Allison 6 spd trans

[rvten]

See where WCC is going to put the Allison 6 SPD in all the W-20,22,&24 chassis. Wonder if I can upgrade my 5 SPD?

[rvten]

See where WCC is going to put the Allison 6 SPD in all the W-20,22,&24 chassis. Wonder if I can upgrade my 5 SPD?

["007"]

I'll second that maybe they can add to the SSC package, don't see why not same engine isn't it. "007"

[M&EM]

I believe the rear axle ratio also is different wth the 6 speed to achieve the benefits.

[YosemiteBobR]

I did hear that the rpm difference between 5th and 6th is only 250 rpm. I guess over the long haul it would be worth it.

[rvten]

Upgradeing the Trans. would be cheaper than a new MH.

[Cruzer]

All the 6 speeds get the 5.86:1 rear axle ratio versus the 5.38:1 of the earlier W22/W20 series with the 5 speeds. The 5 speed W24 always did have a lower ration so that it could pull the extra GCWR but that was a swap at highway speeds because it was revving higher than it needed to.

The new W20/W22 6 speeds will give you more power by tightening up the rev range and the extra overdrive gear will retutn the cruising RPMs to a nice low level, resulting in good fuel economy. The W24 always did have the pulling power but now it get's a bit of a rest at highway speeds.

If you want to retrofit a 6 speed to an older 5 speed I can't see the advantage on a W20/W22 unless you regear the axle to take advantage of it. The W24 I could see as beneficial because it allready has the lower axle gearing. However, I'd hate to see what this would cost in parts and labor. You could probably buy a lot of gas (even at today's prices) for that much green.

[Tom N]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> All the 6 speeds get the 5.86:1 rear axle ratio versus the 5.38:1 of the earlier W22/W20 series with the 5 speeds. </div></BLOCKQUOTE>

Close but not all true.

If the chassis is equiped with 19.5" tires the rear end ratio is 5.13. Only the chassis' equiped with 22.5" use the 5.86 rear.

[Cruzer]

That's correct, I was only detailing the 22.5" tired chassis.

"Tired Chassis" is that a politically correct statement?

[Blaster]

Question? I have got a switch on dash to lock out overdrive and another one on panel where light and fan switches are, it show to be tran. brake. What is it how do it work?

[rvr2352]

Is it "Trans" or "Grade" brake? Mine is "grade" and what it does is to prevent the trans from upshifting after I have enabled it AND slowed down enough for a downshift to occur. The slow-down can be effected by applying the brakes or manually using the shift lever. Obvously this is used on downgrades. When I reach the top of a grade and start to go down or when I approach a downgrade, I disable the OD and enable the grade brake.
Steve