Krob

I checked every bottle to ensure it was redline MTL i cant find amsoil anywhere up here.

wilsonsh

MTL is fine...If it isn't grinding or holding up, I'd run it for a week or so. It's the right oil so as long as you have enough in the tranny you should be fine. Sure someone else will chime in that has Redline in their tranny...

Homestead

It makes no difference what oil you run, be it Redline, Amsoil, factory stuff, whatever. The thing is to change it on a regular basis!

However you look at it, oil is cheap compared to a replacement transmission or a rebuild. Change it at whatever interval you want but make sure you over fill it and change it regularly. You'll have a happier transmission.

Jeff

JSPulliam21

My buddy changed his from the stock fluid to Pennzoil Synchromesh, because he did not know when it was changed last. We even overfilled it by 1 quart, as many recommend. It shifted the same as stock for a while. Then it got worse going into gear when cold, and would grind if not allowed to drop into gear. He then changed to Redline MTL, hoping the better synthetic fluid would ease his shifting woes. He overfilled by 1 quart as before. The shifting has not gotten any better. Is there something else about these NV5600's that could be causing the problems many are seeing? He also finds it hard to put in gear while stopped.

Krob

This sounds just like what i was experiancing and may with the new change but i havnot been able to drive enough to get an idea. (Cant afford to go for a drive anytime i want to anymore)

chadder1313

Im getting to change mine here real soon and i think im gonna go with Amsoil.

afoulk

Well, just changed my fluid from royal purple to the redline mtl. I put 6qts. in it and added Geno's filter to the pass. side of the tranny. It seems to shift slightly better when cold, but it shifts much better once warmed up. I still have the same problem as you robins...It takes forever before it wants to drop in gear when I shift, however it is slightly better with the MTL. However, my clutch master cyl. has slowly been leaking fluid past the seal and I think thats most of my problem. I've probably got a bit of air in the system, cause some days it seems to shift half descent and other days its a bear, even when I double clutch it. I'll be taking care of the hydraulics when I do the clutch this spring.

wilsonsh

Ahh...good point afoulk. This could be another point of interest for the other folks having shifting problems by not letting the clutch fully dis-engage. Slave cylinder/fluid problems are common.

supr

For what it's worth, The Penzoil syncromesh has the same exact specs as the factory lube, which can only be bought at the dealer. These trannys are very sensitive, due to syncros. I think Factory, MTL, and Penzoil are the 3 most used.
Anyone use the Factory fill? What does it cost?

afoulk

I checked at my local dealer a few years ago when I had my jeep (it used the same stuff) and it was only a few cents more than the royal purple stuff from Napa. I think it was a little over $10 a quart, but that might have been with my discount I get through works since we have an account with them. Its been so long I don't really remember.

ffdfireman

are you sure that you dont have a transmission problem? i had the same thing going on in mine when i pulled it out and got to listening to it when i turned the saft it was making a slight noise of metal grinding. Iam taking it somewhere today to have somebody look at it will let you know

Captain

the penzoil syncromesh is the factory oil for the 5600 like the casterol syntourq is the factory oil for the 4500. I have my 5600 in the other truck now with a SBC ofe. I can shift it in .1-.25 seconds. Basicly as fast as I can move my arm I can jam it into the next gear without an issue. I have the syncromesh in it. Now my 4500 with the DD is doing what yours is. It takes some time to shift and if I try to force the issue it will grind. I've replaced the clutch about 7 times now so im starting to think thats not it!

metalli445

ffdfireman,
Any update as to what was wrong with your tranny?

turbo2

I just had the same situation on my truck. I thougth my syncros were going out in the tranny. I tried putting 6 qts of amsoil in the tranny with no change. It turned out the problem was my clutch. At 180000 miles the throwout bearing was tired and the clutch fingers were worn thin. When I pushed on the clutch ,the fingers would bend back just a little bit. The clutch felt normal when it engaged so it threw off my diagnosis. I rented a tranny jack, pulled the tranny on a friday and put it back in on a Saturday. I replaced the clutch lines at the same time as a precaution. Works great now. Like new! Maybe its your clutch? Good luck

Krob

tranny still is not shifting right to me but to my dad and my machanic budy they say it feels like just another heavy truck tran. So im pretty sure i need a new clutch so maybe when i get back from the desert this next time ill put a sbc in.