1st Gen 2.4L Repair Musings: Oil pan & A43D Trans

Hey all.

I just adopted my brother's 1st gen (2003), 2.4L, Taco which decided to stop shifting while he was driving around town. After tossing it up on jacks, I noticed a longstanding oil leak that caked oil over the lower engine and also what appeared to be a transmission leak.

The source of the oil leak's not quite obvious. The heaviest buildup was at the lower front edge of the oil pan, which is also the lowest part of the engine. There's also some buildup on the lower belt assembly, which makes me think either the oil pump or crank seal. Though the oil pan itself isn't the most likely source, the freshest oil was around the lip of the oil pan, so I just RTV sealed (black, not grey) a new pan on there after learning that gasket remover spray and painted oil pans are a bad combination. Using heavy amounts of degreaser, the surrounding area has been cleaned fairly well and should be a little more telling about where the oil's coming from. On that note, hopefully I sealed the pan well enough. Doh.

The A43D transmission's behavior acts like a transmission that has no fluid to push for proper shifting behavior, so that compliments the leak discoloration. I dropped the transmission, degreased the outer casing, and bought a rebuild kit to play around with until I break it and buy a rebuilt A43D from elsewhere. Should anyone come across this post via Google, the transmission was practically fused to the engine even with all the bolts and mounts removed. It took some serious abuse to get the unit to fall off its two guide posts, the upper showing mild rust. I highly recommend greasing such posts if anyone does transmission work.

Anyway, just checking in for my first post.

-Jeff

 

Many months have passed and unfortunately I haven't had solid time to work on this. However, the transmission's fully disassembled, cataloged, and mostly cleaned with a painted casing.

The problem turned out to be a damaged front pump as a result of the fluid leak. The pump seized up, the inner gear crumbled, and fragments of metal began to work into the internal components. Interestingly, the lack of fluid protected much of the inner workings by not moving much around and since the pump died, nothing else was moving. So no other damage appears to have occurred and no fragments made it down to the filter or pan magnet.

I was able to pull a pump out of a junkyard A43D (which had some casing damage) and intend to start reassembling components soon. The real downer came about when I started matching up the ATP rebuild kit's seals for this transmission: Not all fit! (EDIT: it turns out this kit was miscatalogued by the vendor and is intended for the A43DL.) Buying direct from Toyota parts dealers might be the only other option.

After a lot of research about transmission fluid, I decided to avoid the Toyota WS fluid and take a risk with Valvoline Dex/Merc ATF fluid. Coincidentally, the A43D rebuild manual flat out says to use ATF Dexron II for "dry fill" and "drain and refill". Dexron III is typically interchangeable with Dexron II.

Additionally, given the high mileage, I bought a rebuilt torque converter.


-Jeff

 

The last few weeks I've put in an enormous amount of time into disassembling the Toxic Taco's A43D transmission subcomponents, cleaning them, and rebuilding them with new seals, gaskets, clutches & frictions discs, and evaluating what needs to be replaced due to severe fatigue. In some ways the process has been immensely cathartic and I've had lots of Car Talk, AGCO Automotive Hour, Car Craft, Hot Rod Magazine Live, and Rod & Custom Radio podcasts to keep me company. The rebuild has also allowed me to meet some business owners and technicians in the area who have had colorful histories in the local drag racing scene.

For those interested, here are a handful of photos taken from hundreds that more fully document the entire process:




^ This is the Aisen A43D automatic transmission from my Toyota Tacoma. There are many like it, but this one is mine.




^ Here's my kitchen/transmission workshop where the magic happens. I don't cook much, but when I do...it involves an impact wrench and lots of Q-Tips.




^ All small parts are kept in labeled zip-loc bags and sorted by steps to match a repair manual.




^ These are parts to be discarded at some point.




