Front transfer case drive shaft play

[07keo02]

I was checking some things out underneath my truck today and noticed my front drive shaft had a decent amount of up and down play inside of the transfer. Probably at least a quarter inch. This seems like a lot to me but I could be wrong. I am also wondering about the transmission mount as well. I can push up on the back of the transfer and somewhat easily move the transfer/transmission up and down with the rubber flexing. Same thing happens with the 2 piece drive shaft carrier bearing rubber. The rubber isn't torn or anything it just seems to me I have a lot of drive train slop that contributes to the surge and bucking under low speed throttle. I am looking at merchant auto's trans mount to see if it fits the zf6 and probably going to do a one piece drive shaft conversion as well but I am starting to wonder if something is wrong with the transfer case.

 

[Sledheadxp800r]

You'll always be able to move the trans mount and driveshaft center support bearing around by hand and there's probably going to be some play where the front driveshaft goes into the t case. sounds pretty normal to me unless the rubber is oil soaked or torn.

I'm pretty sure if you run a 1 piece rear driveshaft you will get a vibration. There's a reason GM used a 2 piece and i doubt it was to to save money.

 

[02CCSB]

The front shaft should have no play at all. The front output bearing must be on its way out. The trans mount and hanger bearing should have some play. Solid trans mounts create a lot of vibration.

 

[07keo02]

You'll always be able to move the trans mount and driveshaft center support bearing around by hand and there's probably going to be some play where the front driveshaft goes into the t case. sounds pretty normal to me unless the rubber is oil soaked or torn.

I'm pretty sure if you run a 1 piece rear driveshaft you will get a vibration. There's a reason GM used a 2 piece and i doubt it was to to save money.

Gm has a tsb for allison CC trucks to change the 2 piece to a 1 piece aluminum because of shudder and vibration problems. The zf-6 was not included because the 1480 series yoke in the rear differential but a 1410 yoke swap or 1410/1480 combination U-joint will solve that. There is a thread somewhere where a guy with the Zf-6 had GM research the vibration/shudder issue in his truck and they actually did the swap for him. He was very pleased with the outcome.

 

[07keo02]

The front shaft should have no play at all. The front output bearing must be on its way out. The trans mount and hanger bearing should have some play. Solid trans mounts create a lot of vibration.

How about a Poly mounty such as Merchant Auto's?

 

[Sledheadxp800r]

Gm has a tsb for allison CC trucks to change the 2 piece to a 1 piece aluminum because of shudder and vibration problems. The zf-6 was not included because the 1480 series yoke in the rear differential but a 1410 yoke swap or 1410/1480 combination U-joint will solve that. There is a thread somewhere where a guy with the Zf-6 had GM research the vibration/shudder issue in his truck and they actually did the swap for him. He was very pleased with the outcome.

I was referring to a 1 piece steel driveshaft causing a vibration. An aluminum one will work but won't be as strong. If you sled pull, drag race, or beat the truck to death like a lot of the people on this site then aluminum probably isn't the best way to go.


The poly trans mount will be stiffer than the oem one

 

[07keo02]

Ok I see, I do not beat on my truck much. I am just looking for less drivetrain slop and clanking. I also have a shudder under hard acceleration but have not tried to shim the carrier. I am still not sure about the front diff prop shaft seems there are alot of opposing opinions. I will probably just see how it goes for now. I changed the fluid out a couple weeks ago and it actually looked really good.