Hard shifting and manifold problems.

[DeltaT]

I've been driving my FJ daily for years and never had any issues to speak of but a couple of weeks ago my poor FJ40 started acting up.
I was doing some groceries and on my way back home shifting into gears became more difficult. It worsened quickly to the point where I couldn't use second anymore. And sometimes it just popped out of the gear. I never experienced that before.
I managed to get home and and diagnosed that the clutch master or slave was to be replaced. No big deal so I ordered the (oem) parts at CoolCruisres in Texas and waited for them to arrive. (a great source for parts btw).
While waiting I thought it might be a good idea to replace the manifold gasket.
It started to leak a bit when cold, making a sound like a train, tshk,tshk,tshk, if you know what I mean.
All parts arrived and I attacked the clutch first. A half a banana job. I took it for a test drive and the problem was still there. My diagnose was wrong
I suspected that there might be something wrong with the shifter itself, so I opened up the top and noticed some dirt (or at least that's what I thought). So I cleaned it all out, did some googling and found this thread The dirt was the disintegrated plastic seat (the blue ring in the other thread
So I got a new seat and boot (it was torn) at the Toyo dealer, put it in and wha-da-ya-know, it shifts like new again.
So now I have a spare master and slave clutch cylinder because the replaced parts where in perfect working order.

This is what was left of the seat:

So then I started on my manifold gasket problem.
I really had a hard time accessing the bolt near the fire wall. There is just not enough space. There is a heat shield that when taken off might give me some more room to work, but (of course) one of the bolts stripped so taking it off wasn't possible.
I finally managed to loosen all the bolts (the last one while sitting on the battery (lol).
I then cleaned up the surface using some fine grid sand paper, put the new gasket in adn bolted everything down.
Then started her up..... the leak was worse the before
I am guessing that the exhaust manifold is slightly warped. Not much, because when the engine heats up the sound goes away.
I loosened the bolts again and tightened them in a different order. starting in the middle, but that didn't help. I might need to machine the manifold. But I am not looking forward unbolting everything again so I will try the 'C trick' (ring cut in half or a stepped washer) described here first. Wish me luck.

 

[DeltaT]

I made a washer that is thicker on one side and tried to torque it enough to seal it but it didn't work. And in the process I pretty much stripped one of the studs

I think I will have to take off both manifolds, have them machined and replace the stud or re-thread it. Today is not a good day. It could have been an easy fix.

 

[DeltaT]

I took off the manifold today and brought the to a shop to have them plained.
Then I went to the dealership and ordered new studs and bolts. I will replace them all. So sense in re-using them old rusted bolts again.

I will try and take out the studs by welding on a nut. Unless somebody here has an better idea.

At the dealer I couldn't help notice this:

 

[DougAustinTx]

It seems that you can expect the manifolds to have some warpage on virtually every one of these trucks. You ALWAYS want to check the surface that meets the head for warpage, because a new gasket is not going to fix that issue. I went out and bought a 2' x 3' granite surface plate to both check and repair my manifolds and heads. After attaching some sanding belts to the granite plate, I can get them back to a nice flat machined surface without having to wait for the machine shop.

 

[handcannon]

A bit of advice here. Separate the intake and exhaust manifolds, clean up the mating surfaces, make sure the heat riser valve is working properly, and then put the manifolds back together with good gaskets BEFORE having them surfaced. Have the manifolds surfaced as a set.

Don

 

[DeltaT]

Thanks for the tips! Too late though, the deed has been done. I talked to the guy on the phone and he seemed very knowledgable. He did surfaced them as a set and he told me it was in a pretty bad shape when he started.
Good idea to take a look at the heat riser now that it's off.
Any tips on getting that thing operational. I am pretty sure it is stuck. They always are.
And is it really necessary to keep the rear heat shield? One of the bolts broke off when I took the shield off and it is in the way when I have to torque the rear manifold bolt.

 

[FJ40Jim]

If the heat riser is not operational, don't worry about trying to repair it. Chop off the bimetallic spring, rotate the flapper to the hot position, and weld one end of the shaft, so it stays in the hot position forever.

The rear heat shield is nice to have. Both bolts are not necessary. As you know, even if there were no bolts, the shield is trapped between manifold and body. Before mounting the manifolds, trim away the heat shield at the top to allow better wrench access for tightening the rearmost manifold bolts, then install the shield with one bolt and a larger washer.

 

[FJ40Jim]

I went out and bought a 2' x 3' granite surface plate to both check and repair my manifolds and heads. After attaching some sanding belts to the granite plate, I can get them back to a nice flat machined surface without having to wait for the machine shop.

Doug, is there any special trick for keeping the swiveling ends lined up with the main part of the manifolds?
I've used a couple of weld beads, but it doesn't work that well.

 

[DeltaT]

If the heat riser is not operational, don't worry about trying to repair it. Chop off the bimetallic spring, rotate the flapper to the hot position, and weld one end of the shaft, so it stays in the hot position forever.

Just to be sure, what it the hot position of the flapper?

 

[handcannon]

Fully open so there is no restriction to the exhaust flow.

The original purpose of this flapper, when closed, was to slow down and hold exhaust heat in against the underside of a cold aluminum intake manifold for a quicker warmup and better atomization of the fuel/air mix coming from the carb.

