'95 PREVIA VALVE COVER- SCREW/BOLT PROBLEM

[kiowa]

Having trouble with some hard to get to screws/bolts. Top row was easy, but the right bottom corner, around the bottom to the left, have been a pain -in-the-gas! Trying to replace the gasket. Your advice and experience would be a great help. Thanks!:pissed:

[pdgizwiz]

Hmmm... right bottom, to the left? I'm confused.
Still, I've had a bunch of these off and never had any issue getting to any of the valve cover bolts. Maybe you need a different tool? A box end wrench instead of a socket, maybe?

[kiowa]

I should have said that thebottom was easy and that I'm having trouble with the top row and the sides. I have used box rachet wrenches and this has helped, but my rotary cuff problem has gotten the best of me. so I'll have to try it at a later date. I also tried to check on the fluid levels in the two diffs and the transfer case, but the previous owner had pretty much rounded off all the fill plugs. Any advice for their removal, tried vise grips and they wouldn't work either. I guess I'll have to make some mechanic rich!!

[pdgizwiz]

Ah, in that case I have to ask: Have you taken the engine cover under the passenger seat off?

[kiowa]

Oh! Yes! I've owned a Previa since Oct 1990! It was fun to go to the Jiffy Lub for the first oil change and they had to call a Toyota Dealer and ask " Where the Hell is THE Engine??" Had gone to buy the older model and a salesman said, "I"d like to show you something a little different" Bought IT!

[pdgizwiz]

OK, sorry to suggest the obvious...
Bummer about the buggered fill plugs. I've no way to advise an attack on either of your fastener problems without a visual, though. I know that the front differential fill plug is hard to get to. I bought a combination wrench of the right size for that one and had to grind one face of the box end flat to get better engagement on the shallow hex of the plug. I can't remember the size.. 24mm? 32mm?

[timsrv]

Here's a quote from another thread that may help you prevent this problem in the future:


It's 24mm metric but 15/16" SAE fits it nicely too. You should use a 6 point socket as there isn't much surface area here. It's common for these to round-off so be careful. I'm sure they make special sockets for this, but I use a 6 point 15/16" socket that I ground down on a disc grinder. I removed some of the open side to get rid of the interior chamfer (this provides more surface area between the socket and plug). That socket fits nice and tight and I don't need to worry about it slipping and rounding the plug. BTW, this is the same size used on the fill plug too. The front differential (for you 4wd owners), manual transmissions & transfer cases use this same plug size. Broached sockets (relieved areas between sides of hex, like the one below) are also preferred as they are less likely to round off the plug. Tim


http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/Drive%20Train/IMG_2003_zpscc4bc3d9.jpg


When it comes to removing plugs that are already damaged there are different ways to accomplish. Whichever way you use be sure to have a new plug on hand before removing the old. One way is to use a chisel on the edge of the plug. Once you have a groove started, lean the chisel to one side as to direct force in the direction of desired rotation. Usually a few well placed blows will do the job. In the past I've welding things to the plug, then grabbing onto that to remove. Tim

[TheMAN]

sounds like it's time to replace all of those rounded out bolts... you can buy those "round off" kits from sears and parts stores, they work great for bolts that have not been cross threaded/seized in