Might have found a fix for hard shifting

[South Bend Clutch]

We had a gentleman call us the other day that has been installing clutches in the diesels for some time now. He has installed many of ours as well as others, even the OEM replacements. He stated that people were coming in with shifting problems prior to new clutch and also had problems with other vehicles after replacing the clutch. There was no pattern, some would be fine, and others would have problems. He started thinking that with all the different clutches that he has installed and how some reacted fine and some did not that he determined that it was not clutch related. So he started playing with the transmission fluids. Working on his own first, he tried a few different variations until he came up with installing Red Line Transmission Fluid and one pint of Prolong and his shifting problem went away immediately. After about 18-20,000 miles the shifting problem came back, so he drained the transmission and repeated the fluid change with Red Line and Prolong and the shifting problem went away again. Now he has been doing this with multiple vehicles and has resolved 95% of the hard shifting problems that come in the door. His recommendation is to flush and replace every 18-20,000 miles.



I hope this helps and I would love to hear some feedback from anyone who has tried this or is going to try this that are having shifting problems. We need to find a way to resolve this problem and this is the first concrete evidence of repetative success that anyone has come to me with.



Peter

 

[Dane]

Peter,

Interesting post. I found the same to be true when I changed my NV5600 fluid at 10,000 miles. I always change fluids in new vehicals to get the the break-in metal out regardless of what the mfg says. When new the transmission was very stiff and required shifting into 3rd before going into reverse or 1st.



Anyway, after changing the fluid with the Texaco factory juice the transmission shifted easier right away. At 28,000 it shifts very easy all the time.



I think all lube fluids should be changed every 30,000 regardless of driving habits. It's cheap insurance imo...

 

[tarussell]

I changed my fluid at less than 3000 miles for the same reason that Dane did and my 5600 has always shifted very nice. Now the truck has close to 25,000 miles on it and I plan on changing the fluid soon. I don't know if this will help but that's what I did and it has alway's shifted well . Thomas

 

[klenger]

Is this recipe for the 5 speed or 6 speed. They are very different.

 

[Vaughn MacKenzie]

Clarification

Peter, do you mean Redline MTL "Manual Transmission Lube"?



What is Prolong, an oil additive? I've heard of it, just not sure what to look for.



Thanks for the great information

I have several quarts of Redline MTL ready to change into my 6-speed so I'm glad you posted this before I made the change.



Vaughn

 

[Pit Bull]

Makes sense, mine shifts fine but I have to take it easy going into 3rd gear when it is cold, not a problem when it is hot. I plan on changing mine every year (20K) just for the fun of it



Question, if I used Redline and prolong would that void my warranty if I had a transmission problem? Or could they tell that I did not use the factory fluid???

 

[HVAC]

Prolong

Yup, Prolong is an oil additive. I had a dual disc clutch which didn't release very well. I also used Prolong to improve shifting.

 

[Sled Puller]

I don't see a problem with changing the lube more often, (probably the main secret to smoth shifts )but I advise caution with additves of any sort. Check the comapany's record with the FTC before buying.



For the record, I have never had a problem shifting with any transmission, with factory lube or not, stock clutch or not.

 

[John Berger]

I went to Amsoil's GL-4 synthetic lube, from the Series 2000 stuff, and my shifting problem has pretty much went away. I still have trouble when backing the 5'ver going from Reverse to 1st and back and such, but it shifts into second now on the first attempt and doesn't feel like it's sticking coming out of second going into third. Good info. I still think I may have a slave cylinder problem, but I can't prove it, unless I want to spend the money.

 

[South Bend Clutch]

klenger



I believe it is for both, 5 & 6 sp.



Peter

 

[Gary - K7GLD]

Only thing to be aware of and watch out for, is SOME trannies use fiber syncro facings that can be VERY sensitive to, and damaged by, non-spec lubes - the 6-speed in my '98 Camaro SS was one of those, and I understand the syncros in the 6-speeds used in our trucks do also - but don't know for sure...

 

[Diesel Freak]

My transmission gets very hard to get into gear when I abuse tha crap out of it... but after a while it clears up. It acts like the clutch is draging. any thoughts.

 

[MCummings]

ProLong has additives that aren't normally used for lubricating. If I recall correctly, I heard from a guy (take this for what it's worth) That, Prolong has eithe Bleach or Chlorine in it, and they are being sued for ruining many motors and other metal things (like hinges, locks, etc).



