Need Trans swap help. WTF is wrong

I'm swaping a 700r4 with a turbo 350. It's bolting up to a 305 SBC.....
It's taking me about 6 hours (over 3 days) just to bolt it up to the motor. once I got the bolts started I went to line up and start bolting the flex plate to the torque converter . Now I can't spin the torque converter or the flex plate to get the bolts to line up......

What am I doing wrong, I'm using the t350's torque converter.
Did I need to change the flex plate?
I've been told to bolt to the bell housing before bolting the torque converter ...

I'm doing this by myself, and this is my first time pulling a trans.....

Please help, I'm about to push it to the curb and sell it for scrape

Thanks

 

You did spline up the converter into the tranny, right????

 

Sounds like you would need the 700R4 converter. I don't know if the 350 converter is compatible, I think they have different splines at the pump and input shaft. The flex plate will be the same.



jerry

 

Am i reading this correct, in that the NEW trans is the TH350? If so, the torque converter's not all the way in the trans. It has "THREE" seperate steps. Then you put a straight edge across the bellhousing and make sure you have a FULL inch to the pads where the 3 converter bolts go. If you tightened the bellhousing bolts, you've probably fucked up the front pump (broke the gears in it). Maybe even broke the case/bellhousing. I know this AIN'T what you want to hear but................

 

PS-if you push it to the curb, where's this curb?

 

The th350 is the new trans. I didn't wrench down when I bolted up the bell housing. Never herd anything that sounded like cracking metal. When I was tryin to get it in yesterday the torque converter was not all the way in. But I never even got to bolt it up. Today I took down the trans and got the torque converter in what looked like it had about an inch past the bell housing.....

 

If it makes it to the curb it will get there in a fire ball of fuel

 

That's funny, but i hope it works for you.

 

the 350 Turbo and 700R4 take a completly different convertor. and maybe flexplate depending on the application.....some early 90's 305's had an external balacne weight like a 400 SBC had
You will need a 700R4 tourque convertor FOR SURE..

 

You don't have the torque converter seated all the way dude. Like Groucho said, one, two, three steps til it's in. Don't install it until you feel all the steps fall into place. You can get them in without and break all kinds of stuff, pump housings mostly. But that's waht it sounds like. You can tell once it's in. You should be able to spin the converter to line it all up and when it's not in it will bind.

 

Ok all 3 steps were felt. It's the same gap as before so I did have it seated all the way. So the next step is the other converter....

 

You need to keep the 350 converter with the 350.

As you spin the converter on the front of the trans, pushing on it a bit, no matter what one it is, it'll wobble a bit at first, then click in and move inwards a bit. Then keep spinning and pushing as you do it, it'll pop in again and again.
When the bell housing is bolted all the way down, you should still be able to turn the converter in there.

A few things more. I think you might need a different flexplate, but not positive, the converter bolts may be different from one to the other, like the 350 is probably standard thread, the 700 r metric.

Also you should pour a few quarts of trans fluid in the converter before you install it. Spin it on the floor as you pour it in, you'd be amazed how much it takes. A little grease or trans fluid on the seal before you pop on the converter helps too.

The term my trans guy uses for what you may have done is "stacking the pump". If so, you need a new one. Not a whole rebuild, just a pump.
If chev trannys are like ford C4's, there are 3 or so converters over the years that dont swap.

Good luck.

 

there are indeed 3 different types of converters (in the spline area), but I don't think he'd get it that close if it was wrong...there's the regular 350/400 type, there's the lockup 350 which has a smooth pilot with an o ring at the end of the input shaft, and there's the switch pitch 400 that has a very short stator spline and a journal behind that.

If the tranny case was bolted to the engine with the converter not engaging the pump gear, then it's possible it broke the pump.

But it could be that the converter pilot (the round knob on the middle of the front of it that fits in the hole in the crankshaft) has a burr on it so it won't move when the converter is installed correctly in the trans.

It's really hard to see what's going on over the internet...maybe a local buddy who knows how this stuff works needs to scope it out.

 

But it could be that the converter pilot (the round knob on the middle of the front of it that fits in the hole in the crankshaft) has a burr on it so it won't move when the converter is installed correctly in the trans."QUOTE"

I recall seeing that before when the converter has been dropped at some point, or beaten into submission with a hammer.
I'm not saying you did either, just something more uncommon to look at.

 

did you try holding the convertor up to the flexplate by itself to see if it mates? sounds like there may be a burr on the snout that fits inside the end of the crank like mentioned above.

 

Wow. the info is all over the place on this post. Thanks everyone for taking the time to post your info. So now I still don't know what to do
I think I'll have to bite the bullit and see if the junk yard I bought the th350 still has the 700r4 and pay the extra few hundred $$$ ... This car is killing me.....

 

"WHAT" other converter? Did you leave something out of your story????????

 

Ment the 700r converter, should I try that one

 

NO! a 700 converter won't fit in a th350.

 

If you are putting in a 350 turbo, you need the 350 turbo converter. You can not use the 700r4 converter on a 350 turbo tranny.
If you put the converter on the way you said, the only thing I can see is when you are trying to put the bolts in the flex plate, somehow you are cocking the converter on the shaft.
Get all of the bolts in the flex plate and snug them up as you bump the flex plate around, do not tighten one and go to the next untill they are almost all the way in.
The bolts out of the converter on the 350 turbo are standard and the bolts on the 700r are metric, you can not interchange them.
I have done this swap on two different cars although mine was from 350 turbo to 700r4.
You will have to use the starter or something to turn the flex plate when you get the converter bolted up to it.

 

The 700r4 converter.

Is it possible the flexplate on the SBC ('77) that had the 350 turbo on it is different from the one he has? (305 centerbolt ('87)SBC/ 'had' 700r4 trans)

 

Ok got ta swallow some pride and tell all that the torque converter must have sliped while I was getting it in place .... Sooooo I fked up....But I never bolted the bell housing tight. there was always a 3/4 in gap so I hope I didn't stack the pump.... Once I got the torque converter on the bell housing would bolt up thight. Now there is a 1/4 in. gap between the flex plate and the torque converter. the 350 torque converter dosen't have anything to screw the bolts on. So now I need new bolts and nuts.. Does this sound right????

 

Yes, the TH350 converter will have three tabs for bolts and nuts to hold it to the flywheel. The 700 converter had three bungs that bolts screwed into.

You need three short 3/8 bolts with matching nuts. Real short...

 

yup...make dang sure the ends of the bolts don't hit the converter housing when they're tightened all the way.

 

Huh...I thought all that Chevy stuff was the same....whodathunk...

 

Is there anyway I can tell If I fucked the pump when I bolted the trans up the first time... Or will I find out once I start the car

 

If you didnt crank or force the bellhousing to mate w/ the motor, I think you should be fine.

No forced connectivity? No damage.

 

Use some loc-tite on the three bolts.