Mack Experts Help! Need Non Existent Part..please Read..unimount And Gears

[macks and brockways]

I have an 89 superliner that I need some help on please read all the way through ..please feel free to call 704-507-2453 if you can help. My axles are CRDPC112 front and CRD113 geared 5.02, I need to gear them somewhere in the 3.87 to 4.17 range..and was hoping to find something out there used that would work and be cheaper than MACK dealer quote..here is the next probelm I also want unimount hubs and drums to fit these axles..the daytons I don't like and it is hard to find the dayton drums for these axle and even if I had a pile of dayton drums for these I would still want the unimounts. I have no VIn # for a truck with these heavy axles and unimount wheels and i am having trouble getting a mack dealer to help me research it. Thanks in advance Rob

[macks and brockways]

BTW if any Mack parts guys have time to help me research this by going on bearing size my vin is 004515, its an RW713, want unimount hub Part #s and brake drum parts #'s etc.

[chris88]

What weight axles are they? Where about are you located? Any decent truck junk yard should be able to get you two mack rears and hubs for those axles. Hubs are no big deal at all, the only thing that i think is differnt is the studs for the axle. I belive bearings are the same but i could be wrong. Brake drum part number for would be a 3600A, I belive thats a gunite number. I cant think of the part number for a hub, but the hubs i deal with are 44k hubs with 6 studs, yours probably have 8.

[fjh]

I have an 89 superliner that I need some help on please read all the way through ..please feel free to call 704-507-2453 if you can help. My axles are CRDPC112 front and CRD113 geared 5.02, I need to gear them somewhere in the 3.87 to 4.17 range..and was hoping to find something out there used that would work and be cheaper than MACK dealer quote..here is the next probelm I also want unimount hubs and drums to fit these axles..the daytons I don't like and it is hard to find the dayton drums for these axle and even if I had a pile of dayton drums for these I would still want the unimounts. I have no VIn # for a truck with these heavy axles and unimount wheels and i am having trouble getting a mack dealer to help me research it. Thanks in advance Rob

if your runing a v8 the 417 387 ratio is a poor choice!The v8 will eat them for breafast if your pulling any weight! Middle of the road choice is 4.64! 5 02 change down requires a lot of gear changing and can get pricy!Good luck in your search thou used drop ins are your best bet.

[David]

Will a unimount wheel fit over the cap on the end of your axle? Your best bet may be to change the axles to 44k. Buy a used cut off. That will give you everything wheel to wheel with choice of ratio. If you use this truck off highway, the 4.17 and faster ratios won't hold up. That is why mack uses slow rears and very fast transmissions.

[macks and brockways]

Thanks for the help, I have Two friends with v8's 1 is 3.65 or 3.56 and has 1.6 million, the other has 3.87's So I know they can live if driven correctly, and yes a chrome cap will fit over my 8 bolt axle. My transmission is not a .60 "fast" mack trans it is a slow .74 Eaton 8ll, I think I might just Buy another truck and leave my 90k mile Superdawg alone for heavy hauls or sell it.

[OneWelder]

i am new to this forum

but years ago I Rearranged allot of Trucks I can answer some questions, but not all.

How is this truck setup ? What is this truck going to be used for ? If setup as 10 wheeler dump, definitely go with the 4.10 or lower. I have forgotten the exact number but at approx. 4.00 and below mack used a stronger gear.We Had some expensive lessons with 10 wheelers and gear ratios in the 3.-- S

If setup as tractor we ran A trailer dump for a number of years with 3.87 in it with no problems until we changed it to a wheeler. Wow Big Problems then!