Sonnax Zip Kit A340 Late Installation

Installed the Sonnax Zip Kit in my A340e Transmission a couple of weeks ago. Hope this experience helps others in keeping their Gen 1's in good running condition.

Symptoms:
Occurrence of P0770 last year (no codes since).
Downshift hesitation under acceleration from 3rd to 2nd when hot.
One incident of 1st to 3rd shifting on side streets after exiting the highway (no codes).

Results:
After installation of the Zip Kit, I am getting short crisp shifts in all gears. Downshifts under acceleration happen without hesitation (cold and hot). Usually, by the end of my work commute I could always reproduce the 3rd to 2nd hesitation issue. After several tests I have no issues. My trans temp is now within FSM spec on and off of the highway (<176). I am looking forward to testing it for longer hops and also carrying some weight.

More Reading…
If you want to learn more about resources for transmissions I would suggest this post by Gearcruncher.

Disclaimer:
I don't know anything about transmissions . Proceed at your own risk. If after reading this you have doubts you might consider going to a shop or sending your valve body in to IPT. Let's get started.

Truck:
2000 Prerunner Ext Cab 3.4l Automatic (A340e 20 spline input), electronic locking diff, 31x10.5 BFGoodrich AT K0s, Hayden 678 Trans Cooler. 138K miles

The short version of what I did...

1. Remove the transmission dipstick and upper tube
2. Drain the pan and remove it
3. Unhook the solenoid wiring and possibly the throttle connector
4. Remove the filter
5. Check your parts for a match
6. Remove bolts (note locations) and lower the valve body
7. remove the bolts from the upper valve body(note locations)
8. Flip the valve body over (upper facing down)
9. Lift the lower valve body off of the assembly
10. Remove filters, spring and plunger (note locations)
11. Remove lower gasket, separator plate and upper gasket
12. Remove check balls from upper valve body (note locations!)
13. Make sure everything is clean
14. Perform the Zip Kit steps
15. Place the gaskets and plate over the upper valve body
16. Replace the filters/strainers on the plate. use lube to hold the spring and plunger in the lower valve body
17. Lower the lower valve body on to the assembly (check alignment)
18. Flip the valve body over (lower facing down)
19. Replace the bolts in the upper vb
20. Replace any hardware that fell out of the trans during removal (use lube to hold in place)
21. Raise the vb in place with the manual valve aligned to the gear selector linkage in the trans.
22. Replace the bolts in the lower vb.
23. Connect the throttle linkage if applicable
24. Connect the wiring to the solenoids
25. Replace the pan
26. Add a couple of quarts of fluid
27. Start the vehicle and let it heat up
28. Continue adding fluid as necessary

Pictures for Reference...

A view of the valve body after removing the pan…



After removing the lower valve body, some strainers/filters are visible...



The upper valve body with check balls (According to Sonnax the configuration may vary)



In the center of this photo is a shim which holds an end plug or sleeve…



Getting ready to finish the Valve Body assembly



Parts used:

• Sonnax A340 Late Zip Kit
• ATP Filter and Pan Gasket
• Toyota Upper and Lower Valve Body Gaskets
• Trans lube assembly grease (i went with firm)
• Valvoline Synthetic Dex/Merc

Tools used:

• A torque wrench capable of 57 Inch Pounds (not foot pounds!
• Something big enough (larger than the trans pan) to catch fluid during vb removal and while the trans is open.
• Tweezers to remove the shims that hold end plugs in place. A magnet might work too.
• I used plastic bags to keep hardware and parts organized.
• I used a lithium ion impact driver to remove bolts (there are a lot of them), and then to snug the bolts back in place (then used a torque wrench to tighten to spec)
• A funnel with a small opening that fits in the trans dipstick tube.
• Basic sockets and extensions. You could do 90% of this job with a 1/4 drive ratchet and a 8mm & 10mm socket and extension.

Now the long version…

Removal and Disassembly:

1. Remove the trans dipstick.
2. Remove the top section of the dipstick tube. There is a 12mm bolt holding the top to the engine head. Remove the bolt and pull the dipstick tube up. Twisting while pulling helps.
3. Drain the trans (about 3qts). Put the drain plug back.
4. Remove the pan bolts (19 for me), keep holding the pan up (it probably still has fluid in it).
5. Tilt one corner of the pan over a container to drain additional fluid.
6. Take a look inside the pan, mine had some black goo around the magnets (fine metal particles). If you have chunks you might have more going on.
7. Take a picture of the valve body (vb)... note the connections for electronics, AND observe the alignment of the shift linkage. Also, this would be a good time to compare the vb shape and casting number with the Zip Kit documentation to make sure the kit covers the vb (Type 4 for mine). Look at your gaskets to to make sure they have the rough outline of your vb.
8. Remove the trans filter (3 bolts for mine, placed in a bag with the filter). Be ready for more fluid.
9. Disconnect the electronics (three solenoid connectors on mine)
10. If you have a throttle cable connection like mine, roll the cam, this will expose the cable end which you slide out (just like the throttle body on top of the engine). I left the linkage assembly attached to the vb throughout the process without a problem.
11. With a 10mm socket, I removed all of the bolts holding the vb to the trans case. The following bolts can stay...
    1. The brass bolt on the detent spring for the shift linkage.
    2. The 8mm bolt between the S1 and S2 solenoids
    3. The 8mm bolt at the square end of the vb
    4. The bolt for the lockup solenoid can probably stay (but I took it out at the time)
12. Hold the vb up as you remove the last couple of bolts. Be ready for more fluid. Also, as you lower the vb, a few parts will probably drop (watch the IPT video on 340 vb installation). On mine two larger springs dropped along with a checkball and smaller spring. Get the vb to a safe clean place and bag the parts that dropped. Bag the bolts as well with the bracket for the solenoid wires.
13. Note: The Valve Body is made of the upper vb, an upper gasket, a metal separator plate, a lower gasket and then the lower vb. The bolts holding the vb together are on the upper vb side (as shown in the zip kit doc).
14. As I removed the bolts in the upper vb I had a cloth nearby where I placed the bolts in the same pattern as they were removed.
15. Note: Here is the trick, the check balls are in the upper vb which is currently facing up. If I lifted the upper vb up they would spill out! Per the Zip Kit doc I need to document my own checkball locations because they vary across different versions of the 340 and vb castings.
16. I held the upper and lower vb sections together with my hands (like a sandwich), and then I flipped it over so the upper vb section is facing down.
17. I then gently lifted the lower vb away (leaving the gaskets and separator plate). You may need to hold the upper vb down. If the gaskets are sticking you do not want things to come apart with a jerk.
18. When I removed the lower vb 3 shims that hold some of the end plugs in dropped out. It seems scary at first, however the Zip Kit is all about removing and replacing end plugs, you will see how the shims work soon enough.
19. If those shims fall out, that means the end plugs in the vb might not be secure. The contents of the vb behind these plugs may come out as well. I looked around and found the end plugs without shims on the lower vb. On mine I just removed the contents behind two of the end plugs (the third end plug held tight on its own), I bagged the shims and contents and set them aside. Set aside the lower vb in a safe clean place.
20. Back to that upper vb... there are a few filters along with a spring and plunger that were left when I lifted the lower vb away. The location of these items is shown in on of the Zip kit doc diagrams. I also snapped some pics of them. Remove and bag these items.
21. Carefully remove the gaskets and separator plate. Set the separator plate in a safe clean place.
22. Do those gaskets look like the ones you bought?
23. Use the Zip Kit diagram that shows the check ball location and compare it to the upper vb. I had one check ball that was different on mine and noted it in red ink right on the doc.
24. Take pictures of the upper and lower vb's to note the location of checkballs and shims.
25. I then removed the checkballs and cleaned the upper and lower vb's with solvent.
26. Follow steps 1 through 11 of the Zip Kit doc to replace end plugs and valve hardware

Notes on component replacement:

1. When removing the end plugs, first remove the shim for that plug. You may have to push on the end plug to relieve pressure on the shim.
2. I used trans assembly lube around the new end plugs with o rings to help with getting the end plugs in. This helps to prevent damage to the o rings as well.
3. For the TTC lockup sleeve and valve, I did not get the spring aligned the first time! This resulted in P0770 codes. Use some assembly lube to attach the spring to the valve to hold everything in place during assembly.
4. Assembly lube can also help with making sure shims stay in place if they are loose.
5. My valve body looked pretty clean to me. I did not find any scoring, grooves, shiny spots on end plugs or any debris. I suspect the trans and valve body may have been rebuilt by the PO. That said, the existing end plugs were loose enough that it made you wonder how much pressure was being lost, especially after the trans would warm up.

VB Reassembly:

Note: After you are finished with steps 1 through 11 of the Zip Kit Doc, it is time to put everything back together.
Moving forward I am double checking everything to make sure it is clean before it goes back together.​

1. Carefully align the upper vb gasket on the upper vb.
2. Place the separator plate over the upper vb gasket (clean with zero residue).
3. Align the lower vb gasket with the separator plate.
4. Place the little filters back on the separator plate (i used assembly lube to hold them in place). Use the photos and Zip kit docs for reference.
5. Over at the lower vb, place the spring and plunger in place with lube.
6. Also, if you had shims fall out, get the hardware and shims back in place. Use lube to hold the shims in place.
7. Carefully place the lower vb on top of the upper vb with separator plate and gaskets. Make sure the filters, plungers, separator plate and gaskets are all aligned. I had to do this a few times to get things right.
8. Thread the upper vb bolts hand tight into the vb assembly. Use a torque wrench to tighten the bolts to spec (found in the Zip Kit docs).
9. Marvel at the rebuilt vb assembly.

