This topic of discussion seems to be one that I constantly get asked. With the help of Terry of Precision Industries aka Vig converters I wanted to post this. This text is what comes with all converters that they have built in the past few weeks. I feel that it is good stuff and wanted to share with all of you. Here it is.


Torque Converter Installation

1. Using a lift or jack stands raise car off the ground far enough to be able to slide transmission out from under the vehicle.

2. After the vehicle is raised, drain the transmission fluid into a drain pan by removing the pan bolts from the rear half of the pan then slowly loosen the remaining bolts to allow pan to tilt down towards the ground allowing the fluid to drain into the drain pan.

3. Remove the battery cable, starter (if necessary), driveshaft, torque converter bolts, exhaust (if
necessary), cross member and all of the transmission bolts except for one near the dowel pin.

4. Raise the transmission up slightly by placing a suitable transmission jack under the transmission.

5. Remove the last bellhousing bolt and remove the transmission.

6. Check the flexplate for cracks and chipped teeth on the ring gear. Take the new torque converter and hold it against the flexplate to see if the application is correct by checking that the pilot size and bolt circle are correct.

7. Add a quart of new transmission fluid to the torque converter. Using the aid of a helper, stand the transmission on the tail shaft and carefully install the torque converter onto the transmission. Spin the torque converter and listen for 3 distinct clicks as it drops into the transmission. The following are measurements you can make to insure the torque converter is all the way in the transmission:

GM-TH350, Powerglide=1.125" from bellhousing to the converter pads.

GM TH400 = 1.187" from bellhousing to converter pads.

GM 700 R4, 4L60E, 200-4R = 1.125" from bellhousing to converter pads.

GM 4L80E = 1.030" from bellhousing to converter pads.

Distance may vary +/- .050".

8. Remove any debris in the crankshaft pilot hole and lubricate. Clean and lubricate the dowel pins. Check to see that dowel pins will be in the transmission bellhousing by more than .250".

9. Mount transmission to the back of the engine block making sure the bellhousing fits squarely against the block. If it does not, find out why! Is there something between the bellhousing and block or has the torque converter slipped out of the transmission? DO NOT PULL UP THE
BELLHOUSING TO THE BLOCK USING THE BELLHOUSING BOLTS!!!!

10.After the transmission bellhousing bolts are tightened, check to see if the torque converter will turn by hand. Push the torque converter back into the transmission as far as it will go. Using feeler gauges or calipers measure the gap between the flexplate converter mounting pad and the torque converter mounting pad. If gap distance is between .060" and .187" it is OK to bolt up the torque converter. If the gap is greater than .187" install a .060" flat washer between the torque converter and flexplate.

11. Finish installing the cross member, exhaust, driveshaft, etc. Add 5 quarts of good quality transmission fluid. Start the engine and immediately add 2 more quarts. Check the fluid and finish filling the transmission to proper level.

 

The idea for me here was really about converter spacing. The problem we face as builders is guy's do not get the converter in all the way and break the pump and converter on the install. Or do not get the spacing correct and damage a pump and converter down the road. I was basically posting the directions that PI is now supplying. I thought it would be useful for some of you. Vince

 

You know after we talked about this subject last night Vince I decided to do some research myself... and have not had the time to do so. I will take a look at some literature I have from another manufacturer. The spacing specifications listed in the narrative you supplied looks correct to me, no reason to doubt it IMHO. I have seen that spec before with other tranny and converter manufacturers.

BUT........... When it comes to the Converter to Flexplate spacing I have always (and that's a very long time) shimmed any converter when the spacing exceeded 3/16". And have never had 1 problem with any of the race units I have installed. Only one that went south was on my own M3 to TH350 swap when I was 18 yrs old.... didn't have any spacers and that caused the flexplate to overextend and crack, consequently beating the crap out of my tranny pump. It happens.

g

 

It is also the most common installation error I hear about , In fact we just fixed one for a customer last week who did that same thing. We didnt charge anything but its fustrating for them and for us as builders vendors too .

 

I have really only run th350's and powerglides in the race cars and always gone by the 'push it all the way in, pull it out 3/16" and then fill the gap'. Never thought about it with new trannies as most people dont bother to shim stock units. I have never had a problem with it coming up less than 3/16". So i guess my question is this.

Can you damage anything by having the converter to far into the tranny due to overshimming? And is a pretty good rule of thumb for all GM trannies?

 

Yes you can drive the pump gear/rotor into the stator side of the pump. I personally think 1/8 is perfect. The thing here is that you also need to make sure that the pilot of the converter is in the back of the crank. Two ways to look at it but in most cases the pilot is not the issue. Vince

 

Using a drill bit as a reference. I find that most people own a set or can get their hands on a set of drill bits. Use the part that you would chuck in the drill as a feeler gauge so to speak. Just have to find a place to be able to access the converter pad to flexplate distance and go from there.

 

Two years ago I damaged the front pump due to improper installation. I learned my lesson and now measure the distance each and every time. Live and learn.

Anyway, It just so happens I just installed a new converter (no engine in the car) today and the measurement you posted is almost dead on to what I measure. I would add the 3rd and last clunk is the toughest to engage.

 

I used it for my install, parts of it anyway.(dont know about standing the tranny on its tailshaft) I didnt quite hear the 3 distinct clicks but the 1.030" was very useful thanks.

 

Good info. I learned the hard way about having the converter seated correctly.

 

Vince, How about a few pics next time you guys R&R a customer's tranny. Getting the top bellhousing bolt and not loosing the clips are things you can add too.

 

Cliff notes-Ragtop you need to stop by the shop next time you are in town. We do not do r-n-r here. No lifts or cars. To old for that! We strictly build the best transmissions on the market. The reason for this thread was for converter spacing before installing the trans. Also once the trans is installed to make sure that the flexplate to converter spacing be checked. Many seem to over look this when doing installs.

 

great foot note !! thanks

 

i started to wonder about my stall installation. i fully seated it with three clicks, pulling it back out and redoing it to double check. i measured with a straight edge and it was about one inch. installed the tranny without moving the converter. then i remember like a 1/8 gap between the converter and the flexplate so i slid it out till they met up. should i have used a washer??

 

An 1/8 is just fine.

 

does the motor need to be supported when the trans is removed? I didn't see anything about that in the instructions. Might be replacing mine soon and dont want any surprises.

 

We ran into an interesting issue installing the Circle D. Clicked in 3 times but didn't seem to seat in as far as the fuddle. In the end it was seated fine, but it through us for a loop.

 

No....

 

Great info saving this

 

Bump for an old thread.