shimming a converter

[stagemonster]

has any one ever herd of shimming a converter to get the proper spacing between the tranny and flexplate because i had to shim mine its a bradco 9 inch unit N/L and i have three washers spacing it out on each bolt so its a roughly 1/4 to 3/8 off the fly wheel this dose not seem right to me and i think this converter may be causing me a knock problem any input would be great thanks

 

[Lee Thompson]

Whoa!!!

I would be calling BRADCO. I put one in a friend car Friday before leaving for BG this past spring. It ATE the trans the first pass on Tuesday. Thinking maybe the trans just gave it up, I installed a perfect fresh spare that I had brought along--ATE it the fisrt pass. Wasted week for my fiend not to count the amount of $ he was out ( and the work I was out). Found out later that the convertor was not made right--only allowed the convertor to engage into the pump spline about 1/8 in. just enough to get the car going. Under a load it stripped the pump rotor. I even talked to Brad later @ a local event. Yes, that is what happened, never even said "I'm sorry, or what can I do to make it right" They may be a good convertor, but not for me. I would never give them any business or a good word. Glad this post come up allowing me to vent, but sorry for your trouble. Best of luck.

 

[VadersV6]

I had to pull my D-5 way forward to get it to meet up with the flexplate. Makes me think that somthing isnt engaging right cause the lockup doesnt work right. But if i were to shim it out to get the splines deeper in, that cone looking thing on the face of the converter wont sit in the back of the crank and take the radial loads like it should...

 

[Marc87GN]

After reading so much about thrust bearing failures, I did alot of measuring in this area to make sure it was set right. I believe the specs are the distance should be between 1/8(.125) - 3/16(.1875). When I measured the distance on my car it was .188-.189 so it was on the edge. I found 3 identical washers that were .052 thick and put them in which made the gap between the converter and pump .136.

 

[VadersV6]

Dont you mean the gap between the flexplate and converter? Are you pushing the converter all the way towards the tranny, and then shimming it back out from that position and getting your number? Is your number the distance between the converter and flexplate, or is it the number you get from where the converter seats all the way in, to the position away from the tranny its at now? When I pulled my converter forward to bolt it up to the flexplate, it moved forward at least a half inch. It had me concerned from the get go. Cant see why it would be so far off when Im using stock components.. I want to get it right, but im really worried about no longer having that locating cone on the converter doing its job. It should be seated in the back of the crank to handle those radial loads. Or does it really matter? Seems like the thrust bearing would destroy itself if that cone wasnt seated in there. Think I could have the wrong flexplate? I have this bad rattling sound coming from my converter area when my engine is cold and I first start it up. Sounds like a losse piece of sheetmetal rattling around, but the converter dust cover is on there tight. I didnt see any cracks in the flexplate.
With the converter pulled so far forward, I would definetely think that the splines arent as engaged as they should be. I have only jumped on it maybe 3 times since i installed the D-5, and Im scared to do it again.

 

[Marc87GN]

If we move past the technical info for a moment and get to the heart of what we are tying to do. It appears that the idea is to strike a balance between engaging the crank and engaging the pump with the converter. The only way to measure the the full travel of the converter is measuring the distance between the converter ears(for lack of a better word) and the flexplate. If the distance is greater than 3/16, the pump might not be engaged properly. If it's less than 1/8th, the converter probably isn't installed correctly and/or the flexplate might not have enough room to flex and pressure will be pushed into the crank. This is just a theory I have based on my limited experiences.

There are guys in this section with tons more knowledge than myself on this subject, but I believe this is the jist of what we are trying to do. My understanding is you want to measure the full distance between the ears and the plate with the converter pushed all the way into the transmission. If it's outside of the 1/8-3/16, lets over 3/16, then you would shim it back until you are within that range. Basically measuring the washer and deducting the amount from the total.

I apologize if this is not accurate information, but this is my understanding of setting up the converter properly. Experts please currect me if I'm wrong.

 

[VadersV6]

Yeah, thats originally how I figured it to be, but there were some posts that started making me think there may be a different way of measuring. I wanted to shim the converter back to engage the pump better, but the main issue is that there is a cone shaped feature on the flexplate side of the converter. This cone locates into the hole on the rear of the crank. This is designed this way to keep all the radial loads from being concentrated on the flexplate. It seems like if this cone were pulled away and all the potential imbalances found their way into the flexplate, it would lead to flexplate cracking and damaging harmonics. Plus, the converter would be able to move forward and rearward depending on the load. This is bad for obvious reasons. If the cone were planted properly in the rear of the crank, then the converter would only be able to move rearward and less "tweaking" of the converter would happen.

 

[3point8]

TC installation

Yeah, thats originally how I figured it to be, but there were some posts that started making me think there may be a different way of measuring. I wanted to shim the converter back to engage the pump better, but the main issue is that there is a cone shaped feature on the flexplate side of the converter. This cone locates into the hole on the rear of the crank. This is designed this way to keep all the radial loads from being concentrated on the flexplate. It seems like if this cone were pulled away and all the potential imbalances found their way into the flexplate, it would lead to flexplate cracking and damaging harmonics. Plus, the converter would be able to move forward and rearward depending on the load. This is bad for obvious reasons. If the cone were planted properly in the rear of the crank, then the converter would only be able to move rearward and less "tweaking" of the converter would happen.

That plus the fact if the TC "nose cone" is not seated in the crank pocket the center of the TC vs the center of the crank could/would be off and the resulting vibration may cause destruction of a lot of things.
At least in my opinion.
Peter

 

[VadersV6]

I think I was so tired when I got the tranny back in, that I wasnt seeing things as they were. I unbolted my converter yesterday, and the converter only fell back between 1/8"-3/16". Dont know why I remembered the gap being so big.