Can anyone tell me if this Vvt unit is supposed to have gear in sections or is it broken. Scared to take other one off as I can't get this one back together

 

Dale, I have no idea on the workings on the inside of the VVT. I don't remember see a post about repairing one. If you can't get it back together I have a set of VVT from a 99xj8 that had a bad rod. It ran so I assume that they are good. If interested you can send me a PM.

 

If I can't get this one back together I'm interested but still faced with problem of can't find anywhere to put tool to retard timing. That how I wound up taking this one apart

 

Look inside of the VVT where the bolt goes. You will see the hole on the center for the bolt and outside of that hole are 2 small holes opposite from each other. That is where the tool goes. Be careful not to use too much pressure like I did and broke the ears off the tool.

 

That's what I thought but my tool will not fit thru hole on outside. With gear out it fits fine which is how I wound up with this one apart. The one in pic is still together on car

 

The one on top of the photo is for the exhaust cam and the tool on the bottom is for the VVT/ intake. My VVT tool is missing the two pins that I broke off and need to replace them.

 

I have both tools but the one for Vvt intake is too large to fit into hole. Maybe I got a flawed one

 

Mine fits very snug too. Try using a little oil first and if that doesn't work sand the finish off the tool, clean it up apply a little oil and try again.

 

Here is a forum post from 2011 on taking the VVT apart. In one of the photos, it looks like the gear is in sections, but I can't be sure.

https://www.jaguarforums.com/forum/x...writeup-54805/

Here is my take on retarding the VVT...not fact, just my thoughts...

I have read in several Jaguar manuals that you should check to see if the VVT is in the retarded position, for the purpose of primary chain tightening. However, in reading the description of VVT operation, it seems that the retarded position is the default position. Also, this is the first post that points out that the two prong tool is for the VVT. If I had known that, I might have tried to use it. Too late now, but maybe for the best because it seems to me that the VVT is some sort of SteamPunk device and the only person who could possibly adjust or take one apart and put it back together is the wizard who designed it and waved his magic wand as it passed by on the assembly line conveyor belt.
In short, I have decided to leave mine alone before re-assembling my engine. My primary chains are taught - not piano wire taught, but tighter than my old motorcycle chain taught. I don't know if this is correct, but at some point the rubber has to meet the road and the car has to go back together.

In a few days, I hope to be able to tell you that this (leaving the units alone) is the proper procedure for reassembling a (1997 4.0 liter) engine.

PS. Good luck.

 

My suggestion Truck Graphics is to rotate the engine manually in a clockwise direction a couple of revolutions using the balancer bolt. Then recheck you timing. I do it because I want to make sure I got it timed correctly before I put everything back together. If the chain or tensioners settle after rotation your timing will be off.

 

BobRoy: Your advice is on my check list ! Thank you !

 

I have worked the better part of two days to put mine back together but after reading the write up above I got the nerve to tap it lightly with a hammer. Went right in but can barely turn so I'm going to replace both. I'll wait for those to arrive along with new guides cause the ones in my kit are too long

 

Ok. I'm going to give my thoughts on this VVT retarding. If my theory is wrong or if one our Jag mechanics that have done this more than I have please correct me or have this post deleted because the last thing I want to do is give misinformation.

What is trying to be accomplished by the retarding is to keep the drive side of the chain, the side without the primary tensioners, tight without any slack. If you tighten the VVT or exhaust sprocket without retarding, putting tension in a counterclockwise direction, the sprockets will naturally will want to turn in the direction you are tightening the bolt. If it does this it will put slack between the cams and the crank sprocket. So then when the engine turns over in the clockwise direction the crank will turn and remove the slack before the cams move. Now you are out of time. The car may run good but it won't be at top efficiency because it is slightly out of time.

Now the trouble Dale and others are having retarding the VVT. If you look to where the tool goes in. This is all part of the outer housing, it's all one piece. Why can't you just use a adjustible strap oil filter wrench on the outside of the VVT and put pressure counterclockwise while tightening the bolt.

My thoughts and any input positive or negative will be appreciated. Thanks.

 

Bob,
I think if you do it that way, then there's a risk that the inner sleeve will follow the bolt movement and you could end up with the cam timing out (or at least the piston in the wrong place) :- or have I missed something?


Separately, there's a really good description of how both variants of the VVT mechanisms work on Gus' site:

http://www.jagrepair.com/images/Trai...ual-9-5-01.pdf

starting at section 9.5 for the AJ27. It doesn't offer any practical advice, but gives a good insight of what it's supposed to do.

Mike

 

Thanks michaelh for that link. You are correct you do need the tool to retard the inner sleeve. Looking at it from outside and not seeing that diagram I thought it was one piece but it's not.

Thanks again it helps me understand the workings better.