorrow - just annoying when I'm ready to do the job.

Lee

 

Urghh, does the key have to come out really ? It looks like there is a collar on the crankshaft that the seal runs on ?

Can anyone confirm ?

Lee

 

No worries. It looks to be the collar which is part of the driving gear for the cam pulley gears, and the key looks slightly lower than the collar.

Lee

 

After the kids had gone to bed I decided to take a look at getting the old crank seal out.

I tried to lever it out with not much luck, tried tiny vice grips on the bent out section and they just slipped off.

So I went for the sheet metal screw method as described elsewhere in f-chat. Carefully drill a small hole in the outer metal shield then screw a self tapper into the hole. I put a magnet near the drill so catch any cuttings and went through the metal very slowly to try and keep any cuttings outside the seal. I gripped the screw head with a pair of vice-grips which I'd modified into a slide hammer by replacing the adjuster bolt with a length of screwed rod (M10 in this case) and used a big socket as the weight. The seal was out within 3 wacks of the slide hammer. See pics. I cut an aerosol top in half to cover the exposed ends of the cam belts to be safe. You can see that the seal runs on the extended collar which is part of the cam pulley driver gear on the crankshaft.

Hopefully the new (and correct) seal will be here tomorrow and I can put it back together.

Lee

'77 GT4
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So with the new seal (using my neat tool) in I bolted it all up and took it for a test run - sadly still peeing oil out, so I guess it wasn't the crankshaft seal - but hey now it has a new one

So I tore it all down again last night and it must be coming from the cam pulley seals the forward one more than the rear.

Shame as I just had the belts done in November at the last service.

I got straight into the job this morning and pulled the forward belt cover off (after removing the air-con compressor - that was a PITA)

Made a pin-nut socket tool for the cam drive nut, tried to air socket it off - no chance, so I drilled small hole through the body of the nut to try and split it - they are soft steel. Gave it a few knocks with a small chisel but the nut material just shaved off, I tried the power wrench again and it came off this time. So I'm at the stage of ready to pull the belt on the forward bank.

I'll line up the timing marks first then, pull the belt. Whilst I'm in there I have two new tensioners and I'll of course be doing the drive pully bearings as well as the seals. Pictures to follow.

Lee

 

Engine set at PM1-4, cams locked with "special" wooden locking tool, everything marked up several times, so ready to go. Just waiting on a puller for the bottom pulley before I take the belt off.

I don't as yet know if the bottom pulley is sealed on the outside or the inside, but the end cover is marked 76 so it's probably the early outside seal type. I've not bought any of the service parts yet either but Superformance usually has them next day delivery.

Lee

'77 GT4
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Thanks man, I hate belts although this job is way easier than some of the belts I've done in the past simply because of access. My experience is with 70's fiats and the space between the chassis and pulleys is less than the wide of the belts. The 308 setup is much easier to see everything so gives you more confidence that you're doing it right. There's not much more to tell about the crankshaft seal - I just pushed it in with a few taps with my tool and that was that.

I'll be taking pictures of the cam pulley job as it progresses but intend to have it wrapped up in a week or so.

Lee

 

I pulled the forward belt (doing them one at a time), and went to fit my three-arm pulley to pull the cam drive pulley, but it just slid off without effort which was nice. Then I spotted the reason for a big oil leak - the seal came out with the pulley! I was hard like plastic so must have hardly been sealing the drive shaft at all. Picture is the old seal. At least then I didn't have to pull work out how to extract it. The key came out pretty easy too with a brass drift and I've pulled the circlip in front of the bearing ready. Just waiting on the bearing puller to be delivered now and I can swap out the bearing. Will order the parts tomorrow from Superformance now I know what I'm looking at.

Just wondering whether of not to replace the tensioner pulley - it looks like new and is nice and tight (like a new bearing is) and I've a feeling it was done only about 5K ago. The reason for doubt is that it looks like a genuine one over the after market ones I have. Any thoughts ?
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I'm looking for the torque settings for the tensioner pulley nut and the cam belt drive pulley nut. Are these the two I need ? translation makes me unsure.

thanks

Lee
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Used the Draper bearing puller tool to pull the old bearings, used the new nuts and various washers and tubes to wind it in. Made a large washer the size of just under the bearing so I could push on the inner and outer races equally. Don't forget the spring ring from behind the bearing.
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The left hand drive pulley key was at the bottom when the engine was at PM1-4 which made it harder to get in. So I used a pair of welding grips with brass sheet to protect the steel to push the key in.
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Torqued the cam drive pulley nuts up by using a socket on the crankshaft nut and pulling against it with the torque wrench on the cam drive nut - this no engine rotation.

Took the car out for a run and everything appeared ok (my first belts job).

Pulled the wheel and inner liner off when I got home to check everything out and wow a trickle of strange black liquid from the left hand cam drive pulley! So whilst the badly leaking right hand pulley is sealed ok, I gutted that the left hand one doesn't seem to be. I did about 20 miles at various speeds and the car was well up to temperature.

I'm thinking/hoping that the new "leak" is actually oil that I squirted around the seal and on the sealing surface of the cam pulley that has drained out now I ran the car. Any thoughts ? The back of the cam drive pulley showed visible wear but not much and was sealing ok with a 30+ year old hard as plastic original seal, so I'm hoping it is just the oil I used to lubricate the seal when I installed it as a new pulley = £200 and doing most of the job on the left hand/rear pulley again.

Also noticed a new leak off the bottom oil cooler hose - bah! Top one was replaced last year so I guess the bottom needs it now. Not too difficult job, but any tips on cracking the nut on the cooler without breaking the cooler ?

Lee
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