^ Notice the shattered gear in the left half of the front pump. You might also notice the imprint it seared into the right half. After 120k miles, you can also see how caked on the transmission fluid is in the surrounding channels. The gloppiness of the transmission fluid's been consistent throughout the entire unit and has made cleaning immensely difficult. Everything had to be cleaned thoroughly since metal fragments made their way out of this pump and into other areas of the transmission.


]

^ This one-way sprag fit around the sun gear assembly. At some point during the transmission failure, it turned into a two-way sprag. If you look closely, you can see how the inner and outer bands have turned out of alignment and caused most of the knuckles to depress.




^ You can see some charring and bowing here of the Number 1 Brake flange and lower friction plates/discs. Both the top flange and snap ring had to be replaced.




^ This is how the case came out after a good cleaning and paintjob. Most of this will get marred up during reinstallation, but I approached the rebuild with a certain amount of pride and want everything looking top notch before reinsallation.




^ To get the truck running temporarily, I masked off parts of the painted bellhousing and reinstalled it so the starter could be situated. After months of neglecting this rebuild, it was nice hearing everything fire up.




^ Though the brownish transmission fluid looks glossy, it's fairly gloppy and clogging up the valvebody.




^ For comparison to the earlier valvebody image, here's a cleaned component.

There were a couple of annoying speedbumps along the way. One was that a transmission rebuild kit was incorrectly marketed on a popular parts website for the '00-04 Tacomas, which used a slightly different version of the A43D from what was in the '95-99 models. Another is that various parts ordered to accommodate the incorrect rebuild kit showed up mangled or incorrect. In the latter case, take a look at the two schematics:

http://www.utoyot8.com/images/440098861/417845084.png
http://www.utoyot8.com/images/440098861/461438033.png

Part 35621A, an outer piston o-ring, shares the same stock number as 35601B, an inner piston o-ring, on almost every Toyota parts site I can find (with the inner ring as the default item stocked). They're sized differently by several inches. In the end, I went with the other center support outer piston o-ring, 35621S, and actually found some instances where Celica users were being sold that as the replacement anyway. If it's not identical, it's extremely close and is currently my best bet.

This is about a week away from reinstallation in the vehicle depending on the resolution of disputes and items arriving soon. Hoping for the best.


-Jeff

 

After a month of crap from clueless vendors, I was finally able to get the right parts and have completed the rebuild.

So close I can smell the charred transmission fluid!



^ Fully cleaned, gasketed, and torqued valve body.




^ Transmission back together with all internal subassemblies



^ The completed unit joining me for a lazy weekend drive across town.


^ Recharge time for the Toxic Taco's battery.


^ A final glamour shot of the completed A43D before it gets rolled and lifted into place tomorrow morning.

If all goes well with the install, I hope to upload a break-in (or breakdown) video in the next 48 hours.


-Jeff

 

Dude. dont take this the wrong way.....I love you. haha thats a task and a half and there are only a few people out there that could accomplish this feat, thanks for sharing that. Oh and I love your kitchen... I cant imagine what your backyard looks like.

 

Thanks, dude. Your encouragement boosted morale during today's work.

Most of the crazy stuff's indoors at the moment and I'm thankful my long distance girlfriend hasn't seen it all (I'm still working on trying to get a small warehouse somewhere before she does).

I'd like to say everything worked out today, but the rebuild has some problems. Specifically, nothing happens in R, though the car accelerates immediately when shifted into D. Since that's happening without the gas pedal being depressed, I'm wondering if 1st gear is out and it's starting at a higher gear. Very frustrating as I checked everything multiple times during and after assembly, but it wouldn't be "DIY" without a few hurdles along the way.

At the moment I'm setting July 4th as the goal to hash things out by, but here are a few action shots from today:



^ Because of the (highly-annoying) rear mount crossmember, we had to angle the transmission up and over it. Once level, there wouldn't be enough clearance for the ATF-filled torque converter, so the whole thing had to be awkwardly manhandled for about half an hour.




^ My friend Anthony helped out with the installation. He's just as invested in this truck as I am since it could mean frequent trips to the local Pull-A-Part or LKQ yard.




