308 Cam Belt Lower Sprocket Seals

No, the seal (and the outer bearing) can be done on the later design without removing the engine nor the timing case cover -- it just requires using the bearing puller with the flattened ball studs that fit into the ball raceways (after breaking the cages and sliding the balls around to give space. And, even if you had the earlier design, replacing those seals without replacing the outer bearings would be insanity -- so they need the same puller too. Many prior threads with photos here...

 

Do searches on the F PNs involved in your projects (like the seal and the bearings in this case). Using 117276 (which replaces 112020) gave this one:

http://www.ferrarichat.com/forum/308-328/248319-cambelt-driveshafts-crankshaft-seals-how-2.html

 

I finished doing this job just this summer, with the engine in. Not hard at all with the magic bearing puller.

(Although because I'm that sort of person I spent a day or so messing around with grinders and welder trying to improvise something before I gave up and bought the right tool).

You'll need the special socket for the nuts on the end of the cam drive shafts. I replaced mine with hex nuts from Superformance.

 

...because there's a high likelihood the reason those seals are leaking is because the bearing is shot and the shaft is wobbling around.

 

On a side note Andrew -- since your Profile lists having a "1981 308 GTB UK Car", and you state that you have a "dry-sump" (carb), could you please add the relevant facts (your build date and SN) to this thread:

http://www.ferrarichat.com/forum/308-328/431150-last-carbd-308-a-5.html

TIA.

 

Just had to pass a seal over a groove and keyway on a shaft this morning (on a Sanden A/C comp), used aluminium foil tape around the shaft.

 

that's a very interesting reading. I have the same leak on my dry sump car 34465 and my mechanic (No. 1 vintage Ferrari mechanic in the world as popularity) shop says that it requires an engine out service: i will inform him immediately. He says that from engine 01105 the seal is inside the engine and they cannot change it without taking out the engine. Maybe this time they need to learn something.

Thank you (all) very much!

ciao

 

I did bearings and seals on my 77 last fall after discovering the leaks. I was a little fear full at the time but once I got into the job it was pretty simple. Just like doing a belt change which I did at the same time. I had the old seal/bearing set up and I replaced the original set. The seal was hard as a rock and I used the screw and pull method to remove it. Took out the outer bearing by breaking the cage and used a ball end socket wrench with two flats in between the balls. Just pulled it out without a problem. reassembled new parts and job done. Easier then I thought it would be. Belt changes were done every 3-4 year at about 2500 miles a year. It was a cheap investment for me as I could not afford the cost of a broken belt and didn't want the fear of the potential grenade going off. Call it mental insurance.

 

I used tape around the shaft so the keyway wouldn't tear up the inner lip of the seal. The outer lip is rigid and easily wide enough to bridge the circlip groove without difficulty. Centering the seal properly was no harder than with any other oil seal on any other car - I positioned it, placed a flat piece of wood over of the edge, tapped gently with a hammer working around the rim until it was started. Once started, I found some suitable round object (don't remember what, might have been a stray PVC plumbing fitting or the outer race of the old bearing) as a driver to send it the rest of the way home.

 

On my '82 I started the seal then followed it in with the C ring. Then I drove the C ring in until it seated and the seal was pushed only to the extent of the C ring.

 

I'm getting ready to tackle this job and have read the sticky threads on this, but was wondering if anyone has some better pictures of the two differing seal arrangements. A high quality diagram would also serve. I look at the WSM, but the detail is not so great. If not, I'll still do it, but will just figure it out as I go...and take pics along the way. My 77 dry sump should have the older arrangement and I know they have never been replaced. Great info here, so thanks for posting.

Not sure if it's possible but this thread would be nice to tag to the end of the sticky DIY on the same subject...most of us read those first, but end up unaware that there are some really, really great "spin off" threads on the same topic that often contain additional info that can help us.

Ciao!

Hannibal

 

There's a good cross-section figure of the later design in the Mondial8/QV WSM.

 

Great...I'll look at it and factor in the described difference for the old design.

Thank you!

 

What about the inner bearings, Gents?

 

Not much of a challenge if you have the right tool.

 

Almost never fails.

 

On my 82 I used a basic seal hook. Pulled it out on 3 different points a little at a time until it twisted enough to slide out.