drive line vibration, 72 LB

[dukcaln]

so I recentley swapped to a TH400 and bought a used two piece driveline with carrier bearing... it all looked and felt solid. Swapped the rear ujoint to a combination joint 1310/1350... got the truck running after putting a different motor in at the same time. I believe I have vibration from the drive line, at least it feels that way... have a slight vibration up to 35mph then at 55mph it is pretty noticable...... was not like this at all with the two piece I removed so I am assuming it is the used two piece I got.

I was told to take the two piece shaft apart at the carrier and rotate it 180 and put back together and see if that helps or changes it.... any other things to look at?

Should I just take it to get balanced?

[Andy4639]

The used shaft have any weights on it anywhere? Take the whole shaft back out and take it to a good drive line shop and have it balanced and rebuilt with all new bearings and u-joints.

[Ol Blue K20]

Also make sure rear shaft is clocked correctly with the front yoke on trans

[dukcaln]

Originally Posted by Ol Blue K20

Also make sure rear shaft is clocked correctly with the front yoke on trans

meaning?

[Ol Blue K20]

I don't remember the clocking off the top of my head but I have an original service manual at home and I'll look it up. What I mean is the u joint yoke on the front shaft has a clocking to the u joint holes on the slip yoke on the rear shaft. If they are off it will cause a vibration. On later trucks they had a index tooth but I dont think these did.

[dukcaln]

ok thank you..... I do recall the two piece seperating during installation at the carrier bearing... this could explain the vibration if it was not put back on in the right position.... guess that would mean clocking..... look forward to seeing what your book tells you

[ERASER5]

Make sure the U-joint is still centered in the yokes. I've them shift several times.

[Ol Blue K20]

I will post what the book says

[Ol Blue K20]

OK, I called home and my daughter looked it up and read it to me. Here goes, put the trans yoke vertical this places front of driveline horizontal. Now slide the slip yoke on vertical, this will make front of rear shaft horizontal. That is the clocking, let me know if this doesn't make sense.

[no_rice]

im going to have to try to look into this too.. mine has a vibration, and i know the trans and rearend were both out before i bought it and changed around

[brad_man_72]

Clocking. Yup that's how you time a driveshaft. The trans yoke could be 180 out. The carrier yoke can be 180 out. The rear shaft could be 180 out or even in backwards. That's if its timed correctly!
Easiest solution is to take it to a driveline shop and have a pro check it out and have it ballanced.
This is what I do for a living.
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[geezer#99]

Google drive shaft phasing!

[Lee H]

If you have lowered your truck have you checked the pinion angle?
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[vectorit]

How is the carrier bearing, new or old?
Is the carrier bearing bolted to it's mount square to the shafts?
Meaning that there is side to side adjustment for carrier bearings at the mount, and if it is off to one side more than it should it will put your drive shafts out of line with the axle pinion and the tail shaft of the transmission.

[brad_man_72]

Originally Posted by Lee H

If you have lowered your truck have you checked the pinion angle?
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Angle problems show up as a low speed shudder/vibration.
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[Andy4639]

As I stated before the fastest easiest way to get it fixed is take it to a good drive line shop and have them fix it. They will know to look at all the differant area's and fix what needs fixing.

[dukcaln]

so here is a picture of the rear yoke behind the carrier bearing. to me it seems like it is not far enough on the spline... so I measured the driveline that was on the truck with the TH350 and it seems the rear shaft is 1 1/2" shorter. So my thought process is that the yoke not being on the spline is causing the driveline to be out of balance and therefore vibrating. fyi, the carrier bearing is bolted up correctly. So it seems that this driveline I bought used that I was told was on a long bed TH400 truck might be shorter. So I will go back to the guy, who had a few drivelines and see if there is one longer... if not is there a yoke that slides onto the carrier bearing that is longer than the one I have

[brad_man_72]

Instead of wasting a bunch of time, energy, and money, why not have your original shaft modified for the new transmission.
You already have the trans yoke so if it needs to be shorter have it shortened and ballanced. If it needs to be longer have it retubed.
Or another popular option is to have a one piece driveline made.

Sorry if I came across as harsh, its just frustrating watching people spend a dollar to save a dime.

Yes the slip not being far enough on the spline can cause a vibration, the slip ans spline could also be worn out enough to cause a vibration (40 year old parts do wear out). If the slip and stub are in great shape you could have the rear shaft retubed an inch longer and have it all ballanced also.
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[dukcaln]

I think I am going to either have a new longer rear tube put on or use a one piece driveline I have sitting at a buddies. Only reason I didnt want to use the one piece is they tend to vibrate and its a used one too so you wont know until you put it on

[brad_man_72]

Originally Posted by dukcaln

I think I am going to either have a new longer rear tube put on or use a one piece driveline I have sitting at a buddies. Only reason I didnt want to use the one piece is they tend to vibrate and its a used one too so you wont know until you put it on

Why would a one piece driveline "tend to vibrate"? I've built and ballanced a couple of thousand of them but I've never experienced a one piece driveline that was more likely to vibrate compared to a multiple piece driveline.
They are far less complicated and if built properly you shouldn't have a problem with it besides ujoints ever.
Either way you should have either shaft checked out, new ujoints and have it ballanced.

You said you want to go 2 piece because you're lowering your truck. Unless you're notching your frame you won't have clearance issues with a one piece.
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[Ol Blue K20]

I'm starting to like the one piece idea, less to go wrong when you decide to use that new horse power. We have some good driveline places close by. I have had good experiances with Bert Wiliams in Napa and Driveline Services in Concord

[dukcaln]

I will head up to my buddies in Sac tomorrow. He has numerous drive lines both one and two piece units. I will measure and take the closes one piece or perfect one as I can find and hope it works.

[brad_man_72]

Error on the side of too long. Its cheaper to have one shortened.
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[Ol Blue K20]

Good luck hunting for it, Drive careful it's supposed to be nasty

[dukcaln]

thanks, got all the measurements... he has over 35 DL from the proper year trucks, so lets hope