^ After many bolts, scrapes, and the mild onslaught of Tropical Storm Debby: installed and torqued.


Despite today's lack of success, it was time well spent with a friend and fortunately we were able to run through the entire install process with all the necessary tools, maintained proper torque ratings, and returned every bolt and nut to their original places. That in itself is a good feeling.


-Jeff

 

Hope you get it all sorted out soon. They are good trucks, it will be worth it in the end.

You are far more patient than I am for sure.

 

To follow where I left off:

After a few more test runs, there was a loud groan from the transmission followed by a vibration which traveled through the truck. This might have been the planetary sun gear grinding against the center support's bearing (if it was, it was somewhat avoidable because there was already minor evidence of wear, but it looked/felt insignificant and I thought it might have been a momentary heat flash...so putting them back in was a judgement call based on parts expense and rarity). I dropped the pan and there was a small cloud of glitter around and on the magnet, which also suggests fragments might have traveled back through the system. Doh. So I took the valve body out and reattached the pan so I could get started evaluating the "easier" part.

The date I suggested passed without any further progress, mostly due to work stress, relationship drama, and my father ending up in the hospital/nursing home. Spare time has thinned significantly.

Nevertheless, the valve body's been fully cleaned and re-rebuilt. The gaskets had only seen brief use, so I put those between shop towels to absorb excess fluid and they went back in nicely. There's one enclosed checkball that sticks despite seemingly-effective cleaning during the last rebuild, so that will definitely be replaced. Everything else in the valve body seems kosher.

However, based on the noise and fragments at the pan magnet, some new subassemblies will be unavoidable. Though infrequent on eBay, A43D subassemblies usually price at $80+ (USD). Just a few days ago I was lucky to find a 2001 Tacoma at a local junkyard. Look how picked clean it was after only a month:



Despite nearly everything of value being ripped out of the abandoned truck, the transmission was left intact. Couldn't believe it. Two days later--today--I took some leave at work, crawled under the cab, laid down on a blue tarp, and wrenched away as several rainstorms curtained the open space around it. Price of the entire transmission with torque convertor? $70.

Given all the stress lately, I hope I can just pull the pan off, see a clean magnet, change the filter, and then throw this into my Tacoma and call it a day. If not, it probably has some good parts to pull from. The fluid had some hints of cherry syrup and didn't smell like popcorn, so that's certainly encouraging.

No matter how this plays out, I learned a hell of a lot and am thinking of picking up a Ford C4 and GM 6L80e for other applications. One friend strongly suggested picking up the differential from the above truck and making it mig spec. So now I really need to get this Tacoma running!


-Jeff

 

More transmission porn:



^ The recent junkyard pull undergoes inspection.




^ A new PowerTorque filter gets torqued. These are the easiest to find over here and come with the pan gasket for about $10. As you can see from the photo, the valve body is incredibly clean.




^ Here's what the pan magnets looked like at first glance. Though my primary transmission didn't have ANY noticeable buildup after 120k miles and had also never been serviced, this one did and had clearly been maintained (based on the cork pan gasket). So this was kind of a surprise, but it's good to see that the magnetic residue looked and spread like butter as opposed to being a collection of fragments. The bubbles are exactly that--bubbles--and not particulate.


-Jeff

 

http://www.youtube.com/watch?v=0K5SCg1pU3s

For some reason it always rains when it's time to get work done.


-Jeff

 

I wish I had seen this a while back. Oh well, better late than never. If you have any other issues after the install, let me know. I am an ASE certified Master tech and have been rebuilding and diagnosing automatic transmissions for close to 20 years.

 

I was able to sandwich in some work today between events:

Out with the old and pretty...


In with the "new" and ugly...


I'm starting to get so good at this that even installing the new one was a solitary activity.

