Discussion Forum - Northstar Chevelle Club

seagrams72 · Active Member

Transmission Problem

Scott Parkhurst · Super Poster

To just have 'nothing' means something isn't hooked up right! Is the linkage working correctly? I see you checked the cable, but is everything working on either end of the cable? I'd surely check the shifter and the linkage going into the trans to ensure everything is moving correctly when the shifter moves.

You checked fluids- okay. And you swapped out the converter- so we have to ask if you made sure it was fully seated and engaged into the front pump. If not, the pump wouldn't pump, and no pressure means you wouldn't have any gear engagement (which is pretty much what you're describing).

Something major is wrong- that's obvious. The best you can hope for is a major component not hooked up correctly (like the 2 I described above) so once they're fixed it'll be 100 percent. If that's not the case, the box will have to come out again for some diagnosis and repair work.

bowtie · Secretary

My guess is the cable, maybe not seated into bracket so it doesn't pull the pivot piece. There should be a change in rpm, a clunk, something I would think.

John D · 2K+ Club

And you swapped out the converter- so we have to ask if you made sure it was fully seated and engaged into the front pump. If not, the pump wouldn't pump, and no pressure means you wouldn't have any gear engagement (which is pretty much what you're describing).

2nd on this... Sounds like zero hydraulic pressure. Quick check, can you push anything thicker than your pinkie finger between the converter and the bellhousing?

If so..

Unbolt the converter from the flexplate, and while turning the converter apply rearward pressure on it, and see if it will "clunk" rearward another 1/8 to 3/16 inch from where it was.

If this happens, the drive lugs on the converter were not engaging the tangs on the pump. Consider yourself lucky, as you didn't shear off the tangs & destroy the pump! You'll need to install some "precision" washers/spacers between the flexplate & converter to maintain the engagement.

seagrams72 · Active Member

I did verify movement after shifting. It did move, but that does not mean everything is right, I am going to try and move by hand tomorrow. Second is the torque convertor, I did have to pull it forward about 1/4-3/8" to seat it against the flexplate, I don't know if that difference could cause disengagement. I may try swapping back in the stocker or trying a different setup. Third is the pump I took out, unistall and reinstall was very straight forward, but that could easily get screwed up.

seagrams72 · Active Member

John D wrote:
And you swapped out the converter- so we have to ask if you made sure it was fully seated and engaged into the front pump. If not, the pump wouldn't pump, and no pressure means you wouldn't have any gear engagement (which is pretty much what you're describing).

2nd on this... Sounds like zero hydraulic pressure. Quick check, can you push anything thicker than your pinkie finger between the converter and the bellhousing?
If so..
Unbolt the converter from the flexplate, and while turning the converter apply rearward pressure on it, and see if it will "clunk" rearward another 1/8 to 3/16 inch from where it was.
If this happens, the drive lugs on the converter were not engaging the tangs on the pump. Consider yourself lucky, as you didn't shear off the tangs & destroy the pump! You'll need to install some "precision" washers/spacers between the flexplate & converter to maintain the engagement.

Thanks John, I was typing while you were posting. I did have to move the convertor forward and that may be the culprit.

John D · 2K+ Club

I did have to pull it forward about 1/4-3/8" to seat it against the flexplate, I don't know if that difference could cause disengagement.

The depth of the tangs/slots is only within about this range! I'll bet your boots, hat, and housecat that by pulling the converter forward this amount you've inadvertantly disengaged it from the pump...

67ss · 1K+ Club

I know some of the LS engines use a spacer on the flywheel depending on transmission application to push the flywheel away from the block. I wonder if you would need that to get the convertor to the correct position.

67ss · 1K+ Club

GM makes a special flywheel and spacer for the use of earlier automatic
transmissions and many unique parts for swapping the LS1 into earlier cars.

          Flywheel for earlier automatic            PN. 12551367
                required spacer                          PN. 12563532
                longer bolts                               PN. 12563533
          Flywheel for earlier manual                PN. 12561680

I make no gaurantee of these numbers I copied them from the internet off another site.

Winston Wolf · Member

Hook a pressure gauge up to the port on the drivers side of the trans, this will confirm your pressure questions. You do not need a special spacer, just go to fastenal or a hardware store and get some thick hardened washers to use as spacers. Push the converter all the way in to the trans, measure the gap, and get enough spacer thickness so you only have to move it 1/8" or less towards the flywheel.

seagrams72 · Active Member

Did a little investigating tonight...

