View Full Version : DriveShaft Repl/Flash Updates
Heard about the drive shaft bulletin; called my dealer; have one on order. I believe a single shaft 1)has less wear and tear than split shaft/carrier bearing assy. 2)looses less power to the rear wheels,etc. I am glad to hear Chevy taking care of business. As we all know, these ain't cheap trucks!
The other thing is the ecm/tcm updates....should I have them done and what will they offer me....
thanks
2001 2500HD alli/max 4x4 cc swb
serious truck for sure!!!
DMax_Doug
11-04-2001, 21:40
wspoon,
Great news on the single shaft. As for the ecm/tcm updates, I would get them done. My truck was built on 10/18/01 and I think I have most of the current updates. I have not noticed many of the symptoms detailed in other posts here; so my read is that these ecm/tcm updates must be improving the Dmax's overall performance.
Just my $.02 worth
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2002 2500HD D/A LS CC SB 4x4
Dark Carmine Red
Simple question. I have a 2500 HD DA 4 x 4 CC SWB with the 2 piece drive shaft. I have not noticed any problems/shudder unloaded or loaded.
If the 2 piece drive is such a bad thing, then why did GM design it that way to begin with? Surely there must be some advantage to a 2 piece driveshaft, cause it's a lot more expensive & complicated to manufacture than the 1 piece telephone poles. Is it just the ground clearance advantage?
HawgGuy
WSPOON,
Can give me bulletin #'S for CC short box. I was told the bulletin only apply to long box CC D/A'S.
Thank you Steve
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2002 2500HD pewter CC Short Bed
Rhino Lining
Roll-N-Lock Cover
Jayco 34ft 5TH Wheel
sonofagun
11-05-2001, 08:58
Fewer moving parts can't be bad. Had my truck done and it has no shudder under heavy towing load (it did before). BE SURE TO TELL THE SERVICE WRITER TO TELL THE SERVICE GUY TO NOT , I SAY NOT, CUT THE CROSS MEMBER. The GM instructions are not clear. Some have had the cross member cut. The only way to get a new one is order a new frame or live with a welded crossmember.
http://www.geocities.com/crackeregg/gmsi.html
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2001 GMC 2500HD D/A olympic white, Manik
SS brush guard and nerfs, Hella driving
lamps, Velvet rides, HD Air Lifts and Compressor
Snugtop cover, Linex,Yakima rails on cover (mt. bikes),
Amsoil 2 stage airfilter. ECM upgrades.
1966 Chevelle convetible 396 4SP (restored)
_ _ _ _ _ _
Working on EGT/Boost guage, 43Gal fuel tank,
4" exhaust.
GOD BLESS AMERICA and those who walk in harms
way to protect us all!!
I took mine in today for all these updates. It's ready to be picked up and they said the parts are on order for the driveshaft replacement. I was worried about the shortbox issue, too. I used the long box bulletin number. So far, so good. I gave the service dept the printout about not cutting the cross member.
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John Brunsgaard-jeb
01 Silverado LT SB CC D/A 4x4 2500HD
Tader Jack
11-05-2001, 17:33
I too have not noticed any shudder loaded or not. I don't know why some seem to have the problem and others do not. I have a CC/SB 2500 and have tried to make it do the "so-called" shudder. Mine won't do it.
The only thing I have felt is a little wheel hop under hard acceleration when burning rubber or when it's a little wet and you get on it too much. Maybe this is what others "think" is the shudder in the drivetrain and don't know the difference.
What is the advantage of having a one-piece over the two-piece if the two piece is working fine? Mine is as smooth as can be at any speed right up the the rev limiter and I kind of hate to take it in and have them ruin it.
What do you guys think?
Jack Schultz, McKean, PA
jackschultz@adelphia.net
http://photos.yahoo.com/bc/jack_schultz2001/lst?.dir=/&.src=ph&.view=t
2001 Chevy Silverado, 4-WD, 2500HD, Crew Cab, Short Box
LT Trim, Black Onyx w/ Tan Leather
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Beltronics 980 Radar Detector
battmain
11-05-2001, 18:41
I have the shudder with my longbox 4x4, but pressing harder on the gas will eliminate it completely. Trying being gentle on the throttle and as the speedo passes between 5-8 mph, you can feel the truck wiggle. Much bigger wiggle when towing the trailer. And that is with a fairly light open car trailer in comparison to what some people are towing here.
