I just picked up an 87 Peterbilt 357 and looking at what the possibilities are for the truck looking to determine the rear axle capacity, there is no tag in the door but did find the tag on the rear axle of the tandems. The numbers are not familiar to me, I am familiar with a 46-160, but this is different. Tag attached
Is basically a later version of the SQ, QR/SQ could use the same housing, standard rating of 34K I believe.
I have Rockwells in my 1972 F850. They are 46-160 rear & I believe same up front. 2 speed axles 4.11 & 3.08. Running a Ford SD 6 speed from an F350 diesel with a Gear Vendors, NP205 transfer case. Engine is CAT3126B for 750hp & 3500trque. Rockwells are good axls
I had an 88 Ford LTL-9000. It had SQ100 Rockwell, which I believe is an updated SQHD. SQ's were 38000 lb axles SL's were 34000 axles. FWD i had
It's the housing rating, along with suspension type. SQ 100 had a total different power divider. Common was a suspension rated at 40 to 44 on a housing that was 17,000 to 18,000 lb rating