Engine/Transmission (1998.5 - 2002) NV5600 & Synchro's

[steved]

Now here in lies a very good question. Was the addition of LSD additive really making things better? or is it all in (y)our head(s)?



I've always wondering if it's me, or the fluid making the difference in cases like this.



Once can kinda feel HP increase, but can one feel slight changes in shifting stiffness?



I think a double blind test is in order!



** Please note: LSD = limited slip differential ** Some of you may have noticed a possible correlation between LSD and "in your head"... Not that LSD.

When I tried the LSD additive, I saw no noticeable improvement, but IIRC I was running Redline at the time and not the factory fluid.



steved

 

[darkhorse]

Interesting thread to this old dog. Like Gary, I never thought much about additives as my transmission shifted pretty nicely & I liked it even better with the Quick Shifter. When I got my SB clutch put in I got an Amsoil refill on the transmission which "might" have made it shift even better. Later the installer told me he owed me a refill as he wanted to change out the motor oil for MTL. If anything, that made it shift even sweeter. I put quite a few miles on it that year & was very happy with how it shifted. Early the next year & had an encounter with some wet ice & slid off the road over an embankment. The truck spent 2 days on it's head & then near 2 years in a salvage yard. The body was wrecked but the chassie & drive train unscathed. It's been rebuilt recently with a new body & when I took possession of it it looked and acted like new. It had new Amsoil products in all the gear boxes. I drove it 20 miles with a big grin when something strange happened. No noises at all but at 50 mph cruising on a 2 lane rural highway I felt a slight hesitation as if I'd poked the brakes lightly. Then suddenly I was screeching to a stop leaving streaks of black from the front tires. I haven't seen the innards but I'm told that the 2 years of storage caused corrosion & the drying out of bearings & sychronizers in both transmission & transfer case. :{ Remanufactured units are on the way & I should be back on the road with it again by this week end & hey, it's only time & money. #@$%! What puzzles me is how it could work so well & make no noises then lock up so fast.

 

[Gary - K7GLD]

Now here in lies a very good question. Was the addition of LSD additive really making things better? or is it all in (y)our head(s)?



I've always wondering if it's me, or the fluid making the difference in cases like this.



Once can kinda feel HP increase, but can one feel slight changes in shifting stiffness?



I think a double blind test is in order!



** Please note: LSD = limited slip differential ** Some of you may have noticed a possible correlation between LSD and "in your head"... Not that LSD.

For sure, I have found myself to be just as easily fooled by "seat-of-pants" impressions as the next guy, and more testing is in order. Since my own transmission seems to be one of the good, few issues ones, a meaningful test is somewhat harder. Plus, the 50% added lube capacity of my transmission with the FastCooler setup and only a relatively small volume of Friction Modifier points up the need to add at least another ounce or so and then see what happens.



A large degree of caution is needed here, lest unwanted side effects from the FM creates a larger unintended consequence than the shifting benefit we're really after...

 

[FLynes]

Just call me Thomas, because I am always skeptical of the "this product will blow you away and is so much better than OEM" crowd. I asked the dealer to put in the LSD modifier for grins and giggles, and I wasn't really expecting anything, but I did notice a difference right away. I will say, however, that shifting has pretty much gone back to the way it was before, which really wasn't horrible to begin with.

 

[Gary - K7GLD]

Just call me Thomas, because I am always skeptical of the "this product will blow you away and is so much better than OEM" crowd. I asked the dealer to put in the LSD modifier for grins and giggles, and I wasn't really expecting anything, but I did notice a difference right away. I will say, however, that shifting has pretty much gone back to the way it was before, which really wasn't horrible to begin with.

Well, here's the thing - at least for me...



In the past, in looking for the "absolute BEST" lube for my 5600, I've tried both Amsoil and Red Line stuff - and BOTH resulted in vastly poor shifting and gear grinding - probably superior lubricants, but NOT compatible with the syncros in my particular transmission - so the stuff got quickly drained and dumped - an expen$sive experiment!



NOW, if addition of FM to those otherwise better lubes could restore proper shifting WITHOUT unwanted side effects or degradation of lube quality, this might be a worthwhile experiment...

 

[Scrappy]

Interesting thread to this old dog. Like Gary, I never thought much about additives as my transmission shifted pretty nicely & I liked it even better with the Quick Shifter. When I got my SB clutch put in I got an Amsoil refill on the transmission which "might" have made it shift even better. Later the installer told me he owed me a refill as he wanted to change out the motor oil for MTL. If anything, that made it shift even sweeter. I put quite a few miles on it that year & was very happy with how it shifted. Early the next year & had an encounter with some wet ice & slid off the road over an embankment. The truck spent 2 days on it's head & then near 2 years in a salvage yard. The body was wrecked but the chassie & drive train unscathed. It's been rebuilt recently with a new body & when I took possession of it it looked and acted like new. It had new Amsoil products in all the gear boxes. I drove it 20 miles with a big grin when something strange happened. No noises at all but at 50 mph cruising on a 2 lane rural highway I felt a slight hesitation as if I'd poked the brakes lightly. Then suddenly I was screeching to a stop leaving streaks of black from the front tires. I haven't seen the innards but I'm told that the 2 years of storage caused corrosion & the drying out of bearings & sychronizers in both transmission & transfer case. :{ Remanufactured units are on the way & I should be back on the road with it again by this week end & hey, it's only time & money. #@$%! What puzzles me is how it could work so well & make no noises then lock up so fast.

