How to remove (that hard to get to) rearmost lower exhaust manifold nut (1FZFE) (1 Viewer)

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Long story to follow: (skip to the photos for a quick read)

So was in the middle of the job tearing things down to remove the head on a 95 model FZJ80 and couldn't get to the rearmost lower exhaust manifold nut. For those that haven't done this job yet, the first five exhaust manifold runners have two nuts/studs each holding them to the head. But the #6 Exhaust runner has three studs/nuts. upper front, upper far rear, and lower rear.

You can get to the upper rearmost #6 exhaust manifold nut from above with a combination of sockets and extensions, not too bad (with the valve cover, heater pipes, hoses, manifold heat shields, and kickdown cable bracket removed already). The front upper #6 exhaust manifold nut/stud (and all the others going forward) are all easily accessible.

But the lower rearmost nut on the back/rear lower side of the rearmost (#6) exhaust manifold runner is pretty much impossible to remove from above. Some people already know this, just wanted to share hoping others don't bang their heads against the wall trying to get to that one nut/stud from above.

I approached it from below on my back, right side of vehicle, squiggle in head first behind the right front wheel then forward a bit and look up, follow the block up to the head and the exhaust manifold at the rear. Using an extra long flex head 14mm (x 12mm) ratcheting box wrench (ICON brand) got it loose and most of the way out. Finished up from above (same wrench still attached from below) when the stud got very loose.

One tip: if the area is oily and grimey, wash it off first. Also helps to have good lighting (pointing up) so you can find the nut and securely place the wrench on it.

The set of ICON brand wrenches were from HF (#56694), price was $199 for five wrenches, so $40 a wrench. Northern Tool sells a similar 12 mm x 14 mm flex head box wrench by itself (and other sizes) for $59 each, so the HF ICON kit is a better buy if you need/want the other sizes.

These two wrenches (ICON and Northern Tool) looked pretty much identical, but the ICON wrench appeared to have a slightly better chromed finish, FWIW. The ICON were made in Taiwan and appear to be fairly good quality (best part, they're not made in Comm Chynna).

So here's the photos, they tell the story:

Looking down and rearward from above (right rear side of engine), heat shields removed, rear lifting hook is at top of photo, firewall inches away toward top of photo, transmission kick down cable in the background, the manifold nut in question is closest (in the photo) to the hook.

There is very little room to work in this area between the firewall, the lifting hook and the location of the nut. Just not enough space to get a tool on that nut working from above and then remove it, particularly if it hasn't been touched in 25 years (wetness is from Aero Kroil Penetrating oil daily x 4 days before starting):

Rear exhaust manifold nuts wide view.jpg




Close up view of the rearmost lower exhaust manifold nut, rear lifting hook at top of photo:

Exhaust manifold nut close up.jpg




Looking up from below: front of vehicle is to the right in the photo (this side of the engine was cleaned off some before starting). Click on photo and magnify for more detail.

Exhaust manifold lower rear nut approach from below.jpg




Close-up view from below of the long flex head ratcheting wrench on the nut; note the rearmost upper exhaust manifold nut has already been removed (stud with yellow paint still in place): For orientation the Firewall is to the left.

Exhaust manifold lower rear nut close up.jpg




Close-up view looking from above down onto the flex head wrench in place on the lower rearmost nut:

Exhaust manifold nut removal from below viewing wrench from abovve.jpg
 
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Photos continued:

View from above, stud almost out, had to turn the wrench from above to remove the stud out the rest of the way (with the wrench still hanging below as shown in the photo) because the stud/nut were stuck in the wrench (removed wrench and stud/nut up and out from above):

Exhaust manfold nut removal almost out view from above.jpg


And the prize:

Exhaust manifold nut removed ICON Flex head wrench.jpg



Close up of nut and stud (applied Aero Kroil for 4-5 days before pulling this out). The penetrating oil did make it to the stud threads in the head and it came out fairly easy once it was broken free. Most of the damage to the nut below was done before using the ICON Flex head wrench, multiple other sockets and wrenches slipped off while trying to get at it from above:

Exhaust manifold nut and stud showing corrosion.jpg




ICON Flex head extra long wrench set (HF #56694)


ICON Flex Head Ratchet Wrench kit.jpg
 
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FWIW: This wasn't meant to be a complete how-to for removing the exhaust manifolds, the rest of the nuts/studs are relatively easy to get to.

Main take home point: don't waste your time trying to find a tool or combination of sockets to remove this particular rearmost lower exhaust manifold nut from above.

With a long box wrench (ratcheting flex head works well) approaching it from below is the way to go, for the same reason as when removing the two rearmost nuts on the upper intake manifold, you just can't get to them from above. HTH's

Props to @flintknapper, @iptman, and a couple others who's posts/tips helped this along.
 
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bencallaway

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I swear you could do an entire 1FZ head gasket replacement with nothing more than a 12mm and a 14mm.
 