Unfortunately, I'm so bad at this that I broke a cardinal rule and didn't secure the transmission (as seen in the second photo) or its jack. It needed to be lowered a little to fit the ATF-filled torque converter and the added weight teetered the trans' front forward, rolled the unbraked scissor-jack backwards, and down everything went. What makes this install so hard is that the rear needs to be raised up and over a horizontal, undetachable, crossmember before the front can be lifted (hence my attempt to fit the torque convertor after lifting). Not fun.

In the process, ATF went everywhere: down my arms, all over the trans, on the impact gun, etc. It made everything so slippery that it took a while and a lot of adrenaline to get things back into position.

Anyway...

The bellhousing's bolted into place, the transaxle's hooked up, and the lines are fastened. Once everything's torqued and prepped, it'll be time to try again. Following that, I'm eager to take the rebuilt one apart and find out what went wrong.


-Jeff

 

Hey, thanks! That and your military service make for an impressive line-up.

I've met a few self-employed transmission guys while looking around for parts, but the conversations have been brief. Guys with shops and businesses generally have their attention elsewhere and that's been tough for an amateur like me.

Despite bumbling around, I've really enjoyed learning more about automatic transmissions and have stocked up on a number of GM, Ford, and Mopar guides along with videos. I also bought quite a few tools and hope to get a good teardown table and workbench at some point.

What got you into transmission work and can you offer some advice to people like me who, despite having a full-time job in another field, want to get more involved in the scene? I started reading the ASE sample questions, but that's not much good without the required minimum of 2 years experience to pull it all together. Building strengthened transmissions for race applications seems like a good self-paced direction, but it would be ideal to find someone who can be a mentor and see where it goes from there.


-Jeff

 

What got me into transmissions? Well a service manager and a mentor did. Back when I was taking ASEP training for GM, I was in the drivability course section and met a guy named Sam Lynch. He had been building transmissions for almost 30 years. Well our service manager was down to two choices, hire a second trans tech, or slot me for the position and wait for me to graduate. Well after working with Sam and having him show me all the tried and true tricks of the trade, I found that I enjoyed the challenge. The rest is history.

 

Thanks for the bio, BamaToy1997. Much respect for your line of work and kudos on the quality shop and reputation. I'll have to swing by there next time I pass through and will do my best not to wear any LSU colors.

I spent last night "mostly torquing" the finals screws into the junkyard transmission. Me and a friend did a stellar job the first time around with my rebuilt original, but this time I wanted to be sure that the latest replacement would even work before investing too much time into finishing up. So torquing will need to be revisited.

At lunch today, I went home, replaced the power steering pressure sensor connector, raised the rear of the truck, and gave it a test run. A few observations:

• The truck has a bit a of vibration coming from the trans, but nothing unsettling enough to get paranoid.
• Shifting into reverse immediately jumped the wheels into a fast rotation even without gas applied. I do know there's a bit of push in 1st gear (forward/reverse), but wasn't expecting that much without any effort on my part.
• Shifting into drive was also much higher than I expected: without applying pressure to the gas pedal, the odometer showed 30-40mph.
• Braking the vehicle never entirely stopped the wheels--they sputtered ever so little from a complete stop.

That last one I'm going to blame on ageing drum brakes that haven't even been used in a year. I took the beast for a road test with low expectations only to find that it drove perfectly. Perhaps all of the above is natural for this transmission while it's off it's haunches and has no resistance...?

Here's a video of my return drive with the first song I could find on the radio (and clearly holding the iPhone the wrong way):

http://www.youtube.com/watch?v=KYf7YXnnHss



-Jeff

 

Just got back from a 750mi round trip without any obvious problems, though the 2.4L engine feels really sluggish once it hits 65mph.

This truck's already helped me through Hurricane Isaac (high water, downed tree limbs and power lines in the road, etc.) and was also timely since my primary car's waterpump crapped itself immediately before the storm hit.

To celebrate the repair, I have some All-Pro bumpers on order and a boxed winch waiting patiently.


-Jeff

 

I'm convinced now that the sluggishness is due to the increased tire diameter (30in). Too much abuse will likely wear the transmission out without a tune and/or gear change.