Brian
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2001 Torreador Red 2500HD GMC Sierra Ext Cab Longbed. 6.0 4x4 Deep Tinted Glass with Defroster. Weathertech Ventvisors.
do not have the bulletin numbers but i will advise them NOT to cut crossmemeber; that can't be a good thing!!!!!I did not notice the shudder but I don't want it to develop later on when I'm out of warranty. I have never liked two piece shafts/carrier bearings,etc.
Guys.
Go here www.picturetrail.com/stevem (http://www.picturetrail.com/stevem) and check out the crossmember album. Print out the picture and bring it to the dealer when they do the update.
I would hate to see another truck BUTCHERED.
Steve.
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2001 CHEVY/2500HD/4X4/ XCAB/LONGBED/DURAMAX / ALLISON/MED CHARCOAL/GRAY LEATHER/LT WITH ALL OPTIONS/CENTERLINE RATTLERS/BFG-AT-KO-285-75-16.
I'd still like to know why they designed it with 2 pieces to begin with. That had to be a more expensive & complicated way to go, so there must've been some advantage.
Hawgguy
Stevem,
Tell me if they are not supposed to cut the crossmember what is the correct procedure.
thanks Steve
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2002 2500HD pewter CC Short Bed
Rhino Lining
Roll-N-Lock Cover
Jayco 34ft 5TH Wheel
http://www.geocities.com/crackeregg/01-04-17-001A.html
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2001 CHEVY/2500HD/4X4/ XCAB/LONGBED/DURAMAX / ALLISON/MED CHARCOAL/GRAY LEATHER/LT WITH ALL OPTIONS/CENTERLINE RATTLERS/BFG-AT-KO-285-75-16.
Tader Jack
11-06-2001, 09:19
The bulletin #01-04-17-001A applies only to Extended and Crew Cab "Long Box" models. It says nothing about the Crew Cab Short Box. Does the same apply or doesn't the problem exist with all the models?
If you read the applicable part numbers on the bulletin, 25743 is the short bed.
15077433 Shaft Asm.- Prop K25743 w/ M74 (Allison Trans)
The title of the bulletin must be mistaken. Many with short beds have had the new shaft installed.
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Mike (dmax) DP Member #2429
2001 2500HD GMC Duramax/Allison Summit White CC/SB Loaded, Amsoil Air Filter, PS2K Propane, 22 Gal. LP Tank, Straight Piped, Allison Deep Pan, Transynd Syn ATF, SPA DG-111 Boost/EGT, Nordskog Digital Fuel Level, VentShades, Husky Mudflaps, 255/85-R16 Dunlop Radial Rover RV's PICTURES (http://onramp.uscom.com/~hoot/cars/duramax/gmc)
1994 K1500 Blazer 350 Loaded, Flowmaster duals
Idle_Chatter
11-06-2001, 09:51
The two piece design is stronger (the short shafts can absorb more torque in less material - one reason why the replacement one-piece is so big) the steady bearing strengthens the assembly and gives a better shaft to differental angle. However, the play and shudder is occurring because of the extra pair of universal joints in the two-piece setup. It was a good idea, and one used all the time in heavy truck applications, it just didn't work out in the Dmax.
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Tom Ashley
2001 DuraMax/Allison
2500HD Silverado LT
Lt Pewter/Graphite Lthr
Ext Cab/Shrt Box/4x4
Line-X/Century Ultra Cap
Tader Jack
11-06-2001, 10:01
Thanks hoot --
I'm still debating whether to take it in or not. I have tried and tried and "cannot" get the shudder that some are experiencing, slow or fast, loaded or unloaded.
I'm almost of the opinion "that if it ain't broke, don't fix it". I feel the same about the ECM updates. I've been very happy with my setup and hate to have them flash it and screw up something that I like. I know that many are saying to get "both" the driveshaft and ECM updates, but I'm not sure if it's just a "me too" thing that everyone is doing for the sake of keeping up with the next guy.
I could understand it if something was wrong . . . but when it's not, I'm very hesitant to take it in at this point. I've learned from experience that the less time a vehicle sees in a dealer garage the better off it is.
