Read the many posts on timing belt change and decided I'd like to share in the fun. I'd call myself an advanced DYI but this would be my first Volvo TB.

Car is a 1990 740, 8 valve, 150,000 miles. TB was last changed at 50,000 miles. The idler and seals, I'm quite sure are original, as is the water pump. I was planning to replace the idler even though it appears to be fine, as well as the water pump, even thought it, too appears fine. I had not planned to replace the seals, solely because it's the kind of job that tends to be fussy and if they leak, well, you just end up doing it again.

I've gotten the car stripped down to the point of removing the belt. When I got the lower TB cover off, I found what I would describe as a small amount of oily, gritty crud to the left of the intermediate shaft (left being the passenger side), as well a somewhat greater amount at the bottom of the lower cover.

As best I can tell, the source of the oily crud is not leaking shaft seal. If anything, it appears to have leaked down from above, from the thermostat housing (when the thermostat was changed), and down behind the back TB cover and then into the TB compartment. There was no contamination whatsoever on the belt or the idler; it's solely on the timing cover itself.

So here's the question: Do I replace the seals or not? Am I likely correct about the source of the oily crud and whether I am or not am I going too far out of my way to avoid a job that really isn't that tough, or likely to leak? Any recommendations on seals, IPD, Ehrling, OEM? Use a store-bought seal press or improvise with sockets or whatever?

Also, should I do the belt first or the water pump? Seems smarter to do the pump first and get that mess cleaned up but I thought to ask those with experience.

Finally, as others have noted it's rather a challenge to locate and line up the timing marks on the crank pulley. Does it make sense to create my own with some white out and if I do that is there a best method or location to make those marks?

Thanks in advance for replies.

PS - For anyone interested, I used the IPD version of the crank holder and it worked exactly as advertised. Also, the belt was pristine, even with 100K miles on it. I know the service interval is 50K but perhaps this too cautious.