What is in the front of the K1500 diff?

[redfishsc]

If you have a G80 in the rear, does that mean you also have a locking diff in the front? This is in a 1999 K1500 Sub.


Ive Googled around and cannot find what front differential carriers were used/offered.

 

[df2x4]

All the front differentials on these trucks were open carriers from the factory. GM never put a locker in the front diff of a GMT400 to my knowledge.

Which is probably a good thing for most people, steering with the front wheels locked could be problematic in certain situations.

 

[redfishsc]

That's a good point. I'm jaded by my Truetrack in my RWD Sub. It drives like an open diff but if you get stuck it looks like behaves like a spool or locker. The rear wheels may be turning at different speeds but it is usually hard to notice.

If I ever end up doing much off road, I'd consider a posi in the front but only a Truetrack.

Correct me if I'm wrong, though. If you have an open diff in the front and a G80 locker in the rear left, then really at best you have 3 wheel drive, since the front wheel that will be getting the main torque will be the one with the less traction. Right? Speaking from inexperience since I've never gotten a 4wd stuck (or even off road for that matter)

 

[df2x4]

Correct me if I'm wrong, though. If you have an open diff in the front and a G80 locker in the rear left, then really at best you have 3 wheel drive, since the front wheel that will be getting the main torque will be the one with the less traction. Right? Speaking from inexperience since I've never gotten a 4wd stuck (or even off road for that matter)

That is correct. Honestly most of the time it's more like two wheel drive, as the G80 rear automatically unlocks at speeds over 15MPH.

I don't think anyone even makes a posi or locker for the front differentials on these trucks... If you did use one then you'd want manual hubs IMO so you at least had the option to unlock one side for normal driving. Which once again I'm not even sure that's possible without doing a solid axle swap.

Long story short, I'd worry about upgrading the G80 rear if you want better traction and leave the front alone.

 

[evilunclegrimace]

You are not going to want to put a True trac in the front diff. the left axle is always engaged and in 2WD that causes the spider gears to spin and that means that the Pass side side gear is spinning backwards. I am not sure the True trac will like this. I am not sure but, I think that ARB makes a locker for the GMT 400 front diffs.

 

[RichLo]

I've always heard that GM 8.25" front diffs are a big no-no for any sort of locker or limited slip due to case strength. The only thing I would personally do is add the mechanical front diff actuator instead of the factory electrical one that can cause problems when you need it most.

 

[Supercharged111]

That is correct. Honestly most of the time it's more like two wheel drive, as the G80 rear automatically unlocks at speeds over 15MPH.

I don't think anyone even makes a posi or locker for the front differentials on these trucks... If you did use one then you'd want manual hubs IMO so you at least had the option to unlock one side for normal driving. Which once again I'm not even sure that's possible without doing a solid axle swap.

Long story short, I'd worry about upgrading the G80 rear if you want better traction and leave the front alone.

I've always heard it's 30mph where it won't lock. To be clear, once it locks it can't unlock until you lift. At that point it won't re-lock until you reduce your speed again.

As mentioned the case will explode with a front locker. There was a company that used to make an air locker, but last I checked they no longer did? You can get a locker for the 9.5 front. There's also a kit that keeps the right axle engaged at all times. This is supposed to improve durability, but it does increase friction. My truck plows in 4WD with an open diff, can't imagine how bad it'd be with a locker up front. But when the going gets rough I imagine it'd really start to shine.

 

[redfishsc]

Never thought about upgrading (down grading?) the actuator to a manual shift. So far this one works fine but it does have 230k miles on it

 

[tomb]

I have a K2500 and have no idea if the front dif is the same as a K1500. I was is in a bone yard and saw a H2 Hummer front diff with a factory elec lock feature. It was out of the truck but it looked just like my diff. Anyone know if this is swappable?

 

[Biggershaft96]

Should be. Take it home with you, even if the mounts on the housing are different, you can pull the carrier and put it in yours.