MrMikeyG

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ooh. That Tekton wrench is 6 sided. I didn't know such an animal existed. HF kicks out a special Icon specific coupon every once in a while.
nice write up @Kernal. I dread the day I start having to work on the exhaust parts. I think it's coming up fast too.
 

iptman

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ooh. That Tekton wrench is 6 sided. I didn't know such an animal existed. HF kicks out a special Icon specific coupon every once in a while.
nice write up @Kernal. I dread the day I start having to work on the exhaust parts. I think it's coming up fast too.

I was thinking the same thing. I like the universal splines for tough nuts but it tends to damage the nut as shown above. A 6 sided ratcheting box end flex head wrench with 80+ teeth would be pretty sweet.
 
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Agree, the TEKTON wrench would be nice, but couldn't find it anywhere locally and just wanted to get this thing done. The spline type box end wrench did not however seem to damage the nut, I think most of that was done trying to get it out from above, half of the wrenches and sockets slipped off due to the acute angle, some wouldn't even go on the nut flush/square all the way due to the cramped space around the nut.

That lack of room close to the nut is apparent in the second to last photo in the first post of the thread. Once the exhaust manifold is removed the "wing" or flashing to the right of the nut/stud could be ground off?? But the major issue when working from above is lack of room when trying to swing a wrench or ratchet.

If you magnify the photo above of the box end of the wrench you can see that the splines are rounded. One mid-length socket I had tried earlier had sharp square-shouldered splines however, that also might have damaged the nut. All nuts and studs will be replaced in this situation of course.
 
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flintknapper

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I was thinking the same thing. I like the universal splines for tough nuts but it tends to damage the nut as shown above. A 6 sided ratcheting box end flex head wrench with 80+ teeth would be pretty sweet.

Tekton is six sided, is fluted so it only contacts the flats, is 72 tooth...so doesn't require much motion (about 5°) to ratchet.

But anything you can find that is similar will work as @Kernal has pointed out. Glad he did this write up. Should help others in the future.

CPNuts2.jpg
TEKTON2.jpg
 

flintknapper

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I swear you could do an entire 1FZ head gasket replacement with nothing more than a 12mm and a 14mm.

I can assure you.....you need much more than just a 12mm and 14mm wrench/socket. But....many of the fasteners are indeed that size....if that was your point. Of course you'd never get the valve cover off to begin with...without a 10mm, the cam caps with the same. Head bolts (kind of important) require a 12 point, 12mm socket (not going to get a wrench on those). Various and sundry other tools to remove hoses, etc....

But we can agree that working on the Land Cruiser (80 series) does involve fewer tools than would be necessary on many other vehicles. I can't help but think that the engineers took into consideration 'ease of repair' under less than ideal conditions.
 

bencallaway

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I can assure you.....you need much more than just a 12mm and 14mm wrench/socket. But....many of the fasteners are indeed that size....if that was your point. Of course you'd never get the valve cover off to begin with...without a 10mm, the cam caps with the same. Head bolts (kind of important) require a 12 point, 12mm socket (not going to get a wrench on those). Various and sundry other tools to remove hoses, etc....

But we can agree that working on the Land Cruiser (80 series) does involve fewer tools than would be necessary on many other vehicles. I can't help but think that the engineers took into consideration 'ease of repair' under less than ideal conditions.
Yep I was joking.
 

Proven

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With the changes in the Craftsman brand, I've been looking at ICON, Tekton and DOYLE.

Knowing that Tekton has 6 point ratchet wrenches...my birthday wish list is getting longer!!
 

flintknapper

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With the changes in the Craftsman brand, I've been looking at ICON, Tekton and DOYLE.

Knowing that Tekton has 6 point ratchet wrenches...my birthday wish list is getting longer!!

The Tekton tools I have purchased recently I've been fairly impressed with. They are definitely gaining popularity. They are not inexpensive...but not overly priced either. Good attention to detail and function (at least with the wrenches I have so far).
 
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I am cracking up...
I just bought the 12/14 extra long teckton for the front DR side gas tank strap bolt. I was going to strip that rusted bugger with a 12 point standard rachet wrench. This thing worked perfectly.

I honestly would have no clue what I would have done if I stripped the head or broke the bolt. There is only about an inch from the bolt head to the frame.

Two thumbs up for these wrenches!
 

iptman

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Screw Amazon.... Homedepot.com has the same prices for most quality tools found on Amazon with free shipping and you don't have to pay $119/year for the pleasure.
 
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Too bad about the Craftsman brand, they had a Pro line of tools up to maybe ?10 years ago, wish I had bought more as they were made in the USA and very good quality. The Chyna kerapp they're making now is just horrible; checked out a recent production Craftsman ratchet (made in chyna) at Lowe's; it could be used to pound nails, weighed three times what a good wrench would weight. Just pure junk.
 

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