5spd manual trans, transfer case, detroit air lockers questions.

[DeathByNissan55]

SO apparently my 94 K1500 4x4 has "detroit air lockers" which is toggled by a switch on the dash. My transmission/transfer case assembly leaks from the RTV sealed areas where you just press the metal together essentially. The outer rear axle seals leak, and lastly my tachometer needle moves sporadically but still seems to follow the revving of the engine. The shift up light sporadically comes on too. The tach, shift uplight problem occurred the exact same time my engine started running like crap too. Just replaced the ECU and PROM after this happened because I found out the guy who had this before me had the wrong ECU but correct PROM in the truck. I got the one that was supposed to be for a 94 K1500 4x4 factory 5 spd manual with 350 tbi. Any idea what these problems could be? And if you could tell me more about the detroit air locker and how hard it would be to do those axle seals, I'd greatly appreciate it.

 

[Snotrocket]

Your electrical problem sounds like a bad ground somewhere.

No idea about the lockers.

 

[outalne94z71]

there is no such thing as a detroit air locker, arb makes a air unit, eaton(detroit) is electric and one is not made for the 1500 front and arb also does not make a front locker for the 1500

rear axle seal change with a locker is pretty much the same as a open rear seal change

 

[LoudnLifted88]

there is no such thing as a detroit air locker, arb makes a air unit, eaton(detroit) is electric and one is not made for the 1500 front and arb also does not make a front locker for the 1500

rear axle seal change with a locker is pretty much the same as a open rear seal change

someone told me that the gears were the same front and rear from a 10 bolt to ifs if thats true wouldnt a locker for the rear work in the front?

 

[outalne94z71]

someone told me that the gears were the same front and rear from a 10 bolt to ifs if thats true wouldnt a locker for the rear work in the front?

no it is not true, the front is a 8.25" ring gear reverse cut, the rear is a 8.5" gear, they are totally different

10 bolt solid axle front can swap parts with a rear

 

[DeathByNissan55]

there is no such thing as a detroit air locker, arb makes a air unit, eaton(detroit) is electric and one is not made for the 1500 front and arb also does not make a front locker for the 1500

rear axle seal change with a locker is pretty much the same as a open rear seal change

Much like everything else on the truck, he most likely lied about it, but there is a switch on the dash and from what I saw when I very briefly tried to follow it was that it went to the trans/tfr case. So i would agree with the electronic one. Is there away to determine if the axles have these lockers? I have no idea what it would look like as this is my first truck/first 4x4/first V8 I've ever owned. All I know is that it has the cv axles in front attached to rigid cylinders that attach to a normal differential housing. The rear has solid axle but idk how many bolt designation the rear diff is. Lastly, I have no idea about the type of tfr case besides that its leaking and its mounted to a 5spd manual trans. I believe the 4x4 worked because when I test drove the truck and switched into it, you could feel that there was more moving on the car and nothing sounded peculiar like anything grinding or binding. So yea, I guess I'll take a look at the rear diff for how many bolts the cover is and ill look for numbers on the manual trans and tfr case.

 

[DeathByNissan55]

Also, I'm sorry for putting this in the wrong section, I'm new to this forum and didnt notice initially that there is a axle and transfer case section.

 

[LT1/TA]

Maybe the switch on the dash is for the front axle actuator(this is what locks the axle shaft for the front axle operation)if this is so you would have the option of 2wheel low.IIRC an air locker will have an air line running from a pump to the rear axle.

 

[outalne94z71]

Much like everything else on the truck, he most likely lied about it, but there is a switch on the dash and from what I saw when I very briefly tried to follow it was that it went to the trans/tfr case. So i would agree with the electronic one. Is there away to determine if the axles have these lockers? I have no idea what it would look like as this is my first truck/first 4x4/first V8 I've ever owned. All I know is that it has the cv axles in front attached to rigid cylinders that attach to a normal differential housing. The rear has solid axle but idk how many bolt designation the rear diff is. Lastly, I have no idea about the type of tfr case besides that its leaking and its mounted to a 5spd manual trans. I believe the 4x4 worked because when I test drove the truck and switched into it, you could feel that there was more moving on the car and nothing sounded peculiar like anything grinding or binding. So yea, I guess I'll take a look at the rear diff for how many bolts the cover is and ill look for numbers on the manual trans and tfr case.

the transfer case is a 32 spline np241c, rear axle should be a 8.5" 10 bolt with a possibility of the optional 9.5" 14 bolt and the front is definitely a 8.25 ifs, in the glove box is a sticker with all the rpo codes for the equipment your truck was built with, if you see g80 in the list that means it had the factory locker, unfortunately that eaton locker is known as the governor bomb as they like to blow up and gm never should have used them, that being said we can only guess if some other aftermarket locker has been added to the rear, removing the cover will be the only way to truly know what is in there.

as far as the locker switch, if it is going to the t-case then that tells me the previous owner may have rigged some sort of system to lock in the front axle, by default the front freewheels until the t-case is shifted to 4wd then there is a detent switch on the t-case that puts power to a actuator on the front axle that locks the axle to the shaft so it is no longer freewheeling, the last owner may have had a issue with the switch or the actuator(common) and decided to rig something up.

the rpo codes also will tell you what gear ratio you have from the factory and of course those could have been changed at some point but something is telling me the last guy would have no clue how to do that so most likely they are still original.

a electric locker would have wires running into the rear axle housing to energize the clutch, a air locker would have a air hose and also a compressor mounted somewhere, not to be confused with the axle breather hose.


gear rpo codes
RPO............Ratio
GM1............2.59:1
GU2............2.73:1
HC2............2.76:1
HE3/G44.....3.07:1
GU4............3.08:1
GU5............3.23:1
GU6............3.42:1
GT4............3.73:1
GT5/GT8.....4.10:1
HC4............4.56:1

most likely you will have gu6 or gt4

 

[DeathByNissan55]

the transfer case is a 32 spline np241c, rear axle should be a 8.5" 10 bolt with a possibility of the optional 9.5" 14 bolt and the front is definitely a 8.25 ifs, in the glove box is a sticker with all the rpo codes for the equipment your truck was built with, if you see g80 in the list that means it had the factory locker, unfortunately that eaton locker is known as the governor bomb as they like to blow up and gm never should have used them, that being said we can only guess if some other aftermarket locker has been added to the rear, removing the cover will be the only way to truly know what is in there.

as far as the locker switch, if it is going to the t-case then that tells me the previous owner may have rigged some sort of system to lock in the front axle, by default the front freewheels until the t-case is shifted to 4wd then there is a detent switch on the t-case that puts power to a actuator on the front axle that locks the axle to the shaft so it is no longer freewheeling, the last owner may have had a issue with the switch or the actuator(common) and decided to rig something up.

the rpo codes also will tell you what gear ratio you have from the factory and of course those could have been changed at some point but something is telling me the last guy would have no clue how to do that so most likely they are still original.

a electric locker would have wires running into the rear axle housing to energize the clutch, a air locker would have a air hose and also a compressor mounted somewhere, not to be confused with the axle breather hose.

When I bought the truck, I was told the engine and trans were rebuilt so I don't know if they actually were, but they're all leaking. However, if they were rebuilt, I dont know if they changed any of the gearing or added any of those actuators you mentioned. Also, I could pretty much confirm that there are no obviously placed air pumps that could be used. I'll look in those places and see if there were any labels for anything.