Exact replacements are relatively expensive compared to generic products. As long as the replacement skylight covers the hole, it doesn't matter what you use. I don't know about your 1998 but, if it has an inner skylight like my 2002, that will cover up any mismatch. Otherwise, I'm sure there's a way to re-trim the inside to make it look good.
114496-01-02A EA PANEL - OUTER SKYLIGHT - 22" X 37"
122191-01-02A EA PANEL - SKYLITE - INNER W/LIGHT CUTOUT - 20.7" X 35.4"
Here's the Outer Skylight Panel on Amazon sold by Winnebago.
And here's the Inner Panel as well.
A quick web search seemed to find roughly the same prices elsewhere, but it's possible you might find cheaper shipping somewhere else--I don't know.
Lichtsinn's is definitely a good source, and they'll give a discount (10%?) for WIT members as well.
Thanks for the input and the part number. I have a manual here some place. But like everything else - don't find it til I don't need it.
The skylight on Amazon is the one I need. The question now is - what goop do I use to seal it? Do I use silkaflex under? then eternbond tape around the edges? Or / dicor sealant on screw holes? So many questions. It gets exhausting reading everything.
Do not use anything containing silicone, it does not seal well long-term. When it begins to loosen, nothing else will stick to it, not even more silicone.
I would use Butyl Tape between the roof and the skylight lip and Dicor over the screws.
Why not use what Winnebago specifies for this purpose? I believe the commercial name of the product is Manus 75 AM. You can go to Winnebago's site and check out the sealant call-out sheet for your rig and newer ones and cross-reference the part numbers.
And not all silicones are created equal. Different sealants are formulated for different purposes with varying degrees of adhesiveness, etc. Proper cleaning, is, however recommended.
To be extra safe on mine, I used Eternabond tape around and over the mounting flange and screws.
For parts on an older coach you might try a salvage yard. There is one in Phoenix, AZ RV Salvage. Give them the year make and model and they may have what you are looking for at a reason noble discount.
I knew not to use silicone - and from what I read - Manus 75 AM has a short shelve life. Would be difficult to obtain new stuff.
I think the butyl tape on flange of skylight then dicor on screw heads then dicor tape over flange may be the ticket.
Besides the skylight replacement - after moisture got under fiber glass roof - the edge seam in the J channel popped up from the cold weather. About a 6 foot section. So - when warmer weather gets here - have my spring project resealing the edge joint of the roof.
Due to the time and labor to replace a skylight I would only use new parts. Hate to buy a used skylight and have it crack.
There is a reason sealing products containing silicone are the cheapest priced on the market.