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john hd · 02-22-2003, 07:04 AM

since chevys seem to be the most popular tow vehicle around here, i was wondering if any one other than me had their two piece replaced?

this aluminum unit was installed to fix a shudder in the driveline under heavy load at slow speed.

the installation eliminated the center support bearing, one u joint, and the middle slip joint.

haven't had a problem since! and there are less moving parts to repair later!

john

john hd · 02-22-2003, 07:05 AM

john

John · 02-22-2003, 07:24 AM

John,

That's interesting because when I rebuilt my 73 C-10, I had the 2 piece drive shaft, and had to have it shorten/rebalanced because I put a 700R4 in replacement of the 4 speed manual. The guy who did the balancing said that the 2 piece drive shaft is better than the 1.

I believe he said that it helped with the torgue. That the 2 piece displacement was less stressful on the driveshaft.

Maybe Chevy felt that it was easier just to replace it with a 1 piece than to have it rebalanced?

John

john hd · 02-22-2003, 07:36 AM

john

i won't disagree on that, what i have found out was that on some extended cab models the problem was not balancing.

they discovered that they could not get the three u joints to phase with each other under heavy load. resulting in a wobble.

at high speed my old two piece unit worked perfectly, so it wasn't balancing.

my problem was at low speed pulling a load. the trucks drive line would "shake" until i hit 25 to 30 mph.

the new unit is huge! my best guess is that it is 9 to 10 inches across!

like i stated before, no more problems at any speed or load.

best of all the fix was covered by my warranty.

john

John · 02-22-2003, 07:49 AM

John,

I need to wake up!! You said that at low speeds under a load, you got the shudder. Of course if it was a balancing problem, you would have felt it on the hwy!!

That is a hugh driveline and I'm sure it was designed for the heavy loads!!

I too love warranty work, but I only have 4,000 miles left

! But it's enough to get me to NM!!

John

john hd · 02-22-2003, 08:25 AM

Launch Shudder on Acceleration (Install New One-Piece Propeller Shaft) #01-04-17-001B

1999-2002 Chevrolet and GMC K2500/3500 Extended Cab Long Box and Crew Cab Short Box Pickup Models
With Automatic Transmission

This bulletin is being revised to add model information, remove procedure steps and change parts information. Please discard Corporate Bulletin Number 01-04-17-001A (Section 04 -- Driveline Axle).

Condition
Some customers may comment on a vibration during acceleration from 0-40 km/h (0-25 mph). This may also be referred to as launch shudder. This condition may be more noticeable when the vehicle is carrying cargo or is used for towing.

Correction
A new propeller shaft is available for service to correct this condition. This new propeller shaft is a one-piece design and will replace the current two-piece design.

Install a new one-piece propeller shaft on affected vehicles. Refer to the service procedure and the parts information listed below. Match the affected vehicle with the appropriate propeller shaft. Refer to the usage information below. This fix does not apply to the Chassis/Crew Cab Models (K35943).

Remove the propeller shaft assembly and the center bearing. Refer to the Propeller Shaft - Two Piece procedure in the Propeller Shaft sub-section of SI2000. For this bulletin, it is not necessary to mark the components for re-assembly.

Important
The center bearing support bracket (1) must be removed in order to provide enough clearance for installation of the one-piece propeller shaft. Avoid damaging the crossmember during removal of the center bracket. For proper clearance, no more than 13 mm (½ in) of the bracket may remain on the crossmember after removal.

Remove the center bearing support bracket from the kick-up crossmember using a cut-off wheel.
After removal of the center bearing support bracket, grind the rough metal edges smooth that remain on the crossmember.
Coat the exposed metal surfaces with frame coating using the information found in the applicable Service Manual and GM Refinish Material Booklet #4901M-D-2002 (English) or #4901M-D-F2002 (French).
Install the new propeller shaft. Refer to the Propeller Shaft Replacement - One Piece in the Propeller Shaft sub-section of SI2000 for installation guidelines and yoke retainer tightening specifications.

Parts Information
P/N
Description
Usage

15077431
Shaft Asm.- Prop
K25953 w/ LQ4, MT1, C6P (99-00 8600# GVW)

15077434
Shaft Asm.- Prop
K25953/35953 w/ M74 (Allison Trans)

15077435
Shaft Asm.- Prop
K25953 w/ LQ4, MT1 (HD Model 9200# GVW)

15077436
Shaft Asm.- Prop
K35953 w/ LQ4, MT1 (11,400# GVW)

15093466
Shaft Asm.- Prop
K25743 w/LQ4, MT1 (HD Model 9200# GVW)

15093467
Shaft Asm.- Prop
K25743 w/M74 (Allison Trans)

john

davidz71 · 02-22-2003, 09:36 AM

Johnhd,
Since we both spend time on the pickuptrucks.com forum, I was familar with the 2 piece drive shaft problem. While looking for a truck to replace the '92 my son rolled trying to miss a deer, I crawled under a number of 2500LW and 2500HD shortbed trucks with extended cab. Some of those models had a 1 piece and others had a 2 piece shaft. I never liked the idea of a center bearing and extra U-joints because that is just something else to replace so I just passed up on these combinations. I'm sure glad I did because some of those guys on the forum had some real problems. Did you catch the one guy who had the crossmenber cut out and they cut too much? If memory serves me right, they gave him another truck.

john hd · 02-22-2003, 09:47 AM

craig,

yes you are correct! i belive that truck was replaced.

i have looked under some half tons, the one piece aluminum shaft is standard on them.

i am glad that my dealer was prompt about fixing this problem. being armed with information when you go for service helps alot! the pickuptrucks.com forum has helped too. it can be a fun place to post!

i like the more mature atmosphere here, maybe we could start a airstream forums version of the "war" room!

my trailer is way better than yours because _____ !(fill in the blank)

waddya think?

john

davidz71 · 02-22-2003, 10:14 AM

Johnhd,
It is a good forum for all aspects of truck ownership. I passed on the 6 liter engine in the 2500hd because of the problems identified. They have fixed those problems for '03 but look how many 6 liter engines are on the road with cold start knock. I think I will pass on the "war room" for Airstreams since I like the atmosphere in it's present condition.

john hd · 02-22-2003, 11:27 AM

craig

i hear ya about the 6 liter, i got lucky! no problems with mine whatsoever!

however, if i had. it would have got the brick on the gas fix!

zooom then booom!

john

davidz71 · 02-22-2003, 11:38 AM

Glad you got a good one. I seriously considered a 6 with Whipple supercharger which I thought would be the super combination for better mileage around town and highway when not towing then enough power/torque when towing. I'm planning on installing a Volant Performance airbox for better air flow but probably will wait until the warranty runs out.

john hd · 02-22-2003, 11:48 AM

craig

i think you did better with the big block than any supercharger set up.

as for the intake, i would want to hear a truck with one before i put it on a tow vehicle. the increased noise might be tiresome on a long trip.

unless you get the metallica box set of cd's before you leave!

john