6 speed HD. How smooth is smooth?

[JTroiano]

THubbard,



"I wouldn't do this all the time but it will give you a good idea on what the trans. wants to see in regards to rpm's to shift. "



I talked to a lot of truck drivers over the years and a few that owned their own trucks and they all said to not use a clutch when shifting. I drove a Mack DM 800 and it had an 18 speed quadraplex trans. that if you used the clutch you could never shift quick enough to keep it moving. (2 shifters) In fact it would not even go into the next gear. This truck had alot of use and never had a problem with the trans. I agree, that our trucks should not be shifted like this all the time due to it wearing on the syncro's. The above post is so that a person can understand the correct rpm's that the vehicle needs to shift. Otherwise you are still being hard on the syncro's because they still have to sync the gears to the engine/driveline speed. When you down shift a standard trans you speed up the gears to match the driveline. The wear surface on the synco is doing this work. So the best way for the trans to down shift is to match the gears as close as possible to prevent wear. To do this you push the clutch in and then put the trans in neutral and then let the clutch out and rev the engine to the proper rpm's and then push the clutch in and down shift. This is to much work and there is a lot of other things that could wear out due to reving the engine etc.

Jon

 

[MikeR]

jtisdale,



'Star' is the technical support center for the Dodge dealers. If the techs can't find or verify problems, then they call Star for help,verifications, or approvals.

 

[jtisdale]

Thanks...

 

[Benson]

A lot of people are using Amsoil series 2000 5W-30 HD oil with apparently no problems. I'd like to keep informed on this issue since I am thinking about going that way.

 

[jodog]

THAT NO CLUTCH THING

is called throtle shifting,and if you drive big trucks you better know how!!!I tried it in HO 6speed it didn't feel natruel but could do it. It might help to double clutch[wich sucks]



1) push clutch in hold

2] Go from gear to neutral

3]let out clutch

4]push in clutch select new gear

5]let out clutch



P. S> had a ford 8000 5speed 3208 cat had to double clutch

 

[Texas Diesel]

Originally posted by JTroiano

THubbard,



" I talked to a lot of truck drivers over the years and a few that owned their own trucks and they all said to not use a clutch when shifting.

TRANSMISSIONS DESIGNED FOR CLUTCHLESS SHIFTING ( 18 WHEELERS, DUMPTRUCKS ETC. ) HAVE ROUNDED EDGES ON THE GEARS, OUR TRANSMISSIONS DO NOT.

 

[NVR FNSH]

Originally posted by Michael Brolin

There has been documented cases of the 6spds not wanting to go into gear at idle. I know of one member who had this problem at 32000 miles. The shop called Star. They said to replace the clutch,pressure plate and flywheel under warranty. There have been rare occurences,especially when towing at or near max GCVW,of weak pressure plates. After the tech removed the clutch they saw that the throwout bearing was not hitting all of the forks on the pressureplate. At this time Star said to replace the slave cylinder because a small internal part will break off unbeknownest to the driver. All of this was done under warranty and has happened to about 600 trucks. BTW,the clutch had no signs of wear. A quality shop who knows which person to talk to at Star can get answers.

Michael,

You wouldn't happen to have the name of who to speak with at STAR would you? My dealer "cannot duplicate/shifts fine to us" and they faxed STAR and got a "no known issues/problems with the 5600" response. I'm going to try another dealer as this is the third time I've had the truck in the shop and they still think it's fine



Brian

 

[forr]

Same observation as Evan Beck. With 20000 miles it's as smooth as silk - well ..... maybe not that great but its alot smoother than new. Neutral to First gear is a little hesitant from a standstill sometimes, but my experience with 'crawler' gear in all shapes and sizes of trucks has been just this. If consistent grinding or unusual shifting force is necessary and you're engaging the clutch pedal fully, then it certainly makes sense to record any problem with your local dealer while the mileage is low - just in case.



Goodluck.

 

[partingd]

Last Sunday returning from a camping trip with my fifth wheel the clutch went out completely. 24K miles on 2001 2500 HO Diesel with manual 6 speed. Trailer is not over weight for this model Dodge, that is why I bought it versus the normal Diesel. I traded in a 97 Diesel. I had some of the problems described in this thread, like shifting into reverse after a long trip became difficult, etc. Had dealer look at this, they had no comment. I had to replace the clutch at my expense, out of town dealer said they found no defect in the clutch. I believe the 6 speed clutch is under sized for the higher torque of the HO Diesel. Will continue to press my case with Dodge and let you know the result.

 

[Wheaties]

Heyboss,

I think it was issue #33 they talk about the additives and the special nature of the transmission oil for the 5 and maybe the 6spd. I don't recall all the details, but it's a use for life oil, and there were very good arguments for not using anything else, not even synthetic.



If people want to try their favorite oil, I say go ahead, but not in my transmission.





Since we talked about where the power is on the ETH, I have started shifting much later once the engine is warmed up, that is when I want it to really go. It seems to shift much easier going up the gears when I do this.



The shift pattern is pretty different on the six, going from 2 at the bottom left to 6 on the top right and it has taken me quite awhile to get the feel for it. Even so, it is a heavy transmission, but I think it's very smooth for all it's size.



I haven't tried tapping on the go pedal when downshifting yet, but I bet it will help the syncros a little.



BTW, check out Fritz' site for the specs on the ETH/DEE combo, the flywheel and clutch are bigger than the ETC to compensate for the increased power.



Matt

 

[Vaughn MacKenzie]

I have the Amsoil HDD 5W30 in my transmission. It seems to like it in most gears better but going into 3rd it bumps the teeth more (doesn't grind though). I only went with this after seeing a couple posts by members who have run it over 50k miles (one has gone about 100k with no problems at all). .



Mine has shifted stiff from day one and is not much better at 52,000 miles. I am sure it is my hydraulics though. Under the dash where the clutch rod enters the master cylinder, it is rather moist so I know it is leaking. I wish someone would come up with HD clutch master and slave cylinders.



Vaughn

 

[Big P]

I noticed that after I added the BD PNP it seemed to shift into 3rd a little better. Maybe the extra torque "seated" the gear or the syncros.