Why not a 2 speed or quick change rear end option

[Taco]

I was just day dreaming today while celebrating at the inlaws and was wondering why no truck maker offers a 2 speed rear end or a "quick change" like the race cars use, rear end option.

You would think it could give the best of both worlds better mpg and better towing/hauling power. With a quick change you could tailor the output of you truck to the anticipated terrain and the weight of the trailer.

[ib516]

My new jeep cherokee trailhawk has a 2 speed rear axle...no transfer case, but 4 low. The way they achieve that is by having a 2 speed (with locker) rear axle. It is possible.

[blt2ski]

BurbMan wrote:

MX-RV wrote:
I'm looking at several a 5.3l 1500 suburban with the 6speed Allison

LOL that's funny since there is no such thing....the 5.3L gets the 4L60E the 6.0 and 8.1 get the 4L80/85E and there was a never an Allison installed in a Subirban.

Actually Don,

GM has not used the 4l60 or 80 for a few yrs now. You now get a 6l90E, which is a 4.10 first gear, to a .64od IIRC. So one can have a 3.42 ra, still be overall lower than a 4l60 with 4.10's! Will nto talk about the 4.80 with 4.10s, one needs a 4.88 IIRC to equal the overall first of the the 4.60/4.10 combo.

The new 6 sp if you could get it behind you 8.1 would be a kewl option! I'd prefer it over the ally 5 sp I had in my 05 dually. Put 4.10's in the gears, 4.10 in first gear vs 3.08, a .64 knocking my freeway rpms at 62 down about 200 rpm or so.......much better for how I drive.

Marty

[carringb]

wilber1 wrote:
Word has it the clutch design of the Gear Venders does not stand up well to exhaust break use.

That is correct. It does not like "reverse" torque, so you cannot engine brake while the GV is in its OD gear. Should be easy to connect the EB signal to disengage the GV, so you'd also get the benefit of lower gearing while engine braking.

[wilber1]

Word has it the clutch design of the Gear Venders does not stand up well to exhaust brake use.

[bmanning]

MX-RV wrote:
Funny as the specs in the brochure specifically said Allison on the 2500 at least the 2010 I was looking at. No matter. I've got a 1500 seirra rwd ATM with the 4s and would love a few more gears.

Pickups get the Ally but the SUVs do not. But again, I think it's no issue as it seems the 4L & newer 6L series GM transmissions hold up quite well.

[BurbMan]

MX-RV wrote:
I'm looking at several a 5.3l 1500 suburban with the 6speed Allison

LOL that's funny since there is no such thing....the 5.3L gets the 4L60E the 6.0 and 8.1 get the 4L80/85E and there was a never an Allison installed in a Subirban.

[jake2250]

I had a Gear Vendor Over drive in a 1990 F350 Super Crew long bed 4x4 7.3 (turbo)5 speed manual. @70 i was turning 1500rpms in OD, with out I would be well into 2800rpm and burning allot more fuel.
Great product Gear vendor, It was on the truck when I got it so I cannot reflect purchase price, but it worked great all the time!!!

[jauguston]

The only drawback if you call it that to the Gear Vendors is the cost. Once you get past that you will love it. I don't think it would really be worth while if you have a 6 speed transmission but with a 4 speed it would be a nice addition.

[MX-RV]

Funny as the specs in the brochure specifically said Allison on the 2500 at least the 2010 I was looking at. No matter. I've got a 1500 seirra rwd ATM with the 4s and would love a few more gears.

[Supercharged]

You couldn't live so long as to get you money back on that deal.

[carringb]

whsk wrote:
I would like to have a gear vendors but the cost scares me away-I have heard 3000+-OUCH!-whsk

You could buy 15-20 Gear Vendors for what a new 1-ton truck runs, and you would still have more total ratios with a GV.

[bmanning]

MX-RV wrote:
I've always been on the look out for something to improve mileage when unloaded. I've looked at tuners, cold air intakes, tire changes, and rear end swaps. But I've never seen one of these before. I'm in the process of a vehicle upgrade I'm looking at several a 5.3l 1500 suburban with the 6speed Allison, a 2500 burb with 6.0l and 6s Allison, a ford Xc with 7.3l psd. As it will be a daily driver the best fuel economy when not towing is important. But for best bang for your buck is something with towing improvements would be nice. Does any one have any experience with these. Everything has a draw back what is it with these.
Thanks b

It doesn't really matter as they are good gearboxes anyhow but the 6-speeds in the Suburbans aren't Allisons.

I wouldn't let that bother you though as they are probably every bit as good as an Allison.

[MX-RV]

I've always been on the look out for something to improve mileage when unloaded. I've looked at tuners, cold air intakes, tire changes, and rear end swaps. But I've never seen one of these before. I'm in the process of a vehicle upgrade I'm looking at several a 5.3l 1500 suburban with the 6speed Allison, a 2500 burb with 6.0l and 6s Allison, a ford Xc with 7.3l psd. As it will be a daily driver the best fuel economy when not towing is important. But for best bang for your buck is something with towing improvements would be nice. Does any one have any experience with these. Everything has a draw back what is it with these.
Thanks b

[C_Schomer]

I grew up with 50s trucks w/2spd rears and I've also repaired them. I preferred the Eatons. US Gear (add-on over or under drive) copied the Eaton design. I like the aux. box or 2 spd rear idea WAY better than just locking out the top trans gears. As mentioned - all the trans gears are still available AND the trans gears are put closer together when the aux. box or rear end are in the lower ratio. All ideas for the dream hauler I plan on building someday. Craig

[rjstractor]

Terryallan wrote:
Wouldn't Hi, and Lo 4x4 be the same thing? Of course. You would need manual locking hubs

Not really, because a transfer case in low range is about a 2.5 to 1 reduction, way too deep be able to shift back and forth during regular driving.