TurboRacer

I drained the oil by taking both pto covers off and cleaned them. The magnets held a lot of the metal shavings. I also cleaned and scooped whatever I could at the bottom of the casing. I used red rtv silicon and sealed the pto covers back up, except for one side I left the top bolt out. I filled 5 quarts of Amsoil 5w-30 Synchromesh through the fill plug. I added about 7 ounces of XPD-Lube oil fortifier in with the oil. You can only use it in manual transmissions not automatics. And I squeeze just over 3/4 of an extra quart through the top bolt hole of the pto plate using a rear-end oil pump. After a few miles the oil began to settle. Now when my transmission heats up, it shifts so smooth almost like a sports car!

taken5875

2. The wrong fluid is what kills the backing plates (synchro's) in these trans. It doesn't take a whole lot of driving to accomplish this. My new trans will run the Texaco/Chrysler fluid until the warranty is up, when I'll switch to the Amsoil version or the Redline. I haven't investigated enough yet to make a decision. The wrong fluid is usually put in at the local Quickie lube, the tech sees a big cast iron case and just assumes gear oil is the required

Exactly What oil did you decide on and how did it work out. If it worked well where can it be purchased.

SIXSLUG

The item you mention as synchro's is actually called "blocker rings"...just a heads up if someone is trying to search this.

I use the Pennzoil synchromesh fluid. I ran the Redline after I found the lube in the fluid in the trans to most likely be the wrong stuff after I bought the truck with 50K on it.

Redline smoothed it out for a while but after not beiing able to get it into reverse with out shutting the engine off, I opted for a rebuild. It was so galled up they couldn't get it apart...new trans installed. Broke in with Chrysler(Texaco) stock required fluid. Change out at 40K to Pennziol version..no problems.

Clunk

The Amsoil is still holding in mine for at least 60k (since 2007).
Smooth shifts & no whine noises.

taken5875

so i can run either of these?

Redline MTL 70W80 GL-4 Gear Oil

OR Pennzoil synchromesh.

SIXSLUG: if i am clear on your post you said you believe your tranz was damaged prior to you owning it correct. then you put redline in it. then it failed quite some time later?

what made you switch from redline to pennzoil?

Clunk

Don't run Redline 70W80 GL4 (gear lube #4) gear oil, it's too thick for the 6 speed transmissions.

Sixslug said it ruined his transmission!
"Redline smoothed it out for a while but after not beiing able to get it into reverse with out shutting the engine off, I opted for a rebuild. It was so galled up they couldn't get it apart...new trans installed."

Be sure what you install is a 5W-30 synchromesh synthetic lube.

taken5875

Hmmm? Clunk he also said the following.



[QUOTE=SIXSLUG;2161255

Because of my warranty we are running the Texaco stock lube for a year and will replace with Redline or Amsoil after it expires. He said the extra qt doesn't hurt your trans, just your wallet. He doesn't feel its needed on the later 5600's with the passage.

And redline has it listed as approved for the nv5600 online?

I really don't have a preference as to what oil I use I just want to use one that is tried and true. My new to me truck has 50k on it and I believe it is still the stock fluid from 01 so I think it's about time to change it.

Clunk

Cool.
I changed mine from stock fluid to Amsoil around 100K and have been running it about 61K.

Best Regards.

Homestead

I've run Amsoil MTF for about 250,000 of my trucks 260,000+ miles.

It wasn't long after I bought it new that I changed out the fluids bumper to bumper for synthetic.

I could have went with the factory Mopar fluid but Amsoil was cheaper and actually more readily available.

Tried Redline MTL, which I liked but felt that the shift quality wasn't as good as the MTF so I went back at my next change (every 10,000 miles)

Truck has always had 6 quarts of fluid through the shift tower and has never had an additive added over and above the Amsoil.

It shifts just as good if not better than new and when it's drained, usually minimal if anything for wear particles, nothing out of the ordinary.

When you pull one or both PTO plates, jack the truck up as high as you can get it from the rear and you will be surprised just how much more fluid pours out.

Another thing to add if you really want to keep the old cast iron girl alive is to add a temp guage to it. You will be amazed at how the temps fluctuate depending on what gear your in while towing. I have seen as high as 230 degrees towing 10K in 6th. A quick downshift to 5th brings the temps down real quick.

I know we all do it, but 6th is not there for towing, it generates to much heat compared to 5th. 5th gear all day, everyday but 6th can make things warm. Trust me, I watch my guage all day when towing.

Jeff

StealthDiesel

Not sure what the above post is all about but it is not correct. Be careful comparing the engine oil rating system eg. 5W-30 versus gear oil rating system eg 75W-90.
They cannot be directly compared numerically.

Redline makes a large variety of transmission and differential lubricants.

Redline MTL and MT90 are perfectly fine for the NV5600. They are GL-4 and safe for manual transmissions.
I've run MTL for years but have been going thicker since I installed my SBC dual disk 3250 clutch.
I ran MT-90 which is slightly thicker than MTL and now I'm running 50/50 MT-90 and Red Line 75W-140NS in my NV5600.
I like the thicker lube for quieting down the trans when towing in the hot summer. I also run Redline 75W-140 regular in the rear diff.
Most gear lubes are not safe for the NV5600 but Redline MTL, MT-90 and Redline 75W-140NS are safe.

I also tow mostly in 5th gear (1:1), never lugging the engine nor trans in 6th gear OD.

nothingbutdarts

Where did you put your sending unit for the trans. temp. gauge?

Homestead

I welded a standard bung into the drivers side PTO cover about a third of the way up from the bottom.

Just using an ISSPRO electric trans temp guage. All the wiring runs straight up through the floor shifter boot and on to where you mount your guage. In my case, I have a Scotty Pod on the dash in front of the driver and the wiring was more than long enough to reach that point.

Other than welding a bung in, easy install for temp monitoring.

Jeff

nothingbutdarts

Thank You!!!

SIXSLUG

Hi guys, just got bak from the wilds....

Whatever teh PO put in my trans messed it up. I drained washed and replaced the fluid with Redline MTL, which improved it significantly but still couldn't help it much. In my opinion the fluid I drained out, an opaque yellow milky mess that smelled like gear oil, was the culprit.

The Redline and Amsoil stuff is supposed to be top shelf, but you have to put the correct one in!

I run the Pennzoil now becasue it is affordable and came recommended from my local trans guy. No problems in about 75K.

taken5875

Thanks for all the replies. I went out and hunted down some penzoil synchromesh. It took 3 stores to get the 6qts. Advanced, pep boys and a local bussiness called salvos. As luck would have it the last place I stopped at had over a dozen bottles on the shelf.