4.10 gear with suregrip (posi) info needed

[MSN Member]

From: Discoverer  (Original Message)
Sent: 12/6/2003 10:45 AM

I am looking for a complete rear axle assembly........is there any model Winnie that this comes in that is a more "standard" gear ratio than either the 4.56 or 4.88 ? How about the posi? 



From: dave76Chieftain
Sent: 12/6/2003 8:09 PM

Dodge manual indicates that the 73-74 RM300 chassis used the Spicer 60HD rear axle that could have either 4.10 or 4.88 to 1 ratio.  The 4.10 to 1 ratio is the best you are going to find for the axles used in the Dodge MH chassis.  The 60HD is listed at 6200lbs with single wheel and 7500lbs with duals.  The Spicer 70 (M300/RM350 and M400 [75 and later]; 4.56 or 4.88) is 7500lbs.  The Spicer 70HD (M375;RM400 and M500/600 [75 and later]; 4.56 only) is 10,000lbs.  None of them were positraction.  Thing is, trucks/motorhomes are not cars.  They need gear ratios that handle the load without overstressing engine, transmission and driveline components.  Many use aftermarket overdrives but more for gearing flexability.  Due to the weight and the boxed front/rear, you just are not going get much gas milage improvement without going to a diesel.

Dave
78 26' Chieftain



From: denison
Sent: 12/7/2003 7:59 AM

My Dodge motor home chassis parts catalog lists the gear ratios just as you say dave76chieftain, but it lists what it calls -antispin- differentials, but only for the 4.88 ratios, and only for the years 69-71. Mine is a 72, with a 413, and the 4.56 ratio, and it serves me well - but then I dont drive off-road. denison



From: dave76Chieftain
Sent: 12/7/2003 8:15 AM

I was over looking through some of the stuff on the Travco site.  Under the chassis section there is an Dodge MH chassis ad that indicates anti-slip differential was avaialble as an option.  Do not know the year of the ad but it was before the 440 was added to their line because it only reffered to the 318 and 413.  I had not noticed any reference to a posi rear end before this.  Thanks for the info Dave.  About the only need I can see for a posi though is winter ice/snow.  Lot of weight riding on them rear wheels!

Dave.