Trans install question/concern

[sy#2921]

Over the winter I swapped out my roadmaster 700 for a waller 700 and also swapped converters as well. It had a yank I believe (red in color) and am using a coan now.

My concern is this,

I measured the TC engaugment with a flat edge from the bellhousing and came up with an inch like shown in the pics floating around in Mike's post (sy2932).

Now when I took out the old trans after unbolting the old converter from the flywheel i moved it back and used a homemade strap to hold it in place so it didnt slide forward or off during remove NOTE: at this time there was clearance between the crank snout and the hub on the converter.

Come to install of the new trans. I use the same strap the hold the converter in place and it fits the same. Now this time I get the trans in place and bolted up and notice the hub on the converter is up against the snout of the crank. It rotates freely but is noticeable closer than the old converter when slid back.

At this time I took the trans down and tried to reseat the converter, remeasured got an inch, put the trans back in the truck and the same result, converter hub is up against the crank snout but rotates freely.

Does this sound like the converter is still not on the input shaft of the trans correctly still? Or is there a difference in converters I am seeing?

 

[MikeRenz]

Re: Trans install question/concern

by crank snout, you really mean the middle of the flexplate right?

are you sure you're seating the tc fully? how many notches did it set into for you

 

[sy#2921]

Re: Trans install question/concern

Yeah the middle of the flexplate. The rear snout if you will. I realize now that most only think of the front of the crank where the balancer mounts as the snout.

The only assurance I have it is fully seated was measuring the mounting pad depth to bellhousing edge. I honestly dont remember how many clicks. I put the trans in a few months ago now and have been slowly finishing the rest of the truck. I have not run it yet with the trans in place. I am just trying to recheck everything before I fire it up and run into a stupid mistake. Its just something that has been on my mind

 

[Tooky]

Re: Trans install question/concern

On mine I could spin the TC freely from under the truck. Then I had to pull it out about 5/8" to mate the converter pads to the flexplate. If yours is tight up against the flexplate to begin with and you can't slide it back, something's gotta be off...

 

[SY2932]

Re: Trans install question/concern

If you have one inch from the mounting pads to the front of the bellhousing you *should* be seeing the difference in the two converters. The easiest way to confirm this is to measure what the height difference is between your old converter and the new one is using that same straight edge. Lay it across the mounting pads and record what the height is from the pads to the snout in the center of the converter. The difference in height will probably be your "lost" clearance. My Hughes converter had a longer snout that my stock converter did.

 

[sy#2921]

Re: Trans install question/concern

Josh, the mounting tabs of the converter were still spaced out from the flexplate itself. I had to still pull the converter up a little to get the TC bolts to engauge then I slowly worked them a few turns at a time before I torqued them down completely. The new TC spun freely but the little hub that goes into the flexplate/crank was just flush/touching already where as when I slid the old converter back there was a small gap.

Mike, I went by your method of measuring the mounting pads and got an inch from the bellhousing to mounting pad.

I also swapped flexplates from stock to an ATI but I dont think that will make the difference I am seeing.

Guess I am looking for experience with the different brands of converters to make me feel better

 

[Tooky]

Re: Trans install question/concern

I have a Yank custom PY3400E converter made for heavy LT1 nitrous/blower combos; 10.5" lockup converter. When my tranny shop tested the converter with my new trans in their test truck, they complained that the "build height" of my converter was "wrong" and didn't think it would work. I had no problems on my truck. But maybe thats some evidence that aftermarket converters differ in height??

I'm not 100% sure but I'd say that since you have an inch you're probably safe. The real risk is when you have too little clearance and the converter can get smashed when you torque the bellhousing.

Sounds like a call to your tranny/converter builder is in order to be sure.

 

[sy#2921]

Re: Trans install question/concern

Time to call waller I guess. I was hoping to catch him on here since I know he is super busy.

 

[sy#2921]

Re: Trans install question/concern

Update::

Just called Coan and got some good news. They told me that as long as the gap from the flexplate to the mounting tabs before I pulled the converter up was 1/8"-3/16" I should be fine. That was basically what I had taking into account the aftermarket flexplate I am running. They also said that some companies make the hub on the converter a little on the short side and that the Coan should be just up against the crank like I saw.