Why huge differentials on trucks?

[ovrszd]

I bet he said a word or two that you can't print!..

Definitely. This is the Blazer. My Son owns it now. It was freshly restored when Mike blew out the rear end.

 

[ruffdog]

Anyone running a Miata axle in those buggies or rock climbers? I wonder why not.:confused3:

 

[k0ua]

By the way, I repaired that lawn mower diffy. I followed the trail of oil back to where the piece popped out of the diffy case, and found the piece. Thoroughly cleaned the case and use "liquid steel" epoxy with metal particles in it to glue the piece back in the case, and replaced the gear and refilled the case. Good to go. Of course that mower was why I bought a welder and learned to weld too. We beat the "he77" out of the little old mower. I finally bought a tractor and finish mower. It was just too much to expect a little cheap lawn mower from K mart to keep up with . It had a lot of ugly welds on it's various pieces including sheet metal with 6013 when I got rid of it. I actually traded it in on the tractor, believe it or not. Got $300 off of the tractor!.

 

[k0ua]

Anyone running a Miata axle in those buggies or rock climbers? I wonder why not.:confused3:

Because you don't want to hear a big loud sound when you climb up on a rock of the diffy letting go.

 

[ovrszd]

Because you don't want to hear a big loud sound when you climb up on a rock of the diffy letting go.

It'd probably more like a little "tink".

 

[LouNY]

As others have said it is a case of how much torque is going to be applied and also how much gear reduction is planned.
If the reduction is going to be after the differential it can be much smaller(the differential).
Most heavy equipment gets a lot of its reduction after the differentials.
Most all tractors front axles get the major part of there gear reduction after the differential.
Most larger units use planetary reductions at the wheels,
lighter duty units will often use a spur and bevel gear reduction at the wheel.
When a differential is the last gear reduction in a drive train it has to handle the complete
amount of torque the engine can put out multiplied by the transmission and any reduction box gear ratios.

 

[kcflhrc]

Do you tow horse trailers and such with your Miata?

 

[oldballs]

:laughing:..................

 

[k0ua]

It'd probably more like a little "tink".

I will bet you have heard similar things. I was at a truck/tractor pull once and an old Ford 4wd pulling for all it was worth, let go in its transfer case. And a gear or case fragment whizzed past my head. Needless to say, I was concerned. I never went back.. That "brush with death" was enough for me. I was a spectator on the sidelines and a pretty fair distance from it also.

 

[4570Man]

I will bet you have heard similar things. I was at a truck/tractor pull once and an old Ford 4wd pulling for all it was worth, let go in its transfer case. And a gear or case fragment whizzed past my head. Needless to say, I was concerned. I never went back.. That "brush with death" was enough for me. I was a spectator on the sidelines and a pretty fair distance from it also.

One of my buddies had his truck hit by a flying driveshaft. But that’s a prime case of why pickup diffs are bigger than a car. At 450 ft pound for from the engine which is way less than modern pickup diesels, big truck diesels, and built pull trucks are putting out you’re getting a 7-1 reduction in rpm from a granny gear trans and a 2-1 reduction in the transfer case for 6300 FP hitting the drive shaft. I’d be surprised if the car is hitting 500 FP on the driveshaft to a 4:11 rear end. The engine toque is lower, the trans gears are higher and there’s no transfer case to further drop the ratio. Most medium duty trucks don’t have super deep trans gears and get most of the gear reduction from the ring & pinion itself. I think my 6500 has 6.50 gears on the high range side of the rear end. A semi truck has way deeper transmission gears. Look how much bigger a semi drive shaft is vs a medium duty.