G56 Fluid & Coolers

[Silver Tex]

Hey All,
So I’ll be installing a new Valair DD Quiet clutch this weekend. I have looked through the forum’s in search of some consensus on fluid type and if aux. coolers are of any value. My max & typically tow weight will be under 12K lbs. and will likely not get to that. My GCVW (truck/5th wheel) usually runs around 18K lbs. according to CAT scales. I live in Colorado and tow in the mountains.

Here’s what I’m thinking. Mobil Delvac Synth. 50 (7qts min.) + 1 quart RP Synchromesh.
Fast Coolers? Yes or No.

Hit me with your thoughts.
Thanks,
Scott.

 

[NIsaacs]

8 quarts? That will create heat and leaks. Some good info here:

https://r.search.yahoo.com/_ylt=Awr...mission//RK=2/RS=OJ227vAjXGu.ZslVAlgmnpcLsMg-

 

[AH64ID]

Living in Colorado I am not sure you will like the Delvac 50, as it doesn't have great cold weaether manners.

Have you looked at any of the GL-4 75w-90 synthetic options? That's one of several OE, MB not FCA, fluid specs.

I know quite a few folks running this with good results.

https://www.amsoil.com/p/manual-transmission-transaxle-gear-lube-75w-90-mtg/

 

[Silver Tex]

OK! So early consensus is not more than 1 quart over (thanks for the article NIsaacs) and don’t run the Delvac 50.
John, I’ve not purchased amsoil before, is it an online order only?

I have been running the ATF+4 since new with the stock clutch. I accept the new DD will be a bit noisier and if there is a fluid that both protects and mitigates some of the gear rollover, that would be desirable.

Do either of you have thoughts on the supplemental coolers that mount to the PTO covers?

I intend on wrapping everything up this weekend, so if I’m going to order more “stuff”, I’ll want to do that today...I think.

I appreciate both your input.
Scott.

 

[bcbender]

I had the Fast Coolers on my NV5600, had to machine the PASS side one shorter to clear the exh pipe.. They added additional lube oil capacity, not sure if they actually lowered the temps because I did not have a temp gauge before installing them but liked having more fluid. I used Amsoil in all the drivetrain and never had any issues with extended intervals. I was towing up to 24k GCVW with my 5er.

 

[Regcabguy]

I've had the best luck with Amsoil 75-90 MTG. 7 qts. It shifts slicker than Delvac 50 and after 25K was amber and the magnet had a minimum of fine metal particles. No yellow stuff. It helps greatly with the rollover noise but the trans will tell you when it's not happy if you're lugging it.

 

[AH64ID]

John, I’ve not purchased amsoil before, is it an online order only?

There are some local dealers around the country, but it's mainly online order.

I can get you some pricing if you want to PM me.

 

[CVR222NV]

I purchased the original Fast Coolers and I have had a difficult time from keeping them from leaking. Since purchase they came out with replacement covers which I believe might solve that problem. I'm going to purchase the covers and give it one more try. I like the idea of the additional fluid.

 

[Darkbloodmon]

I've got dual trans cool coolers on my NV5600, and they make a good bit of difference. The shifting while it's cold is completely different when its hot. It takes a bit longer to heat up if you're not loaded. It's not unbearable but it is something I notice and feel within the first 10 - 15 minutes of driving unloaded. It is most likely different for the G56 since you have an aluminum case and better heat dissipation.

Looking back on my decision I would install a temp gauge first and find out what is a normal unloaded and loaded temp for your setup. You can over cool.

Edit: for reference I'm in a southern climate here in NC

 

[cerberusiam]

If you are going to tow fairly heavy you need and external cooler or it will eat itself up. A thermostat controlled external cooler up front with work the best.

 

[Silver Tex]

Good stuff everyone! I appreciate the feedback.
I do have a couple of follow up questions.

I got the old clutch assembly out, the new in and the trans stabbed back with half the bolts in it. The whole effort has been kind of fun, but would not want to do it regularly. A good trans jack and some patience went a long way, particularly doing it by myself.

I’m curious and frankly am being kind of lazy with the question. What is the original thickness on the factory friction disk? While the stock clutch assembly didn’t show much in the way of slippage, the friction disk measured .347 of an inch out to out. This seemed pretty used up when I compared it dimensionally to just one of the Valair disks that I installed.

I did see the dual mass flywheel spec was to allow 6* of movement to absorb the engine “shock”. I didn’t bother to evaluate that and the friction disk question is, like I mentioned, more of a curiosity than anything as it going into the recycle and trash.

Cerb,
How do you define towing heavy? I certainly won’t be exceeding 12K# and likely won’t touch that. My typical tow weight on my 5ver (per CAT scale) when fully loaded for a 10 day trip is less than 11K#’s. We do this 5-6 times a year currently. The balance will be lighter use. It is not a daily driver and spends many more days in the garage than on the road.

