Torque Converter Installation

[Vince @ FLT]

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. 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 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.

 

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Edited November 28, 2007 by Vince @ FLT (see edit history)

[Krambo]

Great information Vince, thank you for sharing!

 

I also believe that Precision Industries uses different converter bolt lengths correct? I know the ones I received were shorter than stock.

[Z06 DREAMING]

Are PI converters different than Yank on this issue? I've never needed to install washers to the flexplate before.

[thomp62301]

i had to install shims when i put in my yank. it's good idea to check it regardless of what your installing

[misterp]

Great information Vince, thank you for sharing!

 

I also believe that Precision Industries uses different converter bolt lengths correct? I know the ones I received were shorter than stock.

VERY IMPORTANT DETAIL!

 

My TCS also uses shorter converter bolts, ask the manufacturer when you purchase your converter because if you use bolts that are too long they will dig into the housing and not only damage the backside of the converter but also bind-up the internals and on fire-up will turn your converter into instant junk.

 

Also, on F/I and NOS applications get hardened converter bolts and/or an aftermarket flexplate with 6 lugs - it is very possible to shear-off the three factory bolts, I cannot remember exactly who here suffered this problem but it has happened.

 

Mr. P.