Anyone tried to use synthetic ATF fluid for new Getrag 238 6 speed manuals? I've posted before on rough/notchy shifting with the new speed manual and received lots of great feedback (most saying "yep.. it is rough.. live with it.. not as smooth as the NV3500 5 speed it replaces.."). The owners manual states that my tranny uses "regular old" ATF fluid, so I thought I might try synthetic ATF to see if it improves shifting. I'm also wondering if this would cause any warranty problems (if the "stock" fluid is red and the synthetic fluid is red too, I'm guessing the dealer would never know???) Any feedback would be greatly appreciated!

 

You are correct in that many on other forums swear by changing to all synthetic in their various stickshift trannies--Vette 6-speeds specifically come to mind since I have one.

I switched to synth in it (T-56) shortly after getting the car new 24K miles ago and really didn't find it made an appreciable difference in the shifting of that unit (yes, it uses automatic fluid, too). Simply too much mass in the parts to shift like a Miata. I've also put synth in T-5s (except they use engine oil) with similar experiences.

As for warranty, simply be sure that the fluid you use meets the specs noted by Chrysler. They cannot legally require that we use their fluids, as long as we do this.

Give it a try; it cannot hurt... and may help some.

All the best.

 

Agreed.. According to the specs, my tranny takes 4.7 pints, so, even using Amsoil synthetic before any $$ discounts, this is a 3 quart "exercise" which will be less than $30 and will take me 30 mins to do.. If it doesn't make ANY difference, I can refill with "Standard" Chrysler ATF+4 fluid to keep everyone happy on the warranty front.. I REALLY need to get my *ss in gear and go find-then-drive a few other new 6-speeds to see if it is JUST MY tranny that shifts so poorly into 2nd or if they ALL do it.. Then I'll know how aggressively to fight this problem or not.. Thanks!

 

I'm guessing, "...they all do."

Good luck.

 

Avanti, you could be right.. The strange thing is that is is rough ONLY into second gear, and only about half the time. Granted, my truck had 230 miles on it when I bought it, so I SUPPOSE if some bonehead who never drove a stick before test drove this truck, he/she could have done some minor damage to the synchros?? Supposedly, per the specs, this tranny has "triple cone synchros" in 1st and 2nd for "smooth shifting" :-) Not surprisingly, it DOES shift a bit smoother once it warms up. AND, for reasons I can't explain, it is rougher shifting from 1st to 2nd (i.e. upshifting) compared to going from 3rd to 2nd (downshifting..).. I thought synchros "worked harder" when downshifting.... The rest of the shifts are quick and smooth (or as quick and smooth as a truck manual gets with a foot long shift lever..) I'm STILL hoping (maybe foolishly) that it will shift better once I get some miles on it.. (right now, only have 800 miles on it..). I still might try the full synthetic fluid as I describe above.. For $30 and a half hour, nothing much to lose..It is annoying as hell... Thanks!

 

Well, you could be describing to some degree about any 4-, 5-, or 6-speed I've ever owned (too long since I've had a 3-speed). For some reason, perhaps the gap in the ratios or higher rpms involved, the 1-2 shift seems to be the roughest and to vary most from shift to shift in most transmissions--even in a new Miata, which is about the slickest shifting thing around. Not being a tranny repairer, I've no other insights why. However, I noticed that my T-56 got markedly better shifting, in general, somewhere about 10K miles. But, who knows, in that case I installed a modified B&M short-shifter the day after I picked up the car, and it may have finally gotten broken-in, too.

Hang in there.

 

Avanti, Yep.. will do..(drive it a while that is and see what happens..) Since this is my only vehicle, the miles will rack up fast. With the 3/36 bumper-to-bumper and the 7-70 powertrain warranty, "I got time" :-) Thanks a bunch for your feedback! Still will try the full synthetic ATF since it is so easy to do and cheap.. (Due to the 20" wheels, my stock (4X2) truck sits high enough off the ground where I can just crawl underneath it without jacking it up.. I'll update this forum after I do the fluid swap.. RB

 

Yep... everyone was right... Drained factory fluid and put in Amsoil synthetic ATF. (The Amsoil rep was great in getting me a good product at a good price..so thanks to Ken!) Unfortunately, NO DIFFERENCE!! I guess I feel good about the fact that I have a high quality full synthetic fluid in the tranny, but, it still shifts like crap from 1st to 2nd. Really notchy.. Worse when cold.. SOME (but not much) better when it warms up. The only way to make it shift "smooth" is to TRY to make the shift quickly (i.e. really "shove" it into 2nd hard) which isn't natural nor can I imagine it is good for the synchros. I REALLY need to get down to the dealership and try to find then drive a 2005 or 2006 with a 6-speed to compare to mine. IF I find that the new ones I drive shift as lousy as mine, then I'll KNOW that this is "the way they all are" and I won't have much recourse if/until Dodge comes out with some kind of TSB. If, on the other hand, the new ones shift much better, I'll know that either: A) I have a defective tranny or B) The test drives before I bought it (bought late in the year, had 230 miles on it when I took delivery) were really hard on the tranny. This is REALLY disappointing.. One of the major reasons I BOUGHT the Dodge Ram is because it was the only full size half ton truck you could buy with a V8 and a manual. The shift effort (again, mostly into second) reminds me of the old U-Haul moving trucks I used to rent 15 yrs ago. Dodge should be ashamed of putting in a tranny like this.. If I DO have a defective tranny (i.e. all the new ones I drive are ok), I'm going to figure out how to meet with a Dodge factory service rep as I got NOWHERE with my local dealer.. (they had the "shop foreman" drive it and he said "no trouble found"). I've done this in the past with Ford reps and had some good success. SO, now the ball is in my court to drive a new one or two.. Thanks for the good advice. RB

 

rbrowm-----I have the g-56 in mine. While I don't have the shift problems you are having (not smooth, but not tough either), I questioned the dealer specifically concerning the change to synthetic gear oil. I want to use NEO in mine. He cautioned me to this stating that until the truck is out of warranty, if something goes south on the trans, DC probably won't cover it due to the incorrect fluid use. :0( So far, the guys at the dealership haven't steered me wrong, so I'll just wait. My biggest concern was the compatibility of the seals in the tranny, as I don't know the composition of ATF+4. I do know that somewhere around 12K miles, my shifting smoothed out a lot.

 

I will just drive it a while.. I only have 1200 miles on it now.. I have thought about the service issue of having fluid in the tranny that is something other than what Dodge puts in it from the factory.. If I DO ever have to take it in for service on the tranny, I'll be sure to drain the aftermarket fluid and put in the standard Dodge stuff so I don't have any warranty issues. Somewhere else on this forum, I heard the standard Dodge ATF+4 fluid is 80% synthetic, and it looks the same as the Amsoil I put in (both are red), so I don't expect any real problems with the Amsoil stuff I used. (I probably shouldn't have been surprised that the Amsoil didn't make much difference given that the factory fluid is supposedly 80% synthetic and the Amsoil is 100% synthetic.. Oh well... for $30, I had to give it a shot..