VB Installation:

1. Get the vb, vb to case bolts and everything that fell down when you removed the vb. Get the bolt diagram from the zip kit docs.
2. Everything that fell down now needs to magically stay up when you raise the vb in place. The assembly lube makes this fairly easy. Set those up now.
3. Identify a couple of bolt holes on the vb and get the right bolts using the diagram. Quickly... before weight drops those parts in the previous step.
4. Raise the vb, aligning the shift linkage to the end of the manual valve from the vb... now get those first bolts threaded.
5. If you have a throttle cable linkage, make sure it is hanging down and not bound between the vb and transmission case.
6. Thread the remaining bolts in the right locations per the diagram. Don't forget the electronics bracket and solenoids if you removed those too.
7. Torque all of the bolts down to spec.
8. If you have a throttle linkage, roll it around and insert the cable end (same as it works on a throttle body)
9. Install the filter. Mine was 3 bolts.
10. Take pictures.
11. Get the pan gasket aligned on the pan (use lube or starter bolts to hold it in place)
12. Lift the trans pan in place and connect the dipstick tube.
13. Get the trans pan bolts threaded and torqued to spec.
14. Make sure the drain plug is in and tight.
15. Use a clean funnel to pour a couple of quarts of trans fluid into the dipstick tube.
16. Start the engine. Let it warm up.
17. As the vehicle warms up monitor the fluid level and add as needed. Mine took 4 3/4 quarts (with an aux trans cooler).

More Background:

• Last year (2015) I received a P770 code while decelerating off of the highway during a long trip. The outside temp was over 90 degrees and this section of highway had large hills. Even though my Tacoma is a 2000, this started to sound like the Toyota tech bulletin for the 2002s that needed vb modifications.
• Researched A340 info and posts (Thanks to Gearcruncher and others on TacomaWorld)
• Added a Hayden 678 trans cooler and replaced the trans fluid. Started monitoring my fluid temps.
• During the course of the year, experienced some hesitation while downshifting from 3rd to 2nd on acceleration (only when hot). All other shifts were crisp with no problems. No trouble codes.
• This year (2016) at the end of a shorter trip the trans went in to distress mode after turning off the highway on to side streets.The trans was shifting from 1st to 3rd. After it cooled off it ran OK.
• Thinking that I might have a solenoid problem, I ordered a set of solenoids
• (ATP RE5 includes S1,S2,Lockup). These turned out to NOT be the correct set of solenoids for my A340E. Before closing the trans up I noted the vb casting (8539) and checked the resistances on the existing solenoids (OK). I also took photos noting the filter config.
• Assuming that my solenoids are OK, and thinking I might have a hydraulic circuit problem in the vb (similar to the tech bulletin), I ordered the Sonnax A340-Late-Zip Kit. I contacted Sonnax, and confirmed the kit does not come with gaskets. I ordered the upper and lower vb gaskets from toyotaonlineparts.com. This is an east coast toyota dealer who has the cheapest genuine toyota parts prices that I can find. I emailed them with my VIN as well as the model part and serial number information off of my transmission. They were able to confirm the right part numbers for my vb gaskets.
• I watched the A340 vb installation video from John at IPT a number of times while waiting for parts.

 

Awesome Jim! Thanks for the write-up!

 

For some reason I just came upon this post now .
Can we get an update on how everything in the transmission department is functioning after 6 months ?
Excellent write up !

 

sub'ed

 

Very nice write up. Interested to hear how everything is holding up.

 

ya buddy, maybe these things are like an old kenmore washing machine. You start to hear it thrashing around, leave it a while, smell something burning, then finally consent to taking it apart. While you're in there find a part or two that ain't right, order up some from the catalogue and throw 'em in. good as new. Or at least I'd like to think so.

 

Hi all, I have put about 14K miles on the truck since I installed the Zip Kit. The performance of the transmission has been solid ever since. I never received any further trouble codes. The truck downshifts in all gears as it should. The shift points are right on. I have mostly forgotten that I ever had an issue. My wife and I took the truck on a road trip a couple of months ago. It was about a 2600 miles with no problems.

When I was having problems with the trans, I would get transmission fluid temps upwards of 200-230 degrees getting off the highway on to side streets. My highway temp is now around 130 degrees and then gets up to 140 degrees when I get off of the highway (with an 80 degree outside temp). I think those are good temps and hope that helps to prolong the life of the transmission. I am using Enginelink with the custom PIDs found to measure the Trans temp.

