Th350 Swap Thread

TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
Hello, Im looking to make one thread on everyones success and problems with the Th350 swap.

Im having months of issues with my swap that i just cant seem to get right.

Ill start off by listing my issues so far.

Im running an ATI adapter plate, ATI flex plate, ATI Custom converter. Trans is a Th350 thats be rebuilt. Drive shaft is a one piece steel shaft that i had balanced.

Im having two problems.

First is a vibration on free rev starting at 2000rpm that only gets worse with more rpm. Im thinking out of balance converter or its not spinning perfectly true on the flexplate.

Im also having a drive shaft vibration at speeds approx 30mph and up. Drive shaft is balanced and the difference in angle of the output shaft to the pinion is under 2 degrees.

Im looking for people with successful swaps or people with first hand knowledge of how this should be set up.

Hopefully theres a few people out there who can help me out.

Thanks,
Dan
 
suprarich

suprarich

Guest
Nov 9, 2005
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ohio
Do you have the hub adapter on? Flex plate square to the crank hub? Bent Flex plate maybe from hanging the transmission on the torque converter during removal and install, Converter tabs off center. Center to center on the transmission is off.

Did the previous owner have these issues?
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
Trans setup was never run until it came into my hands that i know of. All parts are installed, I verified all the parts with ATI before i installed.

I was playing with the car more and i think the drive shaft vibration and engine rpm vibration are one in the same. I get a good vibration going in the 2000rpm range and when im coasting down the road at 50 or so the converter picks the engine rpm up to about 2000rpm.

I took the car out again and got it up to about 50-60 and put the trans in neutral and a large majority of the vibration went away. I guess for some reason i thought that with the high stall converter the engine rpm would go lower then that and any resulting vibration would be from the driveline.

Im going to try unbolting the converter from the flex plate and starting the motor to see what it does. If i get no vibration then i know its in the converter.

A buddy of mine suggested that maybe the flex plate was balanced with a 28oz or 32oz balance type deal like chevy's have. I dont think anything for any of these engines come with an imbalance. I guess i always assumed that Toyota zero imbalanced there engines and all aftermarket parts would match that zero balance. Could this possibly be an issue?
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
First you would need some way of attaching the th350/400 to the 7m/j series motor. ATI makes a kit that consists of a plate that bolts to the motor with the bolt pattern of both chevy and BOP. It also comes with a flexplate and crank spacer. The flexplate is drilled with a custom 6 bolt pattern.

Next you would need a converter. If you use the ATI kit you would use a custom ATI fuel and blown converter that is basically the top of the line ATI converter. Has anti balloon plate and all the bells and whistles. The bolt pattern of that converter is what the flexplate is drilled for.

You would of ofcourse need a th350/400 built to your liking.

You would need a custom driveshaft however you would like set up.

The transmission crossmember needs to be modified because the th350 trans mount is located a few inches further forward then the stock trans mount. I cannot comment on the th400 as I have no experience with that unit.

You would need to make custom trans cooler lines to suit your cooler setup

You would need a shifter and cable that is compatible with the trans your using.

That's pretty much it as far as the swap goes.

As far as pricing, for new, your looking at 750 for the ATI adapter kit, 1000 for the ATI converter, 400-500 for a driveshaft, the add in whatever shifter, trans and cooler line setup you would want.
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
Well the crank spacer fits on the crank the same fashion the stock flexplate fits. The ATI flexplate also fits the back of the crank in the same fashion.

The converter pilot fits the crank directly. The spacer just spaces the flexplate back from the crank.

I'm pretty sure its a balance problem with the converter. When I unbolt the converter there's no vibration. The flexplate and spacer are still in place bolted to the crank.

It has to be either the converter or the front pump/input shaft of the trans. I just highly doubt it's the trans as I just had it rebuilt and it's a very severe vibration.
 
suprarich

suprarich

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Nov 9, 2005
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Send the converter back to ATI to be checked. Converters are a bit self balancing being a full of fluid and spinning, but something has to wrong. When we spoke over the phone a while ago I mentioned about the pilot being too long or the adaptor not being thick enough. If this is true, then as you tighten the torque converter, the bolts will pull the flex plate into a bent state. The solid flex plate is a machined piece and is zero balanced. Do all the converter mount tabs touch flush to the flex plate without the bolts?
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
Yea after i spoke with you i had removed the trans. I originally had an issue with the flex plate bolt heads being to thick and contacting the crank side of the converter so i had used washers to space the converter off the bolt heads.

I had a knocking noise at that time that im not exactly sure the cause of was, but since we spoke i have removed the trans and clearanced the bolt heads for the flex plate. I have been speaking with Dave AKA Joliroger4 (Huge Thanks BTW if your reading this) And he informed me that he ran into the same issue with one of his cars and he did the same clearancing without issue. ATI supplies bolts for this but neither of us had them.

I now have the converter directly bolted to the flex plate and the converter mounting pads seems to contact it as evenly as my eye can tell. And my eye is pretty good. The noise i previously had, has also vanished. Theres also no resistance in the converter to pilot into the crank. When i look at the converter from under the car, it seems to be turning true as far as my eye can tell.

Im planning on either sending it to ATI or bringing it to a local place (Pro Torque) to have the balance checked.

The converter functions perfectly as far as i can tell. Its just the balance of it causing this vibration that is the issue.

The only other thing i can think of is its the input shaft or whatever else is driven off the input shaft when in all gear selector ranges like the front pump. I dont believe any of the drums/clutches are spinning in park though.

Because the vibration vanished when i unbolted the converter it has to be between the drive shaft and the flex plate not including either. I dont think anything with enough mass to cause the vibration is spinning inside the trans in park, so it seems to only leave the converter as the culprit. Even though every one i talk to says its highly unlikely the converter lost its balance.

Hopefully this monsoon rainstorm will pass quickly so i can get the converter out and checked.
 
suprarich

suprarich

Guest
Nov 9, 2005
2,187
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0
ohio
At this point you could also look into the alignment of the transmission onto the plate. It is possible for the trans to be slightly off center from the mounting holes of the plate being slightly off. It is a production run type of part so it is possible a plate could be off kilter. If the trans is not perfectly center to center with the torque converter /flexplate/crank hub, it can cause that vibration for sure.
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
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I come from a land down under
lsx020.jpg
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
I was thinking that but the converter seems to pilot perfectly.

Also the problem with the method IJ shows is there isnt a true circle in the center of the adaptor plate. In order to check i would likely have to put the trans up with no converter and use the dial indicator from the crank to the input shaft.
 
TurboStreetCar

TurboStreetCar

Formerly Nosechunks
Feb 25, 2006
2,776
3
38
Long Island, Ny
When I called ati they said they usually don't have Any issues with the alignment and to try un bolting the converter from the flexplate to see if it's the motor or flexplate.

I havnt called them back after finding I have no vibration after unbolting the converter. I'll call them today and see what they think.
 
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