Too big and hog too much power. The th350 is muc tighter then I thought it would be. The bellhousing and the pan rail are massive compared to the stock a340e.
Th350 Swap Thread
- Thread starter TurboStreetCar
- Start date
Converter is on its way to ATI. Having it loosened a little while its there.
Still looking for other people who swapped..
Still looking for other people who swapped..
4L60E would have been a better choice Dan 
LOTS of aftermarket, 4 speed with a lockup TC and small like a 350.
LOTS of aftermarket, 4 speed with a lockup TC and small like a 350.
I know lots of people that blow those apart with not so much power. Thats the only problem. The TH350 is proven reliable when beat up with high power launches. There also cheap to fix and i dont need an expensive controller anymore.
If i could just get it working right haha.
Hopefully wheni get the converter back i wont have any vibration and ill be able to drive my car again.
If i could just get it working right haha.
Hopefully wheni get the converter back i wont have any vibration and ill be able to drive my car again.
Just called ATI. They checked the balance and doesn't seem to be out of balance. F*ck.
They haven't cut it open yet though so I'm hoping there's still a chance there going to find something wrong with the insides that is causing my vibration.
They haven't cut it open yet though so I'm hoping there's still a chance there going to find something wrong with the insides that is causing my vibration.
Well converter was cut open, loosened a little and refreshed and nothing was found to be wrong with the converter.
What else could cause an engine rpm vibration. It feels like something heavy. I'm gonna check the mounting holes on the flexplate to make sure there all the same spacing from the center bore.
How could I check the alignment of the adaptor plate?
My worst fear right now is putting this back together and having the same vibration and having to pull it put again.
What else could cause an engine rpm vibration. It feels like something heavy. I'm gonna check the mounting holes on the flexplate to make sure there all the same spacing from the center bore.
How could I check the alignment of the adaptor plate?
My worst fear right now is putting this back together and having the same vibration and having to pull it put again.
Nosechunks;1753695 said:
It's kind of funny, I'm having the exact same problems with one of my customers cars. TH400 swap with the SP kit. The kit uses - stock flexplate, Sp converter, chopped bellhousing on a th400(freshly rebuilt) with the adapter plate for the J3 bellhousing.
So..yeah, the story with this car is exactly as you explained yours - to the T. The converter should be back from SP today. They said they didn't find any problems with it but they "replaced a bushing"? lol. I dunno about all that, but I'm going to check runout on everything and make sure everything is concentric. If the problem still persists..well I guess I'll think about that if that time comes. Anyways, I'll let you know how it goes and any findings that I might have.
Your having a severe vibration at 2000rpm? Unbolt the converter and it's gone?
I hope for both our sakes having the converter gone threw fixes the issues.
I hope for both our sakes having the converter gone threw fixes the issues.
enslaved87;1753887 said:
Any update?
Im just got my trans back yesterday so im hoping to install today. Hopefully it is good this time and i dont have to remove everything for a 5th time.
Reinstalled and still have vibration.
Check converter fitment into the crank before i installed the trans and the pilot fits as perfectly as it can into the back of the crank. When the trans is installed i can spin the converter while piloted without any resistance witch tells me the trans has to be as close as it needs to be aligned with the motor.
Im going to try a dial indicator on the converter to make sure it spins true. Shouldnt be a problem with that as it was just gone threw by ati though.
Anyone have any idea what spins inside a th350 while in park? It almost seems less of a vibration while in gear and reving against the converter.
Check converter fitment into the crank before i installed the trans and the pilot fits as perfectly as it can into the back of the crank. When the trans is installed i can spin the converter while piloted without any resistance witch tells me the trans has to be as close as it needs to be aligned with the motor.
Im going to try a dial indicator on the converter to make sure it spins true. Shouldnt be a problem with that as it was just gone threw by ati though.
Anyone have any idea what spins inside a th350 while in park? It almost seems less of a vibration while in gear and reving against the converter.
Sorry about the late update. It's been a busy/long weekend. Well, after changing the converter, flex plate+spacers, bolts, crank pulley,bolt....the vibration is still there. So really it comes down to two things: the engine and the transmission. I've never had a transmission feel this way before, but I guess it's not out of the realm of possibilities. I will say that when the A340 exploded on this car before - it vibrated exactly like this after it happened. The only reason that I looked past the engine is because when I unbolted and slid back the converter the engine ran smooth as silk and revved like a damn F1 engine. But now...I'm not so sure. So to sum it up - the car is still F'd until I do more investigating.
Jay, I think that car was in the deep 500's . I have never ran into this issue with my setups before. but both my setups I used a stock flywheel.
Dan, when you pulled the converter off and ran the engine, did you keep the ati flexplate on there?
Dan, when you pulled the converter off and ran the engine, did you keep the ati flexplate on there?
suprahero;1756294 said:
Yeah it was very easily into the 500's. The engine was very happy until this happened.
Here's a thought- if you think the converter isn't spinning true, is it a possibility for you to use a bolt that has a taper on the shank to center the converter that way? It runs off of the assumption that the flexplate and its holes are actually true, but it removes the pilot bearing/bushing from the equation... I'll see if I can find a pic of the kind of bolt I'm talking about. It may or may not work, just a thought!
Edit: something like the one on the left
Edit: something like the one on the left
toyotanos;1756671 said:Here's a thought- if you think the converter isn't spinning true, is it a possibility for you to use a bolt that has a taper on the shank to center the converter that way? It runs off of the assumption that the flexplate and its holes are actually true, but it removes the pilot bearing/bushing from the equation... I'll see if I can find a pic of the kind of bolt I'm talking about. It may or may not work, just a thought!
Edit: something like the one on the left
Only problem with that is the converter pilots into the crank perfectly. Trying to center the bolts would fight the crank pilot if something was off.
IJ.;1756682 said:
If the adaptor plate was off. How hard would it be to pilot the converter? The converter moves with very little resistance when piloted and the pilot has very little play.
Also, if the adaptor plate was off would that give a vibration?
Nothing in the flexplate or flexplate adaptor can be off be aide the converter pilots directly into the back of the crank.
Dunno Dan, just throwing it out there as a possible cause, I'd have ran the engine with the TC bolted up and noted vibration then moved it one hole to the left and tried again repeating for the last hole, I'm assuming a 3 bolt GM convertor?
It may be on centre just not parallel this would cause a vibration.
It may be on centre just not parallel this would cause a vibration.
Nosechunks;1756668 said:
How deep does the pilot go into the crank? when you say it has little play, how much are we talking ? when you lay the flex plate down, and set the converter on it, does the face mate nice and even with out using the converter bolts.