Thanks for the tip EdPruss! Will definitely keep an eye open. Ah shoot, after reading panel fan's post I remembered mine has the drive shaft handbrake, so that would definitely complicate installation.
Last edited by BurningTracks; Fri Apr 29 2022 02:52 PM.
Hi Grant , I take it your hand brake is a drum on the rear of your trans. which would complicate getting a safety if you switch to an overdrive trans. A truly expensive option would be to locate a Gear Vendors over drive divorced unit which could be mounted in the place of your hanger bearing which come I understand with a .80 O/D . You never know what you can find on the internet used . Good luck .
Many Brownies came with Tru-Stop disc brakes on the rear. Many were disabled with the advent of Spring Brakes, however they make for a convenient and legal setup with a brake on the last gearbox. There is a place in Denver that has new pads. On my ‘54 GMC, someone had inserted a smaller disc that had worn so badly, I had to back-up to get it to release. Luckily I had saved the proper size disc in my junk.
Photo shows 5531 installation in my ‘55.2 GMC.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
My Brownie has a drum e-brake with external contracting band. The brake was made up after its original installation and has the anchor for the band welded to the rear cross member. I think it dates from before spring-brakes as the brass tag says 6231A Spicer Brown-Lipe. But why the custom brake setup? It was in a GMC log truck when I got it, behind a 6-71 diesel.
Seeing that your original rear end is an HO72, the third member can be swapped out with one from a 3/4 ton HO52 rear end for a possibly better ratio. I've read somewhere that '67-72 Chevy 3/4 tons with an auto trans have a 3.73 gear, but I bet finding one in New Zealand would be rather difficult.
A 14 bolt would be good to swap under your truck, and would be easier.
Hey gang -- once again I get to blow my whistle and throw a flag out onto the field ...
Before we get him too tall on his gearing, shouldn't we be asking about the other links in the power chain -- such as what engine, which size wheels and tires, blah blah blah?
Just asking as it seems to me that if he's got a 6-cylinder engine, he may not have enough power/torque for Brownies, tall gear sets, etc ....
In my own experience, I did the whole gear swap for faster speeds ... but ... I had a 1-ton, as well. 4.10 gear in rear and 17-inch wheels. Only I had it all powered by a 216. My truck couldn't get out of its own way, much less anyone else's. Over geared and under powered. Gotta look at the whole equation, not just one part.
John Cisgendered heteronormative aggressor perpetrating problematic toxic ideas of Chevrolet normativity
Hey gang -- once again I get to blow my whistle and throw a flag out onto the field ...
Before we get him too tall on his gearing, shouldn't we be asking about the other links in the power chain -- such as what engine, which size wheels and tires, blah blah blah?
Just asking as it seems to me that if he's got a 6-cylinder engine, he may not have enough power/torque for Brownies, tall gear sets, etc ....
In my own experience, I did the whole gear swap for faster speeds ... but ... I had a 1-ton, as well. 4.10 gear in rear and 17-inch wheels. Only I had it all powered by a 216. My truck couldn't get out of its own way, much less anyone else's. Over geared and under powered. Gotta look at the whole equation, not just one part.
If it was my rig I've got a NP540 direct 5spd I'd put In it. 4.10 would be good in direct for crusing along until you hit a hill or headwind, then run in 4th.
BC 1960 Chevy C10 driver 261 T5 3.73 dana 44 1949 GMC 250 project in waiting 1960 C60 pasture art Retired GM dealer tech. 1980 - 2022
NP-540 series is a good choice. I put one in my early Bronco with a Buick V-6(fuel mileage) and used the top 4 gears all the time except with large load(10 thousand lbs.)
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
What we had on our old forklift was a pinion mounted parking brake. It was a large disc (14"??") with the caliper bracket mounted to the pinion flange bolts. Was super effective since any force applied to the rotor was multiplied by the rear end ratio, 6.67 in this case. Have seen this set up on hot rods with both mechanical or hydraulic calipers. The newest Factory Five kit cars have both a large and small park caliper on the rear discs.