I have seen some of the vid’s on pieced together, active flow systems. I don’t think I’m a qualifier for something like those with my weights and usage. Am thinking more along the lines of the passive, bolt on systems that DBM & CRV mention. I did talk to Geno’s and their Cool Trans are backordered until end of month, so I’m thinking I’ll wait till that is available. It’ll be a re-drain and fill, but that’s OK.

AH64ID,
Got the oil. Thanks!


Best to all,
Scott.

 

[cerberusiam]

Is the 12K GCVW (truck and trailer) or just the trailer? If that is GCVW then you likely will not need a cooler unless you spend a lot time in the mountains. If that is JUST the trailer then you are on the heavy side.

 

[Silver Tex]

Is the 12K GCVW (truck and trailer) or just the trailer? If that is GCVW then you likely will not need a cooler unless you spend a lot time in the mountains. If that is JUST the trailer then you are on the heavy side.

Nope! That would only be the trailer (11995# max GVW). GCVW on the scales runs in the high 17’s with the truck portion loaded for travel at a svelt ~7300 - 7400#’s so that puts the trailer somewhere in mid 10’s for weight for our normal loading. I do pull the mountains and it sounds like I’m checking a lot of the boxes you are suggesting Cerb. Once manufacturing comes back on line in the US maybe perhaps some of these products will be a bit more available. I had a Hellwig rear sway bar ordered for the past 5 weeks and just got a notice that my order was cancelled.
Thanks,
Scott.

 

[cerberusiam]

Yeah, if you are in the mountains or towing heat the trans temps are going to push 300 degrees and that will kill the bearings in the front of the trans. Might take a while to do it but you are a candidate for a cooler. All you need is a pump rated for oil, the cooler for an auto truck in your year, some oil rated hose and fittings, and a thermostat. You can probably source all that thru NAPA or local warehouses. Something to think about and investigate.

 

[Ozymandias]

Better you buy a whole kit, it's easier to order then everything separate.

Something like that (just as an example).
https://www.driftmotion.com/Driftmotion-Manual-Transmission-Oil-Cooler-Kit-p/dm3561.htm

 

[Silver Tex]

Hi All,
Attached is a picture of what my old clutch assembly looked like when I pull the trans. I mentioned earlier it did not show any signs of slippage. Prior to removal and at idle in neutral, the shifter knob would shake pretty well.

The new Valair quiet clutch is installed and the shifter know in neutral doesn’t move a bit.

Do you suppose a failing dual mass flywheel was the reason for the shifter knob vibration in neutral, at idle? This new clutch makes the trans feel brand new. I have very little noise associated with it and it shifts really nice.

My initial review of the Valair, Organic dual disk, quiet clutch is 2 thumbs up!

Anyway, thoughts on the vibration?

Thanks,
Scott.

 

[cerberusiam]

Yes a DMF can cause issues like that when they wear.

 

[RBurn]

Hello, Silver Tex, what oil did you end up using?

I had a SB g56-ok-hd installed about a 1k miles ago. I now have 80k on my truck. The dmf was fine until I added smart jr tow mode. I had them add 1 qt to the existing dodge atf. The truck shifts great and is pretty quiet when not towing. I do notice some growl at low rpm “after towing and its at running temp. I tow 5er 12k loaded. Luckily I was traveling and was able to stop at grainger in sac and pick up the delvac 50. My area is hot and very mild winters so I figured on trying the delvac at this time.

Rob

 

[Regcabguy]

Hello, Silver Tex, what oil did you end up using?

I had a SB g56-ok-hd installed about a 1k miles ago. I now have 80k on my truck. The dmf was fine until I added smart jr tow mode. I had them add 1 qt to the existing dodge atf. The truck shifts great and is pretty quiet when not towing. I do notice some growl at low rpm “after towing and its at running temp. I tow 5er 12k loaded. Luckily I was traveling and was able to stop at grainger in sac and pick up the delvac 50. My area is hot and very mild winters so I figured on trying the delvac at this time.

Rob

Mine sounded like marbles down there after the same clutch was installed. I've used Delvac 50 and found it didn't shift noticeably as slick as with Amsoil 75-90 MTG. I just drained it after 35K and it was amber with only fine hairs on the magnet. A member from Alberta Canada recommended it.

 

[JField]

Hey All,
So I’ll be installing a new Valair DD Quiet clutch this weekend. I have looked through the forum’s in search of some consensus on fluid type and if aux. coolers are of any value. My max & typically tow weight will be under 12K lbs. and will likely not get to that. My GCVW (truck/5th wheel) usually runs around 18K lbs. according to CAT scales. I live in Colorado and tow in the mountains.

Here’s what I’m thinking. Mobil Delvac Synth. 50 (7qts min.) + 1 quart RP Synchromesh.
Fast Coolers? Yes or No.

Hit me with your thoughts.
Thanks,
Scott.

That’s the oil I used and my G56 is very quiet with little or no gear rattle even when lugging.