The lift and tires really make the truck much more enjoyable. Despite this 2WD powertrain already being severely underpowered for any "upgrades", it's really tempting to throw on some Procomp 7069 (15x8) rims and a set of 33x12.5R15 BFG KR2s. Completely superficial, but I could easily see that as motivation towards strengthening the chassis, adding a stronger suspension system, and exploring different axles and engine/trans options as a sort of expensive academic exercise.


-Jeff

 

No offense but I think you would have been better off saving yourself the hassle and just swapped it to the manual trans. Yes there is a few more things you need to add on but it looks like you are capable to do that.

Great job though for the most part!

 

Shortly after getting things running again, I ran the truck through some general maintenance procedures since nearly everything is stock (120k miles later).

A rough fuel filter replacement walkthrough:
(Click to enlarge images)



^ Despite information stating otherwise in my service manual, I found the fuel pump relay stuffed below the in-cabin fuse box (to the lower left of the dash by the driver's door). I read that the dash had to come apart and that the relay was elsewhere, but learn from my mistake--you should be able to get to this without any serious tooling.

• Remove the gas tank cap to relieve pressure on the fuel system, pull the relay, then start the truck until it dies. That will clear out some of the remaining pressure and fuel.

^ Fuel filter location in the 2RZ-FE 2.4L engine. If you look at the center of the photo, you can just see my thumbnail. The fuel filter's threaded on both sides and is bolted in below the intake manifold which is just below the throttlebody. I had to work above and below the engine to get it out.

• Be aware that plenty of gas will still escape while removing the fuel filter, so strategically place some disposable rags under both ends of the filter to protect the surrounding parts of your engine and also consider cleaning any dirt off of the banjo bolts that feed into both sides of the filter. Wear some latex or nitrile gloves during the removal.

^ Here's the stock fuel filter after removal. I found it easiest to remove the two fuel line ends and then the entire bracket (as opposed to loosening the bracket nuts and then loosening the clamp bolt). Note that there are 2 sealing washers that fit on either side of each banjo bolt and they're easy to lose during removal of each banjo bolt. I don't exactly recall the wrench and socket sizes needed for all this, but for the moment I'll say that the fuel line connector nuts use a 17mm boxwrench, the bracket nuts will need a 10mm socket with extension, and the clamp can be loosened/tightened with a 7mm socket.



^ Here was the first econo fuel filter I came across at the local parts shops. It has a slightly different shape to keep from rotating out of place in the clamp, but is essentially identical to the stock filter. This will make more sense when you slip the clamp over the new filter and line up the banjo bolt retainers on either end to point the correct way for re-installation. Your fuel filter should come with 4 new sealing washers. It's a good idea to use the new ones, though I opted for my existing aluminum washers as opposed to the new copper ones as I've found copper to be too soft in some applications.

• All these bolts--and especially the flange nuts on either end of the fuel-line--should be torqued, but there's really no way in hell to fit a torque wrench in such immensely cramped location, regardless of extensions. So I used some hillbilly luck to firmly tighten the clamp around the fuel filter while still allow the bracket bolt holes to line up with those on the engine block. The fuel line ends don't need to be super tight as you could end up twisting the lines or messing up the flanged ends.

Once done, replace the fuel tank cap and relay. Turn on the engine, try it out, and be watchful for any leaking fuel around the filter or on the ground below.


-Jeff

 

No offense taken and I completely agree, especially since I've got a buddy who designed a rock solid engine management system that isn't yet prepared for automatic transmissions (that's for a future post). I'm pretty stubborn about broken things and I really wanted to see the original automatic work again solely out of principal. The junkyard clone was strictly out of immediate availability and offered the potential to get the truck running again quickly.

One interesting side note about the A43D is that since it's pretty dumb, you can manualize it with some trickery even if it's still fundamentally an automatic. Might be a fun (and irreverent) project to put paddle shifters on the steering column.


-Jeff