What needed hardware, torque converter to flex plate

[NGN]

What hardware do I need to hook up my torque converter to my flex plate, I'm pretty sure a bolt, lockwasher and nut but, and what about a washer on the bolt first, also is this specific hardware for this hookup.
Thanks Nick
NGN

[maverickmk]

Most torque converters (I'm going to assume TH350) have threaded holes for the bolts. They are 3/8" coarse thread 1/2" long -
https://www.classictransmissionsolut...4aAibBEALw_wcB

Or if the holes are unthreaded then these bolts with nuts are what you need -
https://www.classictransmissionsolut...AaAml4EALw_wcB

[AZBuckHunter]

If the nuts aren't welded to the tc (torque converter) you will need the 3 nuts and 3 bolts. I've never used washers or lock washers and I don't think they come in the kits you can buy for hw.
Not a bad idea to throw some blue loctite on the bolts

[Sheepdip]

Originally Posted by NGN

What hardware do I need to hook up my torque converter to my flex plate, I'm pretty sure a bolt, lockwasher and nut but, and what about a washer on the bolt first, also is this specific hardware for this hookup.
Thanks Nick
NGN

Those bolts are a special hardness, buy the correct kit or you could shear them.
A friend years ago put hardware store grade 5 in his and sheared them while doing a burnout.

Amazon will bring them to you.

https://www.amazon.com/Spectre-Perfo...5235231&sr=8-6

[71CHEVYSHORTBED402]

Notes for my 71 C10 with 402/400TH. The bolts are original:

Ensure the converter spins freely until it’s mounted onto the flex plate.

If the torque converter is seated correctly after that transmission has been mounted to the engine block, then there should be an approx. 1/8” gap between the contact points on the converter and flex plate. Pull the torque converter forward to the contact points, ensure the torque converter spins in this position and then mount it.

The torque converter mounts to the flex plate using three (GR 5) 9/16" flange bolts. The bolt threads are 3/8-16 x 9/16. NOTES: One bolt is stamped "TR" and the other two are stamped "RBM". The bolts were torqued to 40 ft. lbs.

[NGN]

Originally Posted by 71CHEVYSHORTBED402

Ensure the converter spins freely until it’s mounted onto the flex plate.

If the torque converter is seated correctly after that transmission has been mounted to the engine block, then there should be an approx. 1/8” gap between the contact points on the converter and flex plate. Pull the torque converter forward to the contact points, ensure the torque converter spins in this position and then mount it.

Before I put the torque converter on, I noticed there were two little metal squares all the way in the back of the input shaft. Are those just for guidance, and if so would that be the reason it doesn't spin freely?

Thanks NGN
Nick

[71CHEVYSHORTBED402]

Originally Posted by NGN

Before I put the torque converter on, I noticed there were two little metal squares all the way in the back of the input shaft. Are those just for guidance, and if so would that be the reason it doesn't spin freely?

Thanks NGN
Nick

I'm not sure what you mean, can you take a picture? The TC should go on smoothly, you jiggle and spin a little bit until you feel 2-3 clicks. When it's on right you'll barely be able to put your finger (if at all) between the housing and back of TC from underneath.

[NGN]

Originally Posted by 71CHEVYSHORTBED402

I'm not sure what you mean, can you take a picture? The TC should go on smoothly, you jiggle and spin a little bit until you feel 2-3 clicks. When it's on right you'll barely be able to put your finger (if at all) between the housing and back of TC from underneath.

I'm sorry but I can't seem to be able to post pictures. I've heard its hard from others guys as well. But anyways, yes the TC is in all the way and I can't fit my finger in between the housing and the back of the TC. And its hard to explain in a message, but what I'm trying to say is that when its all the way back and I can't fit my finger in between, should it be able to spin or do I have to move it forward for it to spin? Because mine isn't spinning right now when it's all the way back.

Thanks NGN
Nick

[70STOVEBOLT]

Nick you should be able to spin the converter even after it is engaged with the oil pump lugs, which are the squares you are talking about. The input shaft should spin freely all the time. The TC will move fore and aft even while fully seated. I would use the correct bolts, just to be safe. They are grade 5 and flanged, as Tony stated. Hope this helps.

Mark

[maverickmk]

If you cannot spin the TC you have more problems then what hardware to use. You need to get it looked at by someone that works on transmissions.

[71CHEVYSHORTBED402]

Originally Posted by NGN

I'm sorry but I can't seem to be able to post pictures. I've heard its hard from others guys as well. But anyways, yes the TC is in all the way and I can't fit my finger in between the housing and the back of the TC. And its hard to explain in a message, but what I'm trying to say is that when its all the way back and I can't fit my finger in between, should it be able to spin or do I have to move it forward for it to spin? Because mine isn't spinning right now when it's all the way back.

Thanks NGN
Nick

I agree with the post above, have someone look at it. There's more to it than having the right TC, including proper lubrication.

Posting pictures is easy. Select Advanced mode if necessary, select the paper clip icon (attachments), select your picture, upload and save.

[NGN]

Originally Posted by 71CHEVYSHORTBED402

Posting pictures is easy. Select Advanced mode if necessary, select the paper clip icon (attachments), select your picture, upload and save.

Thank you Tony for the help with posting pictures. I must have been doing something wrong when I was trying to put pictures up. Now I'm going to have to start gathering up pictures for my for sale ads.

Nick