I have to call BS on this, the only way the FRONT wheels only are going to leave blackmarks is for something in the FRONTEND to go bad! and IF it was in 4wd then you would leave blackmarks from all 4 if the trans or tcase locked up.

 

[darkhorse]

I have to call BS on this, the only way the FRONT wheels only are going to leave blackmarks is for something in the FRONTEND to go bad! and IF it was in 4wd then you would leave blackmarks from all 4 if the trans or tcase locked up.

Sorry dude, but you wern't there. That is exactly what happened.

 

[CSnyder]

I have to call BS on this, the only way the FRONT wheels only are going to leave blackmarks is for something in the FRONTEND to go bad! and IF it was in 4wd then you would leave blackmarks from all 4 if the trans or tcase locked up.



I am the guy doing the repairs to Darkhorses truck and the trans is definately the problem. I have both the trans and t-case out and they are both full of metal shavings. Dont be so quick to call BS!

 

[Scrappy]

Sorry dude, but you wern't there. That is exactly what happened.

I have to call BS on this, the only way the FRONT wheels only are going to leave blackmarks is for something in the FRONTEND to go bad! and IF it was in 4wd then you would leave blackmarks from all 4 if the trans or tcase locked up.



I am the guy doing the repairs to Darkhorses truck and the trans is definately the problem. I have both the trans and t-case out and they are both full of metal shavings. Dont be so quick to call BS!

Sorry, that came off a little harsh!

Please give me a little more info about when it locked the front wheels up, were you in 4wd?

Does the truck have a CAD front axle? if it does then the front wheels are completely isolated fron the rest of the drivetrain in 2wd, so how did this happen?

If it was in 4wd I CAN see the lock up happening becaue of the trans/ t-case BUT all 4 would lock up unless something else failed in the tcase allowing the rearend to disconnect.

How far into the T-case have you gone? is the chain still intact?

the ONLY way I could see the frontend locking up is if it doesn't have a CAD and the chain failed and wadded up around the front output sprocket.

 

[JasonCzerak]

Sorry, that came off a little harsh!

Please give me a little more info about when it locked the front wheels up, were you in 4wd?

Does the truck have a CAD front axle? if it does then the front wheels are completely isolated fron the rest of the drivetrain in 2wd, so how did this happen?

If it was in 4wd I CAN see the lock up happening becaue of the trans/ t-case BUT all 4 would lock up unless something else failed in the tcase allowing the rearend to disconnect.

How far into the T-case have you gone? is the chain still intact?

the ONLY way I could see the frontend locking up is if it doesn't have a CAD and the chain failed and wadded up around the front output sprocket.

Hubs could of failed. Maybe the lake of lube in the diff could help out as well.

 

[darkhorse]

No problem. Yes it's a vacuum operated front axle. I hadn't touched the transfer case lever & just assumed it was in 2wd. The 4wd light was not lit. The rear tires may have locked up too but they did not leave skid marks. As for fluids in the differentials; Chris had just changed out the OEM with Amsoil. The front was pristine but the read was dark.

 

[NVR FNSH]

Olie Poole reported and showed us a while back that a clutch slave was not pushing all the way. Pushing clean to the floor, is your slave failing?

Happen to have a link to the particular slave cylinder thread?



Brian

 

[DOrlando]

So far, my best experience has been 2 quarts of Redline MT-90 and 7 quarts of Redline MTL... for summer driving only.



I tried 2 quarts of RP 85w190 and 7 quarts of Synchromax, but the shifting fell off within 8k miles... I have since went back to Redline.



I need to change out my current fill of MT-90/MTL for a straight run of MTL for winter use, but this fill has lasted the longest... 15k miles.



steved

How in the world are you able to get NINE quarts of oil into your trans???

 

[JKinney]

Happen to have a link to the particular slave cylinder thread?



Brian

Here you go https://www.turbodieselregister.com...02/178174-new-clutch-only-good-installer.html

 

[steved]

How in the world are you able to get NINE quarts of oil into your trans???

Fast coolers... plus a little overfull.



Not that hard actually...



steved

 

[NVR FNSH]

Here you go https://www.turbodieselregister.com...02/178174-new-clutch-only-good-installer.html

Thanks



Brian

 

[steved]

Bringing this back to the top... for a good read.

 

[CRWilliams]

GREAT READ. In all the years I have been on this site and others, I have never heard of putting LSD additive in a 5600.

 

[cap-n-cray]

Any updates?



I have a friend with a '01 3500 with a six speed in Socal. He is having problems with shifting into first, second, and reverse. He had the clutch replaced a while ago along with the clutch hydraulics. His mechanic is telling him that it is the transmission and parts are no longer made for it. No one wants to work on it and it is going to be expensive. Any thoughts?



Would some FM help his trans? He just did a fluid change with Dodge fluids. It seemed like the shifting problem started a little after the fluid change.



Cary

 

[JKinney]

I believe their are two companies that rebuild these, both are tdr advertisers,

blumenthal and standard transmission. Git er done before the case cracks... .