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Yea dicer, I was curious how they get the converters apart. He said they turn them on a lathe and mill the weld away and go from there. If I were building the trans for a turbo Supra or something I would look at all the upgrades but I just want dependability right now.
You fly planes for your job and I do machine tools. Yes they turn them on a lathe to cut them apart. They don't mill the weld away, its still called turning, milling is done with rotating cutters like end mills or face mills.
And when they are all done cleaning and reworking them they then weld them back together, I just wonder how much heat distortion there is. I never have liked the idea of welded together torque converters, because they are impossible for the average tech to take apart. With the bolt together TC's you don't have to replace them to clean them or replace worn parts. The welded ones came about because of cheap manufacture costs and not because they are better. Its just like using sintered parts in engines or transmissions, just cheap and easy to make.
You fly planes for your job and I do machine tools. Yes they turn them on a lathe to cut them apart. They don't mill the weld away, its still called turning, milling is done with rotating cutters like end mills or face mills.
And when they are all done cleaning and reworking them they then weld them back together, I just wonder how much heat distortion there is. I never have liked the idea of welded together torque converters, because they are impossible for the average tech to take apart. With the bolt together TC's you don't have to replace them to clean them or replace worn parts. The welded ones came about because of cheap manufacture costs and not because they are better. Its just like using sintered parts in engines or transmissions, just cheap and easy to make.
I see OEM, aftermarket and rebuilt torque converters that are powder coated; ie blue paint. There are two issues here...
1.) Is the paint applied uniformly that it does not create an imbalance (one converter rebuider balances within 1 gram)
2.) Contemporary heat dissipating coatings would utilize the converter surface area to further cool the system, vs. slathering it with paint for appearances sake. Located this chart on TCI website...suggesting that thermal dissipating coatings on torque converter housings are relevant
Used this image because it depicts A340 Lexus torque converter..painted blue....Not sure this blue paint is optmized for heat dissipation. The tapped mounting pads are also painted on most rebuilt and aftermarket converters...I feel this is bad practice..
And remember powder coat needs the part to be put in an oven at 300 degrees F long enough to heat the whole part to 300 degrees to make the powder coat work.
In most shop manuals they say not to heat bearings to over 250 degrees F. So are they ruining parts before you even purchase the item. I am one that does not need the torque converter to look cute. What is going to make the converter pump housing dissipate heat is air flow into the bell housing it runs in, it won't matter what the paint is or does if the air can not carry the heat away.
The Dacco converters are painted grey. I could do without the paint. Toyota doesn't paint them. I'm still waiting on the kit. For now I'm just twiddling my thumbs since the valve body is ready to go minus the new separator plate gaskets.
Maybe I should go ahead and disassemble the other 2 units I have laying around and inventory the parts. There is really no chance that all of the pressure plates in this trans will work for the correct clearances with new steels and frictions so I may need to have 2 others sets on hand rather than ordering them for $50 each from Toyota and waiting a week to get them.
And remember powder coat needs the part to be put in an oven at 300 degrees F long enough to heat the whole part to 300 degrees to make the powder coat work.
In most shop manuals they say not to heat bearings to over 250 degrees F. So are they ruining parts before you even purchase the item. I am one that does not need the torque converter to look cute. What is going to make the converter pump housing dissipate heat is air flow into the bell housing it runs in, it won't matter what the paint is or does if the air can not carry the heat away.
i have an e-mail into the aftermarket rebuilder on this point. Will share their comments. At a minimum they should not be using coatings that present issues you mention. Optimally they use heat dissapation coatings. Not sure how the heat escapes the transmission housing...
perhaps Lexus will sort this out..
i have an e-mail into the aftermarket rebuilder on this point. Will share their comments. At a minimum they should not be using coatings that present issues you mention. Optimally they use heat dissapation coatings. Not sure how the heat escapes the transmission housing...
perhaps Lexus will sort this out..
You're not sure how heat escapes the transmission 'housing?' What do you mean?
You're not sure how heat escapes the transmission 'housing?' What do you mean?
In response to a previous post inferring insufficient airflow where torque converter resides...
Right now at a Brazilian Carnival....and am going to pay attwntion to the incredible visuals here..If anyone prompts I would be happy to share...Good night
Haha let's not derail this thread anymore but feel free to PM us with that!
Regarding torque converter cooling that's obviously done by running the fluid trough the trans cooler in the radiator. The coatings on the converter probably wouldn't make any appreciable difference in heat control. I would be more concerned with balance than anything.
The overhaul kit and converter arrived today. I'll post some more photos of the kit as I get it taken apart as there are hundreds of parts.
