Alfa Romeo Owners Club of Australia Forum

Technical => 105/115 Series (105 Coupe/Spider/Berlina) => Topic started by: 1300-GT-Junior on February 21, 2011, 01:57:32 PM

Title: Replacing a crankshaft front oil seal
Post by: 1300-GT-Junior on February 21, 2011, 01:57:32 PM

This is just a question regarding the progress of my resto / fixing up of my 1300 GT Junior.

The person looking at the car said that when running there is an oil leak now and that he thinks it is the crankshaft front oil seal.

My question is, is this a difficult job to do on a 1972 1300 GTJ?

Thanks guys.
Title: Re: Replacing a crankshaft front oil seal
Post by: 1300-GT-Junior on February 21, 2011, 02:32:10 PM
Also is there anything like that which may also need replacing given the car has sit idle for 9 years and now has a leak down that way after starting?
Title: Re: Replacing a crankshaft front oil seal
Post by: AikenDrum105 on February 21, 2011, 02:38:07 PM
Hi there,

It's pretty straightforward - I think you'll need to pull the radiator and the front grille to get better access.  Getting the pulley nut loose is usually the hardest part.

It goes something like this:

* Hammer pulley lockwasher flat, place car in gear with handbrake on tight, and undo crankshaft pulley nut.  These are torqued on very tight (I forget the setting, but it's one of the highest on the car)  From memory the socket you require is 36mm (but I've never done a 1300 so they might be different).  and a breaker bar.   and a length of pipe :)   

Because you're using the gearbox / rear wheels to lock the engine - the flex of the giubo in the driveline can absorb your efforts to *shock* the nut loose (or overstrain a dying giubo)  so you may need to lock the engine another way.  I've seen a bar wedged between the gearbox output flange and the giubo to brace against the floor used - and also rope in the cylinders to block them.... You should be ok with the handbrake / in gear method though.  I have heated the pulley nut with a propane torch a couple of times to help persuade it.

* once it's off - you *should* be able to get the pulley off with a little wd-40 wiggling / light tapping with a hammer to loosen it and slide off.  It has a woodruff key to prevent it rotating on the crankshaft and they bind up in the slot sometimes.  A 3 or 2 jaw puller might help if you can get it in there.

* pulley off and you can pry out the old seal, clean up the housing surface and use that 36mm socket to gently tap the new seal in (I lubricate the edges of the seal with a little grease to help it slide in without binding.

* check the sealing surface on the back of the pulley - often worth polishing this up so the new seal has a smooth surface to work with- grease the polished surface and slide the pulley back down the crankshaft and into the seal.

* reassembly is reverse of removal - or something like that. If the lockwasher for the pulley is really chewed up might be worth finding / making a new one.

If your waterpump is a bit dodgy - now's a good time to do it as it's tricky to remove with the pulley on.


I'm sure I've forgotten something, but hope that helps !

Cheers,
Title: Re: Replacing a crankshaft front oil seal
Post by: 1300-GT-Junior on February 21, 2011, 02:43:42 PM
Thanks very much for your help.
Title: Re: Replacing a crankshaft front oil seal
Post by: 1750GTV on February 22, 2011, 03:22:30 PM
Most suppliers also stock new 36mm pulley nuts. Worth replacing, particularly if you've 'slightly rounded' the old one getting it off.

Chris
Title: Re: Replacing a crankshaft front oil seal
Post by: 1300-GT-Junior on February 22, 2011, 04:06:13 PM
Another question, not really worth a new thread.

I think from memory I may have an issue with the thermostat.

Am I right that the thermostat is a screw in type? Also I am assuming it would not take too long to do?

Cheers
Title: Re: Replacing a crankshaft front oil seal
Post by: AikenDrum105 on February 22, 2011, 09:36:51 PM
The screw in type fits into the intake manifold, and then the upper hose goes over it and clamps behind it. They can be seized in there and sometimes you need to soak with crc 5.56 or another penetrant, and hammer it around with a chisel or similar to get it off.   If you can get it out ok - chuck it in a pot of boiling water and see if it opens or not.

you'll need a large shifter (or vice grips  :o )  to fit it.

When you put the new one in - grease the threads a little and don't do it up tight..  the hose stops it from going anywhere - you want to be able to get it out next time :)
Title: Re: Replacing a crankshaft front oil seal
Post by: 1750GTV on February 23, 2011, 12:05:27 PM
Early thermostats were screw in, later models were mounted differently.
I've attached a photo of the late model system.
Chris