2001 AW4: drilling/tapping cast temp sensor location?

Hey all,

I've searched up and down but haven't found anything on this particular topic...

Early AW4's had a drilled/tapped temp sensor port just forward of the hot fluid line that was commonly fitted with a sensor in Toyota applications. Although no sensor was fitted on XJs, owners simply need to pull the bolt out and slap in a sensor of the appropriate thread and they're ready to rock.

Given that mine's a 2001 model, said hole is not drilled or tapped, although it is still part of the housing casting (seen here).

I have the transmission and T-case pulled for some cleanup and light work (new seals, etc), and was debating pulling the pump in order to replace whatever O-rings and seals are reasonably easily accessible (it has 240k on it, but was shifting rock-solid prior to being parked).

If I pull the pump (and possibly the bellhousing), and take EXTREME care to protect the transmission internals from bits of aluminum, would it be feasible for me to drill and tap this location? Or did internal assemblies/structures change over the years that led to Aisin-Warner deeming said port unusable? It looks like I should be able to get to the back side of it simply removing the pump, but would love to know more before doing anything stupid.

Thanks in advance.

I thought about that on my 2k, but with everything I've done to keep the temps down and a inspection last year along w/ a Trango shift kit I said "Why". The pan was "spotless" with no debris what-so-ever.

Fascinating idea, but I suspect that for most folks it'd be easier to tee a fitting into the soft part of cooler input line and put the sensor there.

Still, very interesting find, and certainly something to think about during a rebuild...

RCP Phx said:

I thought about that on my 2k, but with everything I've done to keep the temps down and a inspection last year along w/ a Trango shift kit I said "Why". The pan was "spotless" with no debris what-so-ever.

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I hear ya... I haven't done any internal mods (since most can be done with it in the vehicle), and really just want to do this while the transmission is out and accessible. If I'm not mistaken, the top surface was still machined, it just wasn't drilled/tapped.

In the same vein, I'm guessing it'd be unwise to install a temp sensor in the pressure test port toward the rear of the housing? From what I've read, it's not an ideal measurement point. I just really don't want a sensor in the pan.

I've been here about 15 years and this is the first I've heard of this. I have a renix aw-4 in the trailer. Tempted to go look.....

Ghost said:

I've been here about 15 years and this is the first I've heard of this. I have a renix aw-4 in the trailer. Tempted to go look.....

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Actually, that'd be a huge help if you wouldn't mind snapping a couple pics as well. On the earlier AW4's, the factory-installed plug (between the hot line and the bellhousing) is a T55 head, M14x1.50 thread. Think you could remove the plug and snap a photo of the hole? I'd like to see if they reamed it before the threads, or if it's just a straight drill/tap.

M14x1.50 calls for a 12.7mm pilot hole, which mercifully is exactly 1/2", making this a whole lot easier.

I don't think this would be reasonable to try to do in the vehicle purely because of the extremely high likelihood of introducing aluminum shards into the transmission. At this point I'm pretty much convinced I'm going to do it (so much so that I already ordered the gauge and corresponding M14x1.50 sensor), but would love any additional info I can get before proceeding.

Well I went out there before you posted. The port sits in the valley before the high pressure line.

https://imgur.com/a/suLt8Ej

Ghost said:

Well I went out there before you posted. The port sits in the valley before the high pressure line.

https://imgur.com/a/suLt8Ej

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Hot damn, beautiful - thanks sir! If the casting is more or less the same, that'll make debris containment a borderline non-issue.

If you get a chance to remove the T55 plug and snap a photo of that side, I'd be eternally grateful. Since the parts were ordered from Summit (...along with $400 in other crap), I should have the sensor and other parts within the next 24 hours.

I'll see what I can do tomorrow. Unfortunately my T55 is MIA. I have 2 T50's and even a T60 but no T55 to be found atm.

Ghost said:

I'll see what I can do tomorrow. Unfortunately my T55 is MIA. I have 2 T50's and even a T60 but no T55 to be found atm.

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I know the feeling, man... I do a ton of work on numerous vehicles (one of the reasons this god-forsaken project has dragged on so long) and can't sympathize with all the damn 10mm memes. Never in my life have I lost a 10mm, but I've had to buy several sets of Torx bits over the last decade.

Rob Mayercik said:

Fascinating idea, but I suspect that for most folks it'd be easier to tee a fitting into the soft part of cooler input line and put the sensor there.

