Thread: dumb problem: 302/c4 torque converter issues

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Here is my problem, I am currently building a 302 to put into my truck. I temporarly mounted the 302 to the c4 so i could mock up the engine mounts (302 has no heads on it right now).

Anyway, when the engine is mounted to the transmission you can not turn it with your hands at all. I cant even get it to turn with a wrench to the crank, it almost feels like the engine is stuck. However, when you pull it off the engine is not stuck.

On the C4, there are two splines that come out, the smaller one can turn freely, the bigger one can't. However, i know this transmission was good when i pulled it off the truck to begin with (it might not have a full amount of transmission fluid in it though).


The one thing i noticed is the torque converter might not be full of oil as well. Not that i cared, i was just mocking up the engine mounts, but my question is..

Why couldn't it turn? Is the torque converter bad?

Make sure the torque converter is slid all the way into the notches for the front pump, sounds like maybe you didn't get the converter in all the way.....

Originally Posted by Dave Severson

Make sure the torque converter is slid all the way into the notches for the front pump, sounds like maybe you didn't get the converter in all the way.....

is it possible to have the block mounted to the transmission and still not have the converter slid in all the way?

yes, and it will put way too much pressure and not allow anything to turn. If the torque converter is in all the way, there should still be a slight bit of back and forth movement of the converter before it contacts the flex plate... or possibly the flexplate is wrong for the converter you are using????

upon further investigation if i put the covert on the transmission by itself it will go all the way back and spin normally. However it looks like my flexplate is bent..

i believe that to be the issue... Looks like i will be getting a new flexplate..

Yup, figured it had to be something simple. I believe there are a couple different flexplates with different spacings to the converter.....Don't remember how to tell which is which, hopefully someone with a better memory will jump in here....

I am not sure about this but i think i need to get a different flex plate... I am trying to mate the following

1987 FE 302 - tagged E7TE

with a 1969 or 1970 C4 that came from a fairlaine or torino:

tagged:

PEE V1
D0OPDK22

Originally Posted by Dave Severson

Yup, figured it had to be something simple. I believe there are a couple different flexplates with different spacings to the converter.....Don't remember how to tell which is which, hopefully someone with a better memory will jump in here....

Pull up the TCI website for more info, but there are several flex plates
10.5 and 11.5 bolt patterns plus 157 and 164 tooth ring gears then the 50 in balance and 28 inch balance to add to the confusion. There is also a 0 balance one, but only for special cases.

My guess is that you didn't have the torque converter fully in place before you started drawing down the nuts - like Dave S. has said.

To install a C4 and probably every other tran, you put the converter in place first by putting it on the male spline and rotating it until it fully clunks in place, then the trans is bolted up to the vehicle.

Another problem area is the smaller inner splined (input) shaft - it is directional as well - the shorter splined end goes into the trans itself - if installed backwards, it can damage the converter .

Originally Posted by Irelands child

Another problem area is the smaller inner splined (input) shaft - it is directional as well - the shorter splined end goes into the trans itself - if installed backwards, it can damage the converter .

can actually also damage the transmission and the engine as well.... i had one do it not too long ago... pushed extra pressure against the crank, which spun some bearings and broke a rod bolt which of course made the rod bend and cause damage to the block... and once the pressure was relieved in the motor the shaft slammed back and damaged the tranny too

Originally Posted by thesals

can actually also damage the transmission and the engine as well.... i had one do it not too long ago... pushed extra pressure against the crank, which spun some bearings and broke a rod bolt which of course made the rod bend and cause damage to the block... and once the pressure was relieved in the motor the shaft slammed back and damaged the tranny too

i never removed the smaller input shaft so i have no doubt it is correct. The torque converter was not seated correctly. It is now. However I have to wait for a new flex plate because this one was a 28 oz, and the motor i am using is an 87, so i need a 50 oz.

Originally Posted by Create

i never removed the smaller input shaft so i have no doubt it is correct. .

Suggest you check it anyhow - JIC !! It was put together by humans.

Usually if you can't get your fingers between the converter and the back of the bellhousing your fully seated..... Butttttttttt the most overlooked problem with a C-4 is the converter has a drain plug that has to be lined up with a hole in the flexplate,if not it will jamb it up as you desribe.