drive line vibration, 72 LB

[dukcaln]

ok, I do not know where or why this was missed, but I feel kinda stupid for not checking this in the first place. So I know the drive line I have on the truck as it sits after the TH400 swap is 70" from center ujoint to center ujoint (front behind trans to rear before diff) So I went out and measured the drive line I took off the truck when the TH350 was taken out and from center ujoint to center ujoint it is 70". OK, seems like a match. So knowing the yokes for the TH400 are larger, all I need to do is swap the current yoke for the TH400 onto the driveline I had on the truck before. This will give me the 70" total length I need and the correct yoke on the end for the TH400 spline.... How I missed this in the begining is beyond me... so the combination ujoint will be used to ad the TH400 yoke to the front of drive line and done!

[brad_man_72]

You should have the shaft re ballanced and checked by a pro. Many time new ujoints right out of the box will have excessive endplay (especially precision/house brand). Trans yokes are not ballanced and where the ujoints mount isn't the exact same from yoke to yoke so the shaft won't run true to the way it was previously ballanced.

You have a shaft that fits, that's a great first step. Now you have to make sure it will work.
Here's an example of why its important to have a pro check it out. The rear shaft came out of a truck, the owner refused to bring us the front shaft because it was OK after much arguing we finally convinced him just to let us check it out. In the video is a new rear shaft that is straight and the "good" front shaft.
https://www.youtube.com/watch?v=fPeN...e_gdata_player

And here's a video of a shaft a guy welded up to save some money... and after 2 cracked transfer cases we are building him a new one. (Lmao, you may want to ignore the commentary)
https://www.youtube.com/watch?v=MdH4...e_gdata_player
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[mixermike]

The commentary is what makes the video so GOOD.....LMAO
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[Lee H]

Ha!! That's a good one.

[Ol Blue K20]

Wow! I never thought to ask, Opps lol

[dukcaln]

got the new u joints on, the new TH400 yoke and ready to install in the morning.... cross your fingers please! using my original DL which was balanced not to long ago....

[Ol Blue K20]

We'll be waiting for good news

[brad_man_72]

Originally Posted by dukcaln

got the new u joints on, the new TH400 yoke and ready to install in the morning.... cross your fingers please! using my original DL which was balanced not to long ago....

Sometimes we ballance a shaft 2 times in a day (usually when someone puts the wrong trns yoke on one and we have to swap it out).
It doesn't really matter how much time has passed, its the modifications made since the last ballance.
Never hurts to have a little luck.
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[dukcaln]

back on the road again. after a short drive all seems good. I will take the truck to town in a few for a longer drive. The funny thing about this entire process is, I ended up using the DL I had on the truck with the TH350 trans. All we did was replace the motor and swap the trans from a TH350 to a TH400. Had to move the trany cross member back to bolt the tranny down and I was told I needed another DL and yoke. I bought a DL from a local chevy guy and was told it was for a factory TH400 LB.... well it was shorter than my original DL by 3" and.... so measuring it a few times I decided my original DL will work and all I had to do was replace the fron yoke to accomadate the TH400.... crazy as it sounds!

[Ol Blue K20]

Maybe it was from a long shaft 400

[dukcaln]

yes, could be. freaking crazy thing today happens to... I hit the freeway for a test drive... all is smooth then all of a sudden the truck starts bouncing around... I am like WTF.... pull off the freewaY and check the DL... no visual issues... start off and crazy shaking and vibration.. pull off the road and look and find the front tire coming apart.... so four new tires today! WENT RIDE IN REAR and smaller in front... since my wheels are staggered too... looks great

[Ol Blue K20]

Where did you get them, I get family discount at Americas Tires on Hamburger Hill there in VV

[dukcaln]

just at one of those cheap shops..... went to 5 different places, even where u mentioned and for the best bang for my buck, and the only place that actually had them in stock.... so I pulled the trigger

[Ol Blue K20]

So it's up and running, Good going and enjoy

[dukcaln]

up an running but I think I still have either a DL issue or possibley motor or tranny mount.... so I guess since I changed the front yoke from a TH350 to a TH400 yoke I should really get the DL balanced. Going to drop it off monday. Just need to figure out where...

[Ol Blue K20]

I've had good luck with Bert Williams in Napa but I called and they're closed down. So on that note there is Drive line Service of Concord (925)427-1200 I've used them also and was happy with em. Drive Line Service in W. Sac (916) 371-3332 I've never used em but they been there a long time so can't be all bad. Those are the ones I know of in our proximity

[dukcaln]

thnak you very much. I looked too. I think Monday I will drop it off in w sac....

[Ol Blue K20]

No Problem, glad I could help.

[brad_man_72]

I know theirs a couple of "powertrain industries" in california. I work at the one in missouri. These guys know their stuff, they make machines that ballance drveshafts and have parts that other manufacturers don't make cast for them. Definetly not your run of the mill driveline shops. Our shop here in mo used to make shafts for hot rod tv.
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[dukcaln]

driverline back from being balanced..... installed and all good, pretty much vibration free. just chasing down a few rattles

[Ol Blue K20]

Glad to hear that it is good on the vibration problem. Now good luck on the rattles.
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[dukcaln]

thanks, getting there...... seems this motor for some reasons isnt as smooth as the last one.... hince my rattles and all....

[Ol Blue K20]

Holler if you need help