This brings up a question I have about the heat riser system. I have heard/read that with constant contact with the aluminun intake manifold the hot exhaust can, over time, crack the aluminum. Does anybody have personal experience with this?

Don

 

[DougAustinTx]

Doug, is there any special trick for keeping the swiveling ends lined up with the main part of the manifolds?
I've used a couple of weld beads, but it doesn't work that well.

Jim: I always did the two end pieces separately from the center section of the exhaust manifold because, until recently I didn't have a granite surfacing stone that was big enough to handle the assembled manifold. I make sure they are flat and true and have not had any trouble getting them to pull up tight on the head. I suppose that, if I ground an excessive amount off either the center section, or the end pieces, it could cause them to fail to pull down evenly with the other pieces, but so far that has not happened. When you tack weld them together, are you pre-assembling them on a very flat surface and welding using nickel rod? I may try that method on my next set since I have a surface plate that is big enough to do it now.

 

[DougAustinTx]

Fully open so there is no restriction to the exhaust flow.

The original purpose of this flapper, when closed, was to slow down and hold exhaust heat in against the underside of a cold aluminum intake manifold for a quicker warmup and better atomization of the fuel/air mix coming from the carb.

This brings up a question I have about the heat riser system. I have heard/read that with constant contact with the aluminun intake manifold the hot exhaust can, over time, crack the aluminum. Does anybody have personal experience with this?

Don

Yes, the aluminum intake will often develop a crack running down the center of the plenum. It is hard to get a good tig weld inside the plenum. I have had success separating the intake manifold from the exhaust manifold and milling off enough of the bottom of the intake to get a 1/4" thick steel block-off plate bolted to the top of the exhaust manifold. In Austin, I have found no need for all that exhaust heat directly cooking the intake. Since the exhaust block-off plate is within a quarter inch of the intake, there is plenty of heat transfer to help atomize the gas.

 

[DeltaT]

I took a look at my flapper and it works smoothly so my heat riser seems to work.

I still have to get the two studs out of the head, one is pretty much stripped and if one is done for, I might as well replace both.
My friend got a tip (from the machinist that took care of the surfacing) that you can extract the studs using iodine. I never heard of that before. I will get some at the local pharmacy and give it a try.

 

[FJ40Jim]

When you tack weld them together, are you pre-assembling them on a very flat surface and welding using nickel rod?

I bolt the cleaned manifold assy to the side of a bare, cleaned head without a gasket, then tack acros the swivel ends w/ MIG.

I don't do a "proper" preheat and nickle rod weld, because I don't want a good weld. But the MIG weld on cold iron will sometimes crack in handling, so has to be done a few times. On the plus side, it's easy to make the weld, and easy to cut apart.

 

[DeltaT]

My nuts and bolts came in yesterday so I am ready to go.

Any tips on yanking out those old studs out of my head?

I've been applying iodine but I am not sure if that has any effect.

 

[Weber Sarge]

Use paraffin canning wax and heat . Heat the stud pretty hot and apply a liberal amount of wax . Let it cool and the stud should come right out . This works even better if you weld a nut to the stud and apply wax .
Sarge

 

[FJ40Jim]

I've never had any problem getting the studs outta the head. If they going in the trash, just grab 'em w/ a big pair of vise grips and turn. If they are stubborn, soak w/ penetrant and hit straight on the end w/ a ball-peen, try again.

Getting the exh studs outta the exh manifold can be a royal PITA.

 

[DeltaT]

Yes ! I got'r done !

I think the iodine did its work. I have been applying the stuff for a day and I managed to get two nuts on and I could apply enough force to loosen the studs.
I then proceded to clean the outer manifolds and loosened the springs, sanded them smooth and applied a bit of grease.
I put the new studs in, put the gasket back in place and put the manifolds back on and torqued all the bolts and nuts in the appropriate order. I was all proud with my progress when I noticed that I had put the gasket on wrong

So I had to take everything off again and damaged one of the studs again They are soft like butter and even sliding the manifold over the threads was enough.

I managed to take the stud back out and salvaged one of the old ones.
And then proceded to put everything together again.

I took me all day, but when I was done and started her up, she purred like a kitten !
I couldn't be happier. I also noticed an exhaust leak at the back but I am not going to worry about it for now.

I noticed that she is peppier too when I took her for a testdrive. I couldn't be happier.

Thanks for all the input!

 

[DeltaT]

...I also noticed an exhaust leak at the back but I am not going to worry about it for now....

So I thought that today would be a fine day to fix my exhaust. So I got a small piece of exhaust which I wanted to weld on the flange so I could re-attach the pipe to the muffler.

I got everything ready, drive to my shop, got my tools and..... It's gone (WTF?!) The whole back muffler is gone. It is strange, sitting on you knees looking at where once a muffler used to be and it takes a while to actually grasp that it is not there.
I thought I had probably lost it somewhere, but I didn't even noticed it. And it is quite a big muffler.
I thought it had a different sound when I was driving but it was by no means loud.
My two inch piece was not going to fix that so I went back home. So I drove back slowly scanning the roadside but couldn't find it.
Then my wife confessed that she thought she drove over a cat when she saw something tumbling down the road.

It's at the shop now for a new muffler. What can I say...