Unbolted the converter and I was only able to move it back a total of about 1/8 - 3/16 of an inch. tried to see if it would seat in the pump tangs and no luck, it spun the same the same no matter what I did.

I figure my options are:

1) I picked up the convertor off of CL about 7 or 8 months ago. It is quite possible this could be bad or incorrect since I was unable to trace back a mfg or viable part number.

2) Somehow I messed up the pump during the stator support install.

At this point what I know is I am able to move the convertor back and forth about 1/8 - 3/16 of an inch and it has the same give either all the way back against the tranny or pushed against the flexplate. The friction of the spin was very low, i forget how this is suppose to be. I can grab it, give it a good spin and it goes about another 1/4-1/3 turn.

I am going to pull the pan to see how everything looks before I drop it, but I figure either way I should pull it out to verify operation and conduct a through inspection.

Anymore insight would be helpful and if anyone has a tranny jack (cradle that attaches to a floor jack) they are willing to loan for a weekend I would put down a deposit to rent it.

67ss · 1K+ Club

I have an adapter for a floor jack for pulling transmissions. You are welcome to borrow it. Shoot me a PM.

Lost in the 60s · President

seagrams72 wrote:
Did a little investigating tonight...

Unbolted the converter and I was only able to move it back a total of about 1/8 - 3/16 of an inch. tried to see if it would seat in the pump tangs and no luck, it spun the same the same no matter what I did.

I figure my options are:

1) I picked up the convertor off of CL about 7 or 8 months ago. It is quite possible this could be bad or incorrect since I was unable to trace back a mfg or viable part number.

2) Somehow I messed up the pump during the stator support install.

At this point what I know is I am able to move the convertor back and forth about 1/8 - 3/16 of an inch and it has the same give either all the way back against the tranny or pushed against the flexplate. The friction of the spin was very low, i forget how this is suppose to be. I can grab it, give it a good spin and it goes about another 1/4-1/3 turn.

I am going to pull the pan to see how everything looks before I drop it, but I figure either way I should pull it out to verify operation and conduct a through inspection.

Anymore insight would be helpful and if anyone has a tranny jack (cradle that attaches to a floor jack) they are willing to loan for a weekend I would put down a deposit to rent it.
That sucks, Andy. Sorry to hear you have to pull it out again.
I have a set of headers I need to return to Chris at his work in Roseville. If you guys work out using his adaptor, I might be able to get it from him and bring it here for you. Don't kn w if that will help much, but he lives up by Canada otherwise....
Chris, are you planning on going to the swap meet at the fairgrounds Sunday ? I could meet you there too, unless it's pouring. I won't go if it's raining steady.

67ss · 1K+ Club

Hey mitch I don't know if I am going to make it down for the show or swap. Trying to catch up with home projects that I have to get done.

bowtie · Secretary

You guys can always use me at work as a trading off point too, but I'm off tomorrow

seagrams72 · Active Member

Looks like my manager at my part time gig has one. I'm hoping to pull and investigate tomorrow. Could be the vertor or a bad pump, hoping for the first option.

Bowtieman427 · Active Member

Did you find out what was wrong ?

seagrams72 · Active Member

Well it seems the convertor was not fully engaged and it did not screw up the pump. Thats the good news... The bad news is that since the tranny is out and this was bought as a factory running tranny (could be original 87' for all I know) I am having it gone through. I hope to have it back by mid may and have it on the road within a week or two of that.

Lost in the 60s · President

seagrams72 wrote:
Well it seems the convertor was not fully engaged and it did not screw up the pump. Thats the good news... The bad news is that since the tranny is out and this was bought as a factory running tranny (could be original 87' for all I know) I am having it gone through. I hope to have it back by mid may and have it on the road within a week or two of that.
If there is a way to test the converter while it's out, that could put your mind at ease about it's condition too.

seagrams72 · Active Member

I am not sure without sending it out. The best thing to put my mind at ease at this point is to get the appropriate convertor and the tranny gone through. I figure it is better to get it done now than be down for 2-3 weeks during the summer. I drop it off tomorrow and am picking it up Friday or early next week.

seagrams72 · Active Member

Should be getting the tranny back this week. Chevelle has sat dormant the last two weeks and it is the final push to get it going for the season this week. Took it to Steve Shepherd in Bloomington (Shepherd Motor Sports). Total bill should be just under $1K, also picking up a 2500 stall converter on top of that. Great guy, builds many race and street trannys, what he is doing for the price is great. Tranny will have lockup, added clutches, an updraded front pump, and all the goodies inside to support my current and future modifications.