Also, I may need to use a different trans case for the build. The rear bushing in the case that the rear planetary ring gear rides in has some scoring and seems a little worn. Toyota say's if the bushing measures more then 1.5031" to replace the case. I do not think the bushing is serviceable and a few trans shops around agree. The good news is that I have two other parts units in the garage. I'll probably need to disassemble both to get the pressure plates of different thicknesses to get the clearances right so washing up one of those cases wouldn't be much more work if the bushing is better. Using a snap gage, and I'm not machinist, I measure about 1.505", or 2-thousandths larger than min spec. A trans shop I stopped by today to pick up a pump bushing took a look at it and said he would use it but he didn't measure anything. He just stuck his greasy finger in there and said "don't look too bad." I don't know if I am comfortable with that especially with the fact that I have two other cases I could use. Since this trans has ran on low pressure more than a couple times my guess is that the lubrication was degraded during those events in certain parts of the trans. Really the only problem I see is the case bushing so far.
You can see the scoring in this photo, on the bushing not the aluminum of the case.
The overhaul kit and converter arrived today. I'll post some more photos of the kit as I get it taken apart as there are hundreds of parts.
Also, I may need to use a different trans case for the build. The rear bushing in the case that the rear planetary ring gear rides in has some scoring and seems a little worn. Toyota say's if the bushing measures more then 1.5031" to replace the case. I do not think the bushing is serviceable and a few trans shops around agree. The good news is that I have two other parts units in the garage. I'll probably need to disassemble both to get the pressure plates of different thicknesses to get the clearances right so washing up one of those cases wouldn't be much more work if the bushing is better. Using a snap gage, and I'm not machinist, I measure about 1.505", or 2-thousandths larger than min spec. A trans shop I stopped by today to pick up a pump bushing took a look at it and said he would use it but he didn't measure anything. He just stuck his greasy finger in there and said "don't look too bad." I don't know if I am comfortable with that especially with the fact that I have two other cases I could use. Since this trans has ran on low pressure more than a couple times my guess is that the lubrication was degraded during those events in certain parts of the trans. Really the only problem I see is the case bushing so far.
You can see the scoring in this photo, on the bushing not the aluminum of the case.
Noticed the Raybestos brand friction components..
Raybestos is a quality brand....
Does anyone know if Raybestos represents an upgrade over OEM (presuming Aisin..excellent Japanese quality)?
Does the transmission rebuild kit specify where components are manufactured?
Does anyone know if Raybestos represents an upgrade over OEM (presuming Aisin..excellent Japanese quality)?
Does the transmission rebuild kit specify where components are manufactured?
The Raybestos frictions are made in the USA per the label on the package. The steels are not labeled. I have confidence in the Raybestos frictions and steels. I can't speak for the quality versus the Aisin components but I don't think it get's much better than the OEM frictions and steels. I'd like to think the Raybestos are every bit as good but I sure can't they are better. There may be an aftermarket compound better suited to high heat high horsepower applications but typically all they do in those cases are cram another section or two of plates which sometimes requires special machining of things like pressure plates, spacers, and pistons. In my stock application I am confident that the Raybestos parts are of the same quality as the OEM components.
My favorite part of the Precision kits is probably the rubbers. I was originally told by my supplier that Precision uses old stock OEM rubbers. I was doubtful but ordered the kit anyways. When I received the kit that was confirmed from my observations. If you have used OEM resealing kits from Toyota/Lexus for things like power steering pumps and such the packaging and diagram printed on it in the image below will look VERY familiar. The packaging alone tells me they are the same packages you get from the dealer. The rubbers for the drum pistons and accumulators as well as the plastic spacers are in OE Toyota packaging. Really the only thing in the kit that's in a Precision International bag are the scarf cut seals (sealing rings.) But, I've ordered one or two right from the Toyota dealer if I accidentally damaged one and I took note to compare the dealer part with the one I damaged. I compared the hardness of the material with my fingernail, mic'd the thickness and visually inspected the 'sparkly-ness' of the compound under a bright light and they were identical. The only other thing that is probably not OEM are the valve body separator plate gaskets. This is mainly because I don't think Toyota ever offered anything like this. The separator plate gaskets are bonded to the metal plate and that is how Toyota sold that part. It was pretty expensive as well but they are no longer available. When installing the gaskets on the separator plate on the last overhaul I spent a long time looking at every single hole and channel and the gasket lined up 100% perfectly.
