Transmission help!!

[miller511]

Hi all,

I finally got the CS motor to fire up...woo hoo!!! (with the right sized carb and getting the timing correct... I was 180 degrees out on the distributor!!! Ugh!!!)

My/our elation was short lived...

We got the motor idling smooth and up to temp. After about 30 minutes...making sure all was well with fluid levels (transmission fluid, oil, PS fluid, etc) and no leaks, not over-heating, good oil pressure, I decided to take it out of park and put it into reverse (stock C4 tranny). It killed the engine immediately.

Some background-

I did not remove the tranny out of the CS when I did the swap out of the 302 to the 347..although it did just hang down a bit for several months on the tranny mount. I did put a new higher stall speed torque converter in it. The shifter linkage should be intact (maybe it's not?). Could there be an issue with the vacuum line?(since it's a long duration cam 222/232) I've got the vacuum line connected to manifold vacuum (on the rear of the manifold...along with the power brakes...same basic configuration as with the old motor).

When I fired it up the next time and still in park, the tranny and engine have a pretty major shaking issue (I only ran it for a second like this). I haven't attempted to run the shifter through the gears.

Any suggestions?

Thanks, Jeff

 

[joedls]

Did you use the old flexplate? If so, is your engine balanced to 28 oz. or 50 oz.? If it's 50 oz. and you use the old flexplate, that could be your problem.

 

[robert campbell]

Jeff,
When you put in the new torque converter did you feel it went all the way into the transmission? When in the car it is very hard to tell. The best way to ensure that it went all the way in and engaged the front pump is to have the tranny stood up on its tail shaft in a vertical position and then you slowly put the torque converter down in the tranny. You gently spin it around and gravity will allow it to drop into the last step that engages the front pump. If your fingers are behind the converter when it drops on the last step into the pump, you will not be happy if it is a standard converter in diameter. It will smash you finger tips!! If it is 10 inch or smaller converter you will not notice.

Another way to notice this problem is when you bolt up the engine to the tranny there should be about a quarter inch of “play” between the torque converter and the flex plate. Meaning the torque converter is not pressing into the flex plate.

If I were you at this point I would drop the forward bell housing cover and unbolt the torque converter from the flex plate. It you cannot move the torque converter away from the flex plate, you do not have the torque converter fully engaged. That could be your vibration.

The other thought on flex plate balance is valid. Although it should have been shaking the moment it lit off. You indicated that it idle smoothly. If you had the wrong balance it would have been all over the place as soon as it was lit off.

Rob

 

[miller511]

Joe/Rob,

New flex plate at 28.2oz balance.

The car ran fine and smooth after start-up. It was just after putting it in reverse. It's like something is binding? Also, when the car is off, I am able to run it through all gears without any linkage binding issues (It behaves just like it did before the motor swap...feels normal).

I don't think the flex plate would have bolted up nicely (like it did) to the torque converter if it wasn't fully engaged, correct?

-Jeff

 

[robert campbell]

Jeff,
Yes, it will bolt up easily if not engaged fully into the tranny.

The only way to check for sure is to unbolt the converter from the flex plate. It should easily back away from the flex plate. If when all four nuts are released, and the converter does not back away and the studs stay firmly through the flex plate, it is bound or pinned and will not engage the front pump. It could cause all sorts of problems.

A very easy thing to verify. When putting a converter on a tranny in the car it is very difficult to engage the last step into the front pump. If you feel it is not engaged fully to the front pump, you will need to unbolt the bell housing from the engine and back the tranny back enough to spin the converter freely from the flex plate. Firmly push it in towards the tranny and spin it slowly. You may need to work it up and down side to side to side as you push it firmly into the tranny. You should finally feel it drop in. Once in it is very hard to get your fingers in behind it between the converter and the bell house.

You need to confirm this as a first step.

Rob

 

[miller511]

Thanks Rob,

Will do what you are suggesting this weekend.

Hope I didn't ruin anything if it wasn't on there fully.

-Jeff

 

[miller511]

Maybe a dumb question, but- To back the tranny back enough to wiggle the torque converter on further, is it required to take the drive shaft off (at least on the far end (at the differential)? Or is there enough play in the yoke?

Thanks, Jeff

 

[robert campbell]

Jeff,
Yes you will have to drop the drive shaft at the rear end. Also disconnect the linkage, and yes I hate to say, disconnect the tranny cooler lines. You should be able to disconnect at the radiator if it is using a stock cooler. If you have plumbed in an after market cooler, you may have rubber lines with enough "stretch". You will need to drop the starter also.