Might be worth noting... I don't think the Zip Kit is the silver bullet for all trans problems, but in my case it worked out great.

 

How much did that run cost wise? What was the experience like - an "oh shit did I forget anything, is this going to work" or a simple methodical process?

 

Hey Danny Boy,

I put some rough cost numbers down next to the items that i bought. You may already have some of these items on hand. The rubbermaid container is worth the price compared to cleaning up the puddles of trans fluid. I had doubts as to whether the zip kit would fix my problem. However, i was pretty sure I had a problem with a torque converter lockup.... and this was cheaper than going to a trans shop.... and easier than replacing the torque converter as a first step.

In terms of difficulty, I think the challenge is just keeping track of where things go...

• The valve body has a lot of screws of different lengths. Check the Zip kit install doc.
• When you remove the valve body, a few springs are going to fall out of the trans, you need to keep track of where they go.
• When you open the valve body, you have to keep track of the size and location of the check balls.

Parts and cost...

• Sonnax A340 Late Zip Kit ($200)
• ATP Filter and Pan Gasket ($25)
• Toyota Upper and Lower Valve Body Gaskets ($25)
• Trans lube assembly grease (i went with firm) ($12)
• Valvoline Synthetic Dex/Merc ($40)
• Also...
• 1/4 drive torque wrench (inch pounds) ($25 @ Harbor Freight)
• A long flat rubber maid container to catch trans fluid that drips ($10)

 

Hey NvrSyNvr just finished rebuilding my 30-40LE Trans. and installed a Transgo A340 zip kit which did take care of the harsh shifts and chirps the tires in reverse but when it heats up to operating temp. it slips bad in reverse. and I see that this kit comes with the O-rings on the end plugs which includes reverse. wondering if this would take care of my problem? Any thoughts?

 

Hey Rick, congrats on the trans rebuild. That is beyond anything I have done. That said, I had a couple thoughts on your reverse issue...

• Do you have a cable that connects from the throttle body to the trans (and then to the valve body)? Supposedly the cable plays a role in regulating pressure. If you have one maybe it needs to be adjusted? I have heard of some people adjusting the cable thinking that they could increase pressure. Maybe this could be done temporarily for troubleshooting?
• I follow your reasoning on the o rings with the end plugs. The hotter the fluid, the thinner it gets and then it slips past those end plugs. Before installing the zip kit, I noted that some end plugs were loose. It made me wonder how much of a pressure problem I may have had. After installing the kit the end plugs were all tight. Also, I think one of the best things I did during the rebuild was to replace the valve body upper and lower gaskets. My old ones came out in one piece but they were brittle and came apart easily.
• Not sure, Sonnax might sell valves individually. However, if you have the money, it might be worth it to just do the whole kit since you have the valve body open.
• Also, if you post a discussion in the gen 1 forum, you might get some more answers too.

Just curious, when you did the trans rebuild, did you go with a rebuild kit? What prompted you to rebuild? Did you do clutches as well?

Hope that helps, Jim

 

How ya doin Jim Thanks for replying, I was a Cat Mechanic for 7yrs. and did nothing but Powertrain rebuilds and yea big difference between Caterpillar and Toyota Valve bodys, LOL! Anyways I have no more than maybe 110 miles on the transmission and have had the Valves out cause I did not torque the Valve body itself properly. but once I did big difference and as I said before first thing in the morning reverse works great but once it reaches operating temp it slips in reverse and you could be right about the cable it is cracked right where it goes into the valve body between the metal collar and plastic. I just received the kit so I'm gonna drop the Valves and change out the plugs and related parts and cross my fingers. If it was a clipped seal inside of the transmission I would notice it slipping right away. The reason for the rebuild? Sons Neglect! I originally bought the truck for my boy and kept telling him to take it in and have the Transmission serviced so when he trashed it and told us he didn't want the truck anymore about a week after I picked it up the O.D. Planetary ate itself. So pretty a catastrophic failure. So yes it is a complete rebuild with the exception of the output bearing which was still in good shape. So again thanks for the advice I'll let ya know how thing work out.

 

Pro write up. Well done

 

love the writeup! This is going to save a lot of trouble. The reason I had to open the valve body is that the pistons to the shifter solenoids broke off when removing them to replace with new.

These fell out of the valve body when I opened it. I don't know exactly where they go.


edit: found it, I did indeed assemble those the wrong way

 

https://www.atsg.us/atsg/import-manuals-1/toyota-a340-cd.html
I will split the cost with you . Shows all valve body configurations through to 2015

Got some info here that may help


https://www.tacomaworld.com/threads...sions-write-up-your-4-speed-automatic.325531/

and here

https://d2q1ebiag300ih.cloudfront.n.../595/A340E-F_VBL_Interactive.pdf?v=1483625156