Possible manual transmission alternative

[Wayne M.]

Messing around on Instagram before, I got one from QuickDraw, who I follow, who’s been banging out some interesting diesel swap kits. They’re mating cool engines to any transmission. I am not familiar with this Tremec trans, and I don’t know how it stacks up against a 5600 or G56, but here is an alternative. I asked if it’s a direct swap, and they answered YES.

 

[TFucili]

If this is the right one the torque capacity is on the low side???

 

[petersonj]

How many forward gears?

 

[BigPapa]

How many forward gears?

That one is a 5-speed.

If this is the right one the torque capacity is on the low side???

Yeah, that’s too light for a Cummins. Tremec makes good hot-rod transmission’s, though.

If I wanted to go to a manual and could have my choice, I’d go with the Ford ZF-6.

 

[Wayne M.]

Yea I see what TF attached. Hmmmmm.
I guess this would be great for a 12 valve getrag replacement or a nice 4B project.

Scott, I bet they’d make a bell for that ZF6. They seem real crafty. Their insta page is interesting.

 

[Ozymandias]

@Wayne M. Not many medium duty transmissions around with that high of torque capacity.

Hopefully they did some misuse tests before sending out that transmission to customers.
For example the "idiot start" test, one of the harshest tests for the whole drivetrain.
From the OEMs the vehicle should withstand that 20x in a row.

 

[NIsaacs]

I want the TR-SO66-7B

http://www.tremec.com/anexos/Literature/TREMEC_7-Speed.Commercial.Transmission.pdf

 

[Wayne M.]

Nick, that’s a killer trans.

 

[caterpillar345]

@Ozymandias What is the "Idiot Start Test" you're describing? Starting the truck without the clutch depressed?

 

[petersonj]

I have made up a chart to show gear ratio comparisons between the NV5600, the Mercedes G56, and the TREMEC TR-SO66-7B transmissions. In the chart I am showing the percent of torque retained from the previous gear during upshifts for each transmission. My hope is that this will make it easier to see how a transmission will perform when towing or hauling heavy loads.

Please look over the chart carefully. If you note any errors or you see something doesn’t make sense, please let me know.

To me, it looks like the TR-SO66-7B would be an awesome transmission. Does anyone know if it would fit a second or third generation truck without major modifications?

- John

 

[Ozymandias]

@Ozymandias What is the "Idiot Start Test" you're describing? Starting the truck without the clutch depressed?

Side stepping the clutch at 2/3 to full throttle on dry asphalt, fully loaded truck - first gear and reverse.
10 to 20 times in a row without breaking a part on the drivetrain.
Doin so the momentum of output is up to 3 times bigger then the engines rating because of the rotating mass.

German term for it is "Knallstart", a common abuse test procedure that pre-serie Vehicles have to accomplish prior to serial production.

Here is a video with some more stuff they do in Germany to their test mules.



And thats just the most spectacular ones in the video.

@petersonj thank you for the amazing chart, yes up to the Gen3 the Tremec would be an awesome and sure durable transmission.

 

[petersonj]

@Ozymandias - great video! I currently have 325,000 miles on my original NV5600. It is still running strong, but I am going to research the cost of this TREMEC transmission and find out if it would be a reasonable modification to perform on my truck. It would certainly a great upgrade after the good life of the NV5600.

- John

 

[Ozymandias]

Please keep us updated about your findings @petersonj , to me personally that would be a great transmission for a RAM, with that low of a first gear even i would consider it for my offroad rig.

Ozy

 

[Wayne M.]

Yup. The only reason I even started this is because I believe the 5600 isn’t the easiest to get parts for anymore. Mines good, I just need that little plastic shift gate tip. The gates get funny once in a while.
I thought it would be worthwhile to investigate an alternative- just forward thinking.

 

[Wayne M.]

Looking at the ratio chart, I think 3.42 would be great but if you have 4.10, you might even start off in 3rd if running light!

 

[Ozymandias]

*wrong post, to fast.

 

[NIsaacs]

To me, it looks like the TR-SO66-7B would be an awesome transmission. Does anyone know if it would fit a second or third generation truck without major modifications?


Two big issues. It requires an SAE#2 bellhousing, they are big. I doubt there is a 4x4 adapter so a remote mount t-case would be needed.

That first gear would be awesome. My 5.63 just don't get it loaded heavy.

 

[GCroyle]

@Wayne M. Not many medium duty transmissions around with that high of torque capacity.

Hopefully they did some misuse tests before sending out that transmission to customers.
For example the "idiot start" test, one of the harshest tests for the whole drivetrain.
From the OEMs the vehicle should withstand that 20x in a row.

Not 100% sure if this is what Ozzy is referring to but there is a torque stall capacity test that a OEM clutch supplier has to pass in the vehicle as a part of the approval process.

Back about 94-95 I witnessed this test at the Sachs facility in Troy MI in the Jeep being tested. Roughly goes like this.

Parking brake locked.
Service brake applied.
Engine running, at temp.
Clutch pedal on floor, clutch released.
Select 4th (or one to one gear)
Accelerate engine to peak torque and hold RPM.
Now simultaneously floor it and lift foot instantly off of clutch pedal.

The clutch must stall the engine. Don't have test criteria worksheet but the cycles were timed, data recorded and serious.

When it goes into runaway (slipping) under power smoke escapes from clutch housing and it STINKS!

IIRC Sachs test was 25X w/o engine runaway.

I saw a previous test clutch that didn't complete the cycle due to engine failure. The clutch was PURPLE from heat and trashed but intact. Next to it was a melted crank position sensor. It got so hot (gas engine located in bell housing triggered off of FW notches) the plastic melted, engine died prior to test completion. They had to repeat test with approval and a battery charger and 3' dia warehouse fan to provide enough cooling to complete the test.

The act of engaging the clutch (pedal coming UP) is the one time that YOUR L foot and R foot are purpously slipping the clutch and creating HEAT. Just motoring down the road, clutch sees ambient temp from engine etc. but it's not MAKING heat.

Heat = big consumer of clutch disc facings.

Gary

 

[Prairie Dog]

Yup. The only reason I even started this is because I believe the 5600 isn’t the easiest to get parts for anymore. Mines good, I just need that little plastic shift gate tip. The gates get funny once in a while.
I thought it would be worthwhile to investigate an alternative- just forward thinking.

I've heard this rumor before and talked to the trans shop I've used for years. The owner told me there's absolutley no problem getting rebuild parts for it.

Scott

 

[AH64ID]

Wasn’t Tremec an OE supplier at one point?

Either way I don’t recall ever reading too many positive comments about them behind a CTD.