Engine/Transmission (1998.5 - 2002) 6 speed differences 2002 - 2003?

[Pit Bull]

Are there any differences in the 6 speed transmissions from the 2002 model to the 2003 model?

 

[Gary - K7GLD]

Dunno about the transmission itself - but understand the clutch disk is now larger in diameter...





OH - and they don't have that tag on the transmission that sez ya gotta use the MS-9224 lube...

 

[tarussell]

I read that the shifter tower is different on the 2003's and that the rest of the transmission( internally ) is the same - except for the sticker on the PTO cover as mentioned above. I think the shifter tower had to be changed because of the new truck not a design change.



Thomas

 

[Pit Bull]

Originally posted by Gary - KJ6Q



understand the clutch disk is now larger in diameter...

I think that changed a couple of years ago. Along with the input shaft size. Unless they made it bigger again. I would think better would be perfered to bigger

 

[dresslered]

I've always wondered about the differences as well. Supposeably, the pre-2003 six speeds had an input maximum torque rating of 550-lbs. If the 2003 HO puts out 555-lbs. , is DC exceeding their own specification? If they beefed it up, how?

 

[Pit Bull]

Originally posted by dresslered

I've always wondered about the differences as well. Supposeably, the pre-2003 six speeds had an input maximum torque rating of 550-lbs. If the 2003 HO puts out 555-lbs. , is DC exceeding their own specification? If they beefed it up, how?

David that's a good point. If the transmission was rated for 550 lbs then what did they change to have it handle 555 lbs. besides the marketing material :-laf I know the shaft and clutch were increased after 2000 so what have they done lately?

 

[dresslered]

I believe that New Venture initially came out with a much higher rating for the 6-speed and it was a DC specification that was implemented. The clutch seems to be the weak link. Has this been upgraded for the '03?

 

[tarussell]

I saw some literature a while back that said the 5600 in a medium duty application had a input torque rating of 650 ft. lbs. , I don't know what service factor that was on though . I figured there was a shaft up-grade or something ??? Does anybody know what other applications that use the 5600 ?



Thomas

 

[Paulsdodge]

Trans Lube

Ok guys,

If the sticker is not on the new six speed transmissions, what kind of lube does the new six speed call for? And will it work and keep the warranty intact on a 2001 six speed ?

 

[Pit Bull]

Originally posted by tarussell

I saw some literature a while back that said the 5600 in a medium duty application had a input torque rating of 650 ft. lbs. , I don't know what service factor that was on though . I figured there was a shaft up-grade or something ??? Does anybody know what other applications that use the 5600 ?



Thomas

This is very interesting, I don't think we have investigated this before. I wonder if the only change is in the literature?

 

[jerryrigg]

As far as I know NV5600 has always been 555lbs



http://www.newventuregear.com/transmissions.html

 

[tarussell]

I saw the torque rating on the New Venture web site too , but I wonder how up dated that info is. I am in NO WAY saying that the info NVG is putting out on there own web site is wrong but I don't know if it tells the whole story.

Ex: some one, who is very knowledgeable on the TDR, a few weeks ago posted that the input torque on the 241H. D. and the 271's & 273's where the same but the NVG web page states otherwise. I have no idea if that info is accurate or not but there might be more to the truth about ratings than what general publications put out. My point is, the info that is put out to the general public is usually generalized and not specific to all applications.

If anyone has any friends or contacts at NVG they should be able to answer all of our questions???

Just as an example the old 4-speed CH 465 GM transmission's that had a 1-1/2 10 spline had a much higher weight and input torque capacity than the standard 1-1/8 10 spline version. The only difference between the two were the input shafts. Maybe NVG has a vesion of the 5600 that is at a higher rating???

I got no problem with the impressive torque capacity of our version of the 5600 but it would be nice if we all could find out what the next step up in strength is.



Thomas

 

[Vaughn MacKenzie]

Comparing shifting performance, the '03 6-speed I drove blows my 6-speed away. It shifted absolutely wonderful, felt like a much lighter-duty transmission in my hand than the truck transmission it is. Slid through the gears so smooth and easy, no hint of notchiness, went into 1st and reverse as easy as pie.



I have driven a couple other '02 & older 6-speeds and they are comparable to mine. Me thinks they improved the synchros or something.



Vaughn

 

[Gary - K7GLD]

Vaugh, with all due respect, you'd need to ALSO drive several of the '03 6-speeds as you have the older ones to form any realistic baseline... There are a few here complaining about various degrees of shifting problems with the older 6-speed trannies - and I suspect some of them equate a 6-speed TRUCK transmission to 6-speed performance car transmission... Ain't likely to happen!



My own 6-speed shifts beautifully - sometimes (rarely!) mild resistance to reverse - as easy to correct as simply let out the clutch, and then try again, as the gates line up better - otherwise, mine shifts smooth as butter, and with only 6500 miles on it, just keeps getting better.



BUT, if I got out of mine, and into an '03 that just happened to be one of the HARD/stiff shifters, it might slant my whole outlook on the '03's... Maybe they HAVE made improvements on the '03's, we've heard about the shift tower change, and that CAN change the leverage, length of throw and "feel" of the shifter... Time will tell...



MEANWHILE, it takes more than one or two trees to make a forrest...

 

[Vaughn MacKenzie]

You're right Gary, I've only driven one '03 and if I drove more of them my opinion may be different.



My 6-speed shifts good though, I don't have trouble going into 1st or Rev. like I used to. After installing a new slave cylinder and putting Redline oil in the transmission it shifts much better now at 80,000 miles than it did when new

It was very heavy and notchy when new.



Vaughn

 

[mgoncalves]

I am going to take a guess on this one, I have heard that the 03 ho will rev itself between shifts to help keep boost up when accelerating. IF this is true, I think they would have to have some sensors to know when you are shifting and not just pushing in the clutch. Like I said, that's just a guess I haven't driven one. I have 11,000 on my six and it is by far the best transmission I have ever owned, actually when I first got it I wanted to shift into 7th when on the interstate. Now I kill my chevy work truck every time I need to backup!!