Also, I remeasured the case bushing with the snap gage with a better 1-2" micrometer this evening. I'm getting about 1-thousandth over limit still. The weirder thing is that the bushing seems to be slightly oval'ed. The snap gage will clear fairly easily one way but if you turn it 90 you really can't get a reasonable amount of drag moving over center with it. This and the scoring is making me lean 90% towards using a different case. I'm going to start on the drums and see how my pressure plate thickness situation is and if I will need to harvest some parts from the other two anyways.
I've got the valve body mostly fully assembled with the new gaskets except for the small housing with the 2 strainers in it. It also has a small separator plate that two small round strainers pop into and it's a bonded gasket as well. I'll need to boil and scrap that clean tomorrow before finishing assembly. There are 15 rubber ***** in certain spots in the upper valve body half. There are 2 1/4" ***** and 13 smaller ones. The larger once have to go in their correct spots obviously. These ***** serve as check *****. They drop into holes in the separator plate. Speaking of the separator plate, that is fastened to the upper half of the valve body with 2 phillips head screws. Line the gasket holes up with the separator plate and snug those screws up. Then a check valve plunger and spring is set into the lower valve body half. Then lay the other separator plate gasket on the lower valve body half. With that in place you flip the upper half with the separator plate fastened on over and place it on the lower valve body half. Carefully push it down to depress the check valve plunger, line up the holes, and install the 28 8mm head bolts. There are 3 different sizes that go in certain spots. The 28 bolts are torqued to 56 in/lb. Then slide in the manual valve which his a long valve that directly connects to the shift control lever on the side of the trans. This is called a manual valve because it manually diverts fluid to certain places in the trans without valve body or electronic assistance. With the manual valve in place the detent spring can be install. The detent spring has a little roller on the end that engages with the ratchet teeth on the shift control shaft. As mentioned earlier in this thread, this gives your shifter the 'notches.' After this I was able to go ahead and install the over-pressure relief valve with is just a ball, spring, and retainer. This will vent an overpressure situation out of the valve body rather than exploding something. I was also able to install the pressure control and lock-up solenoids. The other two solenoids plug into the lower valve body half cover that houses the two screens so those will have to wait until I clean off the bonded gasket tomorrow. Once I get the lower valve body cover and two strainers installed I'll be able to install a couple of the wiring clips that utilize that components' bolts and it will be able to be set aside ready for installation on the new trans.
I'm starting to wonder if Toyota did offer these gaskets as an OE part. They were in a package similar to the o-rings I was speaking of minus a diagram. It had the SUB-K**** number on the package though. The bag contained the two exact valve body gaskets needed plus the two exact gaskets needed for the lower valve body cover separator plate so they very well could be sourced OE parts as well. I just know Toyota primarily sold the separator plate as an assembly.
Looking at the last photo of the assembled valve body, most of the controlling is done through 4 of the 6 holes that are in a straight line towards the right, one of the two holes in the black area to the left, and one of the holes on the far left. The left hole controls first gear, the middle holes does second, and the 4 in that row of holes control 3rd, 4th, and the forward clutch for all forward gears. The pump provides the volume of fluid and pressure through the larger openings to the far right. The holes adjacent to the fluid control holes are bolt holes that hold the valve body to the case. The bolts are as near as possible to the control holes to provide close proximity clamping force for the best seal possible. You don't want any pressure leaks.
Upper valve body half with the 15 rubber ***** installed. Can you find them all? :P One of the gaskets lined up with the bare separator plate. Some of the valve body passages are bleeding through the holes in the image but it lines up dead nuts perfect. This is the completed valve body assembled minus the lower half cover that is facing down in this image. This is the top of the top half and is the half that faces up into the unit.
#1 so where did you order the kit from?
#2 Snap gauge ? Telescope gauge? Not a good thing to use on soft bores they will always read larger since they push into the material since the proper way is to angle them so they are larger than the diameter being checked then locked then twisted or swept to acquire the diameter. A better choice is a bore mic or even ID mic and the last takes time and a good feel or bore gauge for soft bores.
#3 A $5 to $10 bushing is a great way to sell a brand new case, its kinda how John Deere sells new blocks. Go to a few machine shops with some 660 bronze with some dimensions and see if they can make you one or 2 for cheap. Actually if you knew the dimensions you may even find something online that will come close.
Bronze specs http://www.dura-barms.com/bronze/lea...nze/c93200.cfm
If it was me I would be either making or looking for another bushing, I bet the other ones are also worn.
#4 And I wonder who used the red RTV? Not a fan of RTV on transmissions, though I have used it on a few pan gaskets, the crap is just so hard to clean off.
#5 Snap on tools and harbor freight DMM quite the contrast.
#6 Transmission shops just wham bam places, and likely don't know what a precisian measuring tool is. If the parts fit they use them.
02-25-17, 01:18 AM
