Engine/Transmission (1994 - 1998) 5spd lube

[SRehberg]

I just bought a '96 3500 with the 5spd manual trans. I've had automatics so this is my first manual. I want to change all the fluids in the truck so I know where I stand maintenance wise. I have read the fluid of choice is Syntorq or something like that, but it seems pretty pricey for a gallon of the stuff. Has anyone used an alternative with good results? Seems D/C is always specifying some sort of exotic lube especially for their products and wondered if it is necessary. If it has to be that then I will buy it, but with all the years of manual transmissions using 90wt hypoid, it seems odd that all of a sudden these things need special oil. I know in some earlier years engine oil was spec'd for gear lube, but I figured it was for fuel economy/ease of shifting in cold weather etc. Any ideas?

 

[Kernel]

Amsoil has a newer lube out for the 5spds that is a fraction of the cost. I am satisfied with it so far, they call it MTG. Maybe Wayne (amsoilman) can give you more info.



Scott

 

[Texas Diesel]

I will suggest Royal Purple Max Gear 75W-90. It has worked flawlessly for 60k miles. The transmission had Amsoil in it when we bought it and it shifted terribly. I mean BAD. We drained it and refilled with Royal Purple and the difference is astounding.



I dont know why the Amsoil didnt work because others have had good luck with it. It just didnt work in mine.

Who knows, bad batch maybe.

 

[PKirby]

I use Redline, 2 quarts MT-90 and 2 quarts MTL as recommended by the Redline tech dept. What ever you use, make sure it is a full synthetic GL-4 rated for transmissions and not a GL-5 rated for differentials. With the GL-5 your syncros will not work correctly. If the fluid contains sulphur it will destroy the blocking rings.

 

[SRehberg]

Thanks for the help, at least it looks like there are some choices other than Chrysler spec'd fluid. Is Royal Purple a brand name or a sub name for a major oil company product? I know Redline and Amsoil names. I want this trans to live a long time but don't want to be robbed in the process.



I have seen Geno's advertise a filter setup for the side cover area, anyone had any experience with this? I can't see where a non pressurized system a filter could be useful.

 

[TXDSLSHOP]

Royal Purple is brand name. Available at Napa and I'm sure other parts stores as well. I have used it in my 5 Speeds for many miles and they have always shifted perfect and no problems. I use Max Gear 75w-90 and love it. I have a friend who rebuilds manuals and he uses it in all applications that call for a GL-4 / 5. Good luck.

 

[RT66DOC]

The trans filter works great. I've had one for about five years. Collects alot of junk. Not pressure but the gears sling the lube at it.

 

[SRehberg]

Thanks for the information on the filter, I wondered how it would be effective.



I went online and looked at Royal Purple Max Gear lube, and it is listed as a GL-5 lubricant. In one of the posts above, it mentioned I need to stay with a GL-4 due to non-corrosive qualities. Is there a GL-4 in this line? Was Syntorq a GL-4 lube as well? I see Redline meets the requirement and they offer a GL-5/6 rating as well. Thanks for all the help.

 

[MHalloran]

I just bought a '96 3500 with the 5spd manual trans. I've had automatics so this is my first manual. I want to change all the fluids in the truck so I know where I stand maintenance wise. I have read the fluid of choice is Syntorq or something like that, but it seems pretty pricey for a gallon of the stuff. Has anyone used an alternative with good results? Seems D/C is always specifying some sort of exotic lube especially for their products and wondered if it is necessary. If it has to be that then I will buy it, but with all the years of manual transmissions using 90wt hypoid, it seems odd that all of a sudden these things need special oil. I know in some earlier years engine oil was spec'd for gear lube, but I figured it was for fuel economy/ease of shifting in cold weather etc. Any ideas?

I also own a 96 with the 5-speed. My trans also had that "syntorq" tag on it. Went to the dealer to ask about it and they said to use their own DC brand synthetic lube and that is was the same quality as the Castrol. 200,000 miles later - no problems. I think the stuff cost around $16 a quart.

 

[SRehberg]

I was doing some checking on the Royal Purple oil where they say it can be used where a GL-4/GL-5 grade is spec'd. However, the Max gear lube is GL-5 rated. From the jest of the literature I have read, the GL-4 at high temps will not release sulphur in adequate quantities to pit or corrode the synchro's and thrust washers. The GL-5 oils have extreme pressure additives which according to what I read, provide almost twice the protection for pressure/shearing. The downside: the additives when very hot, release sulphur that now pits/corrodes the synchro's/thrust washers. I have a email into Royal Purple to their tech section for a clarification.



Is the Syntorq available at other supply outlets in chain type auto supplies or is it a dealer item? I see Standard Transmission in the TDR magazine advertises it, but shipping comes into the cost as well. The dealer's oil, is it rebadged Syntorq?



Redline and Amsoil are considerations and seem to be GL-4 rated. I never thought buying a gear oil would be so involved.

 

[MHalloran]

I don't know if the dealers oil is re-badged Syntorq but hey, if they say to use it , why not? Like I said , 200,000 miles and no problems. Hot or cold weather. No slippin' or grindin' and smooth shifting. If they say to use their lube in their product then they would stand behind it if you had a problem. Just keep your receipts if you use theirs. Good luck.

