Royal Purple Synchromax...

[steved]

Well, I decided to give RP Synchromax a second try to see if I just had a strange occurrence in my NV5600 a few years ago... I wanted to try it because I can get it locally.



Well, it lasted significantly longer this time around... but its still far from a spectacular performer at 8k miles and needing changed. And it seems to happens all at once... one day its shifting fine and the next its very stiff.



Operating temperatures never change, so that's telling me its still protecting, but the additives that make the shifting perform well are breaking down.



I did get it hot when traveling to TX last week, but that was from the outside temps being hot (over 100*F). My trans runs a little more than a proportionate linear trend... at 70*F, its 140*F; at 100*F its pushing 205*F... which is still 30*F cooler than it did before the Fast Coolers were installed. I'm wondering if increased temps during this run caused the shifting to deteriorate (the shifting performance additives to fail)?



So, I'm changing back to Redline MTL which seems to be the only Synchromesh-type oil of the main three (Amsoil, Redline, and RP) that lasts in my trans. I will add that I have over 100k on RP Synchromax in my tcase with excellent results.



steved

 

[radcam]

First let me say that I think that your experiences are informative as I live in an area where the OAT routinely top 100*F, and I am using Royal Purple syncromax in my ZF5 transmision, BW t-case, and I'm considering running it in my Mustangs 5sp trans as well. The question I have, and I'm asking just to be better informed, as I do not own a NV5600.



Doesn't the NV5600 use gear oil, and isn't Royal Purple syncromax for transmissions that use ATF? Or am I confusing it with another RP product?

 

[steved]

No, the NV5600 calls specifically for Synchromesh-type fluids. RP Synchromax can be used in MANUAL transmissions calling for ATF... that is either stated on their website or on the bottle. I've been using RP Synchromax in my Tcase (on the same truck) for over 100k and it always looks like new when I drain it (all of 3 times to date)... the tcase calls for ATF+4 and you also got to consider the fact the tcase is an all aluminum housing that really helps with heat... so even in 100*F temps, in an all aluminum trans, you'd probably be fine.

And upon further inspection of the fluid in my NV5600, the RP is BROWN! It doesn't smell burnt, it appears clean, and it still feels good between the fingers (compared to virgin RP). And based on temperature readings I have been seeing, it doesn't appear to be lacking protection from before, so I think the fluid is good, but whatever additive packages are in the fluid for shifting performance are gone.

And another thing to remember is that the three popular synchromesh-type fluids are all slightly different in viscosity... RP is the thinnest, Redline is the thickest, and Amsoil falls right in the middle. And coming from someone who has ran all three of these fluids, RP was the best shifting fluid initially, Redline lasts the longest, and Amsoil falls somewhere in the middle on both accounts. All three seem to have varying degrees of effectiveness... some run well for some folks, but not for others... there doesn't seem to be a trend of one fluid being significantly better than another across the board. So if you're not impressed with one fluid, try another and see if it works better.

And what works well in one trans might not work well in another, that's the reason I always state "my trans", because I know there are guys on this board that really like RP Synchromax in their NV5600s.

steved

 

[HEMI®Dart]

Off topic...

Here is the degree symbol if you want it: °

 

[steved]

Here is the degree symbol if you want it: °

Don't confuse me like that... :-laf



steved

 

[Boondocker]

Steve,



Do you not like the Mopar fluid for the NV5600? I changed mine at 40K just to be a good boy. I'm now at 82K and don't detect any deterioration in performance. My summertime towing trips are routinely in OAT above 110-degrees (I don't know how to type the symbol either). I don't have Fast Coolers or a transmission temp gauge, so I'm not being fastidious about transmission temp management.

Anyway, I'll just stick with the Mopar goo because it give me satisfactory results as best I can tell.



Cheers,

Neil

 

[steved]

The closest thing to the Mopar fluid I used was the Pennzoil stuff... and neither it nor the factory fill performed as well as even "worn" RedLine MTL does in my trans.

For shifting performance in my trans, I'd rate the PZ and Mopar stuff at the bottom of the heap... which doesn't mean that it wouldn't work fine for someone else!

steved

 

[AFoulk]

what is the normal oil capacity of the 5600 and what is the capacity when using the "overfill" technique?

 

[05mxdiesel]

Steve,



So how long have you kept the redline in for? I am still using the Amsoil MTF in mine, and I plan on keeping a 30k interval with it. Here is a link of the last time I changed mine with a uoa report. I might have to try the redline next time around, although the amsoil is smooth as butter over the 30k I have ran it. Bob Is The Oil Guy: Amsoil MTF, NV5600 Six Speed, 29776 Miles on Oil

 

[steved]

what is the normal oil capacity of the 5600 and what is the capacity when using the "overfill" technique?

Uhhh, hmmm? I think it was 4. 75 quarts before the FastCoolers?? I overfilled by pushing the extra in through the top PTO cover bolt. Some guys remove the hump over the trans and fill through the top of the trans.



I only have this to say about overfilling... I just installed 9 quarts of Redline this past weekend. The trans runs slightly hotter overfilled. I was seeing temps around 170*F at 75*F ambient on the drive home with the slightly "used" RP... I was seeing between 185* and 190* on the ride home under the same temps (but I was driving a little harder). I have noticed this a couple times...



There are two possibilities... the overfill is starving something or a previously under-lubricated part is now being cooled better. Being a lot of people have ran overfilled with good results, I can only conclude it is not detrimental. I know that neither the redline or the RP are suffering a foaming issue as I have literally driven home, jumped under the truck and pulled the plug to check... never find any evidence of entrained air.



steved

 

[steved]

Steve,



So how long have you kept the redline in for? I am still using the Amsoil MTF in mine, and I plan on keeping a 30k interval with it. Here is a link of the last time I changed mine with a uoa report. I might have to try the redline next time around, although the amsoil is smooth as butter over the 30k I have ran it. Bob Is The Oil Guy: Amsoil MTF, NV5600 Six Speed, 29776 Miles on Oil

I have ran 20k on the Redline and changed it thinking it needed it... it drained as clear and red as when installed, and there were no shifting issues. I will probably run this fill of redline for a while, unless shifting deteriorates.



I also have a UOA on Amsoil... *my* driving style seems to shear the oils prematurely... Amsoil lasted about 10k before suffering the same fate as the RP I just changed out. And while the UOA indicated the oil sheared, that's not to say something like a "shifting performance additive" didn't start failing and that was actually my problem.



It is a toss up whether it or the RP shifted better initially, but the redline is the only one I have found that stays shifting consistently well for the duration.



I know I'm tired of changing trans fluid... :-laf



steved

 

[Froadin]

The mopar stuff lasts the longest for me.
I would put the Redline as second. RP last place.
The shifting with RP was NICE for a week or two, then went back to 'normal', and a few thousand miles later I was cursing it everytime I wanted to get in 1st, 2nd or reverse!!!
I am in need of another change, and thinking about Redline again. I liked the fluid, and it came out looking good. Just didn't shift that good after 20k miles.
Then again, maybe I will just put a little limited slip additive in this fluid and see if that helps out any.

 

[steved]

Then again, maybe I will just put a little limited slip additive in this fluid and see if that helps out any.

LSD additive made no difference in my trans at all...



steved