Radioactive Man
Active Member
Sorry for the question, but what is the best way to fit?
Would you use a gasket or sealant?
Thanks
Ian
Would you use a gasket or sealant?
Thanks
Ian
Hi James, sorry for what's perhaps a dumb question.
The crank seal I have is from Turner Engineering. It fits the 300tdi and the 2.8 version.
So it has two extra holes in it that line up with the ridge on the gasket that would crush down.
Would you still use a gasket event though a small section won't perhaps be clamped the same? Hope my question makes sense.
Ian
Sorry for the question, but what is the best way to fit?
Would you use a gasket or sealant?
Thanks
Ian
I would not use the gasket, especially if what you take off doesn't have a gasket already.
I changed my seal 3 years ago when the gearbox was off and I bought a good quality rear-seal from Turners (they don't fit or even sell the gasket by the way).
I stripped mine all down and the old one was sealed with RTV. If I then did use a gasket I would alter where the seal lip sits on the journal. If you change the contact point you risk pushing it out onto part of the crank which will be an untouched surface and may also have traces of rust on it, in other words rough. Even if it's just metal discoloration, it will be rough although not detectable by touch. Even if you were to clean it all up and smooth it all down and polish it it would still not be as good as the original part of the crank the seal ran on. It is standard engineering practice to reuse an existing running surface in these sort of applications.
Also, fit two M8 studs into the block to act as guides when your pushing the new seal on. These stop the seal from being put on at a bad angle and possibly damaging it. There is a plastic protector/expander on the oil seal, this stops the oil seal from being damaged and also expands oil seal over the end of the crankshaft as you fit it - DO NOT REMOVE IT - it will pop off at the end of fitting.
Also don't oil or grease the crank to slide it on, the seal, SHOULD BE teflon coated OEM are, which will lubricate it as it slides on, oil or grease will create a thin film which will stop the seal from making contact on the crank and will cause leaks.
Use RTV on a clean surface (solvent clean it all and make sure it drys well) and seal it all up nicely, make sure none gets near the crank or seal. Seal up round the bolt holes nicely, don't go mad or the seal will sit squint.
This has been done 100's of times on the forum and something I note is many people do the job twice...
its std engineering practice to move the seal so it contacts on fresh surface where possible obviously you polish the surface first,whereas sealant is ok gasket is better and less prone to fail,sealant tends to fail after so many heat cycles especially with ali housing bolted to cast block, in my experience
how are you polishing the surface btw?
360 or 400 grit polishing tape
is that the same as emery cloth?
similar but more like emery
thanks all for the comments, reassurance and advice.
360 or 400 grit polishing tape