 

[PKirby]

From what I have read both GM and Dodge fluids for thier NV4500's are repackaged Syntorq. Quad4x4 has a good price on the Syntorq.





http://www.quad4x4.com/

 

[Texas Diesel]

Go here: http://www.royalpurple.com/prodsa/mgeara.html and click on the Synslide hyper link. It will explain that MaxGear is safe for soft metals like synchros.



You are correct not to use a GL-5 catagory, but MaxGear is GL-4 & Gl-5 which means it meets the requirements of both.



I sent an email to a tech guy at Royal Purple and asked him to read this question and respond.

 

[SRehberg]

Thanks for the site referrals. I would be curious as to what Royal Purple has to say about their oil being a GL-5, but yet supposedly compatible with GL-4 requirements. I read the Synslide article and it sounds good. I see some of the members are running the Royal Purple w/o problems. In a earlier reply, 200,000 miles on Syntorq is pretty impressive as well. I went to the Quad 4X4 site, but so far I haven't found the Syntorq oil part. I'll have to go back and look again.

 

[redram]

Someone looked at the incorrect specs for Royal Purple - it is rated both for API GL4 and GL5 applications, see http://www.royalpurple.com/prodsa/mgeara.html. Seems the copy on the website could be clearer.

MaxGear is made with Group IV syntheic base stocks and synthetic additives and is rated for both GL4 and GL5 applications as it is not harmful or potentially corrosive to the soft metals such as a cheaper price sensitive product even at high temperatures.



The Castrol Syntorq LT is actually a hydrocracked base stock and the only reason it is so expensive is the multiple markup through the DC corporate (supplier to DC, DC to Warehosues, Warehouses to Dealers, Dealers to end users all taking 25-45% markup).



Be careful about talking in raw components when chemicals and plastics are concerned. Just because something contains an element does not mean that is is comprised of the same components.

Case in point - Humans need NaCl (salt) in some quantity to survive. However if any of us were to consume large quantities of raw sodium or chlorine we would probably suffer. Do you see the analogy here.



All GL4 rated gear oils will probably contain some form of a sulfur phosphorus EP additive. Most GL5 rated gear oils will also. How they react to soft metals is a function of the formulation and their are many alternatives to the makers of oil to do this. Sounds like some do it the cheaper method and have to reduce the amount of additive to minimize the potential for negative effects to soft metals at higher temperatuers. Others (Re Royal Purple, Amsoil, etc) use higher performance components (base stocks that are thermally more stable, additive packages that do not degrade as readily and do not attack soft metals due to better corrosion protection) use higher performance components that can be rated for both. The major oil companies mind set is to put the least amount of additives in the least refined base stock (re cost) as will be adequate for most intended applications. Hence the reason for GL4 gear oils having roughly 50% of the additive package of a typical conventional mineral gear oil so as to lower the production cost as this gear oil will only be used in manual transmissions - where it would not require the added performance for a ring and pinion load.



Use the RP MaxGear 75W90 - you' ve had numerous people here on the TDR state their long term success.



Ciao -

 

[Texas Diesel]

Not gear oil but an interesting demonstration.



http://www.royalpurple.com/techrp/summary.html



Near bottom center look for "watch the video" link. It's in the first "summary" box, top dead center TV.

 

[SRehberg]

Yes, it's to bad R. P. didn't do the samething for their gear lube, it would have been helpful.



Redram, I know what you're saying about numerous people using the R. P. but the destructive process is a slow one, at least that is what I read on a lenghty article citing the downside to GL-5 fluids used with copper and brass components, where a GL-4 is called for. I definetly keep my trucks for a very long time, so I want to do what I can to make them live a long time. R. P. may very well be the best oil going, and that's what I'm trying to assess. I appreciate all the input here to make an informed decision. I am waiting for R. P. to write back about their compatibility with the GL-4 requirement even thought their oil is labeled GL-5. Why isn't it labeled GL-4/GL-5 rather than just GL-5? I don't know but intend to find out. Thanks for the help.

 

[WDixon27]

it's sorta like putting dot 3 brake fluid in a old british car, the alcohol eats the natural rubber and months later the system takes a dump, it doesn't show up till it's too late



i went to pepboys today looking for rp and damned if they didn't have any or anything that wasn't gl-5, but the shelf was a little bare

 

[SRehberg]

I saw this on the Royal Purple site, thought it might help clear up some confusion:



My vehicle's transmission specifies an API GL-4 gear oil. Can I use Max-Gear®?



Yes. Max-Gear® possesses both API GL-5 and GL-4 certification. Max-Gear® is formulated with Royal Purple's proprietary, Synslide® additive technology to provide the exceptional film strength necessary for GL-5 applications, yet it is noncorrosive to soft metals found in manual transmissions that specify a GL-4 rated lubricant.

 

[CEdwards]

Wish I had read this last week. I just put gl-5 in my nv4500. I went everywhere in town and no one had any gl4 75w-90 synthetic so I put mobil1 gl-5 in it not knowing anybetter. From this discussion I would imagine that it probably won't matter under an empty load, but maybe I should change it before I work it hard and get it hot. I just checked the web site and it does have a high sulphur additive. I guess I will have to order some gl-4 online. While were on this topic, what about differential oil. I used some regular mystic 85w-90. Whats everyone else using?