I put my engine on the stand and assembled all of my shiny new parts, then sat down the read the overhaul manual again.

Dowty washers. A show stopper.

Discussing main bearing removal the manual says to remove and discard the washers. Geez. I didn't even know what a dowty washer was until I googled it. This weekend is the weekend for this project. It is time sensitive. I googled the forums and someone in similar circumstances said he was going to reuse them with RTV.

Has anyone done this? Does it prevent a leak? Can I swap them out later with the engine on the truck?

 

I've used dowty washers a lot, but never on a car. I never knew we had them on Discos!

I find them almost magical in fairly high pressure scenarios. I've done a bit with quite high pressure hydraulics, and always trust a dowty when I've used them. They can be hand tight, and still hold pressure (not recommended). I've blown a car tire up, by venting a Co2 bottle into it (about 350lbs). Or split rocks with hydraulics. Made jet packs with high pressure gasses, (v high pressure). All dowty washer joints. They are fantastic.

I would never use in conjunction with rtv of any sort. They shouldn't need it, and can only hinder its design. I've always been happy to reuse one, if it isnt damaged in any way. It's not like nylocks, where the nylon is 'screwed into' and thus can be considered to have slightly 'worn out'. I would say after about 5-6 times of jointing and unjointing a 1" hose with dowtys, with maybe 150bar of pressure inside, my dowty started to hiss slightly. This is after losing it on the floor, standing on it, being rough in general.

The dowty works by compressing the small black rubber lip, and can only get more compressed under load. It doesn't get aggressive use, if that makes sense.

Of course, it will always be preferable to use a new one, but if it wasn't possible, I wouldn't feel tragic reusing a perfect looking old one.

Help at all?

 

Very helpful. Eases my mind a bit.

I doubt these washers have seen the light of day since 2003. But they have been on a hot engine. How can I tell whether they are okay?

 

I should have mentioned... They are on the side bolts for the rear main bearing.

 

I'm truly at a loss here Charlie. I would imagine that the machine shop would have told you if they felt they needed to be replaced, but I could be dead wrong.

 

Thanks fellas. I pulled all of the bolts out of the box--there are more dowty washers than I thought, reading the overhaul manual--and all but one of the dowty washers is separated. I could press them back together but I assume that defeats the purpose. I'll find some. I was set on doing the engine, transmission, transfer case, and hubs swap this weekend but that might be an optimistic plan anyway. Now that I know what a dowty washer is, they sound pretty cool! But after spending so much time and pesos on this project I would have to have oil leaks at all, much less as a result of some 50 cent washers (or $2.50 each plus shipping, if from AB).

 

Oh. If they delaminated from the metal part, they are toast. Good peace of mind to have new ones in anyway.

 

A little more daylight research and it appears that you have to have 16mm and 19mm dowty washers, and they are hard to find. Ordering from AB.

 

Fifty bucks for eleven (?) washers, overnight and they MIGHT be here tomorrow. Fingers crossed.

 

A local bearing supply house should have them on hand.
Check Trevor at Rovahfarm. $1.93 each and he'll mail priority mail.
http://www.rovahfarm.com/DiscoIEnginePage3.htm