Jack Schultz, McKean, PA
jackschultz@adelphia.net
http://photos.yahoo.com/bc/jack_schultz2001/lst?.dir=/&.src=ph&.view=t
2001 Chevy Silverado, 4-WD, 2500HD, Crew Cab, Short Box
LT Trim, Black Onyx w/ Tan Leather
------------------------------------------------
Beltronics 980 Radar Detector
Idle_Chatter
11-06-2001, 10:07
Stevel5: the service bulletin says under the illustration: "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 13mm (1/2 in) of bracket may remain on the crossmember after removal." Step (9) also pretty clearly states: "Remove the center bearing support bracket from the kick-up crossmember using a cut-off wheel." And step (10) says: "After removal of the center bearing support bracket, grind the rough metal edges smooth that remain on the crossmember." The guy that just chopped the whole section of the crossmember out was a real dim-wit and probably deserves to be fired.
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Tom Ashley
2001 DuraMax/Allison
2500HD Silverado LT
Lt Pewter/Graphite Lthr
Ext Cab/Shrt Box/4x4
Line-X/Century Ultra Cap
DoneRight
11-06-2001, 10:35
Hawg Guy,
They did not design it that way! They just continued to use a gas engine design that they have been using for several years. They just didn't redesign it untill now!
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2002 Chevy 2500HD 4x4 CC, SB, AliMax, Indigo Blue
-LineX Over the Rail
-Piaa 1400's in Rear
-High Idle Kit Installed (2 speeds)
-Tape deck replaced with 300w inverter
-Vaio Laptop with Cell Modem in place of cupholders
MyTruckPics (http://www.picturetrail.com/doneright)
To the top for Big Bob
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2002 4X4 Chevy 3500 LS Ext Cab Dmax/Allison
Only getting 15 MPG, hoping it will get better.
[This message has been edited by mcfly (edited 02-20-2002).]
DaveRuane
05-30-2002, 12:30
OK guys, dug up this old post to ask my question from...
I recently had the single driveshaft installed on my '01 2500HD CC SB 8.1/Allison. The dealer wouldn't do the TCM updates until this work was done and had some field trials. The shaft feels great under acceleration and even seems to have improved mileage? But, now I am noting a strange "bump" in the driveline when I come to a full stop - usually a hard stop. What happens, is in the instance just prior to the stop, I feel a little "bump" or slip. The best way I can describe it is that it is similar to when you are backing up to a trailer, and bump the receiver - you get that "little give" when you bump the trailer but it moves with the impact. Sometimes it seems like it does this twice. Sometimes, if I dont ease of the brake after stopping it does it immediately after letting off the brake.
Could this be this 2-to-1 shift quality issue that a TCM will resolve? I may be biased since I know my TCM update is OEM from February, 01 and I have read so much about this.
Has anyone else noted this, and have any insight on it? Thanks!
DaveRuane,
Sounds just like what others are saying and getting results with the TCM update ..... Take it in ..... It does it in my truck when I'm hard on the gas .. then hard on the brakes .. I don't think a reflash will help me . Just better driving habits .......
MAC :D
DaveRuane,
I just had the latest TCM update done Tuesday,which supposedly addresses the 2-1 downshift, but I still get the same thump/clump coming to a stop that you do - I had the one piece driveshaft installed December last year.
When they first installed the driveshaft, they installed it dry, so it really thumped/clumped coming to a stop. Took it back and they lubed the driveshaft, and no thump/clump for a couple months. Now on a cold start, meaning the truck has sat overnite, I get the thump/clump for the first 15 miles, then it goes away.
Asked the dealer to re-lube the driveshaft on Tuesday, but the tech said nothing was wrong and wouldn't do it. Whatever.
I think the thump/clump coming to a stop with the one piece may be a lube issue more than a tranny issue.
Jimamatic
05-31-2002, 14:43
Hey guys...
I posted this exact same problem with the D/L
clunk and I have the two peice. I'm begining to
think it's a software issue. When it happens to me on the stop, I can feel a slight pulsation
just before coming to a stop. Then I get the
clunk as the truck stops. Then another clunk or
slip on the go. This pulsating effect,(best way I
can describe it) happens just about every time I
get the clunk. Just pulled our 27' 7500# travel
trailer for the first time and was very impressed.
I have the dreaded launch shudder so I'll be
getting the one piece d/l. The only thing
standing between me and pure heaven is this
clunk issue. Hope we get it figured out....
When I had the two piece, I had the thump/clunk coming to a stop, and then again on take-off.
Now with the one piece, I have the thump/clunk only on take-off.
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