Still, very interesting find, and certainly something to think about during a rebuild...

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When in Rome, right?

My XJ has been many years of somewhat piecemeal, "temporary" solutions that became permanent, and I'm really being a bit OCD with this resuscitation effort (TL;DR: broke a piston skirt at 240k, started a stroker build, got sick, got sick again, and now I'm back at it). All transmission and power steering lines have been converted to AN fittings and lines, so I'm trying to avoid any further unnecessary unions in the system. Plus, given that this was the long-standing manufacturer-preferred temperature probe point, I figure that's worth something.

I'm just glad I finally found some 11" wide coolers with -6AN fittings out-of-the-box (Hayden Rapid-Cool 687 for steering, 689 for transmission), so this should come together nicely. This evening I'll be mocking up the radiator/condenser/grill to measure and design the mount(s), and hopefully have DXF's ready to rock for my plasma guy by the end of the week. If it goes well, who knows... I may see about putting together a full kit after this whole experience.

To give you an idea of what I mean:

I bought a T55 and tried this am. Biatch is froze up in there..... I have it soaking and will try again later. The plug also started to deform on me. Love to see a build thread if you have one. I also wonder when they stopped drilling and taping these holes.

Ghost said:

I bought a T55 and tried this am. Biatch is froze up in there..... I have it soaking and will try again later. The plug also started to deform on me. Love to see a build thread if you have one. I also wonder when they stopped drilling and taping these holes.

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Awesome, dude - thanks a ton for doing that. It'll help a ton with a write-up on this process if it works out (and I don't end up ruining my transmission). No clue when they stopped drilling/tapping them, though.

Also, no build thread as of yet. I've taken enough photos though that I might be able to piece something together.

anthrax323 said:

When in Rome, right?

My XJ has been many years of somewhat piecemeal, "temporary" solutions that became permanent, and I'm really being a bit OCD with this resuscitation effort (TL;DR: broke a piston skirt at 240k, started a stroker build, got sick, got sick again, and now I'm back at it). All transmission and power steering lines have been converted to AN fittings and lines, so I'm trying to avoid any further unnecessary unions in the system. Plus, given that this was the long-standing manufacturer-preferred temperature probe point, I figure that's worth something.

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Yeah, I can understand that. I'll also concede that I didn't catch in the original post that older AW4s were factory-set for that and just have a plug to remove. My bad for not reading more carefully.

As to those pics? Gorgeous. LOVE the color you picked for the block.

Rob Mayercik said:

Yeah, I can understand that. I'll also concede that I didn't catch in the original post that older AW4s were factory-set for that and just have a plug to remove. My bad for not reading more carefully.

As to those pics? Gorgeous. LOVE the color you picked for the block.

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Thanks, man - figured AMC blue would be a fitting tribute to its roots (and make it easier to spot the inevitable leaks that will form).

https://www.amazon.com/Seymour-EN-6...ocphy=9010814&hvtargid=pla-308556922771&psc=1


Last three builds with this. Great for a rattle can paint.

bigdaddyjlove said:

https://www.amazon.com/Seymour-EN-6...ocphy=9010814&hvtargid=pla-308556922771&psc=1


Last three builds with this. Great for a rattle can paint.

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Bingo! Exactly what I used.

anthrax323 said:

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You've never really done a thread on your build specs? What oil filter is that? That header/downpipe looks really restrictive.

RCP Phx said:

You've never really done a thread on your build specs? What oil filter is that? That header/downpipe looks really restrictive.

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Yeah, this has been somewhat of a silent build (not as good about documenting stuff as I used to be).

The header/downpipe is indeed restrictive - I opted to stick with my factory cast iron manifolds and a Federal emissions collector/Y-pipe because I got so goddamn sick of cracking one-piece headers. Running a stock 0331 head since it's such a mild build (and it gives me something to upgrade later if desired). Oil filter is an M1-301.

Other specs:

• Custom grind of what is essentially a Comp 68-201-4, but with 113° LSA for EFI.
• AMC 232 crank.
• Bored .030" over.
• 10.3:1 static CR because I couldn't find a goddamn shop to dish my pistons. Next time I'm just ordering parts straight from Russ.
• BBK 1724 throttle body since I had store credit somewhere I had to burn.
• ...lots of brand new parts.

It's ultimately a very mild build (final displacement around 4.2L) but should be a hell of a rejuvenation over its former 240,000 mile self.