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Need advice

I am pulling the cover off the axle tomorrow to see the gears. I will let you all know what I find.

Next question. If the gears are in fact 2.73 and I switch them to a lower gear for example 3.73, will my transmission still be able to handle 35' tires and a 400 HP motor. Keeping in mind this is a stock 700R4 with no performance upgrade.

So 3.73 with 35' tires and a 400 HP motor, will that work or will my tranny fail?
 
Kyle1983 said:
I am pulling the cover off the axle tomorrow to see the gears. I will let you all know what I find.

Next question. If the gears are in fact 2.73 and I switch them to a lower gear for example 3.73, will my transmission still be able to handle 35' tires and a 400 HP motor. Keeping in mind this is a stock 700R4 with no performance upgrade.

So 3.73 with 35' tires and a 400 HP motor, will that work or will my tranny fail?
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The higher the ratio you put the better it will be on the transmission.
3.73 is better than 2.73
4.10 is even better and if you go 4.56 you'll have a very happy transmission and very peppy truck.
I say between the 4.10 and 4.56 it's a driving style choice. I wouldn't bother with the 3.73 unless you find a complete axle ready to go, that would be cheaper and easier
 
Kyle1983 said:
The vehicle has had many owners, I suppose I should remove the cover first and verify it still has those gears.
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You can't believe the glove box sticker for something as commonly swapped as gears. It's especially hard to believe ALL of the previous owners could stand 2.73, since it's awful. If it's truly 2.73 with 35" tires, the transmission will basically never use 4th gear. You can also calculate the gear ratio using GPS for speed if you have a tachometer (or scan tool that reads engine speed). 100km/h would be like 1100RPM.
 
Blue85 said:
You can't believe the glove box sticker for something as commonly swapped as gears. It's especially hard to believe ALL of the previous owners could stand 2.73, since it's awful. If it's truly 2.73 with 35" tires, the transmission will basically never use 4th gear. You can also calculate the gear ratio using GPS for speed if you have a tachometer (or scan tool that reads engine speed). 100km/h would be like 1100RPM.
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Mine was. 2.73 with 35" tires and a roasted 700r4
 
imiceman44 said:
change from the gov loc get limited slip
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I believe the "Gov Loc" is a limited slip device even though it has the term "Loc" in it's name it is not a locking type traction device. My Crew Cab came stock with the (G80) Gov Loc in its 14-Bolt rear diff. Since all I do with my long wheel base Crew Cab is light duty wheeling the Gov Loc should be sufficient for my use.
 
Gov-lock is either open or locked. It is not a friction-type limited slip like Trak-Lok or Power-Lock, it's a locker. Only reason it's called "limited" is because a wheel has to spin for it to engage (hence the word "lock" in it's name).
 
Blue85 said:
Gov-lock is either open or locked. It is not a friction-type limited slip like Trak-Lok or Power-Lock, it's a locker. Only reason it's called "limited" is because a wheel has to spin for it to engage (hence the word "lock" in it's name).
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Are you sure about that. I am not doubting you because I thought the same thing at one time, but some people on this web site that know more than I do about it told me the Gov Loc was a limited slip device like the Trak-Loc or Power-Loc.
 
1-ton said:
Are you sure about that. I am not doubting you because I thought the same thing at one time, but some people on this web site that know more than I do about it told me the Gov Loc was a limited slip device like the Trak-Loc or Power-Loc.
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No, it's a locker.
It has no clutches and no slip.
When locked, it's locked.
 
1-ton said:
Here is a video on how the G80 works. It says there is friction disks like a limited slip.

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It's funny all the videos I have seen before this explain the governor locking part but never go beyond to show the clutches.
This makes it a limited slip with a more pressure on the clutches than a spring which pretty much locks it up.
I still think it's the best design for a stock vehicle
 
I guess the weak point of the Gov-Lock G80 is the fly weights. They are the part that goes BOOM, and give the Gov Loc the "GOV BOMB" name it has.
 
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Kyle1983 said:
I am pulling the cover off the axle tomorrow to see the gears. I will let you all know what I find.

Next question. If the gears are in fact 2.73 and I switch them to a lower gear for example 3.73, will my transmission still be able to handle 35' tires and a 400 HP motor. Keeping in mind this is a stock 700R4 with no performance upgrade.

So 3.73 with 35' tires and a 400 HP motor, will that work or will my tranny fail?
Click to expand...

As long as you are using the truck to just cruise around with and don't hammer on it too much, the tranny should be fine. I would start setting money aside to upgrade it to match the power of the motor at some point, but as long as the transmission is currently healthy its all good.

I agree with @imiceman44 about gear choices though. If your gonna go through the trouble to change the gears, you should go with at least 4.10s
 
1-ton said:
I guess the weak point of the Gov-Lock G80 is the fly weights. They are the part that goes BOOM, and give the Gov Loc the "GOV BOMB" name it has.
Click to expand...
I like that you found that video of them. I had seen the friction discs in one that I pulled out, so I was fairly confident in what you had posted before.
But my train of thought on the "bomb" name is maybe the friction discs get worn and this causes the locking action to happen too abruptly. :dunno:
I had one in a 10B that worked very smoothly up until the day that it lost a tooth off of the pinion. It showed previous damage in the break point when we pulled it apart, but I have no idea how the axle was treated before I got it.
So some may not remember or know that the lower ratio gears have less pinion to ring gear contact area, and can break more easily. But I honestly like having the lower ratio gears for my trucks, I have 4:56 gears in the 12 bolt in my '70, even when it had 33" tires. But one has to remember that there are tradeoffs to be found all of the time. The 2:73 gears have a pinion that is huge and has lots of tooth contact, but isn't good for the torque converter and transmission.
And lower ratios could put more torque to the axles.
But I would still get 4:56s for this truck, if it was mine, but I would be able to to dona semi-float 14B as well. Too bad this probably isn't an option for @Kyle1983 , availability and the welding needed to swap one could make it not an option.

I'm curious to see what ratio is actually under this truck.
And nice K5 by the way!
 
One thing about the G80 is it is supposed to be a low speed engagement only. From what I have found the G80 is not supposed to engage at speeds over 20 - 25 MPH. At any speed over those MPH it is supposed to be an open diff only.
 
1-ton said:
One thing about the G80 is it is supposed to be a low speed engagement only. From what I have found the G80 is not supposed to engage at speeds over 20 - 25 MPH. At any speed over those MPH it is supposed to be an open diff only.
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And at that speed you shouldn't have to worry about slipping as long as you're moving
 
I think what kills the gov-loc is getting one tire spinning fast,then it SLAMS into "lock" and the shock load tends to crack things...
It needs a 100 rpm speed difference between the two tires to engage and that is what probably breaks things..
 
diesel4me said:
I think what kills the gov-loc is getting one tire spinning fast,then it SLAMS into "lock" and the shock load tends to crack things...
It needs a 100 rpm speed difference between the two tires to engage and that is what probably breaks things..
Click to expand...

There are wound springs on the fly wights, and the counter lever gear on the G80. The long arms of the wound springs are known for cracking off, and suddenly loosing their spring tension. If the spring on the fly weight breaks then the diff will never engage, and you have an open diff. If the spring on the counter lever suddenly breaks the G80 will instantly engage. If that happens with the wheels spinning at a speed over the 20 to 25 MPH threshold limit then...KABOOM. Also, if the counter weight spring breaks the G80 engages, and never dis-engages. Then you have to drive it that way until it blows up, towed home, or is fixed.
 
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