Chevy Question

Howard H. · Feb 27, 2020

I?ve got an 05 Suburban that the transmission gave out on.

I had it rebuilt at a top-notch place and put it back in myself.

While I had it out, I also replaced the rear main engine seal, new flex plate, replaced all the seals in the 4x4 transfer case, and put new ujoints in the drive line.

In testing, it runs and shifts fine - but has a slight vibration above 45 that resembles a faint rumble strip. Any suggestions on what I should check that might cause that.

The car has 245k miles but always ran very smooth prior to this. Revving the engine in neutral is smooth as glass.

Thanks for any ideas,
Howard

grizz02 · Feb 27, 2020

u joint stiff or installed wrong , did you put the joints in or had it done? also double check that u -joint is seated in its saddle that's its not up on the tab in the yoke

Janicholson · Feb 27, 2020

Most likely is a bad universal joint in the drive shaft. A bad joint might not show up until it was moved beyond its normal range of motion. The rusty bearings can even fall out of the cups. Even putting it into the trans in a different spline can cause an out of balance condition. Make sure the vibration is not a failing tire, but a Ujoint is my first go to repair. Jim

Bob · Feb 27, 2020

(quoted from post at 16:45:22 02/27/20)
I?ve got an 05 Suburban that the transmission gave out on.

I had it rebuilt at a top-notch place and put it back in myself.

While I had it out, I also replaced the rear main engine seal, new flex plate, replaced all the seals in the 4x4 transfer case, and put new ujoints in the drive line.

In testing, it runs and shifts fine - but has a slight vibration above 45 that resembles a faint rumble strip. Any suggestions on what I should check that might cause that.

The car has 245k miles but always ran very smooth prior to this. Revving the engine in neutral is smooth as glass.

Thanks for any ideas,
Howard

I always mark the driveshaft itself and the yoke at the differential, and install with the marks lined up. Perhaps not necessary, but doesn't cost anything, and rules that out as a cause of vibration.

More importantly, did you mark the front yoke and the driveshaft and match the marks when you installed the new U-joint cross?

The driveshafts are dynamically balanced as a unit and not keeping the individual parts in the factory orientation can cause a vibration.

As can bending an "ear" on one of the yokes, getting too rough removing the old U-joint cups, or having needles get lost or out of place.

Did the new joints move freely through what would be their typical range of motion without binding?

guido · Feb 27, 2020

Hello Howard H,

Glade that's done! Check the drive line. Sounds Like it is time for U joints.

Guido.

Dave BN · Feb 27, 2020

Does this vehicle have a midshift bearing?

504 · Feb 27, 2020

Did you time the drive shaft? Pretty sure that has a two piece shaft. It might be worth the trouble to pull the shaft and recheck the u joints,stranger thinks have happened than a bad new joint.

Hobo,NC · Feb 27, 2020

Also check the transmission mount...

Not to make this a I once had reply I had an older chebby in last summer that about drove me crazy I got a bad new mount right out of the box to compound maters I brought one from a different supplier it also was bad out of the box : (

I spent months looking for the issue I was getting ready to pull the transmission when for the ell of it looked the mount over good the cheap arse rubber settled to much when you put weight on it.

On the driveshaft if it does it pulling and coasting I would wager driveshaft issues. If it goes away when you let off the throttle I would wager engine mounts are a dynamic issue caused when the engine is running.

I have a driveshaft shop close by he gets $100 to check it and balance its the best $100 I have spent even if it does not fix it. If says its not the shaft no need to mess with the shaft anymore look elsewhere.

That's the EZ stuff the rest gets much harder to locate.

Howard H. · Feb 27, 2020

Thanks for the ideas!

This driveline has a splined yoke that slips into the transfer case - and then just the main tube all the way back to the differential.

I?ll take it back off and make positive the ujoints are correct. I?ve done plenty of irrigation drive lines but those always had snap rings for perfect positioning. This one had some sort of plastic molding for each cup.

Stephen Newell · Feb 27, 2020

Did you fill the torque converter with fluid? That can cause problems if there wasn't enough.

gab · Feb 27, 2020

That injected plastic is what holds them in originally, if you put new joints in without snap rings your going to have one helluva vibration right before the drive shaft flys out from under it.

Clarence Slydell · Feb 28, 2020

(quoted from post at 01:32:12 02/28/20) Thanks for the ideas!

I?ll take it back off and make positive the ujoints are correct. I?ve done plenty of irrigation drive lines but those always had snap rings for perfect positioning. T[b:1e45f80696]his one had some sort of plastic molding for each cup[/b:1e45f80696].

Are you saying that you installed new u-joints and are relying on the remnants of the factory plastic retaining injections to keep them in place?

ditchwitch · Feb 28, 2020

Check the Torque converter ,Might try take it back loose and rotate it one hole then bolt it back up

Chevy Question

Howard H.

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grizz02

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Janicholson

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Bob

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guido

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Dave BN

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504

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Hobo,NC

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Howard H.

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Stephen Newell

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gab

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Clarence Slydell

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ditchwitch

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