Axle ratio question

[ranchhopper]

I have been thinking of buying a cut off from a 2005 truck frame cut from just before the front axle it a complete camelback suspension axles,valves etc. unit only has 124K on the axles but it has a 5:02 axle ratio that seems pretty low to me the thing would put you down the road a 45 MPH I believe its a 44000 pound axle set up greasable trunnion 8 bolt axle flanges. I wanted the whole low mileage camel back set up for the superliner I need some input from the pros whether this could be made to work in my truck as it is now with the 300+ with a 10 speed trans.

[Superdog]

most of the 300+ powered trucks that were in this area in the day had the RT1110 Fuller and 3:65's or a TRDL1070 Mack 10 speed and 4:17's.This gave you about 68 mph at 1950. Either way,5:02's would be pretty slow

[ranchhopper]

That's what I figured its a shame the cut off is in great shape I do have a set of carriers from my parts truck but that was a 38000 pound axle set up I don't think they will swap into a 44000 pound set up splines on the axles probably different.

[GOOG]

If you really want to use those rears, you need the transmission that was with them. I had an R model with low gears like that, but had a .6:1 over drive. I think it was T2060. It was a single stick six speed. I didn't like the one I had. Some old road ranger 13 speeds had double over drives. They will work too. they are hard to find, and are very noisy.

[BGarofalo]

I have a truck with 4.17's that I'm looking to jump up to 5.02's. Same thing 44k on camelback with a 300 HP E6. Running a 55ton lowboy we need more reduction in the rears. Its a shame your all the way in IL. The 5.02 is a great mix for heavy operating. It give you good reduction but still reasonable on the highway.

[Vladislav]

My Canadian built R688ST, or better to note at least three trucks of that bunch have 5.02's.

They're equipped with E6-350 and T2090 9 speed wich has overdrive of 0.71.

With 11R24.5 I can do 120km/h (about 72mph) looking the speedo but 150km/h (70mph) checking that with GPS.

At that point the truck doesn't accelerate more, looks like the rev limiter works but I'm not sure.

Sorry my tacho is speechless at the moment. Doing her average 55-60mph she sounds quite good and I wouldn't see any trouble if use it for work.

Having a hobby reason I'd like to cruise some parts of big and empty highways making 125-130km/h (75-80mph) and have a couple of options for that. To use 4.17 carriers or put T2060 6 speed with 0.6 OD and less shift steps wich might work better for a single tractor I think.

But again, 5.02's with 0.71 OD and tall tyres seems to me a way off a disaster.

[kt_Engineer]

The 5.02 ratio is a CRD202/203 carrier. This can be converted to 3.63 by changing the Bevel gears in each carrier to 1.06 ratio (from current 1.46). The Helical gears can remain the same. The 3.63 can get you to 68MPH in top transmission gear ratio of 0.71:1 (@1500 Engine RPM & 512 Rev/mile tire).

The 38k axle and 44k axle built after 2002 should be inter-changeable as far as carrier goes (that is the bowl size is same and spindle ends remain same, so the carriers can be swapped out). The axleshafts can remain the same as long as 38k axle also has a CRD202/203 carrier. If it has a CRD92/93 or a CRD150/151 carrier then axle shafts will also need to be changed as Helical bull gear offset position is different for CRD202/203 & CRD150/151 (CRD92/93) carrier.

It you are going to swap-out the pre-2002 38k axle carrier onto your 2005 44k axle then the axle-shafts need to change even of the carriers are from the same series. Also other thing to watch out if you are swapping the CRD202/203 with a CRD150/151 (CRD92/93) carrier will be for drive-shafts will need to be lengthened or shortened due to different pinion gear positions.

Edited November 17, 2015 by kt_Engineer

[ranchhopper]

The cut off was up for auction seems like a bunch of jacking around I will have to find something else down the road.

[Green Dash]

There were a bunch of city tractors where I work that had 5.02 rears. These were single axle CH's with T2050 5 speeds (same .60 in top gear as a T2060) and were governed at 62 mph. RPM's were about 1700 IIRC.

[ranchhopper]

The cut off sold for 650 dollars would have been a great deal for me if the axles would have been what I needed.

[farmer52]

FWIW, my MH has 5.02 with 11R22.5 and T2050...runs 65 at 1650rpm

[HES]

My 2000 RD i just swapped in 5.32s from 4.42s and top speed without switching the dips in the Speedo is 58mph at 1600 rpm. Its couples with mack t2130 13 speed and crushes up and down hills once it gets going. Need to get the dip switches figured out to get some more top end. Anyone have insight on max rpm while highway cruising?