But before you do all that, just drop the shield on the front side of the bellhouse to expose the torque converter nuts. Loosen them and completely remove all four nuts. You may have bolts instead of nuts on some aftermarket converters. The critical thing is to try to push the converter towards the tranny. It may be hanging up on the converter studs through the flex plate and not move easily in. If you stick a pry bar up between the converter and the flex plate you should be able to "gently" pry back using the center of the flex plate as the pry point and gently pull back against the converter. Doing it this way you will not risk bending the flex plate. You could have someone put a 15/16 socket on the vibration damper nut and slowly turn the engine while you gently pry back to see if it will drop in. If you cannot get the conveter to drop away from the flex plate it may be bound up to the front pump. To get a little clearance without going through all of the above in the first paragraph, you can try this. You could back the bell housing bolts off to allow the tranny bellhouse to pull away a bit from the engine block. Maybe a 1/4 of an inch, but not enough to loose your allignment pins that align the tranny bell house to the engine. With this done you can again have someone slowly turn the engine while you pry gently against the converter. The extra play may unbind the converter from the front pump and allow it to turn and drop in the last step.

Or do all of the stuff in the first paragraph. But again, if you drop the converter nuts and bolts and it moves in freely away from the flexplate a quater of an inch or so, then it is not the problem.

Rob

 

[miller511]

Good info Rob!! Thanks. Will try paragraph two first ;-)

The more I think about it, there was no free play in the converter fore to aft when I bolted it up. I think it needs to go that extra 3rd click. Again, I hope no damage occurred. Will let you know what happens.

-Jeff

 

[robert campbell]

Jeff,
Good luck!! You did not/could not drive it so the tranny should be fine. The interface between the torque convertor and the pump may have been spinning against each other, but I think you will be ok. Let me know what happens. I can help with automatic repairs also.

Rob

 

[robert campbell]

Jeff,
Were you successful? I hope so! Nothing more depressing than re-work right at startup. Been there myself before.

Rob

 

[miller511]

Hey Rob,

I did not get to it this weekend. Will tackle it by next weekend. I DID pick up a transmission jack from Harbor Freight last Saturday, though. So, I've got everything I need to get after it.

Will let you know.

-Jeff

 

[miller511]

OK. The CS tranny is back together.
Learned a bit more about how the torque converter "three-clicks" in. The first thing it meshes with is the large spline (click one), then the smaller spline (click two), then the tricky part, meshing up to the pump which is a larger outer diameter with two "slots" across either side...not as easy as meshing splines. I ended up using a sharpie to draw on the front of the torque converter the "flats" locations so that when I lined it up with the pump I knew roughly where to wiggle it on (since you can't see where it is exactly)...(click three!!)

One thing that helped immensely was getting a transmission jack..the adjustable type that tilts for and aft and side to side.

Will fire her up tomorrow after work. Thanks for the help with this Rob!!

-Jeff

 

[robert campbell]

Jeff,
Great to hear!! I bet it runs just fine and you will be ready to stomp chevy's!!! You are a guy after my heart. One who gets under the car and gets his fingers dirty!! With me its because I can't or won't afford someone to do it for me.

Rob

 

[miller511]

Rob,

Yep. I get a tremendous amount of satisfaction from doing things myself. I have gotten so much help/advice from folks on this web site. The collective knowledge base here is amazing (I like to think I contribute some, too!). It's been really great.

-Jeff

 

[robert campbell]

Jeff,
Did you get her going?

Rob

 

[miller511]

Rob,

Thanks for asking...

Got her back together. Then started fussing with the carb...

Then got busy with work and family stuff. Getting really, really close, though.

Will let you all know soon.

-Jeff

 

[robert campbell]

Jeff,
I restore Holley's and rebuild all sorts of carbs for people. If you got some thoughts, let me know. Maybe I can help a bit. 347 stroker!!! YAAAA BAAABBBEEE! You gonna like that!

Rob

 

[miller511]

Rob/all,

Getting closer. The engine now fires easily and consistently. Made sure the tranny has the proper amount of fluid. Put the rear axel on jack stands before trying to put it in gear this time. Started her up and let her get warm.

Then dropped the gear shift into reverse. Yeahhh!!! No clunk and engine kill!!!

Now when I put the brakes on while it's in gear it won't hold idle and dies. It does the same thing in first, second and drive, too.

I have a new vacuum tube from the hard line coming out of the C-4 tranny going to a two port connector that is threaded into the rear of the intake manifold. The other port goes to the power brakes. This is the same setup as before putting the new engine in.

I tried disconnecting the power brake line and capped off the vacuum port to it. It still behaves the same when I apply the brakes. It stumbles and dies.

The idle is set to what I would consider a fair rpm. It's not loping and almost dying in park. Not at all. It's nice and smooth.

It's just not happy under load.

Any ideas? Maybe the modulator valve is bad? I DID put a higher stall speed toque converter in (1600-2100rpm).
Also, the cam is 222/232 and I'm assuming I don't pull as much vacuum as the old 302 that I took out. How do you get more vacuum?

Thanks, Jeff

 

[Mustanger]

... Also, the cam is 222/232 and I'm assuming I don't pull as much vacuum as the old 302 that I took out. How do you get more vacuum?

Thanks, Jeff

You may want to look at this:

http://www.autoanything.com/brakes/61A3151A0A0.aspx?kc=MERCNEXT