G56 gear fluid

[BGoodale]

My brother inlaw who is a member but never checks out this site is having his bearings replaced as we speak. The mechanic that is doing the work has recommended Gorilla Juice. I've never heard of it. It's probably too late since its on the way but we were just curious. It's a 2007 ctd 3500 5. 9 with about 110k miles on it. Also wondering about the dual mass flywheel. It was replaced under warranty and has about 25000 miles on it. His mechanic is saying that going to a solid flywheel is not good. We believe that south bend clutch has a better dmf. Should he replace it or let it go for now. Thanks for your help. Brett

 

[HBarlow]

I never heard of Gorilla Juice either but would select a well known brand instead if I had the choice.

A DMF will fail again but a SBC conventional flywheel will produce more harsh mechanical sounds. Your choice.

Labor to r&r is the biggest expense when replacing a clutch assembly. Some would opt for a new clutch when the transmission is out even though it is working fine. Again, its a judgement call.

 

[seafish]

GJ is an unlabeled custom blend by a diesel shop that has worked alot with upgrading the G56. Some people say it is the cat's meow of G56 transmission fluids, but other people who run it complain of extremely stiff and difficult shifting at least until the transmission warms up . Particularly if your brother lives in a cold climate, I would be very wary of using the stuff. More then several people, have changed back to a lighter fluid after going through the trouble and expense of buying GJ. Likely a better alternative is the Pennzoil Synchromesh that Standard Transmission Servioces recomends... they ALSO have ALOT of experience with the G56. To make a better informed decision, be sure read the link below, it is an unbiased oil analysis of several diffferent brands of transmission fluid that might be used in the G56, including the GJ and the Pennzoil.



http://www.carbonitecummins.com/Documents/Trans Oil Comparison.pdf

 

[Shadrach]

Thanks Seafish Very helpful. Who is using these "new" fluids and what are your comments? Shad

 

[CKelley1]

seafish is correct. do not waste your time with the gj. get one gallon sae 50 synthetic syncromesh transmission fluid and mix one gallon of 5w-30 synthetic syncromesh fluid with it. use 7 quarts, this is one quart over full this is a must to lube and cool the front bearing. that is why you are replacing it now. your mechanic does not know what he is doing. when the dmf fails it can ruin the g56. those that tow can not get more than 75,000 miles out of one. all of ours failed between 35,000 and 75,000 miles. us like most others chose to go back with a southbend single mass flywheel kit rather than getting a dmf put back in under warranty. they have a real ball bearing pilot bearing instead of the mickey mouse bushing. do not let him put it back without the kit. either the single disk conofe or the dual disk 3250 are good choices. the new single mass flywheel is going to be very noisy compared to the dmf. you just have to get used to it. there is a red rubber boot on top of the g56 that will crack if not already. we use 2 different ones depending on witch one i find first. #1 is a dorman #614-002 cvc boot the other is a moose m9206801 atv boot along with 2 hose clamps for either one. brand of oil is not critical royal purple calls there 5w-30 syncromax

 

[mfurrh55]

I'm over 113,000 miles with one and i tow pretty heavy, I use Amsoil synthetic ,And i have a new clutch , solid flywheel and everything to replace the dmf when i need to , Monte

 

[Regcabguy]

I'm over 113,000 miles with one and i tow pretty heavy, I use Amsoil synthetic ,And i have a new clutch , solid flywheel and everything to replace the dmf when i need to , Monte

Which Amsoil are you using?

 

[Shadrach]

A question comes to mind about vibration with a Con OFE. Would a 6. 7 damper on a 5. 9 or a fluid damper help with this? I have never had a dual mass in my truck as the G56 is not the original transmission. Shad

 

[mfurrh55]

pm me your email address,Monte

Which Amsoil are you using?

 

[seafish]

A question comes to mind about vibration with a Con OFE. Would a 6. 7 damper on a 5. 9 or a fluid damper help with this? I have never had a dual mass in my truck as the G56 is not the original transmission. Shad

A 6. 7 damper and 6. 7 fan pulley are sitting in my garage waiting to go on the truck in my sig, so while I do not yet have firsthand experience, from what I have read ALL of the people who run the combination of the 6. 7 viscous dampoer and an aftermarket SMF/dual disc clutch on a 5. 9 REALLY like the reduction in NVH that the upgraded 6. 7 viscous damper is designed to provide to the drivetrain.

 

[CKelley1]

i used a fluidamper instead of the 6. 7. in looking at post's i think they are about the same. on amsoil the 5w-50 used to be labled just that but the last i bought it was labled syncromesh transmission fluid. the amsoil sae50 is labled sae50

 

[Regcabguy]

I got a noticibly smoother idle but no reduction in gear noise with a Fluidamper.

 

[RVTRKN]

I'm a couple of months away of pulling my G56 and having it gone through and inspected by Standard Transmission. (the expanded shop in Arizona) The recommended fluid is Pennzoil synchromesh. The trany only has 48K on it, and because the DMF/clutch is prematurely failing due to the updated programing, I'm going to have a SBC DD 3250 system installed and I'm going one step farther and will install a girdle on the G56 for added strength. I CAN'T WAIT

 

[mfurrh55]

Explain the girdle to me please, Monte

I'm a couple of months away of pulling my G56 and having it gone through and inspected by Standard Transmission. (the expanded shop in Arizona) The recommended fluid is Pennzoil synchromesh. The transmission only has 48K on it, and because the DMF/clutch is prematurely failing due the the updated programming, I'm going to have a SBC DD 3250 system installed and I'm going one step farther and will install a girdle on the G56 for added strength. I CAN'T WAIT

 

[RVTRKN]

The Girdle is an external brace that wraps around the aluminum case to help in preventing the two piece case from flexing. That helps the gears to stay in alignment and mesh properly.

 

[Shadrach]

"A 6. 7 damper and 6. 7 fan pulley are sitting in my garage waiting to go on the truck in my sig"



There's a set of them in my garage also. I WILL get them on before I go to Columbus this June. I only have 20k kms ( 12. 5k miles ) on my G56 but any considering changing/upgrading the fluid anyway. Shad

 

[Regcabguy]

The Girdle is an external brace that wraps around the aluminum case to help in preventing the two piece case from flexing. That helps the gears to stay in alignment and mesh properly.

Do they have an inhouse installation team or do they refer you to someone nearby?

 

[RVTRKN]

Don't know about that, but will supply the installer of the trany with the girdle. I have not worked out the logistics of it yet, but I know I will have Standard Transmission go through the trany, and if I can't find a local shop in Tucson AZ, I'll do it myself. I'll deliver the trans and pick it up as well as the SBC DD 3250 at that time. So if anyone here can recommend a shop that knows the DMF swap to the solid flywheel, your PM is welcome.

 

[Regcabguy]

I would think they'd have a trusty local installer seeing as how they do so much biz. They're about 6 hrs from here. Sure beats Texas for the drive. I would think the girdle would help with the gear racket some also.

 

[RVTRKN]

They just recently expanded there and the gentleman thats running it is retired from the Texas shop, so he will more than likely be the rebuilder. Because they are new there, he couldn't recommend a local shop. So if anyone can recommend... ... ... ... ... ... ... ...