Brandt Posted June 4, 2015 Share Posted June 4, 2015 (edited) I have 4.42's in my truck and am looking for a bit lower rpm at highway speeds. Is it cheaper to find the diffs with the gears I want (4.17 or 3.86) or to buy an entire rear clip?? I have cammelback suspension and want to keep it. I also have spoke hubs and they could stay or go. It would be nice if I could find a set of diffs with lockers, as I spend a good bit of time off road. I don't know what my current axles have for weight rating, but everything on this truck is built heavy. The build sheet says I have CRDPC92 and CRD93 axle assy. Edited June 4, 2015 by Brandt Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/ Share on other sites More sharing options...
alex g Posted June 4, 2015 Share Posted June 4, 2015 I would change gears rather than replace a whole clip I have a set of 3.86 if your interested but that is a pretty tall gear to be off road with you could run 24.5s if your not already to drop your rpms a bit Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292317 Share on other sites More sharing options...
kscarbel2 Posted June 4, 2015 Share Posted June 4, 2015 I like a 4.42 ratio, but 4.17 will accomplish what your want.3.87 (not 3.86) would be to high (low numerically). Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292323 Share on other sites More sharing options...
RowdyRebel Posted June 4, 2015 Share Posted June 4, 2015 I've got 4.17's and had been contemplating 4.42's when I pulled a dump bucket on mostly 55 mph roads. Now that I'm flatbedding and spending more (still not much, though) time in 70 mph zones, if I HAD made the switch a few years ago, I'd be looking to swap back to 4.17's or even 3.94's. It is all in what you do and where you go, though. I'm running 11R24.5 tires, though, so my 4.17 rears are like having lo-pro 22.5's and 3.73 gears. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292327 Share on other sites More sharing options...
Dirtymilkman Posted June 5, 2015 Share Posted June 5, 2015 I run a lot of gravel roads and soft roads with my CL. It has 3.86/3.87 rears and never runs out of power but thats with a 18spd. It runs 1300@55mph 1500@65mph and 1610@70mph 1 Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292337 Share on other sites More sharing options...
Brandt Posted June 5, 2015 Author Share Posted June 5, 2015 I'm running 11R 22.5 tires and with the spoke hubs a switch to 24.5 is as cost effective as regearing.The engine is an EM7 which peak torque is at 1050 and peak HP at 1710rpm. I'm also running a 1070 12 spd, so with the 2 deep reduction gears, I think I would be OK with 3.87's. However I do think 4.17's are ideal.Are all the Mack gear sets interchangable?? Or do I have to get gears from a set of axles that have the same weight rating and model. Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292351 Share on other sites More sharing options...
RowdyRebel Posted June 5, 2015 Share Posted June 5, 2015 Would a 12R22.5 tire work? Nearly the same diameter as an 11R24.5 tire, but fits on a 22.5" rim...you'd just need 9" wide rims instead of 8.25" wide. The load rating is also slightly better than an 11R24.5. Quote When approaching a 4-way stop, the vehicle with the biggest tires has the right of way! Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292357 Share on other sites More sharing options...
Brandt Posted June 5, 2015 Author Share Posted June 5, 2015 I looked into them last summer (before I bought a set of 8 11Rs). I ran into a few hurdles that I couldn't seem to overcome. I don't know if a 315/80/22.5 will work in a "dual" position or not. Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292366 Share on other sites More sharing options...
bts-4120 Posted June 5, 2015 Share Posted June 5, 2015 there is a many waste management roll off on 315 floats all they way around so yeah yes you can Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292367 Share on other sites More sharing options...
Brandt Posted June 6, 2015 Author Share Posted June 6, 2015 Are the 315s ran as duals or are they singled up?? Finding rims for singled up Daytons might be difficult.Can any one tell me more about the CRDPC92 and CRD93 axle assy? Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292456 Share on other sites More sharing options...
6368 Posted June 7, 2015 Share Posted June 7, 2015 The 315s are run as duals. you won't like the price for new but the casings can usually be had pretty reasonably because refuse companies are about the only ones who run em for drives. Yes, they can be put on 8.25 inch rims it is not ideal ( it lowers the weight rating) but you will be fine for drives . The best thing about running them is they are tough. Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292498 Share on other sites More sharing options...
j hancock Posted June 7, 2015 Share Posted June 7, 2015 Can any one tell me more about the CRDPC92 and CRD93 axle assy?That housing combination could be found in various 34,000, 38,000, 40,000 or 44,000 lbs. bogie models. Some were actually set up without a power divider. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-292515 Share on other sites More sharing options...
Brandt Posted June 19, 2015 Author Share Posted June 19, 2015 That housing combination could be found in various 34,000, 38,000, 40,000 or 44,000 lbs. bogie models. Some were actually set up without a power divider.Somewhere I got the idea that they were 43K or 46K axles. I don't know where I got that info from. How do I tell w/o tearing them apart and measuring bearings? Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-293929 Share on other sites More sharing options...
j hancock Posted June 22, 2015 Share Posted June 22, 2015 Since you have the build sheet, it should tell you unless you think someone has changed them. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-294301 Share on other sites More sharing options...
Brandt Posted June 23, 2015 Author Share Posted June 23, 2015 Duh!! Senior moment ;-)It does say SS440C - guessing that means 44K rears Quote Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-294395 Share on other sites More sharing options...
j hancock Posted June 23, 2015 Share Posted June 23, 2015 Yes, 44 on camelback. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-294409 Share on other sites More sharing options...
rsb502 Posted July 6, 2015 Share Posted July 6, 2015 Youll be cheaper in the long run and more than likely happier to swap to 4.17's, I went from 4.64's to 3.65's and I went too far with 11R24.5's, Im looking at going back to 4.17 or 3.87 myself, if I go to the 3.87 Ill swap to low pro 24.5's for a little more gearing. The CRD 92/93's just unbolt and drop in from one gear ratio to another, the only real difference is there are different splines for the power divider input and the axles, just make sure you know what you have and get the same splines. Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment https://www.bigmacktrucks.com/topic/40341-regear-options/#findComment-295783 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.