Anybody heard the same.



Merrick Cummings Jr



P. S. This isn't the "straightest" talker in the neighborhood.

 

[Jack in Alaska]

My 5 speed hangs up going into 1st or reverse. Nothing is consistant about it. Sometimes it does and sometimes it doesn't. It seems to be getting worse though.

I have the factory recommended fluid in it but not original. It has been changed 2 times with 97k miles.

 

[Adam]

Pro Long works

MCummings,



I used to put Prolong in my gas vehicles, and have nothing but good stuff to say about it. On the first change in a '96 Cherokee (4. 0L 5-spd/25,000mi) the coolant temp dropped 15 degrees at highway speeds. As I made no other changes, I attribute this to the Prolong. When I took the valve cover off to replace a gasket, the upper end looked clean, but I couldn't see if there was actually a difference in the wear areas. Both Prolong and Dura-Lube contain ammonia derivatives, which keeps stuff clean, but also contributes to acid formation in the crankcase. I don't know what the long-term effects of the acids are, but I'm sure someone here can answer that question. As for a lawsuit, I haven't heard anything. I don't put any additives in my ETH, but I still use the Duralube on all the wear points in my skeet guns. Works better than grease, and lasts allot longer than light oils...

-Adam

 

[jerryrigg]

For those interested here is the link to the FTC vs Prolong court settlement...



http://www.ftc.gov/opa/1999/9909/prolong.htm





Not to question Southbend or is friend's experience. But 99% of the engine/oil additives are snake-oil. Slick-50, Duralube, Valvoline, Prolong and many others have all faced the FTC in court for basically BSing the public. Could Prolong help with the shifting problems sure it could be possible, but so could filling the transmission with 50% WD-40 but I would not recommend it and neither does New Venture, and your Dodge Manual says don't do it.

Gary bought up the point about lube specs, and he is right the wrong lube can damage rather than help. I'm not trying to preach here, this is just consumer beware advice. A lot of the readers of TDR are always submitting questions about will this or that void my warranty, wrong lube can do it to but then again Dodge could void the drivetrain warranty on 99% of the TDR members... . why...



New Venture specs

NV5600 max 550 lbs-ft

NV4500HD max 460 lbs-ft

NV 4500 max 410 lbs-ft



I'm guilty void my warranty... . I am my own Warranty Station. .

Yes I'm also guilty of experimenting with additives... like I said Consumer Beware... .



-Matt

 

[Diesel Freak]

Originally posted by jerryrigg

New Venture specs

NV5600 max 550 lbs-ft



I'm guilty void my warranty... . I am my own Warranty Station. .

Yes I'm also guilty of experimenting with additives... like I said Consumer Beware... .



-Matt

Me too... I voided my waranty to the tune of 800+ FtxLbf.

 

[amsoilman]

The NV-4500 (5-speed) requires a GL-4 rated gear lube.

The NV5600 (6-speed) requires a 5W-30 engine oil.



I will be putting the 5W-30 engine oil in my new 03' within the next few weeks. It will be the one I am associated with, as I have seen it correct hard shifting as well.





Wayne

amsoilman

 

[Pit Bull]

My (2000) service manual states the following "Required lubricant for the NV5600 is Mopar Manual Transmission Lubricant, P/N 4874464. This is the only lubricant recommended for use. "



Wayne are you saying this is really 5W30 synthetic oil?



I also thought if a special lubricant or type of filter was required to keep your warranty in effect that the manufacture had to provide the part or the fluid for "free"???

 

[Texas Diesel]

Originally posted by Pit Bull

My (2000) service manual states the following "Required lubricant for the NV5600 is Mopar Manual Transmission Lubricant, P/N 4874464. This is the only lubricant recommended for use. "

I know of one case where the owner started using Royal Purple Synchromax lube in a 5600. Synchromax is rated as a GEAR lube for manual tranmissions and safe for yellow metals. I have had two 5600's fail with less than 30k miles, the last one had jellied (OEM) lube.



As Amsoilman pointed out, several TDR members have used Amsoil 5W-30 for nearly 100k with no problems. I believe that atleast some of the 5600 shifting problems are due to lubrication failure of the OEM lube.



Attached is a picture of the OEM lube at 21k miles



Thanks Peter for passing along the info!