Chevy Diesel News & 8-speed Trans. PLUS Ford/Chevy 10 speed Trans.

[cockeyedMFer]

Finally, a transmission that can match my razor

Seriously though, the level of engineering is amazing...but having driven a car with a 7 speed trans, all that shifting is a bit annoying. Takeoff from a light, engine revs...shift shift shift shift and you're at 30 mph. Stop for traffic and start all over again.

 

[lostcause]

I have noticed a number of Cummins 4BT conversions on Youtube. Someone even put one in a '68 or so Camaro. If these guys can do this and have good driveability, then a large 4, or a smaller 6 would work fine in a 1500 series pickup.

whether it works or not doesn't matter. forum members on enthusiast sites may embrace the idea, but they represent such a small (to non-existent) percentage of the people that trade vehicles every three years. enzo ferrari said it best: horsepower sells cars, torque wins races. i don't think the american car buying population is ready to accept a 100hp diesel in a truck, and hardly even in a car. i'm sure the larger displacement diesels we have now would be back to pulling 20+ mpg if we weren't trying to squeeze them for 500hp and 800ft-lb of torque, but we have to keep up or one up our neighbors.

 

[Bird]

I see some recommendations for a 2-speed rear end and of course, way back in the '50s I drove some trucks with the 2-speed rear ends. But many years later, I bought a new 1989 Chevy one ton, extended cab, dually to pull a fifth-wheel travel trailer. Of course in those days, it was just a 3-speed automatic transmission. I put several thousand miles on it before I had a Gear Vendors Overdrive installed. It had some things in common with the 2-speed rear ends, but also some big differences. It didn't change my gas mileage a great deal when pulling the trailer, but did increase my mileage by 20% when not pulling a load. And it really made that truck a pleasure to drive. With no load, it simply amounted to an automatic overdrive, and under heavy load, it was a gear splitter making 6-speeds of that 3-speed transmission.

I later bought a motorhome with a 460 Ford engine and 3-speed automatic, and my brother and I installed a U.S. Gear dual range overdrive on it. It was certainly an improvement over the standard 3-speed Ford transmission, but not nearly as nice as the Gear Vendors, and I see that the U.S. Gear product is no longer made.

 

[TheGoose]

Right...I get it that it helps the engine stay in the peak power range...but at what point are there just too many gears? I'm already shift-happy with my '6 speed. Why not 12 or 14? You will never convince me that you can keep getting a lot out of adding more gears. Anything past 6 gears, for a light-duty truck, is a waste. I was pretty happy with my 4-speed I had before and honestly think 6 gears may be too many.

Right now my opinion falls on the "marketing" aspect of the whole thing. Whoever can say they have the most gears wins the marketing aspect, but in real life it probably gives you little or nothing over a 6 speed.

 

[schmism]

but at what point are there just too many gears? I'm already shift-happy with my '6 speed.

not intended for you to shift them.. but for the computer to shift all 10.... then we can design an engine that is super efficent over an 800 rpm band and never have to leave that band.

which at some point you would think you would just say F the 8-10-12 whatever ridiculous number of gears and just go CVT and be done with it. or series drive hybrid with electric motor and be done with it.

 

[downslope]

Personally I think some sort of electronically controlled split range rear end would be better than an 8 or 10 speed transmission. For the way that most of these vehicles are utilized, even those that tow a lot, there is a point of diminishing returns with the number of gears in a transmission. The gas and diesel engines in pickups are designed to make power over a very wide range of RPM, whereas in the over the road trucks the diesels are often really suited to only a limited RPM range therefore they need more gears to keep them in the smaller sweet spot. For mileage gains I think you'd be able to realize more benefit and a larger difference in final drive ratio by adding a split range rear end.

I think such a setup would be heavier, more complex, more expensive and not as reliable. If it were able to perform true split shifting automatically it would become very complex; imagine trying to automatically control and synchronize what in effect would be 2 separate transmissions. And the disaster you would have if one of them shifted and the other didn't when attempting a split shift. There is a reason you don't see these things anymore, even in manually operated form, on today's medium and heavy trucks.

Once you have an automatic trans with 6 or more speeds a suitable final drive ratio is no problem. Even on some of the current 6-speeds the top two are overdrive. So with 8 speeds or more you would just lock out one or more of the top gears for heavy hauling or towing but still have them available when running empty.

Personally I don't think we will ever see or need split range rears or auxillary trans in a pickup; they are a thing of the past in old manually shifted trucks.

 

[scrappy isb67]

another reason for no 2 speed rearends is no 4wd unless you run 2 two speed rearends.

 

[Carl Bert]

The 10 speed will be a game changer for both Ford and GM.

I still don't see the diesel as a viable option. Today here gas is 2.98 while diesel is about 4.25. $1.25 difference and $6000 upfront will make it a tough sell.

Chris

$2.98 ???????? WOW, that would be nice to see again, but probably never will around my area. I paid $4.09 for regular today.

 

[downslope]

... unless you run 2 two speed rearends.

Yeah, twice the cost, and it would be quite interesting if they ever got out of sync with each other. Didn't they have that situation with tandems.

 

[Bob77064]

$2.98 ???????? WOW, that would be nice to see again, but probably never will around my area. I paid $4.09 for regular today.

Gallatin TN about 50 miles south of me has gas for 2.99 and diesel for 3.79 today.